Cosmopolitan C Library

abort

Terminates program abnormally.

This function first tries to trigger your SIGABRT handler. If there isn't one or execution resumes, then abort() terminates the program using an escalating variety methods of increasing brutality.

@noreturn

@asyncsignalsafe

@see libc/runtime/abort.greg.c

abs

Returns absolute value of x.

@param

int x

@return

int

@see libc/bits/abs.c

accept

Creates client socket file descriptor for incoming connection.

@param

int fd: is the server socket file descriptor
void* out_addr: will receive the remote address
unsigned int* inout_addrsize: provides and receives addr's byte length

@return

int: client fd which needs close(), or -1 w/ errno

@asyncsignalsafe

@restartable (unless SO_RCVTIMEO)

@see libc/sock/accept.c

accept4

Creates client socket file descriptor for incoming connection.

@param

int fd: is the server socket file descriptor
void* out_addr: will receive the remote address
unsigned int* inout_addrsize: provides and receives out_addr's byte length
int flags: can have SOCK_{CLOEXEC,NONBLOCK}, which may apply to both the newly created socket and the server one

@return

int: client fd which needs close(), or -1 w/ errno

@asyncsignalsafe

@restartable (unless SO_RCVTIMEO)

@see libc/sock/accept4.c

access

Checks if effective user can access path in particular ways.

@param

const char* path: is a filename or directory
int mode: can be R_OK, W_OK, X_OK, F_OK

@return

int: 0 if ok, or -1 and sets errno

@asyncsignalsafe

@see libc/calls/access.c

acos

Returns arc cosine of 𝑥.

@param

double x

@return

double: value in range [0,M_PI]; NAN if 𝑥 ∈ {NAN,+INFINITY,-INFINITY}; NAN if 𝑥 ∉ [-1,1]

@see libc/tinymath/acos.c

acosf

Returns arc cosine of 𝑥.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/acosf-tiny.S

acosh

Returns inverse hyperbolic cosine of 𝑥.

@param

double x

@return

double

@define acosh(x) = log(x + sqrt(x*x-1))

@see libc/tinymath/acosh.c

acoshf

Returns inverse hyperbolic cosine of 𝑥.

@param

float x

@return

float

@define acosh(x) = log(x + sqrt(x*x-1))

@see libc/tinymath/acoshf.c

acoshl

Returns inverse hyperbolic cosine of 𝑥.

@param

long double x

@return

long double

@see libc/tinymath/acoshl.c

acosl

Returns arc cosine of 𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result of computation on FPU stack in %st

@define atan2(fabs(sqrt((1-𝑥)*(1+𝑥))),𝑥)

@domain -1 ≤ 𝑥 ≤ 1

@see libc/tinymath/acosl.S

_addrusage

Accumulates resource statistics in y to x.

@param

struct rusage* x
struct rusage* y

@return

void

@see libc/calls/addrusage.c

__addvdi3

Returns 𝑥+𝑦, aborting on overflow.

@param

rdi: is int64 𝑥
rsi: is int64 𝑦

@return

: rax is 𝑥+𝑦

@see -ftrapv

@see libc/intrin/addvdi3.S

__addvsi3

Returns 𝑥+𝑦, aborting on overflow.

@param

edi: is int32 𝑥
esi: is int32 𝑦

@return

: eax is 𝑥+𝑦

@see -ftrapv

@see libc/intrin/addvsi3.S

__addvti3

Returns 𝑥+𝑦, aborting on overflow.

@param

rdi:rsi: is int128 𝑥
rdx:rcx: is int128 𝑦

@return

: rdx:rax is 𝑥+𝑦

@see -ftrapv

@see libc/intrin/addvti3.S

adler32

Updates running Adler-32 checksum with the bytes buf[0..len-1] and return the updated checksum. If buf is Z_NULL, this function returns the required initial value for the checksum.

@return

unsigned long

@see third_party/zlib/zlib.h

Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note that the off_t type (like off_t) is a signed integer. If len2 is negative, the result has no meaning or utility.

@return

unsigned long

@see third_party/zlib/zlib.h

adler32_z

Same as adler32(), but with a size_t length.

@return

unsigned long

@see third_party/zlib/zlib.h

alarm

Asks for single-shot SIGALRM to be raise()'d after interval.

@param

unsigned int seconds: until we get signal, or 0 to reset previous alarm()

@return

unsigned int: seconds previous alarm() had remaining, or -1u w/ errno

@see setitimer()

@asyncsignalsafe

@see libc/calls/alarm.c

aligned_alloc

Same as memalign(a, n) but requires IS2POW(a).

@param

unsigned long a
unsigned long n: number of bytes needed

@return

void*: memory address, or NULL w/ errno

@throw EINVAL if !IS2POW(a)

@see pvalloc()

@threadsafe

@see libc/mem/aligned_alloc.c

appendd

Appends data to buffer, e.g.

char *b = 0;
appendd(&b, "hello", 5);
free(b);

The resulting buffer is guaranteed to be NUL-terminated, i.e. !b[appendz(b).i] will be the case.

@param

char** b
void* s: may contain nul characters and may be null if l is zero
unsigned long l: is byte length of s

@return

long: bytes appended (always l) or -1 if ENOMEM

@see appendz(b).i to get buffer length

@note 20% faster than appends()

@see libc/stdio/appendd.c

appendf

Appends formatted string to buffer, e.g.

char *b = 0;
appendf(&b, "hello %d\n", 123);
free(b);

@param

char** b
const char* fmt
...

@return

long: bytes appended or -1 if ENOMEM

@see appendz(b).i to get buffer length

@note O(1) amortized buffer growth

@see libc/stdio/appendf.c

appendHostInfo

@param

struct HostAdapterInfoNode* parentInfoNode
const char* baseName
struct NtIpAdapterAddresses* aa
struct NtIpAdapterUnicastAddress** ptrUA
struct NtIpAdapterPrefix** ptrAP
int count

@return

struct HostAdapterInfoNode*

@see libc/calls/ioctl_siocgifconf-nt.c

appendr

Resets length of append buffer, e.g.

char *b = 0;
appends(&b, "hello");
appendr(&b, 1);
assert(!strcmp(b, "h"));
appendr(&b, 0);
assert(!strcmp(b, ""));
free(b);

If i is greater than the current length then the extra bytes are filled with NUL characters. If i is less than the current length then memory is released to the system.

The resulting buffer is guaranteed to be NUL-terminated, i.e. !b[appendz(b).i] will be the case even if both params are 0.

@param

char** b
unsigned long i

@return

long: i or -1 if ENOMEM

@see appendz(b).i to get buffer length

@see libc/stdio/appendr.c

AppendResourceReport

Generates process resource usage report.

@param

char** b
struct rusage* ru
const char* nl

@return

void

@see libc/log/appendresourcereport.c

appends

Appends string to buffer, e.g.

char *b = 0;
appends(&b, "hello");
free(b);

The resulting buffer is guaranteed to be NUL-terminated, i.e. !b[appendz(b).i] will be the case.

@param

char** b
const char* s

@return

long: bytes appended (always strlen(s)) or -1 if ENOMEM

@see appendz(b).i to get buffer length

@note 2x faster than appendf()

@see libc/stdio/appends.c

appendw

Appends character or word-encoded string to buffer.

Up to eight characters can be appended. For example:

appendw(&s, 'h'|'i'<<8);
appendw(&s, READ64LE("hi\0\0\0\0\0"));

Are equivalent to:

appends(&s, "hi");

The special case:

appendw(&s, 0);

Will append a single NUL character.

This function is slightly faster than appendd() and appends(). Its main advantage is it improves code size in functions that call it.

The resulting buffer is guaranteed to be NUL-terminated, i.e. !b[appendz(b).i] will be the case.

@param

char** b
unsigned long w

@return

long: bytes appended or -1 if ENOMEM

@see appendz(b).i to get buffer length

@see libc/stdio/appendw.c

appendz

Returns size of append buffer.

@param

char* p: must be 0 or have been allocated by an append*() function

@return

struct z: i is number of bytes stored in buffer; n is number of bytes in allocation

@see libc/stdio/appendz.c

arch_prctl

Don't bother.

@param

int code
long addr
...

@return

int

@see libc/runtime/arch_prctl.c

AreMemoryIntervalsOk

@param

struct _mmi* mm

@return

_Bool

@see libc/calls/arememoryintervalsok.c

__arena_pop

Pops memory arena.

This pops the most recently created arena, freeing all the memory that was allocated between the push and pop arena calls. If this is the last arena on the stack, then the old malloc hooks are restored.

@return

void

@see __arena_push()

@see libc/mem/arena.c

__arena_push

Pushes memory arena.

This allocator gives a ~3x performance boost over dlmalloc, mostly because it isn't thread safe and it doesn't do defragmentation.

Calling this function will push a new arena. It may be called multiple times from the main thread recursively. The first time it's called, it hooks all the regular memory allocation functions. Any allocations that were made previously outside the arena, will be passed on to the previous hooks. Then, the basic idea, is rather than bothering with free() you can just call __arena_pop() to bulk free.

Arena allocations also have a slight size advantage, since 32-bit pointers are always used. The maximum amount of arena memory is 805,175,296 bytes.

@return

void

@see __arena_pop()

@see libc/mem/arena.c

__arg_max

Returns ARG_MAX for host platform.

@return

int

@see libc/runtime/getargmax.c

__asan_check

Checks validity of memory range.

Normally this is abstracted by the compiler.

@param

void* p: is starting virtual address
long n: is number of bytes to check

@return

struct f: kind is 0 on success or <0 on invalid; shadow points to first poisoned shadow byte

@note this takes 6 picoseconds per byte

@see libc/intrin/asan.c

asctime

@param

struct tm* timeptr

@return

char*

@see libc/time/asctime.c

asctime_r

@param

struct tm* timeptr
char* buf

@return

char*

@see libc/time/asctime.c

asin

Returns arc sine of 𝑥.

@param

double x

@return

double: value in range [-M_PI/2,M_PI/2]; NAN if 𝑥 ∈ {NAN,+INFINITY,-INFINITY}; NAN if 𝑥 ∉ [-1,1]

@see libc/tinymath/asin.c

asinf

Returns arc sine of 𝑥.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/asinf-tiny.S

asinh

Returns inverse hyperbolic sine of 𝑥.

@param

double x

@return

double

@define asinh(x) = sign(x)*log(|x|+sqrt(x*x+1)) ~= x - x^3/6 + o(x^5)

@see libc/tinymath/asinh.c

asinhf

Returns inverse hyperbolic sine of 𝑥.

@param

float x

@return

float

@define asinh(x) = sign(x)*log(|x|+sqrt(x*x+1)) ~= x - x^3/6 + o(x^5)

@see libc/tinymath/asinhf.c

asinhl

Returns inverse hyperbolic sine of 𝑥.

@param

long double x

@return

long double

@define asinh(x) = sign(x)*log(|x|+sqrt(x*x+1)) ~= x - x^3/6 + o(x^5)

@see libc/tinymath/asinhl.c

asinl

Returns arc sine of 𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result of computation on FPU stack in %st

@define atan2(𝑥,sqrt((1-𝑥)*(1+𝑥)))

@domain -1 ≤ 𝑥 ≤ 1

@see libc/tinymath/asinl.S

asprintf

Formats string, allocating needed memory.

@param

char** strp
const char* fmt
...

@return

int: bytes written (excluding NUL) or -1 w/ errno

@see xasprintf() for a better API

@threadsafe

@see libc/mem/asprintf.c

__assert_disable

Disables assert() failures at runtime.

@type

_Bool

@see libc/intrin/assertdisable.c

__assert_fail

Handles failure of assert() macro.

@param

const char* expr
const char* file
int line

@return

void

@see libc/intrin/assertfail.greg.c

atan

Returns arc tangent of 𝑥.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see libc/tinymath/atan-tiny.S

atan2l

Returns arc tangent of 𝑦/𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes
𝑦: is an 80-bit long double passed on stack in 16-bytes

@return

: result of computation on FPU stack in %st

@see libc/tinymath/atan2l.S

atanf

Returns arc tangent of 𝑥.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/atanf-tiny.S

atanh

Returns inverse hyperbolic tangent of 𝑥.

@param

double x

@return

double

@define x ? log1p(2 * x / (1 - x)) / 2 : x

@see libc/tinymath/atanh.c

atanhf

Returns inverse hyperbolic tangent of 𝑥.

@param

float x

@return

float

@define x ? log1p(2 * x / (1 - x)) / 2 : x

@see libc/tinymath/atanhf.c

atanhl

Returns inverse hyperbolic tangent of 𝑥.

@param

long double x

@return

long double

@define x ? log1p(2 * x / (1 - x)) / 2 : x

@see libc/tinymath/atanhl.c

atanl

Returns arc tangent of 𝑥.

              1  3   1  5   1  7   1  9    1  11
atan(𝑥) = 𝑥 - - 𝑥  + - 𝑥  - - 𝑥  + - 𝑥  - -- 𝑥   ...
              3      5      7      9      11

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result of computation on FPU stack in %st

@define atan(𝑥) = Σₙ₌₀₋∞ 2²ⁿ(𝑛!)²/(𝟸𝑛+𝟷)!(𝑥²ⁿ⁺¹/(𝑥²+𝟷)ⁿ⁺¹)

@see libc/tinymath/atanl.S

atexit

Adds global destructor.

Destructors are called in reverse order. They won't be called if the program aborts or _exit() is called. Invocations of this function are usually generated by the C++ compiler.

@param

void(*)() f

@return

int: 0 on success or nonzero if out of space

@see libc/intrin/atexit.c

atfork

Registers function to be called by fork() in child.

@param

void* fn
void* arg

@return

int: 0 on success, or -1 w/ errno

@note vfork() won't invoke callbacks

@asyncsignalsafe

@see libc/calls/atfork.c

atof

Converts string to double.

@param

const char* s

@return

double

@see third_party/gdtoa/atof.c

atoi

Decodes decimal integer from ASCII string.

atoi 10⁸              22𝑐         7𝑛𝑠
strtol 10⁸            37𝑐        12𝑛𝑠
strtoul 10⁸           35𝑐        11𝑛𝑠
wcstol 10⁸            30𝑐        10𝑛𝑠
wcstoul 10⁸           30𝑐        10𝑛𝑠
strtoimax 10⁸         80𝑐        26𝑛𝑠
strtoumax 10⁸         78𝑐        25𝑛𝑠
wcstoimax 10⁸         77𝑐        25𝑛𝑠
wcstoumax 10⁸         76𝑐        25𝑛𝑠

@param

const char* s: is a non-null nul-terminated string

@return

int: the decoded signed saturated integer

@see libc/fmt/atoi.c

atol

Decodes decimal integer from ASCII string.

@param

const char* s: is a non-null nul-terminated string

@return

long: the decoded signed saturated integer

@see libc/fmt/atol.c

atoll

Decodes decimal number from ASCII string.

@param

const char* s: is a non-null nul-terminated string

@return

long: the decoded signed saturated integer

@see libc/fmt/atoll.c

AttachDebugger

Launches GDB debugger GUI for current process.

This function abstracts the toilsome details of configuring the best possible UX for debugging your app, for varying levels of available information, on most of the various platforms.

Before calling this function, consider placing ShowCrashReports() in your main function and calling DebugBreak() wherever you want; it's safer. Also note the "GDB" environment variable can be set to empty string, as a fail-safe for disabling this behavior.

@param

long continuetoaddr: can be a code address, 0, or -1 for auto

@return

int: gdb pid if continuing, 0 if detached, or -1 w/ errno

@note this is called via eponymous spinlock macro wrapper

@see libc/log/attachdebugger.c

balloc

Allocates page-guarded buffer.

@param

struct GuardedBuffer* b: is metadata object owned by caller, initialized to zero for first call; subsequent calls will resize
unsigned int a: is alignment requirement in bytes, e.g. 1,2,4,8,16,...
unsigned long n: is buffer size in bytes

@return

void*: b->p

@see ralloc()

@deprecated

@see libc/mem/balloc.c

basename

Returns pointer to last filename component in path, e.g.

path     │ dirname() │ basename()
─────────────────────────────────
0        │ .         │ .
.        │ .         │ .
..       │ .         │ ..
/        │ /         │ /
usr      │ .         │ usr
/usr/    │ /         │ usr
/usr/lib │ /usr      │ lib

Both / and \ are are considered valid component separators on all platforms. Trailing slashes are ignored. We don't grant special consideration to things like foo/., c:/, \\?\Volume, etc.

@param

char* path: is UTF-8 and may be mutated, but not expanded in length

@return

char*: pointer to path, or inside path, or to a special r/o string

@see dirname()

@see SUSv2

@see libc/fmt/basename.c

bcopy

Moves memory the BSD way.

Please use memmove() instead. Note the order of arguments.

@param

void* src
void* dest
unsigned long n

@return

void

@see libc/intrin/bcopy.c

bextra

Extracts bit field from array.

@param

const unsigned int* p
unsigned long i
char b

@return

unsigned int

@see libc/bits/bextra.c

bfree

Frees memory return by balloc().

@param

struct GuardedBuffer* b

@return

void

@deprecated

@see libc/mem/bfree.c

bind

Assigns local address and port number to socket, e.g.

struct sockaddr_in in = {AF_INET, htons(12345), {htonl(0x7f000001)}};
int fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);
bind(fd, &in, sizeof(in));

@param

int fd: is the file descriptor returned by socket()
void* addr: is usually the binary-encoded ip:port on which to listen
unsigned int addrsize: is the byte-length of addr's true polymorphic form

@return

int: 0 on success or -1 w/ errno

@error ENETDOWN, EPFNOSUPPORT, etc.

@asyncsignalsafe

@see libc/sock/bind.c

bing

Turns binary octet into unicode glyph representation.

Cosmopolitan displays RADIX-256 numbers using these digits:

 0123456789abcdef
0 ☺☻♥♦♣♠•◘○◙♂♀♪♫☼
1►◄↕‼¶§▬↨↑↓→←∟↔▲▼
2 !"#$%&'()*+,-./
30123456789:;<=>?
4@ABCDEFGHIJKLMNO
5PQRSTUVWXYZ[\]^_
6`abcdefghijklmno
7pqrstuvwxyz{|}~⌂
8ÇüéâäàåçêëèïîìÄÅ
9ÉæÆôöòûùÿÖÜ¢£¥€ƒ
aáíóúñÑªº¿⌐¬½¼¡«»
b░▒▓│┤╡╢╖╕╣║╗╝╜╛┐
c└┴┬├─┼╞╟╚╔╩╦╠═╬╧
d╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀
eαßΓπΣσμτΦΘΩδ∞φε∩
f≡±≥≤⌠⌡÷≈°∙·√ⁿ²■λ

IBM designed these glyphs for the PC to map onto the display bytes at (char *)0xb8000. Because IBM authorized buyers of its PCs to inspect and/or modify this region of memory, it became widely understood by many developers as a quick way to visualize arbitrary data that's so superior to hexdump -- a use-case that's lived on longer than the CGA graphics card for which it was designed.

@param

int b: is binary octet to pictorally represent
int intent: controls canonical multimappings: ∅␀ ,\n◙,ε∊∈€, λ,etc.

@return

int

@see unbing() for inverse

@see libc/fmt/bing.c

bingblit

@param

int ys
int xs
UNKNOWN M
int yn
int xn

@return

short*

@see libc/x/bingblit.c

bitreverse16

Reverses bits in 16-bit word.

@param

int x

@return

int

@see libc/bits/bitreverse16.c

bitreverse32

Reverses bits in 32-bit word.

@param

unsigned int x

@return

unsigned int

@see libc/bits/bitreverse32.c

bitreverse64

Reverses bits in 64-bit word.

@param

unsigned long x

@return

unsigned long

@see libc/bits/bitreverse64.c

bitreverse8

Reverses bits in 8-bit word.

@param

int x

@return

int

@see libc/bits/bitreverse8.c

BLAKE2B256

Computes blake2b 256bit message digest.

blake2b256 n=0                     191 nanoseconds
blake2b256 n=8                      23 ns/byte         40,719 kb/s
blake2b256 n=31                      6 ns/byte            153 mb/s
blake2b256 n=32                      6 ns/byte            158 mb/s
blake2b256 n=63                      3 ns/byte            312 mb/s
blake2b256 n=64                      3 ns/byte            317 mb/s
blake2b256 n=128                     1 ns/byte            640 mb/s
blake2b256 n=256                     1 ns/byte            662 mb/s
blake2b256 n=22851                   1 ns/byte            683 mb/s

@param

void* data
unsigned long len
unsigned char* out

@return

int

@see libc/str/blake2.c

BLAKE2B256_Final

@param

struct ctx* b2b
unsigned char* out

@return

int

@see libc/str/blake2.c

BLAKE2B256_Init

@param

struct ctx* b2b

@return

int

@see libc/str/blake2.c

BLAKE2B256_Process

@param

struct ctx* b2b
const unsigned long* data

@return

int

@see libc/str/blake2.c

BLAKE2B256_Update

@param

struct ctx* b2b
void* in_data
unsigned long len

@return

int

@see libc/str/blake2.c

brk

Sets end of data section.

This can be used to allocate and deallocate memory. It won't conflict with malloc() and mmap(NULL, ...) allocations since APE binaries load the image at 0x400000 and does allocations starting at 0x100080000000. You should consult _end, or call sbrk(NULL), to figure out where the existing break is first.

@param

void* end

@return

int: 0 on success or -1 w/ errno

@see mmap(), sbrk(), _end

@see libc/runtime/brk.c

bsdthread_create

XNU thread system calls.

@return

int

@see darwin-libpthread/kern/kern_support.c

@see libc/thread/xnu.internal.h

bsearch

Searches sorted array for exact item in logarithmic time.

@param

void* key
void* base
unsigned long nmemb
unsigned long size
int(*)() cmp

@return

void*

@see bsearch_r(), bisectcarleft()

@see libc/alg/bsearch.c

bsearch_r

Searches sorted array for exact item in logarithmic time.

@param

void* key
void* base
unsigned long nmemb
unsigned long size
int(*)() cmp
void* arg

@return

void*

@see bsearch(), bisectcarleft()

@see libc/alg/bsearch_r.c

bsf

Returns position of first bit set.

                      ctz(𝑥)         31^clz(𝑥)   clz(𝑥)
  uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
0x00000000      wut       32        0      wut       32
0x00000001        0        0        1        0       31
0x80000001        0        0        1       31        0
0x80000000       31       31       32       31        0
0x00000010        4        4        5        4       27
0x08000010        4        4        5       27        4
0x08000000       27       27       28       27        4
0xffffffff        0        0        1       31        0

@param

int x: is a 32-bit integer

@return

int: number in range 0..31 or undefined if 𝑥 is 0

@see libc/str/bsf.c

bsfl

Returns position of first bit set.

                      ctz(𝑥)         31^clz(𝑥)   clz(𝑥)
  uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
0x00000000      wut       32        0      wut       32
0x00000001        0        0        1        0       31
0x80000001        0        0        1       31        0
0x80000000       31       31       32       31        0
0x00000010        4        4        5        4       27
0x08000010        4        4        5       27        4
0x08000000       27       27       28       27        4
0xffffffff        0        0        1       31        0

@param

long x

@return

int: number in range 0..63 or undefined if 𝑥 is 0

@see libc/str/bsfl.c

bsfll

Returns position of first bit set.

                      ctz(𝑥)         31^clz(𝑥)   clz(𝑥)
  uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
0x00000000      wut       32        0      wut       32
0x00000001        0        0        1        0       31
0x80000001        0        0        1       31        0
0x80000000       31       31       32       31        0
0x00000010        4        4        5        4       27
0x08000010        4        4        5       27        4
0x08000000       27       27       28       27        4
0xffffffff        0        0        1       31        0

@param

long x

@return

int: number in range 0..63 or undefined if 𝑥 is 0

@see libc/str/bsfll.c

bsr

Returns binary logarithm of 𝑥.

                      ctz(𝑥)         31^clz(𝑥)   clz(𝑥)
  uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
0x00000000      wut       32        0      wut       32
0x00000001        0        0        1        0       31
0x80000001        0        0        1       31        0
0x80000000       31       31       32       31        0
0x00000010        4        4        5        4       27
0x08000010        4        4        5       27        4
0x08000000       27       27       28       27        4
0xffffffff        0        0        1       31        0

@param

int x: is a 32-bit integer

@return

int: number in range 0..31 or undefined if 𝑥 is 0

@see libc/str/bsr.c

bsr128

Returns binary logarithm of integer 𝑥.

  uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
0x00000000      wut       32        0      wut       32
0x00000001        0        0        1        0       31
0x80000001        0        0        1       31        0
0x80000000       31       31       32       31        0
0x00000010        4        4        5        4       27
0x08000010        4        4        5       27        4
0x08000000       27       27       28       27        4
0xffffffff        0        0        1       31        0

@param

rsi:rdi: is 128-bit unsigned 𝑥 value

@return

: eax number in range [0,128) or undef if 𝑥 is 0

@see also treasure trove of nearly identical functions

@see libc/nexgen32e/bsr128.S

bsrl

Returns binary logarithm of 𝑥.

                      ctz(𝑥)         31^clz(𝑥)   clz(𝑥)
  uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
0x00000000      wut       32        0      wut       32
0x00000001        0        0        1        0       31
0x80000001        0        0        1       31        0
0x80000000       31       31       32       31        0
0x00000010        4        4        5        4       27
0x08000010        4        4        5       27        4
0x08000000       27       27       28       27        4
0xffffffff        0        0        1       31        0

@param

long x: is a 64-bit integer

@return

int: number in range 0..63 or undefined if 𝑥 is 0

@see libc/str/bsrl.c

bsrll

Returns binary logarithm of 𝑥.

                      ctz(𝑥)         31^clz(𝑥)   clz(𝑥)
  uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
0x00000000      wut       32        0      wut       32
0x00000001        0        0        1        0       31
0x80000001        0        0        1       31        0
0x80000000       31       31       32       31        0
0x00000010        4        4        5        4       27
0x08000010        4        4        5       27        4
0x08000000       27       27       28       27        4
0xffffffff        0        0        1       31        0

@param

long x: is a 64-bit integer

@return

int: number in range 0..63 or undefined if 𝑥 is 0

@see libc/str/bsrll.c

bswap_64

Byte-order conversion functions.

Endianness is deceptively complicated to the uninitiated. Many helpers have been written by our top minds to address perceived difficulties. These ones got through standardization processes. To protect their legacy, all 19 functions have been implemented in just 17 bytes.

@return

@see READ32LE(), READ32BE(), etc.

@asyncsignalsafe

@see libc/nexgen32e/lolendian.S

btowc

@param

int c

@return

unsigned int

@see libc/str/btowc.c

bzero

Sets memory to zero.

bzero n=0                          661 picoseconds
bzero n=1                          661 ps/byte          1,476 mb/s
bzero n=2                          330 ps/byte          2,952 mb/s
bzero n=3                          220 ps/byte          4,428 mb/s
bzero n=4                          165 ps/byte          5,904 mb/s
bzero n=7                           94 ps/byte         10,333 mb/s
bzero n=8                           41 ps/byte         23,618 mb/s
bzero n=15                          44 ps/byte         22,142 mb/s
bzero n=16                          20 ps/byte         47,236 mb/s
bzero n=31                          21 ps/byte         45,760 mb/s
bzero n=32                          20 ps/byte         47,236 mb/s
bzero n=63                          10 ps/byte         92,997 mb/s
bzero n=64                          15 ps/byte         62,982 mb/s
bzero n=127                         15 ps/byte         62,490 mb/s
bzero n=128                         10 ps/byte         94,473 mb/s
bzero n=255                         14 ps/byte         68,439 mb/s
bzero n=256                          9 ps/byte            105 gb/s
bzero n=511                         15 ps/byte         62,859 mb/s
bzero n=512                         11 ps/byte         83,976 mb/s
bzero n=1023                        15 ps/byte         61,636 mb/s
bzero n=1024                        10 ps/byte         88,916 mb/s
bzero n=2047                         9 ps/byte            105 gb/s
bzero n=2048                         8 ps/byte            109 gb/s
bzero n=4095                         8 ps/byte            115 gb/s
bzero n=4096                         8 ps/byte            118 gb/s
bzero n=8191                         7 ps/byte            129 gb/s
bzero n=8192                         7 ps/byte            130 gb/s
bzero n=16383                        6 ps/byte            136 gb/s
bzero n=16384                        6 ps/byte            137 gb/s
bzero n=32767                        6 ps/byte            140 gb/s
bzero n=32768                        6 ps/byte            141 gb/s
bzero n=65535                       15 ps/byte         64,257 mb/s
bzero n=65536                       15 ps/byte         64,279 mb/s
bzero n=131071                      15 ps/byte         63,166 mb/s
bzero n=131072                      15 ps/byte         63,115 mb/s
bzero n=262143                      15 ps/byte         62,052 mb/s
bzero n=262144                      15 ps/byte         62,097 mb/s
bzero n=524287                      15 ps/byte         61,699 mb/s
bzero n=524288                      15 ps/byte         61,674 mb/s
bzero n=1048575                     16 ps/byte         60,179 mb/s
bzero n=1048576                     15 ps/byte         61,330 mb/s
bzero n=2097151                     15 ps/byte         61,071 mb/s
bzero n=2097152                     15 ps/byte         61,065 mb/s
bzero n=4194303                     16 ps/byte         60,942 mb/s
bzero n=4194304                     16 ps/byte         60,947 mb/s
bzero n=8388607                     16 ps/byte         60,872 mb/s
bzero n=8388608                     16 ps/byte         60,879 mb/s

@param

void* p: is memory address
unsigned long n: is byte length

@return

void: p

@asyncsignalsafe

@see libc/intrin/bzero.c

c16rtomb

@param

char* s
unsigned short c16
unsigned int* ps

@return

unsigned long

@see libc/str/c16rtomb.c

c2rangr

Computes transcedental trigonometry op w/ reactive scaling.

@param

%rdx: points to op function
everything: else delegates

@return

@clob %ax

@see sin,cos,tan

@see libc/tinymath/c2rangr.S

c32rtomb

@param

char* s
unsigned int c
unsigned int* t

@return

unsigned long

@see libc/str/c32rtomb.c

callexitontermination

Installs default handlers for friendly kill signals.

@param

struct sa_mask* opt_out_exitsigs

@return

void

@see ShowCrashReports()

@see libc/log/onkill.c

calloc

Allocates n * itemsize bytes, initialized to zero.

@param

rdi: is number of items (n)
rsi: is size of each item (itemsize)

@return

: rax is memory address, or NULL w/ errno

@note overreliance on memalign is a sure way to fragment space

@see dlcalloc()

@threadsafe

@see libc/mem/calloc.S

CategorizeIp

Classifies IP address.

@param

unsigned int x

@return

int: integer e.g. kIpLoopback, kIpPrivate, etc.

@see GetIpCategoryName()

@see net/http/categorizeip.c

__cbrt

Returns cube root of 𝑥.

@param

double x

@return

double

@see libc/tinymath/cbrtc.c

cbrt

Returns cube root of 𝑥.

@param

%xmm0: holds binary64 number

@return

: %xmm0 holds binary64 result

@see libc/tinymath/cbrt.S

cbrtf

Returns cube root of 𝑥.

@param

%xmm0: holds binary32 number

@return

: %xmm0 holds binary32 result

@see libc/tinymath/cbrtf.S

cbrtl

Returns cube root of 𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result of computation on FPU stack in %st

@see libc/tinymath/cbrtl.S

ceil

Returns smallest integral not less than 𝑥.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see round(),rint(),nearbyint()

@see vroundsd $_MM_FROUND_TO_POS_INF|_MM_FROUND_NO_EXC,%xmm0,%xmm0,%xmm0

@see libc/tinymath/ceil.S

ceilf

Returns smallest integral not less than 𝑥.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see round(),rint(),nearbyint()

@see vroundss $_MM_FROUND_TO_POS_INF|_MM_FROUND_NO_EXC,%xmm0,%xmm0,%xmm0

@see libc/tinymath/ceilf.S

ceill

Returns smallest integral not less than 𝑥.

@param

𝑥: is long double passed on stack

@return

: long double in %st

@see libc/tinymath/ceill.S

cescapec

Escapes byte for string literal.

This turns stuff like (char)0xFF into \0377. The returned string is word-encoded, e.g. '\\'|'0'<<010|'3'<<020|etc.

@param

dil: contains byte to escape

@return

@see libc/nexgen32e/cescapec.c

@see libc/nexgen32e/cescapec.S

cfgetispeed

@param

struct termios* t

@return

unsigned int

@see libc/calls/cfgetispeed.c

cfgetospeed

@param

struct termios* t

@return

unsigned int

@see libc/calls/cfgetospeed.c

cfmakeraw

@param

struct termios* t

@return

void

@see libc/calls/cfmakeraw.c

cfsetispeed

@param

struct termios* t
int speed

@return

int

@see libc/calls/cfsetispeed.c

cfsetospeed

@param

struct termios* t
int speed

@return

int

@see libc/calls/cfsetospeed.c

chdir

Sets current directory.

This does *not* update the PWD environment variable.

@param

const char* path

@return

int

@asyncsignalsafe

@see fchdir()

@see libc/calls/chdir.c

__check_fail

Handles failure of CHECK_xx() macros.

@param

const char* suffix
const char* opstr
unsigned long want
const char* wantstr
unsigned long got
const char* gotstr
const char* file
int line
const char* fmt
...

@return

void

@see libc/log/checkfail.c

__check_fail_ndebug

Handles failure of CHECK_xx() macros in -DNDEBUG mode.

This handler (1) makes binaries smaller by not embedding source code; and therefore (2) less likely to leak sensitive information. This can still print backtraces with function names if the .com.dbg file is in the same folder.

@param

unsigned long want
unsigned long got
const char* file
int line
const char* opchar
const char* fmt
...

@noreturn

@see libc/log/thunks/__check_fail_ndebug.S

@see libc/log/checkfail_ndebug.c

_check_sigchld

Checks to see if SIGCHLD should be raised on Windows.

@return

void: true if a signal was raised

@note yoinked by fork-nt.c

@see libc/calls/sigchld-nt.c

CheckElfAddress

@param

struct Elf64_Ehdr* elf
unsigned long mapsize
long addr
unsigned long addrsize

@return

void

@see libc/elf/checkelfaddress.c

CheckForMemoryLeaks

Tests for memory leaks.

This function needs to call __cxa_finalize(). Therefore any runtime services that depend on malloc() cannot be used, after calling this function.

@return

void

@see libc/log/leaks.c

chmod

Changes permissions on file, e.g.:

CHECK_NE(-1, chmod("foo/bar.txt", 0644));
CHECK_NE(-1, chmod("o/default/program.com", 0755));
CHECK_NE(-1, chmod("privatefolder/", 0700));

The esoteric bits generally available on System Five are:

CHECK_NE(-1, chmod("/opt/", 01000));          // sticky bit
CHECK_NE(-1, chmod("/usr/bin/sudo", 04755));  // setuid bit
CHECK_NE(-1, chmod("/usr/bin/wall", 02755));  // setgid bit

@param

const char* pathname: must exist
unsigned int mode: contains octal flags (base 8)

@return

int

@errors ENOENT, ENOTDIR, ENOSYS

@asyncsignalsafe

@see fchmod()

@see libc/calls/chmod.c

_chomp

Mutates line to remove line-ending characters.

@param

char* line: is NULL-propagating

@return

char*

@see getline

@see libc/str/chomp.c

_chomp16

Mutates line to remove line-ending characters.

@param

unsigned short* line: is NULL-propagating

@return

unsigned short*

@see getline

@see libc/str/chomp16.c

chown

Changes owner and/or group of pathname.

@param

const char* pathname
unsigned int uid: is user id, or -1u to not change
unsigned int gid: is group id, or -1u to not change

@return

int: 0 on success, or -1 w/ errno

@see fchown() if pathname is already open()'d

@see lchown() which does not dereference symbolic links

@see /etc/passwd for user ids

@see /etc/group for group ids

@asyncsignalsafe

@see libc/calls/chown.c

chroot

Changes root directory.

@param

const char* path

@return

int

@raise ENOSYS on Windows

@see libc/calls/chroot.c

_classifypath

Classifies file path name.

For the purposes of this function, we always consider backslash interchangeable with forward slash, even though the underlying operating system might not. Therefore, for the sake of clarity, remaining documentation will only use the forward slash.

This function behaves the same on all platforms. For instance, this function will categorize C:/FOO.BAR as a DOS path, even if you're running on UNIX rather than DOS.

If you wish to check if a pathname is absolute, in a manner that's inclusive of DOS drive paths, DOS rooted paths, in addition to the New Technology UNC paths, then you may do the following:

if (_classifypath(str) & _kPathAbs) { ... }

To check if path is a relative path:

if (~_classifypath(str) & _kPathAbs) { ... }

Please note the above check includes rooted paths such as \foo which is considered absolute by MSDN and we consider it absolute although, it's technically relative to the current drive letter.

Please note that /foo/bar is an absolute path on Windows, even though it's actually a rooted path that's considered relative to current drive by WIN32.

@param

const char* s

@return

int

integer value that's one of following:

0 if non-weird relative path e.g. c
_kPathAbs if absolute (or rooted dos) path e.g. /⋯
_kPathDos if c:, d:foo i.e. drive-relative path
_kPathAbs|_kPathDos if proper dos path e.g. c:/foo
_kPathDos|_kPathDev if dos device path e.g. nul, conin$
_kPathAbs|_kPathWin if //c, //?c, etc.
_kPathAbs|_kPathWin|_kPathDev if //./⋯, //?/⋯
_kPathAbs|_kPathWin|_kPathDev|_kPathRoot if //. or //?
_kPathAbs|_kPathNt e.g. \??\\⋯ (undoc. strict backslash)

@see "The Definitive Guide on Win32 to NT Path Conversion", James Forshaw, Google Project Zero Blog, 2016-02-29

@see "Naming Files, Paths, and Namespaces", MSDN 01/04/2021

@see libc/str/classifypath.c

clearenv

Removes all environment variables.

@return

int

@see libc/runtime/clearenv.c

clearerr

Clears error state on stream.

@param

struct FILE* f: is file object stream pointer

@return

void

@see clearerr_unlocked()

@threadsafe

@see libc/stdio/clearerr.c

clearerr_unlocked

@param

struct FILE* f

@return

void

@see libc/stdio/clearerr_unlocked.c

__clk_tck

Returns system clock ticks per second.

The returned value is memoized. This function is intended to be used via the CLK_TCK macro wrapper.

The returned value is always greater than zero. It's usually 100 hertz which means each clock tick is 10 milliseconds long.

@return

int

@see libc/runtime/clktck.c

clock

Returns how much CPU program has consumed on time-sharing system.

@return

long: value that can be divided by CLOCKS_PER_SEC, or -1 w/ errno

@see clock_gettime()

@see libc/calls/clock.c

clock_getres

Returns granularity of clock.

@param

int clock
struct st_birthtim* ts

@return

int

@see libc/calls/clock_getres.c

clock_gettime

Returns nanosecond time.

This is a high-precision timer that supports multiple definitions of time. Among the more popular is CLOCK_MONOTONIC. This function has a zero syscall implementation of that on modern x86.

nowl                l:        45𝑐        15𝑛𝑠
rdtsc               l:        13𝑐         4𝑛𝑠
gettimeofday        l:        44𝑐        14𝑛𝑠
clock_gettime       l:        40𝑐        13𝑛𝑠
__clock_gettime     l:        35𝑐        11𝑛𝑠
sys_clock_gettime   l:       220𝑐        71𝑛𝑠

@param

int clock: can be CLOCK_REALTIME, CLOCK_MONOTONIC, etc.
ANONYMOUS-STRUCT* ts: is where the result is stored

@return

int: 0 on success, or -1 w/ errno

@error EINVAL if clock isn't supported on this system

@see strftime(), gettimeofday()

@asyncsignalsafe

@see libc/calls/clock_gettime.c

__clock_gettime_get

Returns pointer to fastest clock_gettime().

@param

_Bool* opt_out_isfast

@return

int(*)()

@see libc/calls/clock_gettime.c

clone

Creates thread.

Threads are created in a detached manner. They currently can't be synchronized using wait() or posix signals. Threads created by this function should be synchronized using shared memory operations.

Any memory that's required by this system call wrapper is allocated to the top of your stack. This shouldn't be more than 128 bytes.

Your function is called from within the stack you specify. A return address is pushed onto your stack, that causes returning to jump to _Exit1() which terminates the thread. Even though the callback says it supports a return code, that'll only work on Linux and Windows.

The tls parameter is for thread-local storage. If you specify this then clone() will implicitly rewire libc (e.g. errno) to use TLS:

static char tib[64];
__initialize_tls(tib);
__install_tls(tib);

If you want a main process TLS size that's larger call it manually. Once you've done the above and/or started creating your own threads you'll be able to access your tls thread information block, using

char *p = __get_tls();
printf("errno is %d\n", *(int *)(p + 0x3c));

This function follows the same ABI convention as the Linux userspace libraries, with a few small changes. The varargs has been removed to help prevent broken code, and the stack size and tls size parameters are introduced for compatibility with FreeBSD.

To keep this system call lightweight, only the thread creation use case is polyfilled across platforms. For example, if you want fork that works on OpenBSD for example, don't do it with clone(SIGCHLD) and please just call fork(). Even if you do that on Linux, it will effectively work around libc features like atfork(), so that means other calls like getpid() may return incorrect values.

@param

void* func

is your callback function, which this wrapper requires not be null, otherwise EINVAL is raised. It is passed two args within the child thread: (1) the caller-supplied arg and (2) the new tid is always passed in the second arg for convenience

void* stk

points to the bottom of a caller allocated stack, which must be allocated via mmap() using the MAP_STACK flag, or else you won't get optimal performance and it won't work on OpenBSD

unsigned long stksz

is the size of that stack in bytes, we recommend that that this be set to GetStackSize() or else memory safety tools like kprintf() can't do as good and quick of a job; this value must be 16-aligned plus it must be at least 4192 bytes in size and it's advised to have the bottom-most page, be a guard page

int flags

which SHOULD always have all of these flags:

CLONE_THREAD
CLONE_VM
CLONE_FS
CLONE_FILES
CLONE_SIGHAND

This system call wrapper is intended for threads, and as such, we won't polyfill Linux's ability to simulate unrelated calls (e.g. fork, vfork) via clone() on other platforms. Please just call fork() and vfork() when that's what you want.

Your flags may also optionally also additionally bitwise-OR any combination of the following additional flags:

CLONE_PARENT_SETTID must be specified if you intend to set the ptid argument, which is guaranteed to be updated with the child tid BEFORE BOTH clone() returns and func is invoked
CLONE_CHILD_SETTID must be specified if you intend to set the ctid argument, which is guaranteed to be updated with the child tid before func is called, however we CAN NOT guarantee this will happen BEFORE clone() returns
CLONE_CHILD_CLEARTID causes *ctid = 0 upon child thread termination. This is used to implement join so that the parent may know when it's safe to free the child's stack memory, and as such, is guaranteed to happen AFTER the child thread has either terminated or has finished using its stack memory
CLONE_SETTLS is needed if you intend to specify the tls argument, which after thread creation may be accessed using __get_tls(). Doing this means that errno, gettid(), etc. correctly work. Caveat emptor if you choose not to do this.

void* arg

is passed as an argument to func in the child thread

int* ptid

void* tls

may be used to set the thread local storage segment; this parameter is ignored if CLONE_SETTLS is not set

int* ctid

lets the child receive its thread id without having to call gettid() and is ignored if CLONE_CHILD_SETTID isn't set

@return

int: tid of child on success, or -1 w/ errno

@threadsafe

@see libc/runtime/clone.c

close

Closes file descriptor.

This function may be used for file descriptors returned by functions like open, socket, accept, epoll_create, and landlock_create_ruleset.

This function should never be called twice for the same file descriptor, regardless of whether or not an error happened. However that doesn't mean the error should be ignored.

@param

int fd

@return

int: 0 on success, or -1 w/ errno

@error EINTR means a signal was received while closing in which case close() does not need to be called again, since the fd will close in the background

@asyncsignalsafe

@vforksafe

@see libc/calls/close.c

close_range

Closes inclusive range of file descriptors, e.g.

// close all non-stdio file descriptors
if (close_range(3, -1, 0) == -1) {
  for (int i = 3; i < 256; ++i) {
    close(i);
  }
}

This is supported on Linux 5.9+, FreeBSD, and OpenBSD. On FreeBSD, flags must be zero. On OpenBSD, we call closefrom(int) so last should be -1 in order to get OpenBSD support, otherwise ENOSYS will be returned. We also polyfill closefrom on FreeBSD since it's available on older kernels.

On Linux, the following flags are supported:

CLOSE_RANGE_UNSHARE
CLOSE_RANGE_CLOEXEC

@param

unsigned int first
unsigned int last
unsigned int flags

@return

int: 0 on success, or -1 w/ errno

@error ENOSYS if not Linux 5.9+ / FreeBSD / OpenBSD

@error EBADF on OpenBSD if first is greater than highest fd

@error EINVAL if flags are bad or first is greater than last

@error EMFILE if a weird race condition happens on Linux

@error EINTR possibly on OpenBSD

@error ENOMEM on Linux maybe

@see libc/calls/close_range.c

close_s

Closes file descriptor.

The caller's variable is made -1 so subsequent calls are no-ops.

@param

int* fdp

@return

int: 0 on success, or -1 w/ errno

@asyncsignalsafe

@see libc/runtime/close_s.c

closedir

Closes directory object returned by opendir().

@param

struct dirstream* dir

@return

int: 0 on success or -1 w/ errno

@see libc/stdio/dirstream.c

closefrom

Closes extra file descriptors, e.g.

// close all non-stdio file descriptors
if (closefrom(3) == -1) {
  for (int i = 3; i < 256; ++i) {
    close(i);
  }
}

@param

int first

@return

int: 0 on success, or -1 w/ errno

@error ENOSYS if not Linux 5.9+ / FreeBSD / OpenBSD

@error EBADF on OpenBSD if first is greater than highest fd

@error EINVAL if flags are bad or first is greater than last

@error EMFILE if a weird race condition happens on Linux

@error EINTR possibly on OpenBSD

@error ENOMEM on Linux maybe

@note supported on Linux 5.9+, FreeBSD 8+, and OpenBSD

@see libc/calls/closefrom.c

CloseHandle

Closes an open object handle.

@param

long hObject

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/closehandle.c

closelog

Closes the file descriptor being used to write to the system logger

Use of closelog is optional

@return

void

@asyncsignalsafe

@see libc/sock/syslog.c

CloseSymbolTable

Frees symbol table.

@param

struct SymbolTable** table

@return

int: 0 on success or -1 on system error

@see libc/runtime/closesymboltable.c

cmpsb

Compares 8-bit signed integers.

@param

rdi: points to left integer
rsi: points to right integer

@return

: <0, 0, or >0 based on comparison

@see libc/nexgen32e/cmpsb.S

cmpsl

Compares 32-bit signed integers.

@param

rdi: points to left integer
rsi: points to right integer

@return

: <0, 0, or >0 based on comparison

@see libc/nexgen32e/cmpsl.S

cmpsq

Compares 64-bit signed integers.

@param

rdi: points to left integer
rsi: points to right integer

@return

: <0, 0, or >0 based on comparison

@see libc/nexgen32e/cmpsq.S

cmpsw

Compares 16-bit signed integers.

@param

rdi: points to left integer
rsi: points to right integer

@return

: <0, 0, or >0 based on comparison

@see libc/nexgen32e/cmpsw.S

cmpub

Compares 8-bit unsigned integers.

@param

rdi: points to left integer
rsi: points to right integer

@return

: <0, 0, or >0 based on comparison

@see libc/nexgen32e/cmpub.S

cmpul

Compares 32-bit unsigned integers.

@param

rdi: points to left integer
rsi: points to right integer

@return

: <0, 0, or >0 based on comparison

@see libc/nexgen32e/cmpul.S

cmpuq

Compares 64-bit unsigned integers.

@param

rdi: points to left integer
rsi: points to right integer

@return

: <0, 0, or >0 based on comparison

@see libc/nexgen32e/cmpuq.S

cmpuw

Compares 16-bit unsigned integers.

@param

rdi: points to left integer
rsi: points to right integer

@return

: <0, 0, or >0 based on comparison

@see libc/nexgen32e/cmpuw.S

_cmpxchg

Compares and exchanges.

@param

void* ifthing: is uint𝑘_t[hasatleast 1] where 𝑘 ∈ {8,16,32,64}
long isequaltome
long replaceitwithme
unsigned long size: is automatically supplied by macro wrapper

@return

_Bool: true if value was exchanged, otherwise false

@see _lockcmpxchg()

@see libc/intrin/cmpxchg.c

commandv

Resolves full pathname of executable.

@param

const char* name
char* pathbuf
unsigned long pathbufsz

@return

char*: execve()'able path, or NULL w/ errno

@errno ENOENT, EACCES, ENOMEM

@see free(), execvpe()

@asyncsignalsafe

@vforksafe

@see libc/calls/commandv.c

commandvenv

Finds full executable path in overridable way.

This is a higher level version of the commandv() function. Programs that spawn subprocesses can use this function to determine the path at startup. Here's an example how you could use it:

if ((strace = commandvenv("STRACE", "strace"))) {
  strace = strdup(strace);
} else {
  fprintf(stderr, "error: please install strace\n");
  exit(1);
}

@param

const char* var: is environment variable which may be used to override PATH search, and it can force a NULL result if it's empty
const char* cmd: is name of program, which is returned asap if it's an absolute path

@return

const char*: pointer to exe path string, or NULL if it couldn't be found or the environment variable was empty; noting that the caller should copy this string before saving it

@see libc/log/commandvenv.c

CompareDnsNames

Compares DNS hostnames in reverse lexicographical asciibetical order.

@param

const char* A
const char* B

@return

int: <0, 0, or >0

@see test/libc/dns/comparednsnames_test.c (the code that matters)

@see libc/dns/comparednsnames.c

CompareSlices

@param

const char* a
unsigned long n
const char* b
unsigned long m

@return

int

@see libc/str/compareslices.c

CompareSlicesCase

@param

const char* a
unsigned long n
const char* b
unsigned long m

@return

int

@see libc/str/compareslicescase.c

compress

Compresses source buffer into the destination buffer. sourceLen is the byte length of the source buffer. Upon entry, destLen is the total size of the destination buffer, which must be at least the value returned by compressBound(sourceLen). Upon exit, destLen is the actual size of the compressed data. compress() is equivalent to compress2() with a level parameter of Z_DEFAULT_COMPRESSION.

@return

int: Z_OK if success, Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if there was not enough room in the output buffer.

@see third_party/zlib/zlib.h

compress2

Compresses source buffer into the destination buffer. The level parameter has the same meaning as in deflateInit. sourceLen is the byte length of the source buffer. Upon entry, destLen is the total size of the destination buffer, which must be at least the value returned by compressBound(sourceLen). Upon exit, destLen is the actual size of the compressed data.

@return

int: Z_OK if success, Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if there was not enough room in the output buffer, Z_STREAM_ERROR if the level parameter is invalid.

@see third_party/zlib/zlib.h

compressBound

Returns an upper bound on the compressed size after compress() or compress2() on sourceLen bytes. It would be used before a compress() or compress2() call to allocate the destination buffer.

@return

unsigned long

@see third_party/zlib/zlib.h

connect

Connects socket to remote end.

ProTip: Connectionless sockets, e.g. UDP, can be connected too. The benefit is not needing to specify the remote address on each send. It also means getsockname() can be called to retrieve routing details.

@param

int fd
void* addr
unsigned int addrsize

@return

int: 0 on success or -1 w/ errno

@asyncsignalsafe

@restartable (unless SO_RCVTIMEO)

@see libc/sock/connect.c

_construct

Calls global initialization functions.

@param

r12: is argc
r13: is argv
r14: is environ
r15: is auxv

@return

@see libc/runtime/construct.S

ConvertTicksToNanos

@param

unsigned long ticks

@return

long double

@see libc/calls/oldbench.c

copy_file_range

Transfers data between files.

@param

int infd
long* inopt_out_inoffset
int outfd: should be a writable file, but not O_APPEND
long* inopt_out_outoffset
unsigned long uptobytes
unsigned int flags: is reserved for future use

@return

long: number of bytes actually copied, or -1 w/ errno

@see sendfile() for seekable → socket

@see splice() for fd ↔ pipe

@see libc/calls/splice.c

copy_with_crc

@param

struct z_stream* strm
unsigned char* dst
long size

@return

void

@see third_party/zlib/crc32.c

copyfd

Copies data between file descriptors the slow way.

@param

int infd
long* inoutopt_inoffset
int outfd
long* inoutopt_outoffset
unsigned long size
unsigned int flags

@return

long: -1 on error/interrupt, 0 on eof, or [1..size] on success

@see copy_file_range() for file ↔ file

@see sendfile() for seekable → socket

@see splice() for fd ↔ pipe

@see libc/calls/copyfd.c

_copyfd

Copies data between fds the old fashioned way.

Even though Cosmopolitan polyfills copy_file_range() to fallback to doing this, it's useful to call this function in cases where you know it'd be more helpful to get the larger buffer size with read/write.

Reads are allowed to be interrupted. Writes are uninterruptible. If we get an interrupt when partial data was written, we return the partial amount. Therefore the file descriptors are guaranteed to remain in a consistent state, provided EINTR is the only error.

If n is 0 then 0 is returned and no i/o operations are performed.

@param

int infd
int outfd
unsigned long n

@return

long: bytes successfully exchanged

@see libc/mem/copyfd.c

copyfile

Copies file.

This implementation goes 2x faster than the cp command that comes included with most systems since we use the newer copy_file_range() system call rather than sendfile().

@param

const char* src
const char* dst
int flags: may have COPYFILE_PRESERVE_TIMESTAMPS, COPYFILE_NOCLOBBER

@return

int: 0 on success, or -1 w/ errno

@see libc/calls/copyfile.c

copysign

Returns 𝑥 with same sign as 𝑦.

@param

𝑥: is double scalar in low half of %xmm0
𝑦: is double scalar in low half of %xmm1

@return

: double scalar in low half of %xmm0

@see libc/tinymath/copysign.S

copysignf

Returns 𝑥 with same sign as 𝑦.

@param

𝑦: is float scalar in low quarter of %xmm0
𝑥: is float scalar in low quarter of %xmm1

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/copysignf.S

copysignl

Returns 𝑥 with same sign as 𝑦.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes
𝑦: is the power, also pushed on stack, in reverse order

@return

: result on FPU stack in %st

@see libc/tinymath/copysignl.S

cos

Returns cosine of 𝑥.

@param

double x

@return

double

@note should take ~5ns

@see libc/tinymath/cos.c

cosh

Returns hyperbolic cosine of 𝑥.

cosh(x) = (exp(x) + 1/exp(x))/2
        = 1 + 0.5*(exp(x)-1)*(exp(x)-1)/exp(x)
        = 1 + x*x/2 + o(x^4)

@param

double x

@return

double

@see libc/tinymath/cosh.c

coshf

Returns hyperbolic cosine of 𝑥.

cosh(x) = (exp(x) + 1/exp(x))/2
        = 1 + 0.5*(exp(x)-1)*(exp(x)-1)/exp(x)
        = 1 + x*x/2 + o(x^4)

@param

float x

@return

float

@see libc/tinymath/coshf.c

coshl

Returns hyperbolic cosine of 𝑥.

cosh(x) = (exp(x) + 1/exp(x))/2
        = 1 + 0.5*(exp(x)-1)*(exp(x)-1)/exp(x)
        = 1 + x*x/2 + o(x^4)

@param

long double x

@return

long double

@see libc/tinymath/coshl.c

cosl

Returns cosine of 𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: %st stores result

@domain -(3π/8) < 𝑥 < 3π/8 for best accuracy

@see libc/tinymath/cosl.S

cosmo

Cosmopolitan runtime.

@param

edi: is argc
rsi: is argv
rdx: is environ
rcx: is auxv

@noreturn

@see libc/runtime/cosmo.S

cosmo2flock

@param

unsigned long memory

@return

void

@see libc/calls/metaflock.c

_countbits

Returns population count of array.

@param

void* a: is byte sequence
unsigned long n

@return

unsigned long: number of bits set to one

@note 30gbps on Nehalem (Intel 2008+) otherwise 3gbps

@see libc/bits/countbits.c

countbranch_report

@return

void

@see libc/log/countbranch_report.c

countexpr_report

@return

void

@see libc/log/countexpr_report.c

cprojl

Projects into Rienmann sphere.

@param

z: is complex long double passed on stack

@return

@note needs sse3

@see libc/tinymath/cprojl.S

crc32

Update a running CRC-32 with the bytes buf[0..len-1] and return the updated CRC-32. If buf is Z_NULL, this function returns the required initial value for the crc. Pre- and post-conditioning (one's complement) is performed within this function so it shouldn't be done by the application.

Usage example:

uLong crc = crc32(0L, Z_NULL, 0);
while (read_buffer(buffer, length) != EOF) {
  crc = crc32(crc, buffer, length);
}
if (crc != original_crc) error();

@return

unsigned long

@see third_party/zlib/zlib.h

crc32_combine

Combine two CRC-32 check values into one. For two sequences of bytes, seq1 and seq2 with lengths len1 and len2, CRC-32 check values were calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and len2.

@return

unsigned long

@see third_party/zlib/zlib.h

crc32_pclmul

Computes Phil Katz CRC-32 w/ carryless multiply isa.

This is support code that's abstracted by crc32_z().

@param

edi: is initial value
rsi: points to buffer
rdx: is bytes in buffer that's >=64 and %16==0

@return

: eax is crc32

@note needs Westmere (c.2010) or Bulldozer (c.2011)

@see “Fast CRC Computation for Generic Polynomials Using PCLMULQDQ Instruction” V. Gopal, E. Ozturk, et al., 2009, intel.ly/2ySEwL0

@see libc/nexgen32e/crc32-pclmul.S

crc32_z

Computes Phil Katz CRC-32 used by zip/zlib/gzip/etc.

x^32+x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1
0b100000100110000010001110110110111
bitreverse32(0x104c11db7)

This implementation takes 32 picoseconds per byte or 30 gibibyte/s.

@param

unsigned int h: is initial value
void* data
unsigned long size

@return

unsigned int

@see libc/str/crc32z.c

crc32c

Computes 32-bit Castagnoli Cyclic Redundancy Check.

@param

unsigned int init: is the initial hash value
void* data: points to the data
unsigned long size: is the byte size of data

@return

unsigned int: eax is the new hash value

@note Used by ISCSI, TensorFlow, etc.

@see libc/str/crc32c.c

crc32init

Generates lookup table for computing CRC-32 byte-by-byte.

void crc32init(uint32_t table[256], uint32_t polynomial) {
  uint32_t d, i, r;
  for (d = 0; d < 256; ++d) {
    r = d;
    for (i = 0; i < 8; ++i) {
      r = r >> 1 ^ (r & 1 ? polynomial : 0);
    }
    table[d] = r;
  }
}

@param

rdi: is pointer to uint32_t[256] array
esi: 32-bit binary polynomial config

@return

@note imposes ~300ns one-time cost

@see libc/nexgen32e/crc32init.S

crc_finalize

@param

struct DeflateState* s

@return

void

@see third_party/zlib/crc32.c

crc_reset

@param

struct DeflateState* s

@return

void

@see third_party/zlib/crc32.c

creat

Creates new file, returning open()'d file descriptor.

This function is shorthand for:

open(file, O_CREAT | O_WRONLY | O_TRUNC, mode)

@param

const char* file: is a UTF-8 string, which is truncated if it exists
unsigned int mode: is an octal user/group/other permission, e.g. 0755

@return

int: a number registered with the system to track the open file, which must be stored using a 64-bit type in order to support both System V and Windows, and must be closed later on using close()

@see open(), touch()

@asyncsignalsafe

@see libc/calls/creat.c

CreateDirectory

Creates directory on the New Technology.

@param

const unsigned short* lpPathName
struct NtSecurityAttributes* lpSecurityAttributes

@return

int: handle, or -1 on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/createdirectory.c

CreateFile

Opens file on the New Technology.

@param

const unsigned short* lpFileName
unsigned int dwDesiredAccess
unsigned int dwShareMode
struct NtSecurityAttributes* opt_lpSecurityAttributes
int dwCreationDisposition
unsigned int dwFlagsAndAttributes
long opt_hTemplateFile

@return

long: handle, or -1 on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/createfile.c

CreateFileMapping

Creates file mapping object on the New Technology.

@param

long opt_hFile: may be -1 for MAP_ANONYMOUS behavior
struct NtSecurityAttributes* opt_lpFileMappingAttributes
unsigned int flProtect
unsigned int dwMaximumSizeHigh
unsigned int dwMaximumSizeLow
const unsigned short* opt_lpName

@return

long: handle, or 0 on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see MapViewOfFileEx()

@see libc/intrin/createfilemapping.c

CreateFileMappingNuma

Creates file mapping object on the New Technology.

@param

long opt_hFile: may be -1 for MAP_ANONYMOUS behavior
struct NtSecurityAttributes* opt_lpFileMappingAttributes
unsigned int flProtect
unsigned int dwMaximumSizeHigh
unsigned int dwMaximumSizeLow
const unsigned short* opt_lpName
unsigned int nndDesiredNumaNode

@return

long: handle, or 0 on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see MapViewOfFileExNuma()

@see libc/intrin/createfilemappingnuma.c

CreateMemoryInterval

@param

struct _mmi* mm
int i

@return

int

@see libc/calls/memtrack.greg.c

CreateNamedPipe

Creates pipe.

@param

const unsigned short* lpName
unsigned int dwOpenMode
unsigned int dwPipeMode
unsigned int nMaxInstances
unsigned int nOutBufferSize
unsigned int nInBufferSize
unsigned int nDefaultTimeOutMs
struct NtSecurityAttributes* opt_lpSecurityAttributes

@return

long: handle to server end

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/createnamedpipe.c

CreatePipe

Creates anonymous pipe.

@param

long* out_hReadPipe
long* out_hWritePipe
struct NtSecurityAttributes* opt_lpPipeAttributes
unsigned int nSize

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/createpipe.c

CreatePipeName

@param

unsigned short* a

@return

unsigned short*

@see libc/calls/createpipename.c

CreateProcess

Creates process on the New Technology.

@param

const unsigned short* opt_lpApplicationName
unsigned short* lpCommandLine
struct NtSecurityAttributes* opt_lpProcessAttributes
struct NtSecurityAttributes* opt_lpThreadAttributes
int bInheritHandles
unsigned int dwCreationFlags
void* opt_lpEnvironment
const unsigned short* opt_lpCurrentDirectory
struct NtStartupInfo* lpStartupInfo
struct NtProcessInformation* opt_out_lpProcessInformation

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/createprocess.c

CreateSymbolicLink

Creates symbolic link on the New Technology.

@param

const unsigned short* lpSymlinkFileName
const unsigned short* lpTargetPathName
unsigned int dwFlags

@return

int

@note you need to elevate process privileges before calling this

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/createsymboliclink.c

CreateThread

Opens file on the New Technology.

@param

struct NtSecurityAttributes* lpThreadAttributes
unsigned long dwStackSize: may be 0 for default per executable
unsigned int(*)() lpStartAddress
void* lpParameter
unsigned int dwCreationFlags
unsigned int* opt_lpThreadId

@return

long: thread handle, or 0 on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/createthread.c

critbit0_allprefixed

Invokes callback for all items with prefix.

@param

struct critbit0* t
const char* prefix
long(*)() callback
void* arg

@return

long: 0 unless iteration was halted by CALLBACK returning nonzero, in which case that value is returned

@note h/t djb and agl

@see libc/alg/critbit0_allprefixed.c

critbit0_clear

Removes all items from 𝑡.

@param

struct critbit0* t: tree

@return

void

@note h/t djb and agl

@see libc/alg/critbit0_clear.c

critbit0_contains

Returns non-zero iff 𝑢 ∈ 𝑡.

@param

struct critbit0* t: tree
const char* u: NUL-terminated string

@return

_Bool

@note h/t djb and agl

@see libc/alg/critbit0_contains.c

critbit0_delete

Removes 𝑢 from 𝑡.

@param

struct critbit0* t: tree
const char* u: NUL-terminated string

@return

_Bool: true if 𝑡 was mutated

@note h/t djb and agl

@see libc/alg/critbit0_delete.c

critbit0_emplace

Inserts 𝑢 into 𝑡 without copying.

@param

struct critbit0* t: is critical bit tree
char* u: is nul-terminated string which must be 8+ byte aligned and becomes owned by the tree afterwards
unsigned long ulen

@return

int: true if 𝑡 was mutated, or -1 w/ errno

@note h/t djb and agl

@see libc/alg/critbit0_emplace.c

critbit0_get

Returns first item in 𝑡 with prefix 𝑢.

@param

struct critbit0* t: tree
const char* u: NUL-terminated string

@return

char*: item or NULL if not found

@note h/t djb and agl

@see libc/alg/critbit0_get.c

critbit0_insert

Inserts 𝑢 into 𝑡.

@param

struct critbit0* t: tree
const char* u: NUL-terminated string

@return

int: true if 𝑡 was mutated, or -1 w/ errno

@note h/t djb and agl

@see libc/alg/critbit0_insert.c

crypt

Encrypts password the old fashioned way.

The method of encryption depends on the first three chars of salt:

$1$ is MD5
$2$ is Blowfish
$5$ is SHA-256
$6$ is SHA-512
Otherwise DES

@param

const char* key
const char* salt

@return

char*: static memory with encrypted password

@see third_party/argon2/

@see third_party/musl/crypt.c

crypt_r

Encrypts password the old fashioned way.

The method of encryption depends on the first three chars of salt:

$1$ is MD5
$2$ is Blowfish
$5$ is SHA-256
$6$ is SHA-512
Otherwise DES

@param

const char* key
const char* salt
struct crypt_data* data

@return

char*: static memory with encrypted password

@see third_party/argon2/

@see third_party/musl/crypt_r.c

ctermid

Generates path of controlling terminal.

This function always returns /dev/tty since that's supported by all supported platforms, and polyfilled on Windows.

@param

char* s: may optionally specify an outut buffer L_ctermid in size

@return

char*: pointer to s (or image memory if s was null) which contains path of controlling terminal, or empty string if if this program is a win32 app running in gui mode

@see libc/stdio/ctermid.c

cthread_attr_destroy

@param

struct cthread_attr_t* attr

@return

int

@see libc/thread/attr.c

cthread_attr_getdetachstate

@param

struct cthread_attr_t* attr

@return

int

@see libc/thread/attr.c

cthread_attr_getguardsize

@param

struct cthread_attr_t* attr

@return

unsigned long

@see libc/thread/attr.c

cthread_attr_getstacksize

@param

struct cthread_attr_t* attr

@return

unsigned long

@see libc/thread/attr.c

cthread_attr_init

@param

struct cthread_attr_t* attr

@return

int

@see libc/thread/attr.c

cthread_attr_setdetachstate

@param

struct cthread_attr_t* attr
int mode

@return

int

@see libc/thread/attr.c

cthread_attr_setguardsize

@param

struct cthread_attr_t* attr
unsigned long size

@return

int

@see libc/thread/attr.c

cthread_attr_setstacksize

@param

struct cthread_attr_t* attr
unsigned long size

@return

int

@see libc/thread/attr.c

cthread_memory_wait32

@param

int* addr
int val
ANONYMOUS-STRUCT* timeout

@return

int

@see libc/thread/wait.c

cthread_memory_wake32

@param

int* addr
int n

@return

int

@see libc/thread/wait.c

cthread_self

Returns thread descriptor of the current thread.

@return

struct cthread_descriptor_t*

@see libc/thread/self.c

cthread_sem_destroy

Destroys semaphore.

@param

union cthread_sem_t* sem

@return

int

@see libc/thread/sem.c

cthread_sem_init

Initializes semaphore.

@param

union cthread_sem_t* sem
int count

@return

int

@see libc/thread/sem.c

cthread_sem_signal

Notifies a thread waiting on semaphore.

@param

union cthread_sem_t* sem

@return

int

@see libc/thread/sem.c

cthread_sem_wait

Waits on semaphore.

@param

union cthread_sem_t* sem
int spin
ANONYMOUS-STRUCT* timeout

@return

int

@see libc/thread/sem.c

cthread_sem_wait_futex

Waits on semaphore with kernel assistance.

@param

union cthread_sem_t* sem
ANONYMOUS-STRUCT* timeout

@return

int

@see libc/thread/sem.c

cthread_sem_wait_spin

Waits on semaphore without kernel assistance.

@param

union cthread_sem_t* sem
unsigned long count
int spin
ANONYMOUS-STRUCT* timeout

@return

int

@see libc/thread/sem.c

ctime

@param

const long* timep

@return

char*

@see libc/time/ctime.c

ctime_r

@param

const long* timep
char* buf

@return

char*

@see libc/time/ctime_r.c

__cxa_atexit

Adds global destructor.

Destructors are called in reverse order. They won't be called if the program aborts or _exit() is called. Invocations of this function are usually generated by the C++ compiler. Behavior is limitless if some other module has linked calloc().

@param

void* fp: is void(*)(T)
void* arg: is passed to callback
void* pred: can be non-null for things like dso modules

@return

int: 0 on success or nonzero w/ errno

@note folks have forked libc in past just to unbloat atexit()

@see libc/intrin/cxaatexit.c

__cxa_finalize

Triggers global destructors.

They're called in LIFO order. If a destructor adds more destructors, then those destructors will be called immediately following, before iteration continues.

@param

void* pred: can be null to match all

@return

void

@see libc/intrin/cxafinalize.c

__cxa_printexits

Prints global destructors.

@param

struct FILE* f
void* pred: can be null to match all

@return

void

@see libc/log/cxaprintexits.c

_d2ld2

Thunks double(*fn)(double,double) -> long double fn.

@param

%xmm0[0]: contains double param

@return

: %xmm0[0] contains double result

@note 100% negligible overhead

@see libc/tinymath/d2ld2.S

daylight

@type

int

@see libc/time/timezone.c

DecodeBase64

Decodes base64 ascii representation to binary.

This supports the following alphabets:

ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/
ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_

@param

const char* data: is input value
unsigned long size: if -1 implies strlen
unsigned long* out_size: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/decodebase64.c

DecodeDosArgv

@param

int ignore
struct st_* st

@return

void

@see libc/runtime/getdosargv.c

DecodeLatin1

Decodes ISO-8859-1 to UTF-8.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/decodelatin1.c

DecodeNf32

Decodes u32 from ANSI Nf sequence.

@param

const char* s
char** e

@return

unsigned int

@see libc/fmt/decodenf32.c

_defer

Calls fn(arg) when function returns.

This garbage collector overwrites the return address on the stack so that the RET instruction calls a trampoline which calls free(). It's loosely analogous to Go's defer keyword rather than a true cycle gc.

@param

void* fn
void* arg

@return

void*

@warning do not return a gc()'d pointer

@warning do not realloc() with gc()'d pointer

@warning be careful about static keyword due to impact of inlining

@note you should use -fno-omit-frame-pointer

@see libc/mem/gc.c

__defer

Adds destructor to garbage shadow stack.

@param

struct StackFrame* frame: is passed automatically by wrapper macro
void* fn: takes one argument
void* arg: is passed to fn(arg)

@return

void: arg

@see libc/mem/defer.greg.c

deflate

deflate compresses as much data as possible, and stops when the input buffer becomes empty or the output buffer becomes full. It may introduce some output latency (reading input without producing any output) except when forced to flush.

The detailed semantics are as follows. deflate performs one or both of the following actions:

Compress more input starting at next_in and update next_in and

avail_in accordingly. If not all input can be processed (because there is not enough room in the output buffer), next_in and avail_in are updated and processing will resume at this point for the next call of deflate().

Generate more output starting at next_out and update next_out and

avail_out accordingly. This action is forced if the parameter flush is non zero. Forcing flush frequently degrades the compression ratio, so this parameter should be set only when necessary. Some output may be provided even if flush is zero.

Before the call of deflate(), the application should ensure that at least one of the actions is possible, by providing more input and/or consuming more output, and updating avail_in or avail_out accordingly; avail_out should never be zero before the call. The application can consume the compressed output when it wants, for example when the output buffer is full (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK and with zero avail_out, it must be called again after making room in the output buffer because there might be more output pending. See deflatePending(), which can be used if desired to determine whether or not there is more ouput in that case.

Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to decide how much data to accumulate before producing output, in order to maximize compression.

If the parameter flush is set to Z_SYNC_FLUSH, all pending output is flushed to the output buffer and the output is aligned on a byte boundary, so that the decompressor can get all input data available so far. (In particular avail_in is zero after the call if enough output space has been provided before the call.) Flushing may degrade compression for some compression algorithms and so it should be used only when necessary. This completes the current deflate block and follows it with an empty stored block that is three bits plus filler bits to the next byte, followed by four bytes (00 00 ff ff).

If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the output buffer, but the output is not aligned to a byte boundary. All of the input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. This completes the current deflate block and follows it with an empty fixed codes block that is 10 bits long. This assures that enough bytes are output in order for the decompressor to finish the block before the empty fixed codes block.

If flush is set to Z_BLOCK, a deflate block is completed and emitted, as for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to seven bits of the current block are held to be written as the next byte after the next deflate block is completed. In this case, the decompressor may not be provided enough bits at this point in order to complete decompression of the data provided so far to the compressor. It may need to wait for the next block to be emitted. This is for advanced applications that need to control the emission of deflate blocks.

If flush is set to Z_FULL_FLUSH, all output is flushed as with Z_SYNC_FLUSH, and the compression state is reset so that decompression can restart from this point if previous compressed data has been damaged or if random access is desired. Using Z_FULL_FLUSH too often can seriously degrade compression.

If deflate returns with avail_out == 0, this function must be called again with the same value of the flush parameter and more output space (updated avail_out), until the flush is complete (deflate returns with non-zero avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that avail_out is greater than six to avoid repeated flush markers due to avail_out == 0 on return.

If the parameter flush is set to Z_FINISH, pending input is processed, pending output is flushed and deflate returns with Z_STREAM_END if there was enough output space. If deflate returns with Z_OK or Z_BUF_ERROR, this function must be called again with Z_FINISH and more output space (updated avail_out) but no more input data, until it returns with Z_STREAM_END or an error. After deflate has returned Z_STREAM_END, the only possible operations on the stream are deflateReset or deflateEnd.

Z_FINISH can be used in the first deflate call after deflateInit if all the compression is to be done in a single step. In order to complete in one call, avail_out must be at least the value returned by deflateBound (see below). Then deflate is guaranteed to return Z_STREAM_END. If not enough output space is provided, deflate will not return Z_STREAM_END, and it must be called again as described above.

deflate() sets strm->adler to the Adler-32 checksum of all input read so far (that is, total_in bytes). If a gzip stream is being generated, then strm->adler will be the CRC-32 checksum of the input read so far. (See deflateInit2 below.)

deflate() may update strm->data_type if it can make a good guess about the input data type (Z_BINARY or Z_TEXT). If in doubt, the data is considered binary. This field is only for information purposes and does not affect the compression algorithm in any manner.

@return

int: Z_OK if some progress has been made (more input processed or more output produced), Z_STREAM_END if all input has been consumed and all output has been produced (only when flush is set to Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example if next_in or next_out was Z_NULL or the state was inadvertently written over by the application), or Z_BUF_ERROR if no progress is possible (for example avail_in or avail_out was zero). Note that Z_BUF_ERROR is not fatal, and deflate() can be called again with more input and more output space to continue compressing.

@see third_party/zlib/zlib.h

deflateBound

deflateBound() returns an upper bound on the compressed size after deflation of sourceLen bytes. It must be called after deflateInit() or deflateInit2(), and after deflateSetHeader(), if used. This would be used to allocate an output buffer for deflation in a single pass, and so would be called before deflate(). If that first deflate() call is provided the sourceLen input bytes, an output buffer allocated to the size returned by deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed to return Z_STREAM_END. Note that it is possible for the compressed size to be larger than the value returned by deflateBound() if flush options other than Z_FINISH or Z_NO_FLUSH are used.

@return

unsigned long

@see third_party/zlib/zlib.h

deflateCopy

Sets destination stream as a complete copy of the source stream.

This function can be useful when several compression strategies will be tried, for example when there are several ways of pre-processing the input data with a filter. The streams that will be discarded should then be freed by calling deflateEnd. Note that deflateCopy duplicates the internal compression state which can be quite large, so this strategy is slow and can consume lots of memory.

@return

int: Z_OK if success, Z_MEM_ERROR if there was not enough memory, Z_STREAM_ERROR if the source stream state was inconsistent (such as zalloc being Z_NULL). msg is left unchanged in both source and destination.

@see third_party/zlib/zlib.h

deflateEnd

All dynamically allocated data structures for this stream are freed. This function discards any unprocessed input and does not flush any pending output.

@return

int: Z_OK if success, Z_STREAM_ERROR if the stream state was inconsistent, Z_DATA_ERROR if the stream was freed prematurely (some input or output was discarded). In the error case, msg may be set but then points to a static string (which must not be deallocated).

@see third_party/zlib/zlib.h

deflateGetDictionary

Returns the sliding dictionary being maintained by deflate. dictLength is set to the number of bytes in the dictionary, and that many bytes are copied to dictionary. dictionary must have enough space, where 32768 bytes is always enough. If deflateGetDictionary() is called with dictionary equal to Z_NULL, then only the dictionary length is returned, and nothing is copied. Similary, if dictLength is Z_NULL, then it is not set.

deflateGetDictionary() may return a length less than the window size, even when more than the window size in input has been provided. It may return up to 258 bytes less in that case, due to how zlib's implementation of deflate manages the sliding window and lookahead for matches, where matches can be up to 258 bytes long. If the application needs the last window-size bytes of input, then that would need to be saved by the application outside of zlib.

@return

int: Z_OK on success, or Z_STREAM_ERROR if the stream state is inconsistent.

@see third_party/zlib/zlib.h

deflateInit

Initializes the internal stream state for compression. The fields zalloc, zfree and opaque must be initialized before by the caller. If zalloc and zfree are set to Z_NULL, deflateInit updates them to use default allocation functions.

The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: 1 gives best speed, 9 gives best compression, 0 gives no compression at all (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION requests a default compromise between speed and compression (currently equivalent to level 6).

@return

int: Z_OK if success, Z_MEM_ERROR if there was not enough memory, or Z_STREAM_ERROR if level is not a valid compression level. msg is set to null if there is no error message. deflateInit does not perform any compression: this will be done by deflate().

@see third_party/zlib/zlib.h

deflateInit2

This is another version of deflateInit with more compression options. The fields next_in, zalloc, zfree and opaque must be initialized before by the caller.

The method parameter is the compression method. It must be Z_DEFLATED in this version of the library.

The windowBits parameter is the base two logarithm of the window size (the size of the history buffer). It should be in the range 8..15 for this version of the library. Larger values of this parameter result in better compression at the expense of memory usage. The default value is 15 if deflateInit is used instead.

For the current implementation of deflate(), a windowBits value of 8 (a window size of 256 bytes) is not supported. As a result, a request for 8 will result in 9 (a 512-byte window). In that case, providing 8 to inflateInit2() will result in an error when the zlib header with 9 is checked against the initialization of inflate(). The remedy is to not use 8 with deflateInit2() with this initialization, or at least in that case use 9 with inflateInit2().

windowBits can also be -8..-15 for raw deflate. In this case, -windowBits determines the window size. deflate() will then generate raw deflate data with no zlib header or trailer, and will not compute a check value.

windowBits can also be greater than 15 for optional gzip encoding. Add 16 to windowBits to write a simple gzip header and trailer around the compressed data instead of a zlib wrapper. The gzip header will have no file name, no extra data, no comment, no modification time (set to zero), no header crc, and the operating system will be set to the appropriate value, if the operating system was determined at compile time. If a gzip stream is being written, strm->adler is a CRC-32 instead of an Adler-32.

For raw deflate or gzip encoding, a request for a 256-byte window is rejected as invalid, since only the zlib header provides a means of transmitting the window size to the decompressor.

The memLevel parameter specifies how much memory should be allocated for the internal compression state. memLevel=1 uses minimum memory but is slow and reduces compression ratio; memLevel=9 uses maximum memory for optimal speed. The default value is 8. See zconf.h for total memory usage as a function of windowBits and memLevel.

The strategy parameter is used to tune the compression algorithm. Use the value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no string match), or Z_RLE to limit match distances to one (run-length encoding). Filtered data consists mostly of small values with a somewhat random distribution. In this case, the compression algorithm is tuned to compress them better. The effect of Z_FILTERED is to force more Huffman coding and less string matching; it is somewhat intermediate between Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The strategy parameter only affects the compression ratio but not the correctness of the compressed output even if it is not set appropriately. Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler decoder for special applications.

@return

int: Z_OK if success, Z_MEM_ERROR if there was not enough memory, or Z_STREAM_ERROR if any parameter is invalid (such as an invalid method). msg is set to null if there is no error message. deflateInit2 does not perform any compression: this will be done by deflate().

@see third_party/zlib/zlib.h

deflateParams

Dynamically update the compression level and compression strategy. The interpretation of level and strategy is as in deflateInit2(). This can be used to switch between compression and straight copy of the input data, or to switch to a different kind of input data requiring a different strategy. If the compression approach (which is a function of the level) or the strategy is changed, and if any input has been consumed in a previous deflate() call, then the input available so far is compressed with the old level and strategy using deflate(strm, Z_BLOCK). There are three approaches for the compression levels 0, 1..3, and 4..9 respectively. The new level and strategy will take effect at the next call of deflate().

If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does not have enough output space to complete, then the parameter change will not take effect. In this case, deflateParams() can be called again with the same parameters and more output space to try again.

In order to assure a change in the parameters on the first try, the deflate stream should be flushed using deflate() with Z_BLOCK or other flush request until strm.avail_out is not zero, before calling deflateParams(). Then no more input data should be provided before the deflateParams() call. If this is done, the old level and strategy will be applied to the data compressed before deflateParams(), and the new level and strategy will be applied to the the data compressed after deflateParams().

deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if there was not enough output space to complete the compression of the available input data before a change in the strategy or approach. Note that in the case of a Z_BUF_ERROR, the parameters are not changed. A return value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be retried with more output space.

@return

int

@see third_party/zlib/zlib.h

deflatePending

deflatePending() returns the number of bytes and bits of output that have been generated, but not yet provided in the available output. The bytes not provided would be due to the available output space having being consumed. The number of bits of output not provided are between 0 and 7, where they await more bits to join them in order to fill out a full byte. If pending or bits are Z_NULL, then those values are not set.

@return

int: Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent.

@see third_party/zlib/zlib.h

deflatePrime

deflatePrime() inserts bits in the deflate output stream. The intent is that this function is used to start off the deflate output with the bits leftover from a previous deflate stream when appending to it. As such, this function can only be used for raw deflate, and must be used before the first deflate() call after a deflateInit2() or deflateReset(). bits must be less than or equal to 16, and that many of the least significant bits of value will be inserted in the output.

@return

int: Z_OK if success, Z_BUF_ERROR if there was not enough room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the source stream state was inconsistent.

@see third_party/zlib/zlib.h

deflateReset

This function is equivalent to deflateEnd followed by deflateInit, but does not free and reallocate the internal compression state. The stream will leave the compression level and any other attributes that may have been set unchanged.

deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent (such as zalloc or state being Z_NULL).

@return

int

@see third_party/zlib/zlib.h

deflateSetDictionary

Initializes the compression dictionary from the given byte sequence without producing any compressed output. When using the zlib format, this function must be called immediately after deflateInit, deflateInit2 or deflateReset, and before any call of deflate. When doing raw deflate, this function must be called either before any call of deflate, or immediately after the completion of a deflate block, i.e. after all input has been consumed and all output has been delivered when using any of the flush options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The compressor and decompressor must use exactly the same dictionary (see inflateSetDictionary).

The dictionary should consist of strings (byte sequences) that are likely to be encountered later in the data to be compressed, with the most commonly used strings preferably put towards the end of the dictionary. Using a dictionary is most useful when the data to be compressed is short and can be predicted with good accuracy; the data can then be compressed better than with the default empty dictionary.

Depending on the size of the compression data structures selected by deflateInit or deflateInit2, a part of the dictionary may in effect be discarded, for example if the dictionary is larger than the window size provided in deflateInit or deflateInit2. Thus the strings most likely to be useful should be put at the end of the dictionary, not at the front. In addition, the current implementation of deflate will use at most the window size minus 262 bytes of the provided dictionary.

Upon return of this function, strm->adler is set to the Adler-32 value of the dictionary; the decompressor may later use this value to determine which dictionary has been used by the compressor. (The Adler-32 value applies to the whole dictionary even if only a subset of the dictionary is actually used by the compressor.) If a raw deflate was requested, then the Adler-32 value is not computed and strm->adler is not set.

@return

int: Z_OK if success, or Z_STREAM_ERROR if a parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is inconsistent (for example if deflate has already been called for this stream or if not at a block boundary for raw deflate). deflateSetDictionary does not perform any compression: this will be done by deflate().

@see third_party/zlib/zlib.h

deflateSetHeader

Provides gzip header information for when a gzip stream is requested by deflateInit2(). deflateSetHeader() may be called after deflateInit2() or deflateReset() and before the first call of deflate(). The text, time, os, extra field, name, and comment information in the provided gz_header structure are written to the gzip header (xflag is ignored -- the extra flags are set according to the compression level). The caller must assure that, if not Z_NULL, name and comment are terminated with a zero byte, and that if extra is not Z_NULL, that extra_len bytes are available there. If hcrc is true, a gzip header crc is included. Note that the current versions of the command-line version of gzip (up through version 1.3.x) do not support header crc's, and will report that it is a "multi-part gzip file" and give up.

If deflateSetHeader is not used, the default gzip header has text false, the time set to zero, and os set to 255, with no extra, name, or comment fields. The gzip header is returned to the default state by deflateReset().

deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent.

@return

int

@see third_party/zlib/zlib.h

deflateTune

Fine tune deflate's internal compression parameters. This should only be used by someone who understands the algorithm used by zlib's deflate for searching for the best matching string, and even then only by the most fanatic optimizer trying to squeeze out the last compressed bit for their specific input data. Read the deflate.c source code for the meaning of the max_lazy, good_length, nice_length, and max_chain parameters.

deflateTune() can be called after deflateInit() or deflateInit2(), and returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream.

@return

int

@see third_party/zlib/zlib.h

DeleteFile

Deletes existing file.

@param

const unsigned short* lpPathName

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/deletefile.c

DescribeCapability

@param

char* buf
int x

@return

const char*

@see libc/intrin/describecapability.c

DescribeClockName

Describes clock_gettime() clock argument.

@param

char* buf
int x

@return

const char*

@see libc/intrin/describeclockname.c

DescribeDirfd

@param

char* buf
int dirfd

@return

const char*

@see libc/intrin/describedirfd.c

DescribeFlags

@param

char* p
unsigned long n
struct DescribeFlags* d
unsigned long m
const char* prefix
unsigned int x

@return

const char*

@see libc/intrin/describeflags.c

DescribeFrame

@param

char* buf
int x

@return

const char*

@see libc/intrin/describeframe.c

DescribeFutexResult

@param

char* buf
int ax

@return

const char*

@see libc/intrin/describefutexresult.c

DescribeHow

@param

char* buf
int how

@return

const char*

@see libc/intrin/describehow.c

DescribeIov

@param

struct iovec* iov
int iovlen
long rem

@return

void

@see libc/intrin/describeiov.c

DescribeIovNt

@param

struct ProviderSpecific* iov
unsigned int iovlen
long rem

@return

void

@see libc/intrin/describeiovnt.c

DescribeMagnum

@param

char* b
struct MagnumStr* m
const char* p
int x

@return

char*

@see libc/intrin/describemagnums.c

DescribeMapFlags

@param

char* buf
int x

@return

const char*

@see libc/intrin/describemapflags.c

DescribeMapping

@param

char* p
int prot
int flags

@return

const char*

@see libc/intrin/describemapping.c

DescribeNtConsoleInFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentconsolemodeinputflags.c

DescribeNtConsoleOutFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentconsolemodeoutputflags.c

DescribeNtCreationDisposition

@param

unsigned int x

@return

const char*

@see libc/intrin/describentcreationdisposition.c

DescribeNtFileAccessFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentfileaccessflags.c

DescribeNtFileFlagAttr

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentfileflagattr.c

DescribeNtFileMapFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentfilemapflags.c

DescribeNtFileShareFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentfileshareflags.c

DescribeNtFiletypeFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentfiletypeflags.c

DescribeNtFutexOp

@param

int x

@return

const char*

@see libc/intrin/describefutexop.c

DescribeNtMovFileInpFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentmovfileinpflags.c

DescribeNtPageFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentpageflags.c

DescribeNtPipeModeFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentpipemodeflags.c

DescribeNtPipeOpenFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentpipeopenflags.c

DescribeNtProcAccessFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentprocaccessflags.c

DescribeNtSecurityAttributes

@param

struct NtSecurityAttributes* p

@return

const char*

@see libc/intrin/describentsecurityattributes.c

DescribeNtStartFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentstartflags.c

DescribeNtSymlinkFlags

@param

char* buf
unsigned int x

@return

const char*

@see libc/intrin/describentsymlinkflags.c

DescribeOpenFlags

Describes clock_gettime() clock argument.

@param

char* buf
int x

@return

const char*

@see libc/intrin/describeopenflags.c

DescribePersonalityFlags

@param

char* buf
int x

@return

const char*

@see libc/intrin/describepersonalityflags.c

DescribePollFlags

@param

char* buf
int x

@return

const char*

@see libc/intrin/describepollflags.c

DescribePrctlOperation

@param

int x

@return

const char*

@see libc/intrin/describeprctloperation.c

DescribeProt

@param

char* p
int prot

@return

char*

@see libc/intrin/describemapping.c

DescribeProtFlags

@param

char* buf
int x

@return

const char*

@see libc/intrin/describeprotflags.c

DescribeRemapFlags

@param

char* buf
int x

@return

const char*

@see libc/intrin/describeremapflags.c

DescribeRlimit

@param

char* buf
int rc
struct rlimit* rlim

@return

const char*

@see libc/intrin/describerlimit.c

DescribeRlimitName

Describes setrlimit() / getrlimit() argument.

@param

char* buf
int x

@return

const char*

@see libc/intrin/describerlimitname.c

DescribeSchedParam

Describes clock_gettime() clock argument.

@param

char* buf
struct sched_param* x

@return

const char*

@see libc/intrin/describeschedparam.c

DescribeSchedPolicy

Describes clock_gettime() clock argument.

@param

char* buf
int x

@return

const char*

@see libc/intrin/describeschedpolicy.c

DescribeSeccompOperation

@param

int x

@return

const char*

@see libc/intrin/describeseccompoperation.c

DescribeSigaction

@param

char* buf
int rc
struct sigaction* sa

@return

const char*

@see libc/intrin/describesigaction.c

DescribeSigaltstk

@param

char* buf
int rc
struct uc_stack* ss

@return

const char*

@see libc/intrin/describesigaltstack.c

DescribeSigset

@param

char* buf
int rc
struct sa_mask* ss

@return

const char*

@see libc/intrin/describesigset.c

DescribeSockaddr

@param

char* buf
struct sockaddr* sa
unsigned long sasize

@return

const char*

@see libc/sock/sockdebug.c

DescribeSocketFamily

@param

char* buf
int family

@return

const char*

@see libc/intrin/describesocketfamily.c

DescribeSocketProtocol

@param

char* buf
int family

@return

const char*

@see libc/intrin/describesocketprotocol.c

DescribeSocketType

@param

char* buf
int type

@return

const char*

@see libc/intrin/describesockettype.c

DescribeSockLevel

Describes setsockopt() level arguments.

@param

char* buf
int x

@return

const char*

@see libc/intrin/describesocklevel.c

DescribeSockOptname

Describes setsockopt() optname arguments.

@param

char* buf
int l
int x

@return

const char*

@see libc/intrin/describesockoptname.c

DescribeStat

@param

char* buf
int rc
struct stat* st

@return

const char*

@see libc/intrin/describestat.c

DescribeTimespec

@param

char* buf
int rc
struct st_birthtim* ts

@return

const char*

@see libc/intrin/describetimespec.c

DescribeTimeval

@param

char* buf
int rc
ANONYMOUS-STRUCT* tv

@return

const char*

@see libc/intrin/describetimeval.c

DeserializeDnsHeader

Serializes DNS message h to wire.

@param

struct DnsHeader* h
const unsigned char* p

@return

void: number of bytes read (always 12) or -1 w/ errno

@see libc/dns/dnsheader.c

DestroyHttpMessage

Destroys HTTP message parser.

@param

struct HttpMessage* r

@return

void

@see net/http/parsehttpmessage.c

DeviceIoControl

Does device file stuff on the New Technology.

@param

long hDevice
unsigned int dwIoControlCode
void* lpInBuffer
unsigned int nInBufferSize
void* lpOutBuffer
unsigned int nOutBufferSize
unsigned int* lpBytesReturned
struct inout_lpOverlapped* lpOverlapped

@return

int: handle, or -1 on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/deviceiocontrol.c

__die

Aborts process after printing a backtrace.

If a debugger is present then this will trigger a breakpoint.

@noreturn

@see libc/log/die.c

difftime

@param

long time1
long time0

@return

double

@see libc/time/difftime.c

dirfd

Returns file descriptor associated with DIR object.

@param

struct dirstream* dir

@return

int

@see libc/stdio/dirstream.c

dirname

Returns directory portion of path, e.g.

path     │ dirname() │ basename()
─────────────────────────────────
.        │ .         │ .
..       │ .         │ ..
/        │ /         │ /
usr      │ .         │ usr
/usr/    │ /         │ usr
/usr/lib │ /usr      │ lib

@param

char* path: is UTF-8 and may be mutated, but not expanded in length

@return

char*: pointer to path, or inside path, or to a special r/o string

@see basename()

@see SUSv2

@see libc/fmt/dirname.c

div

@param

int num
int den

@return

struct div_t

@see libc/fmt/div.c

__divmodti4

Divides 128-bit signed integers w/ remainder.

@param

__int128 a: is numerator
__int128 b: is denominator
unsigned __int128* opt_out_rem: receives euclidean division remainder if not null

@return

__int128: quotient or result of division

@note rounds towards zero

@see third_party/compiler_rt/divmodti4.c

__divti3

Divides 128-bit signed integers.

@param

__int128 a: is numerator
__int128 b: is denominator

@return

__int128: quotient or result of division

@note rounds towards zero

@see third_party/compiler_rt/divti3.c

djbsort

D.J. Bernstein's outrageously fast integer sorting algorithm.

@param

int* a
unsigned long n

@return

void

@see libc/str/djbsort.c

djbsort_avx2

D.J. Bernstein's outrageously fast integer sorting algorithm.

@param

rdi: is int32 array
rsi: is number of elements in rdi

@return

@note public domain

@see en.wikipedia.org/wiki/Sorting_network

@see libc/nexgen32e/djbsort-avx2.S

dl_iterate_phdr

@param

int(*)() callback
void* data

@return

int

@see libc/runtime/ldso.c

dlbulk_free

@param

void** array
unsigned long nelem

@return

unsigned long

@see third_party/dlmalloc/dlmalloc.c

dlcalloc

@param

unsigned long n_elements
unsigned long elem_size

@return

void*

@see third_party/dlmalloc/dlmalloc.c

dlclose

@param

void* handle

@return

int

@see libc/runtime/ldso.c

dlerror

@return

char*

@see libc/runtime/ldso.c

dlfree

@param

void* mem

@return

void

@see third_party/dlmalloc/dlmalloc.c

dlindependent_calloc

@param

unsigned long n_elements
unsigned long elem_size
void** chunks

@return

void**

@see third_party/dlmalloc/dlmalloc.c

dlindependent_comalloc

@param

unsigned long n_elements
unsigned long* sizes
void** chunks

@return

void**

@see third_party/dlmalloc/dlmalloc.c

dlmallinfo

@param

struct nm*

@return

struct nm

@see third_party/dlmalloc/dlmalloc.c

dlmalloc

@param

unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_abort

@return

void

@see third_party/dlmalloc/dlmalloc_abort.greg.c

dlmalloc_footprint

@return

unsigned long

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_footprint_limit

@return

unsigned long

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_inspect_all

@param

void(*)() handler
void* arg

@return

void

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_max_footprint

@return

unsigned long

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_requires_more_vespene_gas

Acquires more system memory for dlmalloc.

@param

unsigned long size

@return

void*: memory map address on success, or null w/ errno

@see third_party/dlmalloc/vespene.c

dlmalloc_set_footprint_limit

@param

unsigned long bytes

@return

unsigned long

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_stats

@return

void

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_trim

@param

unsigned long pad

@return

int

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_usable_size

@param

void* mem

@return

unsigned long

@see third_party/dlmalloc/dlmalloc.c

dlmallopt

@param

int param_number
int value

@return

int

@see third_party/dlmalloc/dlmalloc.c

dlmemalign

@param

unsigned long alignment
unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlmalloc.c

dlopen

@param

const char* file
int mode

@return

void*

@see libc/runtime/ldso.c

dlposix_memalign

@param

void** pp
unsigned long alignment
unsigned long bytes

@return

int

@see third_party/dlmalloc/dlmalloc.c

dlpvalloc

@param

unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlmalloc.c

dlrealloc

@param

void* oldmem
unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlmalloc.c

dlrealloc_in_place

@param

void* oldmem
unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlmalloc.c

dlsym

@param

void* handle
const char* name

@return

void*

@see libc/runtime/ldso.c

dlvalloc

@param

unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlmalloc.c

__dos2errno

Translates Windows error using superset of consts.sh.

This function is called by __winerr(). It can only be used on Windows, because it returns an errno. Normally, errnos will be programmed to be the same as DOS errnos, per consts.sh. But since there's so many more errors in DOS, this function provides an added optional benefit mapping additional constants onto the errnos in consts.sh.

@param

unsigned int error

@return

int

@see libc/intrin/dos2errno.c

DosDateTimeToUnix

Converts MS-DOS timestamp to UNIX.

@param

unsigned int date
unsigned int time

@return

long

@note type signature supports dates greater than 2100

@see PKZIP, FAT

@see libc/str/dosdatetimetounix.c

dprintf

Formats string directly to file descriptor.

@param

int fd
const char* fmt
...

@return

int

@see libc/calls/dprintf.c

drem

remainder(𝑥,𝑦) means (𝑥 rem 𝑦) w/ rint()-style rounding.

@param

𝑥: is double passed in lower half of %xmm0
𝑦: is double passed in lower half of %xmm1

@return

: remainder ∈ (-|𝑦|,|𝑦|) in %xmm0

@define 𝑥-rint(𝑥/𝑦)*𝑦

@see fmod(), emod(), operator%

@see libc/tinymath/remainder.S

dsleep

Sleeps w/ higher precision.

@param

long double secs

@return

long double

@see libc/time/dsleep.c

dtime

Returns seconds since epoch w/ high-precision.

@param

int clockid: can be CLOCK_{REALTIME,MONOTONIC}, etc.

@return

long double

@see libc/calls/dtime.c

dtoa

@param

double d0
int mode
int ndigits
int* decpt
int* sign
char** rve

@return

char*

@see third_party/gdtoa/dtoa.c

DumpHexc

Turns data into "\x00..." string literal.

@param

const char* p
unsigned long n
unsigned long* z

@return

char*

@see libc/stdio/dumphexc.c

dup

Duplicates file descriptor.

The O_CLOEXEC flag shall be cleared from the resulting file descriptor; see dup3() to preserve it.

@param

int fd: remains open afterwards

@return

int: some arbitrary new number for fd

@raise EOPNOTSUPP if zipos file

@raise EBADF if fd isn't open

@asyncsignalsafe

@vforksafe

@see libc/calls/dup.c

dup2

Duplicates file descriptor, granting it specific number.

The O_CLOEXEC flag shall be cleared from the resulting file descriptor; see dup3() to preserve it.

Unlike dup3(), the dup2() function permits oldfd and newfd to be the same, in which case the only thing this function does is test if oldfd is open.

@param

int oldfd: isn't closed afterwards
int newfd: if already assigned, is silently closed beforehand; unless it's equal to oldfd, in which case dup2() is a no-op

@return

int: new file descriptor, or -1 w/ errno

@raise EBADF is oldfd isn't open

@raise EBADF is newfd negative or too big

@raise EINTR if a signal handler was called

@asyncsignalsafe

@vforksafe

@see libc/calls/dup2.c

dup3

Duplicates file descriptor/handle.

On Windows, we can't guarantee the desired file descriptor is used. We can however remap the standard handles (non-atomically) if their symbolic names are used.

@param

int oldfd: isn't closed afterwards
int newfd: if already assigned, is silently closed beforehand; unless it's equal to oldfd, in which case dup2() is a no-op
int flags: may have O_CLOEXEC which is needed to preserve the close-on-execve() state after file descriptor duplication

@return

int: newfd on success, or -1 w/ errno

@raise EINVAL if flags has unsupported bits

@raise EINVAL if newfd equals oldfd

@raise EBADF is oldfd isn't open

@raise EBADF is newfd negative or too big

@raise EINTR if a signal handler was called

@see dup(), dup2()

@see libc/calls/dup3.c

E2BIG

Argument list too errno_t.

@type

const int

@see libc/errno.h

EACCES

Permission denied.

@type

const int

@see libc/errno.h

eaccess

Performs access() check using effective user/group id.

@param

const char* filename
int amode

@return

int

@see libc/calls/eaccess.c

EADDRINUSE

Address already in use.

@type

const int

@see libc/errno.h

EADDRNOTAVAIL

Address not available.

@type

const int

@see libc/errno.h

EAFNOSUPPORT

Address family not supported.

@type

const int

@see libc/errno.h

EAGAIN

Resource temporarily unavailable (e.g. SO_RCVTIMEO expired, too many processes, too much memory locked, read or write with O_NONBLOCK needs polling, etc.).

@type

const int

@see libc/errno.h

EALREADY

Connection already in progress.

@type

const int

@see libc/errno.h

EBADF

Bad file descriptor.

@type

const int

@see libc/errno.h

EBADMSG

Bad message.

@type

const int

@see libc/errno.h

EBUSY

Device or resource busy.

@type

const int

@see libc/errno.h

ECANCELED

Operation canceled.

@type

const int

@see libc/errno.h

ECHILD

No child process.

@type

const int

@see libc/errno.h

ECONNABORTED

Connection reset before accept.

@type

const int

@see libc/errno.h

ECONNREFUSED

Connection refused error.

@type

const int

@see libc/errno.h

ECONNRESET

Connection reset by client.

@type

const int

@see libc/errno.h

ecvt

@param

double value
int ndigit
int* decpt
int* sign

@return

char*

@see libc/fmt/fcvt.c

EDEADLK

Resource deadlock avoided.

@type

const int

@see libc/errno.h

EDESTADDRREQ

Destination address required.

@type

const int

@see libc/errno.h

EDOM

Mathematics argument out of domain of function.

@type

const int

@see libc/errno.h

EDQUOT

Disk quota exceeded.

@type

const int

@see libc/errno.h

EEXIST

File exists.

@type

const int

@see libc/errno.h

EFAULT

Pointer passed to system call that would otherwise segfault.

@type

const int

@see libc/errno.h

EFBIG

File too large.

@type

const int

@see libc/errno.h

EfiMain

EFI Application Entrypoint.

This entrypoint is mutually exclusive from WinMain since Windows apps and EFI apps use the same PE binary format. So if you want to trade away Windows so that you can use UEFI instead of the normal BIOS boot process, do this:

STATIC_YOINK("EfiMain");
int main() { ... }

You can use QEMU to test this, but please note that UEFI goes thousands of times slower than the normal BIOS boot

qemu-system-x86_64 \
  -bios OVMF.fd    \
  -nographic       \
  -net none        \
  -drive format=raw,file=fat:rw:o/tool/viz
FS0:
deathstar.com

@param

unsigned long ImageHandle
struct EFI_SYSTEM_TABLE* SystemTable

@return

unsigned long

@see libc/dce.h

@see libc/runtime/efimain.greg.c

EFTYPE

Inappropriate file type or format. (BSD only)

@type

const int

@see libc/errno.h

EHOSTDOWN

Host down error.

@type

const int

@see libc/errno.h

EHOSTUNREACH

Host unreachable error.

@type

const int

@see libc/errno.h

EIDRM

Identifier removed.

@type

const int

@see libc/errno.h

EILSEQ

Unicode decoding error.

@type

const int

@see libc/errno.h

EINPROGRESS

Operation already in progress.

@type

const int

@see libc/errno.h

EINTR

The greatest of all errnos.

@type

const int

@see libc/errno.h

EINVAL

Invalid argument.

@type

const int

@see libc/errno.h

EIO

Unix consensus.

@type

const int

@see libc/errno.h

EISCONN

Socket is connected.

@type

const int

@see libc/errno.h

EISDIR

Is a a directory.

@type

const int

@see libc/errno.h

ElevateSeDebugPrivilege

@return

int

@see libc/calls/sedebug.c

ELOOP

Too many levels of symbolic links.

@type

const int

@see libc/errno.h

EMEDIUMTYPE

Wrong medium type.

@type

const int

@see libc/errno.h

EMFILE

Too many open files.

@type

const int

@see libc/errno.h

EMLINK

Too many links.

@type

const int

@see libc/errno.h

EMSGSIZE

Message too errno_t.

@type

const int

@see libc/errno.h

EMULTIHOP

Multihop attempted.

@type

const int

@see libc/errno.h

ENAMETOOLONG

Filename too errno_t.

@type

const int

@see libc/errno.h

EncodeBase64

Encodes binary to base64 ascii representation.

@param

const char* data: is input value
unsigned long size: if -1 implies strlen
unsigned long* out_size: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/encodebase64.c

EncodeHttpHeaderValue

Encodes HTTP header value.

This operation involves the following:

Trim whitespace.
Turn UTF-8 into ISO-8859-1.
Make sure no C0 or C1 control codes are present (except tab).

If the input value isn't thompson-pike encoded then this implementation will fall back to latin1 in most cases.

@param

const char* data: is input value
unsigned long size: if -1 implies strlen
unsigned long* out_size: if non-NULL receives output length on success

@return

char*: allocated NUL-terminated string, or NULL w/ errno

@see net/http/encodehttpheadervalue.c

EncodeLatin1

Encodes UTF-8 to ISO-8859-1.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length
int f: can kControlC0, kControlC1, kControlWs to forbid

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@error EILSEQ means UTF-8 found we can't or won't re-encode

@error ENOMEM means malloc() failed

@see net/http/encodelatin1.c

EncodeNf32

Encodes u32 as ANSI Nf sequence content.

@param

char* p
unsigned int x

@return

char*

@see libc/fmt/encodenf32.c

EncodeUrl

Encodes URL.

@param

struct Url* h
unsigned long* z: if not null receives string length of result

@return

char*: nul-terminated url string needing free

@see ParseUrl()

@see net/http/encodeurl.c

encrypt

@param

char* block
int edflag

@return

void

@see third_party/musl/encrypt.c

endgrent

@return

void

@see third_party/musl/grp.c

endhostent

@return

void

@see libc/dns/hostent.c

endnetent

@return

void

@see libc/dns/netent.c

endprotoent

@return

void

@see libc/dns/protoent.c

endpwent

@return

void

@see third_party/musl/pwd.c

endservent

@return

void

@see libc/dns/servent.c

endswith

Returns true if s has suffix.

@param

const char* s: is a NUL-terminated string
const char* suffix: is also NUL-terminated

@return

_Bool

@see libc/str/endswith.c

endswith16

Returns true if s has suffix.

@param

const unsigned short* s: is a NUL-terminated string
const unsigned short* suffix: is also NUL-terminated

@return

_Bool

@see libc/str/endswith16.c

ENETDOWN

Network is down.

@type

const int

@see libc/errno.h

ENETRESET

Connection reset by network.

@type

const int

@see libc/errno.h

ENETUNREACH

Host is unreachable.

@type

const int

@see libc/errno.h

ENFILE

Too many open files in system.

@type

const int

@see libc/errno.h

ENOBUFS

No buffer space available.

@type

const int

@see libc/errno.h

ENODATA

No data.

@type

const int

@see libc/errno.h

ENODEV

No such device.

@type

const int

@see libc/errno.h

ENOENT

No such file or directory.

@type

const int

@see libc/errno.h

ENOEXEC

Exec format error.

@type

const int

@see libc/errno.h

ENOLCK

No locks available.

@type

const int

@see libc/errno.h

ENOLINK

Link severed.

@type

const int

@see libc/errno.h

ENOMEDIUM

No medium found.

@type

const int

@see libc/errno.h

ENOMEM

We require more vespene gas.

@type

const int

@see libc/errno.h

ENOMSG

No message error.

@type

const int

@see libc/errno.h

ENONET

No network.

@type

const int

@see libc/errno.h

ENOPROTOOPT

Protocol not available.

@type

const int

@see libc/errno.h

ENOSPC

No space left on device.

@type

const int

@see libc/errno.h

ENOSR

Out of streams resources.

@type

const int

@see libc/errno.h

ENOSTR

No string.

@type

const int

@see libc/errno.h

ENOSYS

System call unavailable.

@type

const int

@note kNtErrorInvalidFunction on NT

@see libc/errno.h

ENOTBLK

Block device required.

@type

const int

@see libc/errno.h

ENOTCONN

Socket is not connected.

@type

const int

@see libc/errno.h

ENOTDIR

Not a directory.

@type

const int

@see libc/errno.h

ENOTEMPTY

Directory not empty.

@type

const int

@see libc/errno.h

ENOTRECOVERABLE

State not recoverable.

@type

const int

@see libc/errno.h

ENOTSOCK

Not a socket.

@type

const int

@see libc/errno.h

ENOTSUP

Operation not supported.

@type

const int

@see libc/errno.h

ENOTTY

Inappropriate i/o control operation.

@type

const int

@see libc/errno.h

__ensurefds

Grows file descriptor array memory if needed.

@param

int fd

@return

int

@asyncsignalsafe

@threadsafe

@see libc/calls/reservefd.c

__ensurefds_unlocked

Grows file descriptor array memory if needed.

@param

int fd

@return

int

@see libc/runtime/memtrack64.txt

@see libc/runtime/memtrack32.txt

@asyncsignalsafe

@see libc/calls/reservefd.c

ENXIO

No such device or address.

@type

const int

@see libc/errno.h

EOPNOTSUPP

Socket operation not supported.

@type

const int

@see libc/errno.h

EOVERFLOW

Overflow error.

@type

const int

@see libc/errno.h

EOWNERDEAD

Owner died.

@type

const int

@see libc/errno.h

EPERM

Operation not permitted.

@type

const int

@note kNtErrorInvalidAccess on NT

@see libc/errno.h

EPFNOSUPPORT

Protocol family not supported.

@type

const int

@see libc/errno.h

EPIPE

Broken pipe.

@type

const int

@see libc/errno.h

epoll_create

Creates new epoll instance.

@param

int size: is ignored but must be greater than zero

@return

int: epoll file descriptor, or -1 on failure

@see libc/sock/epoll.c

epoll_create1

Creates new epoll instance.

@param

int flags: must be zero or can have O_CLOEXEC

@return

int: epoll file descriptor, or -1 on failure

@see libc/sock/epoll.c

epoll_ctl

Controls which socket events are monitored.

It is recommended to always explicitly remove a socket from its epoll set using EPOLL_CTL_DEL before closing it. As on Linux, your closed sockets are automatically removed from the epoll set, but wepoll may not be able to detect that a socket was closed until the next call to epoll_wait().

@param

int epfd: is file descriptor created by epoll_create()
int op: can be EPOLL_CTL_{ADD,MOD,DEL}
int fd: is file descriptor to monitor
struct epoll_event* ev: is ignored if op is EPOLL_CTL_DEL

@return

int: 0 on success, or -1 w/ errno

@error ENOTSOCK on Windows if fd isn't a socket :(

@see libc/sock/epoll.c

epoll_wait

Receives socket events.

@param

int epfd
struct epoll_event* events: will receive information about what happened
int maxevents: is array length of events
int timeoutms: is milliseconds, 0 to not block, or -1 for forever

@return

int: number of events stored, 0 on timeout, or -1 w/ errno

@norestart

@see libc/sock/epoll.c

EPROTO

Protocol error.

@type

const int

@see libc/errno.h

EPROTONOSUPPORT

Protocol not supported.

@type

const int

@see libc/errno.h

EPROTOTYPE

Protocol wrong type for socket.

@type

const int

@see libc/errno.h

ERANGE

Result too large.

@type

const int

@see libc/errno.h

EREMOTE

Remote error.

@type

const int

@see libc/errno.h

ERESTART

Please restart syscall.

@type

const int

@see libc/errno.h

erf

Returns error function of 𝑥.

@param

double x

@return

double

@see libc/tinymath/erf.c

erfc

Returns complementary error function of 𝑥.

@param

double x

@return

double

@see libc/tinymath/erf.c

erfcf

@param

float x

@return

float

@see libc/tinymath/erff.c

erff

@param

float x

@return

float

@see libc/tinymath/erff.c

EROFS

Read-only filesystem.

@type

const int

@see libc/errno.h

err

@param

int eval
const char* fmt
...

@noreturn

@see libc/log/err.c

__errno

Global variable for last error.

The system call wrappers update this with WIN32 error codes. Unlike traditional libraries, Cosmopolitan error codes are defined as variables. By convention, system calls and other functions do not update this variable when nothing's broken.

@type

int

@see libc/sysv/consts.sh

@see libc/sysv/errfuns.h

@see __errno_location() stable abi

@see libc/sysv/errno.c

__errno_location

Returns address of errno variable.

@return

int*

@see __initialize_tls()

@see __install_tls()

@see libc/sysv/errno_location.greg.c

errx

@param

int eval
const char* fmt
...

@noreturn

@see libc/log/errx.c

_escapedos

Escapes command so DOS can run it.

@param

unsigned short* buffer
unsigned int buflen
const unsigned short* unquoted
unsigned int len

@return

_Bool

@see Iain Patterson's NSSM for original code in public domain

@see libc/str/escapedos.c

EscapeFragment

Escapes URL fragment.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/escapefragment.c

EscapeHost

Escapes URL host or registry name.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/escapehost.c

EscapeHtml

Escapes HTML entities.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/escapehtml.c

EscapeIp

Escapes URL IP-literal.

This is the same as EscapeHost except colon is permitted.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/escapeip.c

EscapeJsStringLiteral

Escapes UTF-8 data for JavaScript or JSON string literal.

HTML entities and forward slash are escaped too for added safety.

We assume the UTF-8 is well-formed and can be represented as UTF-16. Things that can't be decoded will fall back to binary. Things that can't be encoded will use invalid codepoint markers. This function is agnostic to numbers that have been used with malicious intent in the past under buggy software. Noncanonical encodings such as overlong NUL are canonicalized as NUL. Therefore it isn't necessary to say EscapeJsStringLiteral(Underlong(𝑥)) since EscapeJsStringLiteral(𝑥) will do the same thing.

@param

char** r: is realloc'able output buffer reused between calls
unsigned long* y: is used to track byte length of *r
const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z

@return

char*: *r on success, or null w/ errno

@see net/http/escapejsstringliteral.c

EscapeParam

Escapes query/form name/parameter.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/escapeparam.c

EscapePass

Escapes URL password.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/escapepass.c

EscapePath

Escapes URL path.

This is the same as EscapePathSegment() except slash is allowed.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/escapepath.c

EscapeSegment

Escapes URL path segment.

Please note this will URI encode the slash character. That's because segments are the labels between the slashes in a path.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/escapesegment.c

EscapeUrl

Escapes URL component using generic table.

This function is agnostic to the underlying charset. Always using UTF-8 is a good idea.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length
const char* T

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see kEscapeAuthority

@see kEscapeIpLiteral

@see kEscapePath

@see kEscapePathSegment

@see kEscapeParam

@see kEscapeFragment

@see net/http/escapeurl.c

EscapeUrlView

Escapes URL component using generic table w/ stpcpy() api.

@param

char* p
struct fragment* v
const char* T

@return

char*

@see net/http/escapeurlview.c

EscapeUser

Escapes URL user name.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/escapeuser.c

ESHUTDOWN

Cannot send after transport endpoint shutdown.

@type

const int

@see libc/errno.h

ESOCKTNOSUPPORT

Socket type not supported.

@type

const int

@see libc/errno.h

ESPIPE

Invalid seek.

@type

const int

@see libc/errno.h

ESRCH

No such process.

@type

const int

@see libc/errno.h

ESTALE

Stale error.

@type

const int

@see libc/errno.h

ETIME

Timer expired.

@type

const int

@see libc/errno.h

ETIMEDOUT

Connection timed out.

@type

const int

@see libc/errno.h

ETOOMANYREFS

Too many references: cannot splice.

@type

const int

@see libc/errno.h

ETXTBSY

Won't open executable that's executing in write mode.

@type

const int

@see libc/errno.h

euidaccess

Performs access() check using effective user/group id.

@param

const char* filename
int amode

@return

int

@see libc/calls/euidaccess.c

EUSERS

Too many users.

@type

const int

@see libc/errno.h

EXDEV

Improper link.

@type

const int

@see libc/errno.h

execl

Executes program, with current environment.

The current process is replaced with the executed one.

@param

const char* exe
const char* arg
...

@return

int: doesn't return on success, otherwise -1 w/ errno

@asyncsignalsafe

@vforksafe

@see libc/calls/execl.c

execle

Executes program, with custom environment.

The current process is replaced with the executed one.

@param

const char* exe
const char* arg
...

@return

int: doesn't return on success, otherwise -1 w/ errno

@asyncsignalsafe

@vforksafe

@see libc/calls/execle.c

execlp

Executes program, with PATH search and current environment.

The current process is replaced with the executed one.

@param

const char* prog: is program to launch (may be PATH searched)
const char* arg
...

@return

int: doesn't return on success, otherwise -1 w/ errno

@asyncsignalsafe

@vforksafe

@see libc/calls/execlp.c

execv

Replaces process with specific program, using default environment.

@param

const char* exe
char** argv

@return

int

@asyncsignalsafe

@vforksafe

@see libc/calls/execv.c

execve

Replaces current process with program.

@param

const char* prog
char** argv
char** envp

@return

int: doesn't return, or -1 w/ errno

@asyncsignalsafe

@vforksafe

@see libc/calls/execve.c

execvp

Replaces process, with path search, using default environment.

@param

const char* file
char** argv

@return

int

@asyncsignalsafe

@vforksafe

@see libc/calls/execvp.c

execvpe

Executes program, with path environment search.

The current process is replaced with the executed one.

@param

const char* prog: is the program to launch
char** argv: is [file,argv₁..argvₙ₋₁,NULL]
char** envp: is ["key=val",...,NULL]

@return

int: doesn't return on success, otherwise -1 w/ errno

@asyncsignalsafe

@vforksafe

@see libc/calls/execvpe.c

_exit

Terminates process, ignoring destructors and atexit() handlers.

When running on bare metal, this function will reboot your computer by hosing the interrupt descriptors and triple faulting the system.

@param

int exitcode: is masked with 255

@noreturn

@asyncsignalsafe

@vforksafe

@see libc/runtime/exit2.c

exit

Exits process with grace.

This calls functions registered by atexit() before terminating the current process, and any associated threads. It also calls all the legacy linker registered destructors in reeverse order

@param

int exitcode: is masked with 255

@noreturn

@see _Exit()

@see libc/runtime/exit.c

_Exit

Terminates process, ignoring destructors and atexit() handlers.

When running on bare metal, this function will reboot your computer by hosing the interrupt descriptors and triple faulting the system.

@param

int exitcode: is masked with 255 on unix (but not windows)

@noreturn

@asyncsignalsafe

@threadsafe

@vforksafe

@see libc/intrin/exit.c

_Exit1

Terminates thread with raw system call.

@param

int rc: only works on Linux and Windows

@noreturn

@see cthread_exit()

@threadsafe

@see libc/intrin/exit1.greg.c

exp

Returns 𝑒^x.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/exp-tiny.S

exp10

Returns 10^x.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see pow(), exp()

@see libc/tinymath/exp10.S

exp10f

Returns 10^x.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/exp10f.S

exp10l

Returns 10^x.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result of exponentiation on FPU stack in %st

@see libc/tinymath/exp10l.S

exp2

Returns 2^𝑥.

@param

𝑥: is a double passed in the lower quadword of %xmm0

@return

: result in lower quadword of %xmm0

@see libc/tinymath/exp2-tiny.S

exp2f

Returns 2^𝑥.

@param

𝑥: is a float passed in the lower quarter of %xmm0

@return

: result in lower quarter of %xmm0

@see libc/tinymath/exp2f-tiny.S

exp2l

Returns 2^𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result of exponentiation on FPU stack in %st

@see libc/tinymath/exp2l.S

expf

Returns 𝑒^x.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see libc/tinymath/expf-tiny.S

expl

Returns 𝑒^x.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result of exponentiation on FPU stack in %st

@see libc/tinymath/expl.S

explicit_bzero

Sets memory to zero w/ accompanying non-optimizing macro.

This is intended for security-conscious applications.

@param

rdi: is dest
rsi: is the number of bytes to set

@return

@see libc/str/explicit_bzero.S

expm1

Returns 𝑒^x-1.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see libc/tinymath/expm1.S

expm1f

Returns 𝑒^x-1.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/expm1f.S

expm1l

Returns 𝑒^𝑥-𝟷.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result of exponentiation on FPU stack in %st

@see libc/tinymath/expm1l.S

_f2ld2

Thunks float(*fn)(float,float) -> long double fn.

@param

%xmm0[0]: contains float param

@return

: %xmm0[0] contains float result

@note 100% negligible overhead

@see libc/tinymath/f2ld2.S

fabs

Returns absolute value of 𝑥.

@param

𝑥: is double passed in lower half on %xmm0

@return

: absolute value in %xmm0

@see libc/tinymath/fabs.S

fabsf

Returns absolute value of 𝑥.

@param

𝑥: is float passed in lower quarter on %xmm0

@return

: absolute value in %xmm0

@see libc/tinymath/fabsf.S

fabsl

Returns absolute value of 𝑥.

@param

𝑥: long double passed on stack

@return

: absolute value in %st

@see libc/tinymath/fabsl.S

faccessat

Checks if effective user can access path in particular ways.

@param

int dirfd: is normally AT_FDCWD but if it's an open directory and file is a relative path, then file is opened relative to dirfd
const char* path: is a filename or directory
int mode: can be R_OK, W_OK, X_OK, F_OK
unsigned int flags: can have AT_EACCESS, AT_SYMLINK_NOFOLLOW

@return

int: 0 if ok, or -1 and sets errno

@note on Linux flags is only supported on Linux 5.8+

@asyncsignalsafe

@see libc/calls/faccessat.c

fadvise

Drops hints to O/S about intended I/O behavior.

It makes a huge difference. For example, when copying a large file, it can stop the system from persisting GBs of useless memory content.

@param

int fd
unsigned long offset
unsigned long len: 0 means ‘til end of file
int advice: can be MADV_SEQUENTIAL, MADV_RANDOM, etc.

@return

int: -1 on error

@see libc/calls/fadvise.c

__fbufsize

Returns capacity of stdio stream buffer.

@param

struct FILE* f

@return

unsigned long

@see libc/stdio/fbufsize.c

fchdir

Sets current directory based on file descriptor.

This does *not* update the PWD environment variable.

@param

int dirfd

@return

int

@see open(path, O_DIRECTORY)

@asyncsignalsafe

@see libc/calls/fchdir.c

fchmod

Changes file permissions via open()'d file descriptor.

@param

int fd
unsigned int mode: contains octal flags (base 8)

@return

int

@asyncsignalsafe

@see chmod()

@see libc/calls/fchmod.c

fchmodat

Changes permissions on file, e.g.:

CHECK_NE(-1, fchmodat(AT_FDCWD, "foo/bar.txt", 0644));
CHECK_NE(-1, fchmodat(AT_FDCWD, "o/default/program.com", 0755));
CHECK_NE(-1, fchmodat(AT_FDCWD, "privatefolder/", 0700));

@param

int dirfd
const char* path: must exist
unsigned int mode: contains octal flags (base 8)
int flags: can have AT_SYMLINK_NOFOLLOW

@return

int

@errors ENOENT, ENOTDIR, ENOSYS

@asyncsignalsafe

@see fchmod()

@see libc/calls/fchmodat.c

fchown

Changes owner and/or group of file, via open()'d descriptor.

@param

int fd
unsigned int uid: is user id, or -1u to not change
unsigned int gid: is group id, or -1u to not change

@return

int: 0 on success, or -1 w/ errno

@see /etc/passwd for user ids

@see /etc/group for group ids

@raises ENOSYS on Windows

@see libc/calls/fchown.c

fchownat

Changes owner and/or group of path.

@param

int dirfd: is open()'d relative-to directory, or AT_FDCWD, etc.
const char* path
unsigned int uid: is user id, or -1 to not change
unsigned int gid: is group id, or -1 to not change
int flags: can have AT_SYMLINK_NOFOLLOW, etc.

@return

int: 0 on success, or -1 w/ errno

@see chown(), lchown() for shorthand notation

@see /etc/passwd for user ids

@see /etc/group for group ids

@asyncsignalsafe

@see libc/calls/fchownat.c

fclose

Closes standard i/o stream and its underlying thing.

@param

struct FILE* f: is the file object, which is always free if it's heap, otherwise its resources are released and fields updated

@return

int: 0 on success or -1 on error, which can be a trick for differentiating between EOF and real errors during previous i/o calls, without needing to call ferror()

@see fclose_s()

@see libc/stdio/fclose.c

fclose_s

Closes standard i/o stream and its underlying thing.

@param

struct FILE** fp

@return

int: 0 on success or -1 on error, which can be a trick for differentiating between EOF and real errors during previous i/o calls, without needing to call ferror()

@see libc/stdio/fclose_s.c

fcntl

Does things with file descriptor, via re-imagined hourglass api, e.g.

CHECK_NE(-1, fcntl(fd, F_SETFD, FD_CLOEXEC));

This function lets you duplicate file descriptors without running into an edge case where they take over stdio handles:

CHECK_GE((newfd = fcntl(oldfd, F_DUPFD,         3)), 3);
CHECK_GE((newfd = fcntl(oldfd, F_DUPFD_CLOEXEC, 3)), 3);

This function implements POSIX Advisory Locks, e.g.

CHECK_NE(-1, fcntl(zfd, F_SETLKW, &(struct flock){F_WRLCK}));
// ...
CHECK_NE(-1, fcntl(zfd, F_SETLK, &(struct flock){F_UNLCK}));

Please be warned that locks currently do nothing on Windows since figuring out how to polyfill them correctly is a work in progress.

@param

int fd
int cmd: can be F_{GET,SET}{FD,FL}, etc.
...

@return

int: 0 on success, or -1 w/ errno

@asyncsignalsafe

@restartable

@see libc/calls/fcntl.c

fcvt

@param

double value
int ndigit
int* decpt
int* sign

@return

char*

@see libc/fmt/fcvt.c

fdatasync

Blocks until kernel flushes non-metadata buffers for fd to disk.

@param

int fd

@return

int: 0 on success, or -1 w/ errno

@see sync(), fsync(), sync_file_range()

@see __nosync to secretly disable

@asyncsignalsafe

@see libc/calls/fdatasync.c

fdim

Returns positive difference.

@param

double x
double y

@return

double

@see libc/tinymath/fdim.c

fdimf

Returns positive difference.

@param

float x
float y

@return

float

@see libc/tinymath/fdimf.c

fdiml

Returns positive difference.

@param

long double x
long double y

@return

long double

@see libc/tinymath/fdiml.c

fdopen

Allocates stream object for already-opened file descriptor.

@param

int fd: existing file descriptor or -1 for plain old buffer
const char* mode: is passed to fopenflags()

@return

struct FILE*: new stream or NULL w/ errno

@error ENOMEM

@see libc/stdio/fdopen.c

fdopendir

Creates directory object for file descriptor.

@param

int fd: gets owned by this function, if it succeeds

@return

struct dirstream*: new directory object, which must be freed by closedir(), or NULL w/ errno

@errors ENOMEM and fd is closed

@see libc/stdio/dirstream.c

feclearexcept

@param

int mask

@return

int

@see libc/runtime/fenv.c

fegetenv

@param

void** envp

@return

int

@see libc/runtime/fenv.c

fegetround

Returns rounding mode.

This implementation retrieves it from the x87 FPU control word.

@return

int

@see fesetround() for changing this

@see libc/runtime/fegetround.c

fentry

Function entry hook stub.

@return

@note cc -pg -mfentry adds this to the start of every function

@see libc/log/shadowargs.ncabi.c

@mode long,legacy,real

@see libc/nexgen32e/fentry.S

feof

Returns true if stream is in end-of-file state.

@param

struct FILE* f: is file object stream pointer

@return

int

@see feof_unlocked()

@threadsafe

@see libc/stdio/feof.c

feof_unlocked

Returns true if stream is in end-of-file state.

@param

struct FILE* f: is file object stream pointer

@return

int

@see feof()

@see libc/stdio/feof_unlocked.c

feraiseexcept

@param

int mask

@return

int

@see libc/runtime/fenv.c

ferror

Returns nonzero if stream is in error state.

@param

struct FILE* f: is file stream pointer

@return

int: non-zero if and only if it's an error state

@see ferror_unlocked(), feof()

@note EOF doesn't count

@threadsafe

@see libc/stdio/ferror.c

ferror_unlocked

Returns nonzero if stream is in error state.

@param

struct FILE* f: is file stream pointer

@return

int: non-zero if and only if it's an error state

@note EOF doesn't count

@see ferror(), feof()

@see libc/stdio/ferror_unlocked.c

fesetenv

@param

void** envp

@return

int

@see libc/runtime/fenv.c

fesetround

Sets rounding mode.

This configures the x87 FPU as well as SSE.

@param

int mode: may be FE_TONEAREST, FE_DOWNWARD, FE_UPWARD, or FE_TOWARDZERO

@return

int: 0 on success, or -1 on error

@see libc/runtime/fesetround.c

fetestexcept

@param

int mask

@return

int

@see libc/runtime/fenv.c

fflush

Blocks until data from stream buffer is written out.

@param

struct FILE* f: is the stream handle, or 0 for all streams

@return

int: is 0 on success or -1 on error

@threadsafe

@see libc/stdio/fflush.c

fflush_unlocked

Blocks until data from stream buffer is written out.

@param

struct FILE* f: is the stream handle, or 0 for all streams

@return

int: is 0 on success or -1 on error

@see libc/stdio/fflush_unlocked.c

ffs

Finds lowest set bit in word.

  uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
0x00000000      wut       32        0      wut       32
0x00000001        0        0        1        0       31
0x80000001        0        0        1       31        0
0x80000000       31       31       32       31        0
0x00000010        4        4        5        4       27
0x08000010        4        4        5       27        4
0x08000000       27       27       28       27        4
0xffffffff        0        0        1       31        0

@param

edi: is the input number

@return

: number in range [1,32] or 0 if no bits set

@see also treasure trove of nearly identical functions

@asyncsignalsafe

@see libc/nexgen32e/ffs.S

ffsl

Finds lowest set bit in word.

  uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
0x00000000      wut       32        0      wut       32
0x00000001        0        0        1        0       31
0x80000001        0        0        1       31        0
0x80000000       31       31       32       31        0
0x00000010        4        4        5        4       27
0x08000010        4        4        5       27        4
0x08000000       27       27       28       27        4
0xffffffff        0        0        1       31        0

@param

rdi: is the input number

@return

: number in range [1,64] or 0 if no bits set

@see also treasure trove of nearly identical functions

@asyncsignalsafe

@see libc/nexgen32e/ffsl.S

ffsll

Finds lowest set bit in word.

  uint32 𝑥   bsf(𝑥) tzcnt(𝑥)   ffs(𝑥)   bsr(𝑥) lzcnt(𝑥)
0x00000000      wut       32        0      wut       32
0x00000001        0        0        1        0       31
0x80000001        0        0        1       31        0
0x80000000       31       31       32       31        0
0x00000010        4        4        5        4       27
0x08000010        4        4        5       27        4
0x08000000       27       27       28       27        4
0xffffffff        0        0        1       31        0

@param

rdi: is the input number

@return

: number in range [1,64] or 0 if no bits set

@see also treasure trove of nearly identical functions

@asyncsignalsafe

@see libc/nexgen32e/ffsl.S

fgetc

Reads byte from stream.

@param

struct FILE* f: is non-null file object stream pointer

@return

int: byte in range 0..255, or -1 w/ errno

@see fgetc_unlocked()

@threadsafe

@see libc/stdio/fgetc.c

fgetc_unlocked

Reads byte from stream.

@param

struct FILE* f: is file object stream pointer

@return

int: byte in range 0..255, or -1 w/ errno

@see fgetc()

@see libc/stdio/fgetc_unlocked.c

fgetln

Retrieves line from stream, e.g.

char *line;
while ((line = _chomp(fgetln(stdin, 0)))) {
  printf("%s\n", line);
}

The returned memory is owned by the stream. It'll be reused when fgetln() is called again. It's free()'d upon fclose() / fflush()

@param

struct FILE* stream: specifies non-null open input stream
unsigned long* len: optionally receives byte length of line

@return

char*: nul-terminated line string, including the \n character unless a line happened before EOF without \n, otherwise it returns NULL and feof() and ferror() can examine the state

@see getdelim()

@see libc/stdio/fgetln.c

fgetpos

@param

struct FILE* stream
unsigned long* pos

@return

int

@see libc/stdio/fgetpos.c

fgets

Reads line from stream.

This function is similar to getline() except it'll truncate lines exceeding size. The line ending marker is included and may be removed using _chomp().

@param

char* s: is output buffer
int size: is capacity of s
struct FILE* f: is non-null file object stream pointer

@return

char*: s on success, NULL on error, or NULL if EOF happens when zero characters have been read

@see fgets_unlocked()

@threadsafe

@see libc/stdio/fgets.c

fgets_unlocked

Reads line from stream.

This function is similar to getline() except it'll truncate lines exceeding size. The line ending marker is included and may be removed using _chomp().

@param

char* s: is output buffer
int size: is capacity of s
struct FILE* f: is non-null file object stream pointer

@return

char*: s on success, NULL on error, or NULL if EOF happens when zero characters have been read

@see libc/stdio/fgets_unlocked.c

fgetwc

Reads UTF-8 character from stream.

@param

struct FILE* f: is non-null file object stream pointer

@return

unsigned int: wide character or -1 on EOF or error

@see fgetwc_unlocked()

@threadsafe

@see libc/stdio/fgetwc.c

fgetwc_unlocked

Reads UTF-8 character from stream.

@param

struct FILE* f

@return

unsigned int: wide character or -1 on EOF or error

@see libc/stdio/fgetwc_unlocked.c

fgetws

Reads UTF-8 content from stream into UTF-32 buffer.

This function is similar to getline() except it'll truncate lines exceeding size. The line ending marker is included and may be removed using _chomp().

@param

int* s: is is nul-terminated string that's non-null
int size: is byte length of s
struct FILE* f: is file stream object pointer

@return

int*

@see fgetws()

@threadsafe

@see libc/stdio/fgetws.c

fgetws_unlocked

Reads UTF-8 content from stream into UTF-32 buffer.

This function is similar to getline() except it'll truncate lines exceeding size. The line ending marker is included and may be removed using _chomp().

@param

int* s: is is nul-terminated string that's non-null
int size: is byte length of s
struct FILE* f: is file stream object pointer

@return

int*

@see fgetws()

@see libc/stdio/fgetws_unlocked.c

filecmp

Compares contents of files with memcmp().

@param

const char* pathname1
const char* pathname2

@return

int: ≤0, 0, or ≥0 based on comparison; or ≠0 on error, in which case we make our best effort to sift failing filenames rightward, and errno can be set to 0 beforehand to differentiate errors

@see libc/x/filecmp.c

fileexists

Returns true if file exists at path.

This function is equivalent to:

struct stat st;
return stat(path, &st) != -1;

Please note that things which aren't strictly files, e.g. directories or sockets, could be considered files for the purposes of this function. The stat() function may be used to differentiate them.

@param

const char* path

@return

_Bool

@see libc/calls/fileexists.c

fileno

Returns file descriptor associated with stream.

@param

struct FILE* f: is file stream object pointer

@return

int: fd on success or -1 w/ errno;

@threadsafe

@see libc/stdio/fileno.c

fileno_unlocked

Returns file descriptor associated with stream.

@param

struct FILE* f: is file stream object pointer

@return

int: fd on success or -1 w/ errno;

@see libc/stdio/fileno_unlocked.c

FindClose

Finds more files in directory.

@param

long hFindFile

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/findclose.c

FindComBinary

Returns path of binary without debug information, or null.

@return

const char*: path to non-debug binary, or -1 w/ errno

@see libc/runtime/findcombinary.c

FindContentType

Returns Content-Type for file extension.

@param

const char* p
unsigned long n

@return

const char*

@see net/http/findcontenttype.c

FindDebugBinary

Returns path of binary with the debug information, or null.

@return

const char*: path to debug binary, or NULL

@see libc/runtime/finddebugbinary.c

FindEmbeddedApe

Returns offset of binary embedded inside binary.

This can be used to load zip assets from an executable that hasn't gone through the objcopy -S -O binary step. We make the assumption that an x86_64-pc-linux-gnu toolchain is being used. This routine would need to be changed to accommodate binaries built locally on Apple, FreeBSD, etc.

@param

const unsigned char* p: needs to be page aligned
unsigned long n: is byte length of p

@return

unsigned char*: base address of image or NULL if not found

@see libc/str/findembeddedape.c

FindFirstFile

Finds first file in directory.

@param

const unsigned short* lpFileName
struct NtWin32FindData* out_lpFindFileData

@return

long

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/findfirstfile.c

FindNextFile

Finds more files in directory.

@param

long hFindFile
struct NtWin32FindData* out_lpFindFileData

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/findnextfile.c

finite

Returns nonzero if 𝑥 isn't INFINITY or NAN.

@param

double x

@return

int

@see libc/tinymath/finite.c

finitef

Returns nonzero if 𝑥 isn't INFINITY or NAN.

@param

float x

@return

int

@see libc/tinymath/finitef.c

finitel

Returns nonzero if 𝑥 isn't INFINITY or NAN.

@param

long double x

@return

int

@see libc/tinymath/finitel.c

_firewall

Checks outbound address against firewall.

The goal is to keep local software local, by raising an error if our Makefile tries to talk to the Internet.

@param

void* addr
unsigned int addrsize

@return

void

@see libc/sock/firewall.c

FixPath

@param

char* path

@return

void

@see libc/runtime/getdosenviron.c

__fixupnewfd

Applies file descriptor fixups on XNU or old Linux.

@param

int fd
int flags

@return

int

@see __fixupnewsockfd() for socket file descriptors

@see libc/calls/fixupnewfd.c

__fixupnewsockfd

Applies non-atomic file descriptor fixups on XNU or ancient Linux.

@param

int fd: of -1 means no-op
int flags

@return

int

@see libc/sock/fixupnewsockfd.c

__flbf

Returns nonzero if stream is line buffered.

@param

struct FILE* f

@return

int

@see libc/stdio/flbf.c

flock

Acquires lock on file.

Please note multiple file descriptors means multiple locks.

@param

int fd
int op: can have LOCK_{SH,EX,NB,UN} for shared, exclusive, non-blocking, and unlocking

@return

int: 0 on success, or -1 w/ errno

@restartable

@see libc/calls/flock.c

flock2cosmo

@param

unsigned long memory

@return

void

@see libc/calls/metaflock.c

flockfile

Acquires reentrant lock on stdio object, blocking if needed.

@param

struct FILE* f

@return

void

@see libc/stdio/flockfile.c

flogf

Writes formatted message w/ timestamp to log.

@param

unsigned int level
const char* file
int line
struct FILE* f
const char* fmt
...

@return

void

@see vflogf()

@see libc/log/flogf.c

floor

Returns largest integral not greater than 𝑥.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see libc/tinymath/floor.S

floorf

Returns largest integral not greater than 𝑥.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/floorf.S

floorl

Returns largest integral not greater than 𝑥.

@param

𝑥: is long double passed on stack

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/floorl.S

FlushFileBuffers

Flushes buffers of specified file to disk.

This provides a stronger degree of assurance and blocking for things to be sent to a physical medium, but it's not guaranteed unless your file is opened in a direct non-caching mode. One main advantage here seems to be coherency.

@param

long hFile

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@note consider buying a ups

@see FlushViewOfFile()

@see libc/intrin/flushfilebuffers.c

_flushlbf

Flushes all line-buffered streams.

@return

void

@see libc/stdio/flushlbf.c

FlushViewOfFile

Syncs memory created by MapViewOfFileEx().

This doesn't wait until the pages are written out to the physical medium. This doesn't update timestamps or file/dir metadata.

@param

void* lpBaseAddress
unsigned long dwNumberOfBytesToFlush

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@note consider buying a ups

@see FlushFileBuffers()

@see libc/intrin/flushviewoffile.c

fma

@param

double x
double y
double z

@return

double

@see libc/tinymath/fma.c

fmax

Returns maximum of two doubles.

If one argument is NAN then the other is returned. This function is designed to do the right thing with signed zeroes.

@param

double x
double y

@return

double

@see libc/tinymath/fmax.c

fmaxf

Returns maximum of two floats.

If one argument is NAN then the other is returned. This function is designed to do the right thing with signed zeroes.

@param

float x
float y

@return

float

@see libc/tinymath/fmaxf.c

fmaxl

Returns maximum of two long doubles.

If one argument is NAN then the other is returned. This function is designed to do the right thing with signed zeroes.

@param

long double x
long double y

@return

long double

@see libc/tinymath/fmaxl.c

fmemopen

Opens buffer as stream.

@param

void* buf: becomes owned by this function, and is allocated if NULL
unsigned long size
const char* mode

@return

struct FILE*: new stream or NULL w/ errno

@see libc/stdio/fmemopen.c

fmin

Returns minimum of two doubles.

If one argument is NAN then the other is returned. This function is designed to do the right thing with signed zeroes.

@param

double x
double y

@return

double

@see libc/tinymath/fmin.c

fminf

Returns minimum of two floats.

If one argument is NAN then the other is returned. This function is designed to do the right thing with signed zeroes.

@param

float x
float y

@return

float

@see libc/tinymath/fminf.c

fminl

Returns minimum of two long doubles.

If one argument is NAN then the other is returned. This function is designed to do the right thing with signed zeroes.

@param

long double x
long double y

@return

long double

@see libc/tinymath/fminl.c

fmod

fmod [sic] does (𝑥 rem 𝑦) w/ round()-style rounding.

@param

𝑥: is double passed in lower half of %xmm0
𝑦: is double passed in lower half of %xmm1

@return

: remainder ∈ (-|𝑦|,|𝑦|) in %xmm0

@define 𝑥-trunc(𝑥/𝑦)*𝑦

@see emod()

@see libc/tinymath/fmod.S

fmodl

fmod [sic] does (𝑥 rem 𝑦) w/ round()-style rounding.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes
𝑦: is the power, also pushed on stack, in reverse order

@return

: remainder ∈ (-|𝑦|,|𝑦|) in %st

@define 𝑥-truncl(𝑥/𝑦)*𝑦

@see emod()

@see libc/calls/fmodl.S

__fmt

Implements {,v}{,s{,n},{,{,x}as},f,d}printf domain-specific language.

Type Specifiers

%s char * (thompson-pike unicode)
%ls wchar_t * (32-bit unicode → thompson-pike unicode)
%hs char16_t * (16-bit unicode → thompson-pike unicode)
%b int (radix 2 binary)
%o int (radix 8 octal)
%d int (radix 10 decimal)
%x int (radix 16 hexadecimal)
%X int (radix 16 hexadecimal uppercase)
%p pointer (48-bit hexadecimal)
%u unsigned
%g double (smart formatting)
%e double (expo formatting)
%f double (ugly formatting)
%a double (hex formatting)
%Lg long double

Size Modifiers

%hhd char (8-bit)
%hd short (16-bit)
%ld long (64-bit)
%lu unsigned long (64-bit)
%lx unsigned long (64-bit hexadecimal)
%jd intmax_t (64-bit)
%jjd int128_t (128-bit)

Width Modifiers

%08d fixed columns w/ zero leftpadding
%8d fixed columns w/ space leftpadding
%*s variable column string (thompson-pike)

Precision Modifiers

%.8s supplied byte length (obeys nul terminator)
%.*s supplied byte length argument (obeys nul terminator)
%`.*s supplied byte length argument c escaped (ignores nul term)
%#.*s supplied byte length argument visualized (ignores nul term)
%.*hs supplied char16_t length argument (obeys nul terminator)
%.*ls supplied wchar_t length argument (obeys nul terminator)

Formatting Modifiers

%,d thousands separators
%'s escaped c string literal
%`c c escaped character
%`'c c escaped character quoted
%`s c escaped string
%`'s c escaped string quoted
%`s escaped double quoted c string literal
%`c escaped double quoted c character literal
%+d plus leftpad if positive (aligns w/ negatives)
% d space leftpad if positive (aligns w/ negatives)
%#s datum (radix 256 null-terminated ibm cp437)
%#x int (radix 16 hexadecimal w/ 0x prefix if not zero)

@param

void* fn
void* arg
const char* format
struct __va_list* va

@return

int

@note implementation detail of printf(), snprintf(), etc.

@see printf() for wordier documentation

@note netlib.org is so helpful

@asyncsignalsafe if floating point isn't used

@vforksafe if floating point isn't used

@see libc/fmt/fmt.c

__fmt_stoa

Converts string to array.

This is used by __fmt() to implement the %s and %c directives. The content outputted to the array is always UTF-8, but the input may be UTF-16 or UTF-32.

@param

int(*)() out
void* arg
void* data
unsigned long flags
unsigned long precision
unsigned long width
unsigned char signbit
unsigned char qchar

@return

int

@see __fmt()

@see libc/fmt/stoa.c

fnmatch

Matches filename.

* for wildcard
? for single character
[abc] to match character within set
[!abc] to match character not within set
\*\?\[\] for escaping above special syntax

@param

const char* pat
const char* str
int flags

@return

int

@see glob()

@see third_party/musl/fnmatch.c

FoldHeader

Collapses repeating headers onto a single line.

@param

struct HttpMessage* msg
char* b
int h
unsigned long* z

@return

char*

@see net/http/foldheader.c

fopen

Opens file as stream object.

@param

const char* pathname: is a utf-8 ideally relative filename
const char* mode: is the string mode/flag DSL see fopenflags()

@return

struct FILE*: new object to be free'd by fclose() or NULL w/ errno

@note microsoft unilaterally deprecated this function lool

@see libc/stdio/fopen.c

fopenflags

Turns stdio flags description string into bitmask.

@param

const char* mode

@return

int

@see libc/stdio/fopenflags.c

fork

Creates new process.

@return

int: 0 to child, child pid to parent, or -1 on error

@asyncsignalsafe

@see libc/runtime/fork.c

FormatBinary64

Converts unsigned 64-bit integer to binary string.

@param

char* p: needs at least 67 bytes
unsigned long x
char z: is 0 for DIGITS, 1 for 0bDIGITS, 2 for 0bDIGITS if ≠0

@return

char*: pointer to nul byte

@see libc/fmt/formatbinary64.c

FormatFlex64

Formats integer using decimal or hexadecimal.

This formats as int64 signed decimal. However it's a:

positive number
with population count of 1
and a magnitude of at least 256

Then we switch to hex notation to make the number more readable.

@param

char* p
long x
char z

@return

char*

@see libc/fmt/formatflex64.c

FormatHex64

Converts unsigned 64-bit integer to hex string.

@param

char* p: needs at least 19 bytes
unsigned long x
char z: is 0 for DIGITS, 1 for 0xDIGITS, 2 for 0xDIGITS if ≠0

@return

char*: pointer to nul byte

@see libc/fmt/formathex64.c

FormatHttpDateTime

Formats HTTP timestamp, e.g.

Sun, 04 Oct 2020 19:50:10 GMT

This function is the same as:

strftime(p, 30, "%a, %d %b %Y %H:%M:%S %Z", tm)

Except this function goes 10x faster:

FormatHttpDateTime  l:        25𝑐         8𝑛𝑠
strftime            l:       709𝑐       229𝑛𝑠

@param

char* p
struct tm* tm: must be zulu see gmtime_r() and nowl()

@return

char*

@see ParseHttpDateTime()

@see net/http/formathttpdatetime.c

FormatInt32

Converts signed 32-bit integer to string.

@param

char* p: needs at least 12 bytes
int x

@return

char*: pointer to nul byte

@see libc/intrin/formatint32.c

FormatInt64

Converts signed 64-bit integer to string.

@param

char* p: needs at least 21 bytes
long x

@return

char*: pointer to nul byte

@see libc/intrin/formatint64.c

FormatInt64Thousands

Converts 64-bit integer to string w/ commas.

@param

char* p: needs at least 27 bytes
long x

@return

char*: pointer to nul byte

@see libc/fmt/formatint64thousands.c

FormatMemorySize

Represents size of memory readably.

@param

char* p: is output buffer
unsigned long x

@return

char*: pointer to nul byte

@see libc/fmt/formatmemorysize.c

FormatOctal32

Converts unsigned 32-bit integer to octal string.

@param

char* p: needs at least 12 bytes
unsigned int x
_Bool z: ensures it starts with zero

@return

char*: pointer to nul byte

@see libc/fmt/formatoctal32.c

FormatOctal64

Converts unsigned 64-bit integer to octal string.

@param

char* p: needs at least 24 bytes
unsigned long x
_Bool z: ensures it starts with zero

@return

char*: pointer to nul byte

@see libc/fmt/formatoctal64.c

FormatUint32

Converts unsigned 32-bit integer to string.

@param

char* p: needs at least 12 bytes
unsigned int x

@return

char*: pointer to nul byte

@see libc/intrin/formatint32.c

FormatUint64

Converts unsigned 64-bit integer to string.

@param

char* p: needs at least 21 bytes
unsigned long x

@return

char*: pointer to nul byte

@see libc/intrin/formatint64.c

FormatUint64Thousands

Converts unsigned 64-bit integer to string w/ commas.

@param

char* p: needs at least 27 bytes
unsigned long x

@return

char*: pointer to nul byte

@see libc/fmt/formatint64thousands.c

__fpending

Returns number of pending output bytes.

@param

struct FILE* f

@return

unsigned long

@see libc/stdio/fpending.c

fprintf

Formats and writes text to stream.

@param

struct FILE* f
const char* fmt
...

@return

int

@see printf() for further documentation

@see libc/stdio/fprintf.c

fprintf_unlocked

Formats and writes text to stream.

@param

struct FILE* f
const char* fmt
...

@return

int

@see printf() for further documentation

@see libc/stdio/fprintf_unlocked.c

__fpurge

Discards contents of stream buffer.

@param

struct FILE* f

@return

void

@see libc/stdio/__fpurge.c

fpurge

Discards contents of stream buffer.

@param

struct FILE* f

@return

int

@see libc/stdio/fpurge.c

fputc

Writes byte to stream.

@param

int c: is byte to buffer or write, which is masked
struct FILE* f

@return

int: c as unsigned char if written or -1 w/ errno

@threadsafe

@see libc/stdio/fputc.c

fputc_unlocked

Writes byte to stream.

@param

int c: is byte to buffer or write, which is masked
struct FILE* f

@return

int: c as unsigned char if written or -1 w/ errno

@see libc/stdio/fputc_unlocked.c

fputs

Writes string to stream.

Writing stops at the NUL-terminator, which isn't included in output. This function blocks until the full string is written, unless an unrecoverable error happens.

@param

const char* s: is a NUL-terminated string that's non-NULL
struct FILE* f: is an open stream

@return

int: bytes written, or -1 w/ errno

@threadsafe

@see libc/stdio/fputs.c

fputs_unlocked

Writes string to stream.

Writing stops at the NUL-terminator, which isn't included in output. This function blocks until the full string is written, unless an unrecoverable error happens.

@param

const char* s: is a NUL-terminated string that's non-NULL
struct FILE* f: is an open stream

@return

int: bytes written, or -1 w/ errno

@see libc/stdio/fputs_unlocked.c

fputwc

Writes wide character to stream.

@param

int wc: has wide character
struct FILE* f: is file object stream pointer

@return

unsigned int: wide character if written or -1 w/ errno

@threadsafe

@see libc/stdio/fputwc.c

fputwc_unlocked

Writes wide character to stream.

@param

int wc: has wide character
struct FILE* f: is file object stream pointer

@return

unsigned int: wide character if written or -1 w/ errno

@see libc/stdio/fputwc_unlocked.c

fputws

Writes wide character string to stream.

Writing stops at the NUL-terminator, which isn't included in output. This function blocks until the full string is written, unless an unrecoverable error happens.

@param

const int* s: is a NUL-terminated string that's non-NULL
struct FILE* f: is an open stream

@return

int: strlen(s) or -1 w/ errno on error

@threadsafe

@see libc/stdio/fputws.c

fputws_unlocked

Writes wide character string to stream.

Writing stops at the NUL-terminator, which isn't included in output. This function blocks until the full string is written, unless an unrecoverable error happens.

@param

const int* s: is a NUL-terminated string that's non-NULL
struct FILE* f: is an open stream

@return

int: strlen(s) or -1 w/ errno on error

@see libc/stdio/fputws_unlocked.c

fread

Reads data from stream.

@param

void* buf
unsigned long stride: specifies the size of individual items
unsigned long count: is the number of strides to fetch
struct FILE* f

@return

unsigned long: count on success, [0,count) on eof, or 0 on error or count==0

@threadsafe

@see libc/stdio/fread.c

fread_unlocked

Reads data from stream.

@param

void* buf
unsigned long stride: specifies the size of individual items
unsigned long count: is the number of strides to fetch
struct FILE* f

@return

unsigned long: count on success, [0,count) on eof, or 0 on error or count==0

@see libc/stdio/fread_unlocked.c

__freadable

Returns nonzero if stream allows reading.

@param

struct FILE* f

@return

int

@see libc/stdio/freadable.c

__freading

Returns nonzero if stream is read only.

@param

struct FILE* f

@return

int

@see libc/stdio/freading.c

free

Free memory returned by malloc() & co.

Releases the chunk of memory pointed to by p, that had been previously allocated using malloc or a related routine such as realloc. It has no effect if p is null. If p was not malloced or already freed, free(p) will by default cause the current program to abort.

@param

rdi: is allocation address, which may be NULL

@return

@see dlfree()

@threadsafe

@see libc/mem/free.S

free_s

@param

void* v

@return

void

@see libc/runtime/free_s.c

freeaddrinfo

Frees addresses returned by getaddrinfo().

@param

struct addrinfo* ai

@return

int

@threadsafe

@see libc/dns/freeaddrinfo.c

freedtoa

@param

char* s

@return

void

@see third_party/gdtoa/dmisc.c

FreeHostsTxt

Frees HOSTS.TXT data structure populated by ParseHostsTxt().

@param

struct HostsTxt** ht

@return

void

@see libc/dns/freehoststxt.c

freelocale

@param

struct __locale_struct* l

@return

void

@see libc/unicode/freelocale.c

FreeResolvConf

Frees resolv.conf data structure populated by ParseResolvConf().

@param

struct ResolvConf** rvp

@return

void

@see libc/dns/freeresolvconf.c

_freestack

Frees stack.

@param

void* stk: was allocated by _mapstack()

@return

int

@see libc/runtime/mapstack.c

freopen

Overwrites existing stream.

This function can be used in two ways. The first is sort of a mutating assignment. The second behavior, if pathname is NULL, is just changing the mode of an already open file descriptor.

@param

const char* pathname: is the file to open or NULL
const char* mode: is the mode string flags, see fopenflags()
struct FILE* stream: is the existing allocated stream memory, which is flushed and closed if already open

@return

struct FILE*: stream object if successful, or NULL w/ errno

@see libc/stdio/freopen.c

frexp

Splits number normalized fraction and exponent.

@param

double x
int* e

@return

double

@see libc/tinymath/frexp.c

frexpf

Splits number normalized fraction and exponent.

@param

float x
int* e

@return

float

@see libc/tinymath/frexpf.c

frexpl

Splits number normalized fraction and exponent.

@param

long double x
int* e

@return

long double

@see libc/tinymath/frexpl.c

fscanf

Decodes data from stream.

To read a line of data from a well-formed trustworthy file:

int x, y;
char text[256];
fscanf(f, "%d %d %s\n", &x, &y, text);

Please note that this function is brittle by default, which makes it a good fit for yolo coding. With some toil it can be used in a way that makes it reasonably hardened although getline() may be better.

@param

struct FILE* stream
const char* fmt
...

@return

int

@see libc/fmt/vcscanf.c

@see libc/stdio/fscanf.c

fseek

Repositions open file stream.

This function flushes the buffer (unless it's currently in the EOF state) and then calls lseek() on the underlying file. If the stream is in the EOF state, this function can be used to restore it without needing to reopen the file.

@param

struct FILE* f: is a non-null stream handle
long offset: is the byte delta
int whence: can be SEET_SET, SEEK_CUR, or SEEK_END

@return

int

@returns 0 on success or -1 on error

@see libc/stdio/fseek.c

fseeko

Repositions open file stream.

@param

struct FILE* f: is a non-null stream handle
long offset: is the byte delta
int whence: can be SEET_SET, SEEK_CUR, or SEEK_END

@return

int

@returns 0 on success or -1 on error

@threadsafe

@see libc/stdio/fseeko.c

fseeko_unlocked

Repositions open file stream.

@param

struct FILE* f: is a non-null stream handle
long offset: is the byte delta
int whence: can be SEET_SET, SEEK_CUR, or SEEK_END

@return

int

@returns 0 on success or -1 on error

@see libc/stdio/fseeko_unlocked.c

__fsetlocking

Does nothing and returns FSETLOCKING_INTERNAL.

@param

struct FILE* f
int type

@return

int

@see libc/stdio/fsetlocking.c

fsetpos

@param

struct FILE* stream
const unsigned long* pos

@return

int

@see libc/stdio/fsetpos.c

fstat

Returns information about file, via open()'d descriptor.

@param

int fd
struct cosmo* st

@return

int: 0 on success or -1 w/ errno

@raise EBADF if fd isn't a valid file descriptor

@raise EIO if an i/o error happens while reading from file system

@raise EOVERFLOW shouldn't be possible on 64-bit systems

@asyncsignalsafe

@see libc/calls/fstat.c

fstatat

Returns information about thing.

@param

int dirfd: is normally AT_FDCWD but if it's an open directory and file is a relative path, then file becomes relative to dirfd
const char* path
struct cosmo* st: is where result is stored
int flags: can have AT_SYMLINK_NOFOLLOW

@return

int: 0 on success, or -1 w/ errno

@see S_ISDIR(st.st_mode), S_ISREG()

@asyncsignalsafe

@vforksafe

@see libc/calls/fstatat.c

fsum

Adds doubles in array.

@param

const double* p
unsigned long n

@return

double

@see libc/tinymath/fsum.c

fsumf

Adds floats in array.

@param

const float* p
unsigned long n

@return

float

@see libc/tinymath/fsumf.c

fsync

Blocks until kernel flushes buffers for fd to disk.

@param

int fd

@return

int: 0 on success, or -1 w/ errno

@see fdatasync(), sync_file_range()

@see __nosync to secretly disable

@asyncsignalsafe

@see libc/calls/fsync.c

ftell

Returns current position of stream.

@param

struct FILE* f

@return

long

@returns current byte offset from beginning, or -1 w/ errno

@see libc/stdio/ftell.c

ftello

Returns current position of stream.

@param

struct FILE* f

@return

long

@returns current byte offset from beginning, or -1 w/ errno

@threadsafe

@see libc/stdio/ftello.c

ftok

Convert pathname and a project ID to System V IPC key.

@param

const char* path
int id

@return

int

@see libc/calls/ftok.c

__ftrace

Function tracing enabled state.

After ftrace_install() has been called, the logging of C function calls may be controlled by changing this variable. If __ftrace is greater than zero, functions are logged. Otherwise, they aren't.

By convention, functions wishing to disable function tracing for a short time period should say:

void foo() {
  --__ftrace;
  bar();
  ++__ftrace;
}

This way you still have some flexibility to force function tracing, by setting __ftrace to a higher number like 2 or 200. Even though under normal circumstances, __ftrace should only be either zero or one.

@type

_Atomic int

@see libc/intrin/ftrace.c

ftrace_init

Enables plaintext function tracing if --ftrace flag is passed.

The --ftrace CLI arg is removed before main() is called. This code is intended for diagnostic purposes and assumes binaries are trustworthy and stack isn't corrupted. Logging plain text allows program structure to easily be visualized and hotspots identified w/ sed | sort | uniq -c | sort. A compressed trace can be made by appending --ftrace 2>&1 | gzip -4 >trace.gz to the CLI arguments.

@return

int

@see libc/runtime/_init.S for documentation

@see libc/runtime/ftraceinit.greg.c

ftrace_install

@return

int

@see libc/runtime/ftracer.c

ftracer

Prints name of function being called.

We insert CALL instructions that point to this function, in the prologues of other functions. We assume those functions behave according to the System Five NexGen32e ABI.

@return

void

@see libc/runtime/ftracer.c

ftruncate

Changes size of file.

@param

int fd: must be open for writing
long length: may be greater than current current file size, in which case System V guarantees it'll be zero'd but Windows NT doesn't; since the prior extends logically and the latter physically

@return

int: 0 on success, or -1 w/ errno

@asyncsignalsafe

@see libc/calls/ftruncate.c

ftrylockfile

Tries to acquire reentrant stdio object lock.

@param

struct FILE* f

@return

int: 0 on success, or non-zero if another thread owns the lock

@see libc/stdio/ftrylockfile.c

ftw

Walks file tree.

@param

const char* path
int(*)() fn
int fd_limit

@return

int

@see examples/walk.c for example

@see nftw()

@see third_party/musl/ftw.c

funlockfile

Releases lock on stdio object.

@param

struct FILE* f

@return

void

@see libc/stdio/funlockfile.c

futimens

Sets atime/mtime on file descriptor.

This function is the same as utimensat(fd, 0, ts, 0).

@param

int fd
ANONYMOUS-STRUCT* ts: is atime/mtime, or null for current time

@return

int

@raise ENOSYS on RHEL5

@see libc/calls/futimens.c

futimes

Sets atime/mtime on file descriptor.

@param

int fd
struct it_value* tv

@return

int

@note better than microsecond precision on most platforms

@see fstat() for reading timestamps

@see libc/time/futimes.c

futimesat

Changes last accessed/modified times on file.

@param

int dirfd
const char* pathname
struct it_value* tv

@return

int: 0 on success or -1 w/ errno

@see utimensat() which uses nanos

@see libc/time/futimesat.c

__fwritable

Returns nonzero if stream allows reading.

@param

struct FILE* f

@return

int

@see libc/stdio/fwritable.c

fwrite

Writes data to stream.

@param

void* data
unsigned long stride: specifies the size of individual items
unsigned long count: is the number of strides to write
struct FILE* f

@return

unsigned long: count on success, [0,count) on EOF, 0 on error or count==0

@threadsafe

@see libc/stdio/fwrite.c

fwrite_unlocked

Writes data to stream.

@param

void* data
unsigned long stride: specifies the size of individual items
unsigned long count: is the number of strides to write
struct FILE* f

@return

unsigned long: count on success, [0,count) on EOF, 0 on error or count==0

@see libc/stdio/fwrite_unlocked.c

__fwriting

Returns nonzero if stream is write only.

@param

struct FILE* f

@return

int

@see libc/stdio/fwriting.c

g_ddfmt

@param

char* buf
double* dd0
int ndig
unsigned long bufsize

@return

char*

@see third_party/gdtoa/g_ddfmt.c

g_ddfmt_p

@param

char* buf
double* dd0
int ndig
unsigned long bufsize
int nik

@return

char*

@see third_party/gdtoa/g_ddfmt_p.c

g_dfmt

@param

char* buf
double* d
int ndig
unsigned long bufsize

@return

char*

@see third_party/gdtoa/g_dfmt.c

g_dfmt_p

@param

char* buf
double* d
int ndig
unsigned long bufsize
int nik

@return

char*

@see third_party/gdtoa/g_dfmt_p.c

g_fds

@type

struct g_fds

@see libc/intrin/g_fds.c

g_ffmt

@param

char* buf
float* f
int ndig
unsigned long bufsize

@return

char*

@see third_party/gdtoa/g_ffmt.c

g_ffmt_p

@param

char* buf
float* f
int ndig
unsigned long bufsize
int nik

@return

char*

@see third_party/gdtoa/g_ffmt_p.c

g_isrunningundermake

@type

_Bool

@see libc/intrin/isrunningundermake.c

g_isrunningundermake_init

@return

void

@see libc/intrin/isrunningundermake.c

g_xfmt

@param

char* buf
void* V
int ndig
unsigned long bufsize

@return

char*

@see third_party/gdtoa/g_xfmt.c

g_xfmt_p

@param

char* buf
void* V
int ndig
unsigned long bufsize
int nik

@return

char*

@see third_party/gdtoa/g_xfmt_p.c

gai_strerror

Turns getaddrinfo() return code into string.

@param

int code

@return

const char*

@see libc/dns/gai_strerror.c

__gc

Invokes deferred function calls.

This offers behavior similar to std::unique_ptr. Functions overwrite their return addresses jumping here, and pushing exactly one entry on the shadow stack below. Functions may repeat that process multiple times, in which case the body of this gadget loops and unwinds as a natural consequence.

@param

rax,rdx,xmm0,xmm1,st0,st1: is return value

@return

@see test/libc/runtime/gc_test.c

@see libc/nexgen32e/gc.S

_gc

Frees memory when function returns.

const char *s = _gc(strdup("hello"));
puts(s);

This macro is equivalent to:

 _defer(free, ptr)

@param

void* thing

@return

void*

@warning do not return a gc()'d pointer

@warning do not realloc() with gc()'d pointer

@warning be careful about static keyword due to impact of inlining

@note you should use -fno-omit-frame-pointer

@see libc/mem/gc.c

_gclongjmp

Jumps up stack to previous setjmp() invocation.

This is the same as longjmp() but also unwinds the stack to free memory, etc. that was registered using gc() or defer(). If GC isn't linked, this behaves the same as longjmp().

@param

rdi: points to the jmp_buf which must be the same stack
esi: is returned by setjmp() invocation (coerced nonzero)

@noreturn

@assume system five nexgen32e abi conformant

@see examples/ctrlc.c

@see libc/nexgen32e/gclongjmp.S

gcvt

@param

double x
int n
char* b

@return

char*

@see libc/stdio/gcvt.c

gdbexec

Attaches GDB temporarily, to do something like print a variable.

@param

const char* cmd

@return

int

@see libc/log/gdbexec.c

gdtoa

@param

struct FPI* fpi
int be
unsigned int* bits
int* kindp
int mode
int ndigits
int* decpt
char** rve

@return

char*

@see third_party/gdtoa/gdtoa.c

GenerateConsoleCtrlEvent

Sends signal to process group that shares console w/ calling process.

@param

unsigned int dwCtrlEvent: can be kNtCtrlCEvent or kNtCtrlBreakEvent
unsigned int dwProcessGroupId

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/generateconsolectrlevent.c

get_current_dir_name

Returns current working directory.

If the PWD environment variable is set, and it seems legit, then that'll be returned.

@return

char*: pointer that must be free()'d, or NULL w/ errno

@threadsafe

@see libc/mem/get_current_dir_name.c

__get_symbol

Returns low index into symbol table for address.

@param

struct SymbolTable* t: if null will be auto-populated only if already open
long a

@return

int: index or -1 if nothing found

@see libc/runtime/getsymboltable.c

__get_symbol_by_addr

Returns name of symbol at address.

@param

long addr

@return

char*

@see libc/log/getsymbolbyaddr.c

__get_virtual

Returns pointer to page table entry for page at virtual address. Additional page tables are allocated if needed as a side-effect.

@param

struct mman* mm
unsigned long* t
long vaddr
_Bool maketables

@return

unsigned long*

@see libc/calls/mman.greg.c

GetAddr2linePath

@return

const char*

@see libc/log/addr2linepath.c

getaddrinfo

Resolves address for internet name.

@param

const char* name: is either an ip string or a utf-8 hostname
const char* service: is the port number as a string
struct addrinfo* hints: may be passed to specialize behavior (optional)
struct addrinfo** res: receives a pointer that must be freed with freeaddrinfo(), and won't be modified if non-zero is returned

@return

int: 0 on success or EAI_xxx value

@threadsafe

@see libc/dns/getaddrinfo.c

getauxval

Returns auxiliary value, or zero if kernel didn't provide it.

This function is typically regarded as a libc implementation detail; thus, the source code is the documentation.

@param

unsigned long at

@return

unsigned long: auxiliary value or 0 if at not found

@see libc/sysv/consts.sh

@see System Five Application Binary Interface § 3.4.3

@error ENOENT when value not found

@asyncsignalsafe

@see libc/calls/getauxval.c

_getauxval

Returns auxiliary value, or zero if kernel didn't provide it.

This function is typically regarded as a libc implementation detail; thus, the source code is the documentation.

@param

unsigned long at: is AT_... search key

@return

struct AuxiliaryValue: true if value was found

@see libc/sysv/consts.sh

@see System Five Application Binary Interface § 3.4.3

@error ENOENT when value not found

@asyncsignalsafe

@see libc/calls/_getauxval.c

getc

Reads byte from stream.

@param

struct FILE* f

@return

int: byte in range 0..255, or -1 w/ errno

@threadsafe

@see libc/stdio/getc.c

getc_unlocked

Reads byte from stream.

@param

struct FILE* f

@return

int: byte in range 0..255, or -1 w/ errno

@see libc/stdio/getc_unlocked.c

getcachesize

Returns CPU cache size.

@param

int type: 1=data, 2=instruction, 3=unified
int level: starts at 1

@return

unsigned int: size in bytes, or 0 if unknown

@see libc/str/getcachesize.c

GetCallerName

Returns name of function that called caller function.

@param

struct StackFrame* bp

@return

const char*

@see libc/log/getcallername.c

getchar

Reads byte from stdin.

@return

int: byte in range 0..255, or -1 w/ errno

@htreadsafe

@see libc/stdio/getchar.c

getchar_unlocked

Reads byte from stdin.

@return

int: byte in range 0..255, or -1 w/ errno

@see libc/stdio/getchar_unlocked.c

getcontext

Gets machine state.

@return

@note please use longerjmp() and setlongerjmp() for fibers

@note currently only gets general registers

@see setcontext()

@see libc/calls/getcontext.S

GetCpuCount

Returns number of CPUs in system.

On Intel systems with HyperThreading this will return the number of cores multiplied by two.

@return

unsigned int: cpu count or 0 if it couldn't be determined

@see libc/calls/getcpucount.c

getcwd

Returns current working directory, e.g.

const char *dirname = gc(getcwd(0,0)); // if malloc is linked
const char *dirname = getcwd(alloca(PATH_MAX),PATH_MAX);

@param

char* buf: is where UTF-8 NUL-terminated path string gets written, which may be NULL to ask this function to malloc a buffer
unsigned long size: is number of bytes available in buf, e.g. PATH_MAX+1, which may be 0 if buf is NULL

@return

char*: buf containing system-normative path or NULL w/ errno

@error ERANGE, EINVAL, ENOMEM

@see libc/calls/getcwd.greg.c

getdelim

Reads string from stream, e.g.

char *line = NULL;
size_t linesize = 0;
while (getdelim(&line, &linesize, '\n', stdin) > 0) {
  _chomp(line);
  printf("%s\n", line);
}
free(line);

@param

char** s: is the caller's buffer (in/out) which is extended or allocated automatically, also NUL-terminated is guaranteed
unsigned long* n: is the capacity of s (in/out)
int delim: is the stop char (and NUL is implicitly too)
struct FILE* f

@return

long: number of bytes read >0, including delim, excluding NUL, or -1 w/ errno on EOF or error; see ferror() and feof()

@note this function will ignore EINTR if it occurs mid-line

@raises EBADF if stream isn't open for reading

@see fgetln(), getline(), _chomp(), gettok_r()

@see libc/stdio/getdelim.c

getdelim_unlocked

Reads string from unlocked stream.

@param

char** s
unsigned long* n
int delim
struct FILE* f

@return

long

@see getdelim() for documentation

@see libc/stdio/getdelim_unlocked.c

getdomainname

@param

char* name
unsigned long len

@return

int

@see libc/calls/getdomainname.c

GetDosArgv

Tokenizes and transcodes Windows NT CLI args, thus avoiding CommandLineToArgv() schlepping in forty megs of dependencies.

@param

const unsigned short* cmdline
char* buf: is where we'll store double-NUL-terminated decoded args
unsigned long size: is how many bytes are available in buf
char** argv: is where we'll store the decoded arg pointer array, which is guaranteed to be NULL-terminated if max>0
unsigned long max: specifies the item capacity of argv, or 0 to do scanning

@return

int: number of args written, excluding the NULL-terminator; or, if the output buffer wasn't passed, or was too short, then the number of args that *would* have been written is returned; and there are currently no failure conditions that would have this return -1 since it doesn't do system calls

@see test/libc/dosarg_test.c

@see libc/runtime/ntspawn.c

@note kudos to Simon Tatham for figuring out quoting behavior

@see libc/runtime/getdosargv.c

GetDosEnviron

Transcodes NT environment variable block from UTF-16 to UTF-8.

@param

const unsigned short* env: is a double NUL-terminated block of key=values
char* buf: is the new environment which gets double-nul'd
unsigned long size: is the byte capacity of buf
char** envp: stores NULL-terminated string pointer list (optional)
unsigned long max: is the pointer count capacity of envp

@return

int: number of variables decoded, excluding NULL-terminator

@see libc/runtime/getdosenviron.c

getegid

Returns effective group ID of calling process.

@return

int: group id

@see libc/calls/getegid.c

GetElfDynStringTable

@param

struct Elf64_Ehdr* elf
unsigned long mapsize

@return

char*

@see libc/elf/getelfdynstringtable.c

GetElfDynSymbolTable

@param

struct Elf64_Ehdr* elf
unsigned long mapsize
unsigned long* out_count

@return

struct Elf64_Sym*

@see libc/elf/getelfdynsymboltable.c

GetElfSectionAddress

@param

struct Elf64_Ehdr* elf
unsigned long mapsize
struct Elf64_Shdr* shdr

@return

void*

@see libc/elf/getelfsectionaddress.c

GetElfSectionHeaderAddress

@param

struct Elf64_Ehdr* elf
unsigned long mapsize
unsigned short i

@return

struct Elf64_Shdr*

@see libc/elf/getelfsectionheaderaddress.c

GetElfSectionName

@param

struct Elf64_Ehdr* elf
unsigned long mapsize
struct Elf64_Shdr* shdr

@return

const char*

@see libc/elf/getelfsectionname.c

GetElfSectionNameStringTable

@param

struct Elf64_Ehdr* elf
unsigned long mapsize

@return

char*

@see libc/elf/getelfsectionnamestringtable.c

GetElfSegmentHeaderAddress

@param

struct Elf64_Ehdr* elf
unsigned long mapsize
unsigned int i

@return

struct Elf64_Phdr*

@see libc/elf/getelfsegmentheaderaddress.c

GetElfString

@param

struct Elf64_Ehdr* elf
unsigned long mapsize
const char* strtab
unsigned int rva

@return

char*

@see libc/elf/getelfstring.c

GetElfStringTable

@param

struct Elf64_Ehdr* elf
unsigned long mapsize

@return

char*

@see libc/elf/getelfstringtable.c

GetElfStrs

@param

struct Elf64_Ehdr* elf
unsigned long mapsize
unsigned long* out_size

@return

char*

@see libc/elf/getelfstrs.c

GetElfSymbolTable

@param

struct Elf64_Ehdr* elf
unsigned long mapsize
unsigned long* out_count

@return

struct Elf64_Sym*

@see libc/elf/getelfsymboltable.c

GetElfVirtualAddressRange

@param

struct Elf64_Ehdr* elf
unsigned long elfsize
long* out_start
long* out_end

@return

void

@see libc/elf/getelfvirtualaddressrange.c

getentropy

Returns random seeding bytes, the XNU/OpenBSD way.

@param

void* buf
unsigned long size

@return

int

@see getrandom()

@see libc/rand/getentropy.c

getenv

Returns value of environment variable, or NULL if not found.

Environment variables can store empty string on Unix but not Windows.

@param

const char* s

@return

char*

@note should not be used after __cxa_finalize() is called

@see libc/intrin/getenv.greg.c

geteuid

Returns effective user ID of calling process.

@return

int: user id

@see libc/calls/geteuid.c

GetExitCodeProcess

Obtains exit code for process.

@param

long hProcess
unsigned int* lpExitCode

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/getexitcodeprocess.c

GetFileAttributes

Gets file info on the New Technology.

@param

const unsigned short* lpPathName

@return

unsigned int: handle, or -1u on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/getfileattributes.c

getfiledescriptorsize

Determines size of open file.

This function is equivalent to:

struct stat st;
!fstat(fd, &st) ? st.st_size : -1

Except faster on BSD/Windows and a much smaller link size.

@param

int fd

@return

long: file byte length, or -1 w/ errno

@asyncsignalsafe

@see libc/calls/getfiledescriptorsize.c

GetFileSize

Returns the byte length of file by path.

@param

const char* pathname

@return

unsigned long: number of bytes, or -1ul w/ errno

@see getfiledescriptorsize()

@see libc/calls/getfilesize.c

GetGdbPath

@return

const char*

@see libc/log/gdbpath.c

getgid

Returns real group id of process.

This never fails. On Windows, which doesn't really have this concept, we return a deterministic value that's likely to work.

@return

int

@asyncsignalsafe

@vforksafe

@see libc/calls/getuid.c

getgrent

@return

struct gr*

@see third_party/musl/grp.c

getgrgid

@param

unsigned int gid

@return

struct gr*

@see third_party/musl/grp.c

getgrgid_r

@param

unsigned int gid
struct gr* gr
char* buf
unsigned long size
struct gr** res

@return

int

@see third_party/musl/grp.c

getgrnam

@param

const char* name

@return

struct gr*

@see third_party/musl/grp.c

getgrnam_r

@param

const char* name
struct gr* gr
char* buf
unsigned long size
struct gr** res

@return

int

@see third_party/musl/grp.c

getgrouplist

@param

const char* user
unsigned int gid
unsigned int* groups
int* ngroups

@return

int

@see third_party/musl/grp.c

gethostbyaddr

@param

void* s_addr
unsigned int len
int type

@return

struct he1*

@see libc/dns/gethostbyaddr.c

gethostbyname

@param

const char* name

@return

struct he0*

@see libc/dns/gethostbyname.c

gethostent

@return

struct hostent*

@see libc/dns/hostent.c

GetHostIps

Returns IP addresses of system.

Normally return values will look like {0x7f000001, 0x0a0a0a7c, 0} which means the same thing as {"127.0.0.1", "10.10.10.124", 0}. Returned IPs will IPv4 anycast addresses bound to network interfaces which come in a NULL-terminated array with no particular ordering.

uint32_t *ip, *ips = GetIps();
for (ip = ips; *ip; ++ip) {
  printf("%hhu.%hhu.%hhu.%hhu\n", *ip >> 24, *ip >> 16, *ip >> 8, *ip);
}

This function supports Windows, Linux, XNU, FreeBSD, NetBSD, OpenBSD.

@return

unsigned int*: null-terminated ip array on success, or null w/ errno

@see libc/sock/gethostips.c

gethostname

Returns name of host system, e.g.

pheidippides.domain.example
^^^^^^^^^^^^

@param

char* name
unsigned long len

@return

int: 0 on success or -1 w/ errno

@see libc/calls/gethostname.c

gethostname_bsd

@param

char* name
unsigned long len

@return

int

@see libc/calls/gethostname-bsd.c

gethostname_linux

@param

char* name
unsigned long len

@return

int

@see libc/calls/gethostname-linux.c

gethostname_nt

@param

char* name
unsigned long len
int kind

@return

int

@see libc/calls/gethostname-nt.c

GetHostsTxt

Returns hosts.txt map.

@return

struct HostsTxt*

@note yoinking realloc() ensures there's no size limits

@threadsafe

@see libc/dns/gethoststxt.c

GetHttpHeader

Returns small number for HTTP header, or -1 if not found.

@param

const char* str
unsigned long len

@return

int

@see net/http/gethttpheader.c

GetHttpHeaderName

@param

int h

@return

const char*

@see net/http/gethttpheadername.c

GetHttpMethod

Converts HTTP method string into internal index

@param

const char* str
unsigned long len: if -1 implies strlen

@return

int: small number for HTTP method, or 0 if not found.

@see net/http/gethttpmethod.c

GetHttpReason

Returns string describing HTTP reason phrase.

@param

int code

@return

const char*

@see https://tools.ietf.org/html/rfc2616

@see https://tools.ietf.org/html/rfc6585

@see net/http/gethttpreason.c

GetInstructionLengths

Returns lengths of x86 ops in binary.

The first decoded instruction is at _ereal. Lengths can be 1 to 15 bytes. Each byte in the return value is in that range, and the array is NUL terminated. The returned memory is memoized, since this costs some time. For example, for a 10mb Python binary, it takes 20 millis so the basic idea is is you can use this output multiple times which is a faster way to iterate over the binary than calling Xed.

@return

unsigned char*: nul-terminated length array on success, or null

@see libc/runtime/getinstructionlengths.c

GetInterpreterExecutableName

Returns path of executable interpreter.

Unlike program_executable_name which is designed to figure out the absolute path of the first argument passed to execve(), what we do here is probe things like /proc and sysctl() to figure out if we were launched by something like ape-loader, and then we return its path. If we can't determine that path, possibly because we're on XNU or OpenBSD, then we return -1 with an error code.

@param

char* p: receives utf8 output
unsigned long n: is byte size of res buffer

@return

char*: p on success or null w/ errno if out of buf or error

@see program_invocation_short_name

@see program_invocation_name

@see program_executable_name

@see libc/runtime/getinterpreterexecutablename.c

GetIpCategoryName

Describes IP address.

@param

int c

@return

const char*

@see CategorizeIp()

@see net/http/getipcategoryname.c

getitimer

Retrieves last setitimer() value, correcting for remaining time.

@param

int which: can be ITIMER_REAL, ITIMER_VIRTUAL, etc.
struct itimerval* curvalue

@return

int: 0 on success or -1 w/ errno

@see libc/calls/getitimer.c

getline

Reads line from stream, e.g.

char *line = NULL;
size_t linesize = 0;
while (getline(&line, &linesize, stdin) > 0) {
  _chomp(line);
  printf("%s\n", line);
}
free(line);

This function delegates to getdelim(), which provides further documentation. Concerning lines, please note the \n or \r\n are included in results, and can be removed with _chomp().

@param

char** line: is the caller's buffer (in/out) which is extended automatically. *line may be NULL but only if *n is 0; NUL-termination is guaranteed FTMP
unsigned long* n
struct FILE* f

@return

long: number of bytes read, including delim, excluding NUL, or -1 w/ errno on EOF or error; see ferror() and feof()

@see fgetln(), xgetline(), getdelim(), gettok_r()

@see libc/stdio/getline.c

getloadavg

Returns system load average.

@param

double* a: should be array of 3 doubles
int n: should be 3

@return

int: number of items placed in a or -1 w/ errno

@raise ENOSYS on metal

@see libc/calls/getloadavg.c

GetMagnumStr

@param

struct MagnumStr* ms
int x

@return

char*

@see libc/intrin/getmagnumstr.c

GetMaxFd

Returns maximum number of open files.

@return

long

@see libc/runtime/getmaxfd.c

GetMemtrackSize

@param

struct _mmi* mm

@return

unsigned long

@see libc/runtime/getmemtracksize.c

getnameinfo

Resolves name/service for socket address.

@param

struct sockaddr* addr
unsigned int addrlen
char* name
unsigned int namelen
char* service
unsigned int servicelen
int flags

@return

int: 0 on success or EAI_xxx value

@see libc/dns/getnameinfo.c

getnetbyaddr

@param

unsigned int net
int type

@return

struct netent*

@see libc/dns/netent.c

getnetbyname

@param

const char* name

@return

struct netent*

@see libc/dns/netent.c

getnetent

@return

struct netent*

@see libc/dns/netent.c

GetNtBaseSocket

@param

long socket

@return

long

@see libc/sock/basesocket.c

GetNtNameServers

Extracts DNS nameserver IPs from Windows Registry.

@param

struct ResolvConf* resolv: points to a ResolvConf object, which should be zero initialized by the caller; or if it already contains items, this function will append

@return

int: number of nameservers appended, or -1 w/ errno

@see libc/dns/getntnameservers.c

GetNtOpenFlags

@param

int flags
int mode
unsigned int* out_perm
unsigned int* out_share
unsigned int* out_disp
unsigned int* out_attr

@return

int

@see libc/calls/createfileflags.c

GetNtProtocolsTxtPath

@param

char* pathbuf
unsigned int size

@return

char*

@see libc/dns/getntprotocolstxtpath.c

GetNtServicesTxtPath

@param

char* pathbuf
unsigned int size

@return

char*

@see libc/dns/getntservicestxtpath.c

__getntsyspath

Obtains WIN32 magic path, e.g. GetTempPathA.

@param

rax: is address of ANSI path provider function
rdi: is output buffer
rdx: is output buffer size in bytes that's >0

@return

: eax is string length w/ NUL that's ≤ edx; rdi is rdi+edx

@see libc/calls/getntsyspath.S

getopt

Parses argc/argv argument vector, e.g.

while ((opt = getopt(argc, argv, "hvx:")) != -1) {
  switch (opt) {
    case 'x':
      x = atoi(optarg);
      break;
    case 'v':
      ++verbose;
      break;
    case 'h':
      PrintUsage(EXIT_SUCCESS, stdout);
    default:
      PrintUsage(EX_USAGE, stderr);
  }
}

@param

int nargc
char** nargv
const char* ostr

@return

int

@see optind

@see optarg

@see third_party/getopt/getopt.c

getpeername

Returns details about remote end of connected socket.

@param

int fd
void* out_addr
unsigned int* out_addrsize

@return

int: 0 on success or -1 w/ errno

@see getsockname()

@see libc/sock/getpeername.c

getpgid

Returns process group id.

@param

int pid

@return

int

@see libc/calls/getpgid.c

getpgrp

Returns process group id of calling process.

@return

int

@see libc/calls/getpgrp.c

getpid

Returns process id.

This function does not need to issue a system call. The PID is tracked by a global variable which is updated atfork(). The only exception is when the process is vfork()'d in which case a system call shall be issued.

On Linux, and only Linux, the process id is guaranteed to be the same as gettid() for the main thread.

@return

int

@asyncsignalsafe

@threadsafe

@vforksafe

@see libc/intrin/getpid.c

getppid

Returns parent process id.

@return

int

@asyncsignalsafe

@see libc/calls/getppid.c

getpriority

Returns nice value of thing.

Since -1 might be a valid return value for this API, it's necessary to clear errno beforehand and see if it changed, in order to truly determine if an error happened.

@param

int which: can be PRIO_PROCESS, PRIO_PGRP, PRIO_USER
unsigned int who: is the pid, pgid, or uid (0 means current)

@return

int: value ∈ [-NZERO,NZERO) or -1 w/ errno

@see setpriority(), nice()

@see libc/calls/getpriority.c

GetProcAddressModule

Returns address of function in a DLL that's already loaded.

@param

const char* module
const char* symbol

@return

void*

@see libc/calls/getprocaddressmodule.c

GetProgramExecutableName

Returns absolute path of program.

@return

char*

@see libc/calls/getprogramexecutablename.greg.c

getprotobyname

@param

const char* name

@return

struct pe0*

@see libc/dns/getprotobyname.c

getprotobynumber

@param

int proto

@return

struct pe1*

@see libc/dns/getprotobynumber.c

getprotoent

@return

struct protoent*

@see libc/dns/protoent.c

getpwent

@return

struct pw*

@see third_party/musl/pwd.c

getpwnam

@param

const char* name

@return

struct pw*

@see third_party/musl/pwd.c

getpwnam_r

@param

const char* name
struct pw* pw
char* buf
unsigned long size
struct pw** res

@return

int

@see third_party/musl/pwd.c

getpwuid

@param

unsigned int uid

@return

struct pw*

@see third_party/musl/pwd.c

getpwuid_r

@param

unsigned int uid
struct pw* pw
char* buf
unsigned long size
struct pw** res

@return

int

@see third_party/musl/pwd.c

getrandom

Returns cryptographic random data.

This random number seed generator obtains information from:

getrandom() on Linux
RtlGenRandom() on Windows
getentropy() on XNU and OpenBSD
sysctl(KERN_ARND) on FreeBSD and NetBSD

The following flags may be specified:

GRND_RANDOM: Halt the entire system while I tap an entropy pool so small that it's hard to use statistics to test if it's random
GRND_NONBLOCK: Do not wait for i/o events or me to jiggle my mouse, and instead return immediately the moment data isn't available, even if the result needs to be -1 w/ EAGAIN

This function is safe to use with fork() and vfork(). It will also close any file descriptor it ends up needing before it returns.

@param

void* p
unsigned long n
unsigned int f

@return

long

@note this function could block a nontrivial time on old computers

@note this function is indeed intended for cryptography

@note this function takes around 900 cycles

@asyncsignalsafe

@restartable

@vforksafe

@see libc/rand/getrandom.c

getresgid

Gets real, effective, and "saved" group ids.

@param

unsigned int* real: receives real user id, or null to do nothing
unsigned int* effective: receives effective user id, or null to do nothing
unsigned int* saved: receives saved user id, or null to do nothing

@return

int: 0 on success or -1 w/ errno

@see setresuid()

@see libc/calls/getresgid.c

GetResolvConf

Returns singleton with DNS server address.

@return

struct ResolvConf*

@threadsafe

@see libc/dns/getresolvconf.c

GetResourceLimit

@param

int resource

@return

long

@see libc/runtime/getresourcelimit.c

getresuid

Gets real, effective, and "saved" user ids.

@param

unsigned int* real: receives real user id, or null to do nothing
unsigned int* effective: receives effective user id, or null to do nothing
unsigned int* saved: receives saved user id, or null to do nothing

@return

int: 0 on success or -1 w/ errno

@see setresuid()

@see libc/calls/getresuid.c

getrlimit

Gets resource limit for current process.

@param

int resource: can be RLIMIT_{CPU,FSIZE,DATA,STACK,CORE,RSS,etc.}
struct rlimit* rlim: receives result, modified only on success

@return

int: 0 on success or -1 w/ errno

@see libc/sysv/consts.sh

@see libc/calls/getrlimit.c

getrusage

Returns resource usage statistics.

@param

int who: can be RUSAGE_{SELF,CHILDREN,THREAD}
struct rusage* usage

@return

int: 0 on success, or -1 w/ errno

@see libc/calls/getrusage.c

gets

@param

char* s

@return

char*

@see libc/stdio/gets.c

getservbyname

@param

const char* name
const char* proto

@return

struct se0*

@see libc/dns/getservbyname.c

getservbyport

@param

int port
const char* proto

@return

struct se1*

@see libc/dns/getservbyport.c

getservent

@return

struct servent*

@see libc/dns/servent.c

GetSiCodeName

Returns symbolic name for siginfo::si_code value.

@param

int sig
int si_code

@return

const char*

@see libc/log/getsicodename.c

getsid

Creates session and sets the process group id.

@param

int pid

@return

int

@see libc/calls/getsid.c

getsockname

Returns details about network interface kernel granted socket.

@param

int fd
void* out_addr
unsigned int* out_addrsize

@return

int: 0 on success or -1 w/ errno

@see getpeername()

@see libc/sock/getsockname.c

getsockopt

Retrieves socket setting.

@param

int fd
int level: can be SOL_SOCKET, IPPROTO_TCP, etc.
int optname: can be SO_{REUSE{PORT,ADDR},KEEPALIVE,etc.} etc.
void* out_opt_optval
unsigned int* out_optlen

@return

int: 0 on success, or -1 w/ errno

@error ENOPROTOOPT for unknown (level,optname)

@error EINVAL if out_optlen is invalid somehow

@error ENOTSOCK if fd is valid but not a socket

@error EBADF if fd isn't valid

@error EFAULT if optval memory isn't valid

@see libc/sysv/consts.sh for tuning catalogue

@see setsockopt()

@see libc/sock/getsockopt.c

GetSymbolTable

Returns symbol table singleton.

This uses multiple strategies to find the symbol table. The first strategy, depends on whether or not the following is linked:

STATIC_YOINK("__zipos_get");

In that case, the symbol table may be read from /zip/.symtab which is generated by o//tool/build/symtab.com. The second strategy is to look for the concomitant .com.dbg executable, which may very well be the one currently executing, or it could be placed in the same folder as your .com binary, or lastly, it could be explicitly specified via the COMDBG environment variable.

Function tracing is disabled throughout the duration of this call. Backtraces and other core runtime functionality depend on this.

@return

struct SymbolTable*: symbol table, or NULL if not found

@see libc/runtime/getsymboltable.c

GetTempPathA_flunk

Calls GetTempPathA() w/ different API.

@return

@see GetSystemDirectoryA(), GetWindowsDirectoryA()

@see libc/calls/gettemppatha-flunk.S

gettid

Returns current thread id.

On Linux, and Linux only, this is guaranteed to be equal to getpid() if this is the main thread. On NetBSD, gettid() for the main thread is always 1.

This function issues a system call. That stops being the case as soon as __install_tls() is called. That'll happen automatically, when you call clone() and provide the TLS parameter. We assume that when a TLS block exists, then

*(int *)(__get_tls() + 0x38)

will contain the thread id. Therefore when issuing clone() calls, the CLONE_CHILD_SETTID and CLONE_CHILD_CLEARTID flags should use that index as its ctid memory.

gettid (single threaded) l:       126𝑐        41𝑛𝑠
gettid (tls enabled)     l:         2𝑐         1𝑛𝑠

The TLS convention is important for reentrant lock performance.

@return

int: thread id greater than zero or -1 w/ errno

@asyncsignalsafe

@threadsafe

@vforksafe

@see libc/intrin/gettid.c

gettimeofday

Returns system wall time in microseconds, e.g.

int64_t t;
char p[30];
struct tm tm;
struct timeval tv;
gettimeofday(&tv, 0);
t = tv.tv_sec;
gmtime_r(&t, &tm);
FormatHttpDateTime(p, &tm);
printf("%s\n", p);

@param

struct ru_stime* tv: points to timeval that receives result if non-NULL
struct timezone* tz: receives UTC timezone if non-NULL

@return

int

@error EFAULT if tv or tz isn't valid memory

@see clock_gettime() for nanosecond precision

@see strftime() for string formatting

@see libc/calls/gettimeofday.c

__gettimeofday_get

Returns pointer to fastest gettimeofday().

@param

_Bool* opt_out_isfast

@return

struct ad(*)()

@see libc/calls/gettimeofday.c

getttycols

Shorthand for getting ws_col from getttysize().

It is recommended that programs err on the side of showing more information, if this value can't be obtained with certainty.

@param

unsigned short defaultcols

@return

unsigned short: terminal width or defaultcols on error

@see libc/log/getttycols.c

getttysize

Returns dimensions of controlling terminal.

It is recommended that programs err on the side of showing more information, if this value can't be obtained with certainty.

@param

int fd
struct winsize* out: stores determined dimensions, only on success

@return

int

@returns -1 on error or something else on success

@see libc/calls/getttysize.c

getuid

Returns real user id of process.

This never fails. On Windows, which doesn't really have this concept, we return a deterministic value that's likely to work.

@return

int

@asyncsignalsafe

@vforksafe

@see libc/calls/getuid.c

getutf16

Decodes UTF-16 character.

@param

const unsigned short* p
unsigned int* wc

@return

unsigned int: number of bytes (NUL counts as 1) or -1 w/ errno

@note synchronization is performed to skip leading continuations; canonicalization and validation are performed to some extent

@todo delete

@see libc/str/getutf16.ncabi.c

getwc

Reads UTF-8 character from stream.

@param

struct FILE* f

@return

unsigned int: wide character or -1 on EOF or error

@threadsafe

@see libc/stdio/getwc.c

getwc_unlocked

Reads UTF-8 character from stream.

@param

struct FILE* f

@return

unsigned int: wide character or -1 on EOF or error

@see libc/stdio/getwc_unlocked.c

getwchar

Reads UTF-8 character from stream.

@return

unsigned int: wide character or -1 on EOF or error

@threadsafe

@see libc/stdio/getwchar.c

getwchar_unlocked

Reads UTF-8 character from stream.

@return

unsigned int: wide character or -1 on EOF or error

@see libc/stdio/getwchar_unlocked.c

getx86processormodel

Identifies microarchitecture of host processor.

@param

short key: can be kX86ProcessorModelKey for host info

@return

struct X86ProcessorModel*

@see https://en.wikichip.org/wiki/intel/cpuid

@see https://a4lg.com/tech/x86/database/x86-families-and-models.en.html

@see libc/str/getx86processormodel.c

GetZipCdirComment

Returns comment of zip central directory.

@param

const unsigned char* eocd

@return

void*

@see libc/str/getzipcdircomment.c

GetZipCdirCommentSize

Returns comment of zip central directory.

@param

const unsigned char* eocd

@return

unsigned long

@see libc/str/getzipcdircommentsize.c

GetZipCdirOffset

Returns offset of zip central directory.

@param

const unsigned char* eocd

@return

unsigned long

@see libc/str/getzipcdiroffset.c

GetZipCdirRecords

Returns number of records in zip central directory.

@param

const unsigned char* eocd

@return

unsigned long

@see libc/str/getzipcdirrecords.c

GetZipCdirSize

Returns size of zip central directory.

@param

const unsigned char* eocd

@return

unsigned long

@see libc/str/getzipcdirsize.c

GetZipCfileCompressedSize

Returns compressed size in bytes from zip central directory header.

@param

const unsigned char* z

@return

unsigned long

@see libc/str/getzipcfilecompressedsize.c

GetZipCfileMode

Returns st_mode from ZIP central directory record.

@param

const unsigned char* p

@return

int

@see libc/str/getzipcfilemode.c

GetZipCfileOffset

Returns offset of local file header.

@param

const unsigned char* z

@return

unsigned long

@see libc/str/getzipcfileoffset.c

GetZipCfileTimestamps

Extracts modified/access/creation timestamps from zip entry.

@param

const unsigned char* cf: is pointer to central directory header for file
ANONYMOUS-STRUCT* mtim: optionally receives last modified timestamp
ANONYMOUS-STRUCT* atim: optionally receives modified timestamp
ANONYMOUS-STRUCT* ctim: optionally receives creation timestamp
int gmtoff: is seconds adjustment for legacy dos timestamps

@return

void

@see libc/str/getzipcfiletimestamps.c

GetZipCfileUncompressedSize

Returns uncompressed size in bytes from zip central directory header.

@param

const unsigned char* z

@return

unsigned long

@see libc/str/getzipcfileuncompressedsize.c

GetZipLfileCompressedSize

Returns compressed size in bytes from zip local file header.

@param

const unsigned char* z

@return

unsigned long

@see libc/str/getziplfilecompressedsize.c

GetZipLfileUncompressedSize

Returns uncompressed size in bytes from zip local file header.

@param

const unsigned char* z

@return

unsigned long

@see libc/str/getziplfileuncompressedsize.c

glob

Finds pathnames matching pattern.

For example:

glob_t g = {.gl_offs = 2};
glob("*.*", GLOB_DOOFFS, NULL, &g);
glob("../.*", GLOB_DOOFFS | GLOB_APPEND, NULL, &g);
g.gl_pathv[0] = "ls";
g.gl_pathv[1] = "-l";
execvp("ls", &g.gl_pathv[0]);
globfree(g);

@param

const char* pat: can have star wildcard see fnmatch()
int flags
int(*)() errfunc
struct glob_t* g: will receive matching entries and needs globfree()

@return

int: 0 on success or GLOB_NOMATCH, GLOB_NOSPACE on OOM, or GLOB_ABORTED on read error

@see third_party/musl/glob.c

globfree

Frees entries allocated by glob().

@param

struct glob_t* g

@return

void

@see third_party/musl/glob.c

gmtime

@param

const long* timep

@return

struct alttm*

@see libc/time/localtime.c

gmtime_r

@param

const long* timep
struct alttm* tmp

@return

struct alttm*

@see libc/time/localtime.c

GoodSocket

Returns new socket with modern goodness enabled.

@param

int family
int type
int protocol
_Bool isserver
ANONYMOUS-STRUCT* timeout

@return

int

@see libc/sock/goodsocket.c

grantpt

@param

int fd

@return

int

@see libc/calls/grantpt.c

gray

Returns gray code for x.

@param

unsigned int x

@return

unsigned int

@see https://en.wikipedia.org/wiki/Gray_code

@see ungray()

@see libc/bits/gray.c

__grow

Grows array.

@param

void* pp
unsigned long* capacity
unsigned long itemsize
unsigned long extra

@return

_Bool

@deprecated favor realloc

@see libc/runtime/grow.c

gzbuffer

Sets internal buffer size used by this library's functions. The default buffer size is 8192 bytes. This function must be called after gzopen() or gzdopen(), and before any other calls that read or write the file. The buffer memory allocation is always deferred to the first read or write. Three times that size in buffer space is allocated. A larger buffer size of, for example, 64K or 128K bytes will noticeably increase the speed of decompression (reading).

The new buffer size also affects the maximum length for gzprintf().

@return

int: Z_OK on success, or -1 on failure, such as being called too late.

@see third_party/zlib/zlib.h

gzclearerr

Clears the error and end-of-file flags for file. This is analogous to the clearerr() function in stdio. This is useful for continuing to read a gzip file that is being written concurrently.

@return

void

@see third_party/zlib/zlib.h

gzclose

Flushes all pending output if necessary, closes the compressed file and deallocates the (de)compression state. Note that once file is closed, you cannot call gzerror with file, since its structures have been deallocated. gzclose must not be called more than once on the same file, just as free must not be called more than once on the same allocation.

@return

int: Z_STREAM_ERROR if file is not valid, Z_ERRNO on a file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the last read ended in the middle of a gzip stream, or Z_OK on success.

@see third_party/zlib/zlib.h

gzclose_r

Same as gzclose(), but gzclose_r() is only for use when reading, and gzclose_w() is only for use when writing or appending. The advantage to using these instead of gzclose() is that they avoid linking in zlib compression or decompression code that is not used when only reading or only writing respectively. If gzclose() is used, then both compression and decompression code will be included the application when linking to a static zlib library.

@return

int

@see third_party/zlib/zlib.h

gzdirect

Returns true (1) if file is being copied directly while reading, or false (0) if file is a gzip stream being decompressed.

If the input file is empty, gzdirect() will return true, since the input does not contain a gzip stream.

If gzdirect() is used immediately after gzopen() or gzdopen() it will cause buffers to be allocated to allow reading the file to determine if it is a gzip file. Therefore if gzbuffer() is used, it should be called before gzdirect().

When writing, gzdirect() returns true (1) if transparent writing was requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note: gzdirect() is not needed when writing. Transparent writing must be explicitly requested, so the application already knows the answer. When linking statically, using gzdirect() will include all of the zlib code for gzip file reading and decompression, which may not be desired.)

@return

int

@see third_party/zlib/zlib.h

gzdopen

Associates gzFile with the file descriptor.

File descriptors are obtained from calls like open, dup, creat, pipe or fileno (if the file has been previously opened with fopen). The mode parameter is as in gzopen.

The next call of gzclose on the returned gzFile will also close the file descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, mode);. The duplicated descriptor should be saved to avoid a leak, since gzdopen does not close fd if it fails. If you are using fileno() to get the file descriptor from a FILE *, then you will have to use dup() to avoid double-close()ing the file descriptor. Both gzclose() and fclose() will close the associated file descriptor, so they need to have different file descriptors.

@return

struct gzFile_s*: Z_OK if there was insufficient memory to allocate the gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not provided, or '+' was provided), or if fd is -1. The file descriptor is not used until the next gz* read, write, seek, or close operation, so gzdopen will not detect if fd is invalid (unless fd is -1).

@see third_party/zlib/zlib.h

gzeof

Returns true (1) if the end-of-file indicator has been set while reading, false (0) otherwise. Note that the end-of-file indicator is set only if the read tried to go past the end of the input, but came up short. Therefore, just like feof(), gzeof() may return false even if there is no more data to read, in the event that the last read request was for the exact number of bytes remaining in the input file. This will happen if the input file size is an exact multiple of the buffer size.

If gzeof() returns true, then the read functions will return no more data, unless the end-of-file indicator is reset by gzclearerr() and the input file has grown since the previous end of file was detected.

@return

int

@see third_party/zlib/zlib.h

gzerror

Returns the error message for the last error which occurred on the given compressed file. errnum is set to zlib error number. If an error occurred in the file system and not in the compression library, errnum is set to Z_ERRNO and the application may consult errno to get the exact error code.

The application must not modify the returned string. Future calls to this function may invalidate the previously returned string. If file is closed, then the string previously returned by gzerror will no longer be available.

gzerror() should be used to distinguish errors from end-of-file for those functions above that do not distinguish those cases in their return values.

@return

const char*

@see third_party/zlib/zlib.h

gzflush

Flushes all pending output into the compressed file. The parameter flush is as in the deflate() function. The return value is the zlib error number (see function gzerror below). gzflush is only permitted when writing.

If the flush parameter is Z_FINISH, the remaining data is written and the gzip stream is completed in the output. If gzwrite() is called again, a new gzip stream will be started in the output. gzread() is able to read such concatenated gzip streams.

gzflush should be called only when strictly necessary because it will degrade compression if called too often.

@return

int

@see third_party/zlib/zlib.h

gzfread

Read up to nitems items of size size from file to buf, otherwise operating as gzread() does. This duplicates the interface of stdio's fread(), with size_t request and return types. If the library defines size_t, then size_t is identical to size_t. If not, then size_t is an unsigned integer type that can contain a pointer.

gzfread() returns the number of full items read of size size, or zero if the end of the file was reached and a full item could not be read, or if there was an error. gzerror() must be consulted if zero is returned in order to determine if there was an error. If the multiplication of size and nitems overflows, i.e. the product does not fit in a size_t, then nothing is read, zero is returned, and the error state is set to Z_STREAM_ERROR.

In the event that the end of file is reached and only a partial item is available at the end, i.e. the remaining uncompressed data length is not a multiple of size, then the final partial item is nevetheless read into buf and the end-of-file flag is set. The length of the partial item read is not provided, but could be inferred from the result of gztell(). This behavior is the same as the behavior of fread() implementations in common libraries, but it prevents the direct use of gzfread() to read a concurrently written file, reseting and retrying on end-of-file, when size is not 1.

@return

unsigned long

@see third_party/zlib/zlib.h

gzfwrite

Writes nitems items of size size from buf to file, duplicating the interface of stdio's fwrite(), with size_t request and return types. If the library defines size_t, then size_t is identical to size_t. If not, then size_t is an unsigned integer type that can contain a pointer.

gzfwrite() returns the number of full items written of size size, or zero if there was an error. If the multiplication of size and nitems overflows, i.e. the product does not fit in a size_t, then nothing is written, zero is returned, and the error state is set to Z_STREAM_ERROR.

@return

unsigned long

@see third_party/zlib/zlib.h

gzgetc

Reads one byte from the compressed file. gzgetc returns this byte or -1 in case of end of file or error. This is implemented as a macro for speed. As such, it does not do all of the checking the other functions do. I.e. it does not check to see if file is NULL, nor whether the structure file points to has been clobbered or not.

@return

int

@see third_party/zlib/zlib.h

gzgets

Reads bytes from the compressed file until len-1 characters are read, or a newline character is read and transferred to buf, or an end-of-file condition is encountered. If any characters are read or if len == 1, the string is terminated with a null character. If no characters are read due to an end-of-file or len < 1, then the buffer is left untouched.

@return

char*: buf which is a null-terminated string, or it returns NULL for end-of-file or in case of error. If there was an error, the contents at buf are indeterminate.

@see third_party/zlib/zlib.h

gzoffset

Returns current offset in the file being read or written. This offset includes the count of bytes that precede the gzip stream, for example when appending or when using gzdopen() for reading. When reading, the offset does not include as yet unused buffered input. This information can be used for a progress indicator. On error, gzoffset() returns -1.

@return

long

@see third_party/zlib/zlib.h

gzopen

Opens a gzip (.gz) file for reading or writing.

The mode parameter is as in fopen ("rb" or "wb") but can also include a compression level ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for Huffman-only compression as in "wb1h", 'R' for run-length encoding as in "wb1R", or 'F' for fixed code compression as in "wb9F". (See the description of deflateInit2 for more information about the strategy parameter.) 'T' will request transparent writing or appending with no compression and not using the gzip format.

"a" can be used instead of "w" to request that the gzip stream that will be written be appended to the file. "+" will result in an error, since reading and writing to the same gzip file is not supported. The addition of "x" when writing will create the file exclusively, which fails if the file already exists. On systems that support it, the addition of "e" when reading or writing will set the flag to close the file on an execve() call.

These functions, as well as gzip, will read and decode a sequence of gzip streams in a file. The append function of gzopen() can be used to create such a file. (Also see gzflush() for another way to do this.) When appending, gzopen does not test whether the file begins with a gzip stream, nor does it look for the end of the gzip streams to begin appending. gzopen will simply append a gzip stream to the existing file.

gzopen can be used to read a file which is not in gzip format; in this case gzread will directly read from the file without decompression. When reading, this will be detected automatically by looking for the magic two- byte gzip header.

@return

struct gzFile_s*: Z_OK if the file could not be opened, if there was insufficient memory to allocate the gzFile state, or if an invalid mode was specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). errno can be checked to determine if the reason gzopen failed was that the file could not be opened.

@see third_party/zlib/zlib.h

gzprintf

Converts, formats, and writes the arguments to the compressed file under control of the format string, as in fprintf. gzprintf returns the number of uncompressed bytes actually written, or a negative zlib error code in case of error. The number of uncompressed bytes written is limited to 8191, or one less than the buffer size given to gzbuffer(). The caller should assure that this limit is not exceeded. If it is exceeded, then gzprintf() will return an error (0) with nothing written. In this case, there may also be a buffer overflow with unpredictable consequences, which is possible only if zlib was compiled with the insecure functions sprintf() or vsprintf() because the secure snprintf() or vsnprintf() functions were not available. This can be determined using zlibCompileFlags().

@param

...

@return

int

@see third_party/zlib/zlib.h

gzputc

Writes character converted to an unsigned char into compressed file.

@return

int: value that was written, or -1 on error

@see third_party/zlib/zlib.h

gzputs

Writes the given null-terminated string to the compressed file, excluding the terminating null character.

@return

int: Z_OK number of characters written, or -1 in case of error.

@see third_party/zlib/zlib.h

gzread

Reads given number of uncompressed bytes from the compressed file. If the input file is not in gzip format, gzread copies the given number of bytes into the buffer directly from the file.

After reaching the end of a gzip stream in the input, gzread will continue to read, looking for another gzip stream. Any number of gzip streams may be concatenated in the input file, and will all be decompressed by gzread(). If something other than a gzip stream is encountered after a gzip stream, that remaining trailing garbage is ignored (and no error is returned).

gzread can be used to read a gzip file that is being concurrently written. Upon reaching the end of the input, gzread will return with the available data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then gzclearerr can be used to clear the end of file indicator in order to permit gzread to be tried again. Z_OK indicates that a gzip stream was completed on the last gzread. Z_BUF_ERROR indicates that the input file ended in the middle of a gzip stream. Note that gzread does not return -1 in the event of an incomplete gzip stream. This error is deferred until gzclose(), which will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip stream. Alternatively, gzerror can be used before gzclose to detect this case.

@return

int: Z_OK number of uncompressed bytes actually read, less than len for end of file, or -1 for error. If len is too large to fit in an int, then nothing is read, -1 is returned, and the error state is set to Z_STREAM_ERROR.

@see third_party/zlib/zlib.h

gzrewind

Rewinds file.

This function is supported only for reading.

@return

int

@note gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET)

@see third_party/zlib/zlib.h

gzseek

Sets starting position for the next gzread or gzwrite on the given compressed file. The offset represents a number of bytes in the uncompressed data stream. The whence parameter is defined as in lseek(2); the value SEEK_END is not supported.

If the file is opened for reading, this function is emulated but can be extremely slow. If the file is opened for writing, only forward seeks are supported; gzseek then compresses a sequence of zeroes up to the new starting position.

@return

long: resulting offset location as measured in bytes from the beginning of the uncompressed stream, or -1 in case of error, in particular if the file is opened for writing and the new starting position would be before the current position.

@see third_party/zlib/zlib.h

gzsetparams

Dynamically update the compression level or strategy. See the description of deflateInit2 for the meaning of these parameters. Previously provided data is flushed before the parameter change.

@return

int: Z_OK if success, Z_STREAM_ERROR if the file was not opened for writing, Z_ERRNO if there is an error writing the flushed data, or Z_MEM_ERROR if there is a memory allocation error.

@see third_party/zlib/zlib.h

gztell

Returns starting position for the next gzread or gzwrite on the given compressed file. This position represents a number of bytes in the uncompressed data stream, and is zero when starting, even if appending or reading a gzip stream from the middle of a file using gzdopen().

@return

long

@note gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR)

@see third_party/zlib/zlib.h

gzungetc

Pushes one character back onto the stream to be read as the first character on the next read. At least one character of push-back is allowed. gzungetc() returns the character pushed, or -1 on failure. gzungetc() will fail if c is -1, and may fail if a character has been pushed but not read yet. If gzungetc is used immediately after gzopen or gzdopen, at least the output buffer size of pushed characters is allowed. (See gzbuffer above.) The pushed character will be discarded if the stream is repositioned with gzseek() or gzrewind().

@return

int

@see third_party/zlib/zlib.h

gzwrite

Writes given number of uncompressed bytes into the compressed file. gzwrite returns the number of uncompressed bytes written or 0 in case of error.

@return

int

@see third_party/zlib/zlib.h

h_errno

Error number global for gethostbyname*(), gethostbyaddr*(), etc.

@type

int

@see libc/dns/h_errno.c

hamming

Counts number of different bits.

@param

unsigned long x
unsigned long y

@return

unsigned long

@see https://en.wikipedia.org/wiki/Hamming_code

@see libc/bits/hamming.c

HasControlCodes

Returns true if C0 or C1 control codes are present

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
int f: can have kControlWs, kControlC0, kControlC1 to forbid

@return

long: index of first forbidden character or -1

@see VisualizeControlCodes()

@see net/http/hascontrolcodes.c

HeaderHas

Returns true if standard header has substring.

@param

struct HttpMessage* m: is message parsed by ParseHttpMessage
const char* b: is buffer that ParseHttpMessage parsed
int h: is known header, e.g. kHttpAcceptEncoding
const char* s: should not contain comma
unsigned long n: is byte length of s where -1 implies strlen

@return

_Bool: true if substring present

@see net/http/headerhassubstring.c

herror

Prints h_errno description to stderr.

@param

const char* s

@return

void

@see perror()

@see libc/dns/herror.c

hextoint

Converts ASCII hexadecimal character to integer case-insensitively.

@param

int c

@return

int: integer or 0 if c ∉ [0-9A-Fa-f]

@see libc/str/hextoint.c

HighwayHash64

Computes Highway Hash.

highwayhash64 n=0                  121 nanoseconds
highwayhash64 n=8                   16 ns/byte         59,865 kb/s
highwayhash64 n=31                   4 ns/byte            222 mb/s
highwayhash64 n=32                   3 ns/byte            248 mb/s
highwayhash64 n=63                   2 ns/byte            387 mb/s
highwayhash64 n=64                   2 ns/byte            422 mb/s
highwayhash64 n=128                  1 ns/byte            644 mb/s
highwayhash64 n=256                  1 ns/byte            875 mb/s
highwayhash64 n=22851              721 ps/byte          1,354 mb/s

@param

void* data
unsigned long size
const unsigned long* key

@return

unsigned long

@see libc/str/highwayhash64.c

hilbert

Generates Hilbert space-filling curve.

@param

long n
long y
long x

@return

long

@see https://en.wikipedia.org/wiki/Hilbert_curve

@see unhilbert()

@see libc/bits/hilbert.c

__hook

Rewrites code in memory to hook function calls.

We do this by searching each function for the nop instruction inserted by GCC when we use the -pg -mnop-mcount flags. There's no risk of corrupting data since the linker scripts won't mix code and data.

Modules built with -O3 and without the profiling flags might have these same nop instructions, but that shouldn't be problematic since they're only there for the puposes of aligning jumps, and therefore aren't actually executed. However codebases that use huge function alignments with wide-nop slides could pose minor issues. Further note that Cosmopolitan sources are almost never intentionally written to use code alignment, since we've only seen a few cases where it helps.

@param

void* ifunc
struct SymbolTable* symbols

@return

int

@see ape/ape.lds

@see libc/runtime/hook.greg.c

__hostos

Teleports code fragment inside _init().

@type

const int

@see libc/bits/initializer.internal.h

hstrerror

Turns h_errno value into string.

@param

int err

@return

const char*

@see libc/dns/hstrerror.c

hypot

Returns euclidean distance.

@param

double a
double b

@return

double

@see libc/tinymath/hypot.c

hypotf

Returns euclidean distance.

@param

float a
float b

@return

float

@see libc/tinymath/hypotf.c

hypotl

Returns euclidean distance.

@param

long double a
long double b

@return

long double

@see libc/tinymath/hypotl.c

i128abs

@param

__int128 x

@return

__int128

@see libc/fmt/i128abs.c

iconv

@param

void* cd
char** in
unsigned long* inb
char** out
unsigned long* outb

@return

unsigned long

@see libc/stdio/iconv.c

iconv_close

@param

void* cd

@return

int

@see libc/stdio/iconv.c

iconv_open

@param

const char* to
const char* from

@return

void*

@see libc/stdio/iconv.c

identity

The identity() function.

@return

: first argument

@see libc/nexgen32e/identity.S

ilogb

Returns log₂𝑥 exponent part of double.

@param

𝑥: is double passed in %xmm0

@return

: result in %eax

@note needs sse3

@see libc/tinymath/ilogb.S

ilogbf

Returns log₂x exponent part of float.

@param

𝑥: is float passed in %xmm0

@return

: result in %eax

@note needs sse3

@see libc/tinymath/ilogbf.S

ilogbl

Returns log₂x exponent part of long double.

@param

𝑥: is long double passed on stack

@return

: result in %eax

@note needs sse3

@see libc/tinymath/ilogbl.S

imapxlatab

Identity maps 256-byte translation table.

@param

char: (*rdi)[256]

@return

@speed 90mBps

@mode long

@see libc/nexgen32e/imapxlatab.S

imaxabs

@param

long x

@return

long

@see libc/fmt/imaxabs.c

IndentLines

Inserts spaces before lines.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length
unsigned long j: is number of spaces to use

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/indentlines.c

index

Returns pointer to first instance of character, the BSD way.

@param

const char* s: is a NUL-terminated string
int c

@return

char*: is pointer to first instance of c or NULL if not found, noting that c being NUL will return a pointer to terminator

@see libc/str/index.c

IndexDoubleNulString

@param

const char* s
unsigned int i

@return

const char*

@see libc/str/indexdoublenulstring.c

inet_addr

Converts dotted IPv4 address string to network order binary.

@param

const char* s

@return

unsigned int

@see inet_aton()

@see libc/sock/inet_addr.c

inet_aton

Converts dotted IPv4 address string to network order binary.

@param

const char* s0
ANONYMOUS-STRUCT* dest

@return

int

@see libc/sock/inet_aton.c

inet_ntoa

Converts IPv4 network address to array.

@param

struct in in

@return

char*

@see libc/sock/inet_ntoa.c

inet_ntop

Formats internet address to string.

@param

int af: can be AF_INET or AF_INET6
void* src: is the binary-encoded address, e.g. &addr->sin_addr
char* dst: is the output string buffer
unsigned int size: needs to be 16+ for IPv4 and 72+ for IPv6

@return

const char*: dst on success or NULL w/ errno

@see libc/sock/inet_ntop.c

inet_pton

Converts internet address string to binary.

@param

int af: can be AF_INET
const char* src: is the ASCII-encoded address
void* dst: is where the binary-encoded net-order address goes

@return

int: 1 on success, 0 on src malformed, or -1 w/ errno

@see libc/sock/inet_pton.c

inflate

inflate decompresses as much data as possible, and stops when the input buffer becomes empty or the output buffer becomes full. It may introduce some output latency (reading input without producing any output) except when forced to flush.

The detailed semantics are as follows. inflate performs one or both of the following actions:

Decompress more input starting at next_in and update next_in and avail_in accordingly. If not all input can be processed (because there is not enough room in the output buffer), then next_in and avail_in are updated accordingly, and processing will resume at this point for the next call of inflate().
Generate more output starting at next_out and update next_out and avail_out accordingly. inflate() provides as much output as possible, until there is no more input data or no more space in the output buffer (see below about the flush parameter).

Before the call of inflate(), the application should ensure that at least one of the actions is possible, by providing more input and/or consuming more output, and updating the next_* and avail_* values accordingly. If the caller of inflate() does not provide both available input and available output space, it is possible that there will be no progress made. The application can consume the uncompressed output when it wants, for example when the output buffer is full (avail_out == 0), or after each call of inflate(). If inflate returns Z_OK and with zero avail_out, it must be called again after making room in the output buffer because there might be more output pending.

The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much output as possible to the output buffer. Z_BLOCK requests that inflate() stop if and when it gets to the next deflate block boundary. When decoding the zlib or gzip format, this will cause inflate() to return immediately after the header and before the first block. When doing a raw inflate, inflate() will go ahead and process the first block, and will return when it gets to the end of that block, or when it runs out of data.

The Z_BLOCK option assists in appending to or combining deflate streams. To assist in this, on return inflate() always sets strm->data_type to the number of unused bits in the last byte taken from strm->next_in, plus 64 if inflate() is currently decoding the last block in the deflate stream, plus 128 if inflate() returned immediately after decoding an end-of-block code or decoding the complete header up to just before the first byte of the deflate stream. The end-of-block will not be indicated until all of the uncompressed data from that block has been written to strm->next_out. The number of unused bits may in general be greater than seven, except when bit 7 of data_type is set, in which case the number of unused bits will be less than eight. data_type is set as noted here every time inflate() returns for all flush options, and so can be used to determine the amount of currently consumed input in bits.

The Z_TREES option behaves as Z_BLOCK does, but it also returns when the end of each deflate block header is reached, before any actual data in that block is decoded. This allows the caller to determine the length of the deflate block header for later use in random access within a deflate block. 256 is added to the value of strm->data_type when inflate() returns immediately after reaching the end of the deflate block header.

inflate() should normally be called until it returns Z_STREAM_END or an error. However if all decompression is to be performed in a single step (a single call of inflate), the parameter flush should be set to Z_FINISH. In this case all pending input is processed and all pending output is flushed; avail_out must be large enough to hold all of the uncompressed data for the operation to complete. (The size of the uncompressed data may have been saved by the compressor for this purpose.) The use of Z_FINISH is not required to perform an inflation in one step. However it may be used to inform inflate that a faster approach can be used for the single inflate() call. Z_FINISH also informs inflate to not maintain a sliding window if the stream completes, which reduces inflate's memory footprint. If the stream does not complete, either because not all of the stream is provided or not enough output space is provided, then a sliding window will be allocated and inflate() can be called again to continue the operation as if Z_NO_FLUSH had been used.

In this implementation, inflate() always flushes as much output as possible to the output buffer, and always uses the faster approach on the first call. So the effects of the flush parameter in this implementation are on the return value of inflate() as noted below, when inflate() returns early when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of memory for a sliding window when Z_FINISH is used.

If a preset dictionary is needed after this call (see inflateSetDictionary below), inflate sets strm->adler to the Adler-32 checksum of the dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise it sets strm->adler to the Adler-32 checksum of all output produced so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described below. At the end of the stream, inflate() checks that its computed Adler-32 checksum is equal to that saved by the compressor and returns Z_STREAM_END only if the checksum is correct.

inflate() can decompress and check either zlib-wrapped or gzip-wrapped deflate data. The header type is detected automatically, if requested when initializing with inflateInit2(). Any information contained in the gzip header is not retained unless inflateGetHeader() is used. When processing gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output produced so far. The CRC-32 is checked against the gzip trailer, as is the uncompressed length, modulo 2^32.

@return

int: Z_OK if some progress has been made (more input processed or more output produced), Z_STREAM_END if the end of the compressed data has been reached and all uncompressed output has been produced, Z_NEED_DICT if a preset dictionary is needed at this point, Z_DATA_ERROR if the input data was corrupted (input stream not conforming to the zlib format or incorrect check value, in which case strm->msg points to a string with a more specific error), Z_STREAM_ERROR if the stream structure was inconsistent (for example next_in or next_out was Z_NULL, or the state was inadvertently written over by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if no progress was possible or if there was not enough room in the output buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and inflate() can be called again with more input and more output space to continue decompressing. If Z_DATA_ERROR is returned, the application may then call inflateSync() to look for a good compression block if a partial recovery of the data is to be attempted.

@see third_party/zlib/zlib.h

__inflate

Decompresses raw deflate data.

This uses puff by default since it has a 2kb footprint. If zlib proper is linked, then we favor that instead, since it's faster.

@param

void* out
unsigned long outsize: needs to be known ahead of time by some other means
void* in
unsigned long insize

@return

int: 0 on success or nonzero on failure

@see libc/runtime/inflate.c

inflate_fast

Decodes literal, length, and distance codes and write out the resulting literal and match bytes until either not enough input or output is available, an end-of-block is encountered, or a data error is encountered. When large enough input and output buffers are supplied to inflate(), for example, a 16K input buffer and a 64K output buffer, more than 95% of the inflate() execution time is spent in this routine.

Entry assumptions:

 state->mode == LEN
 strm->avail_in >= INFLATE_FAST_MIN_INPUT (6 bytes)
 strm->avail_out >= INFLATE_FAST_MIN_OUTPUT (258 bytes)
 start >= strm->avail_out
 state->bits < 8

On return, state->mode is one of:

 LEN -- ran out of enough output space or enough available input
 TYPE -- reached end of block code, inflate() to interpret next block
 BAD -- error in block data

Some notes:

INFLATE_FAST_MIN_INPUT: 6 bytes

- The maximum input bits used by a length/distance pair is 15 bits for the length code, 5 bits for the length extra, 15 bits for the distance code, and 13 bits for the distance extra. This totals 48 bits, or six bytes. Therefore if strm->avail_in >= 6, then there is enough input to avoid checking for available input while decoding.

INFLATE_FAST_MIN_OUTPUT: 258 bytes

- The maximum bytes that a single length/distance pair can output is 258 bytes, which is the maximum length that can be coded. inflate_fast() requires strm->avail_out >= 258 for each loop to avoid checking for available output space while decoding.

@param

struct z_stream* strm
unsigned int start: inflate() starting value for strm->avail_out

@return

void

@see third_party/zlib/inffast.c

inflate_table

Builds set of tables to decode the provided canonical Huffman code. The code lengths are lens[0..codes-1]. The result starts at *table, whose indices are 0..2^bits-1. work is a writable array of at least lens shorts, which is used as a work area. type is the type of code to be generated, CODES, LENS, or DISTS. On return, zero is success, -1 is an invalid code, and +1 means that ENOUGH isn't enough. table on return points to the next available entry's address. bits is the requested root table index bits, and on return it is the actual root table index bits. It will differ if the request is greater than the longest code or if it is less than the shortest code.

@param

enum type type
unsigned short* lens
unsigned int codes
struct here** table
unsigned int* bits
unsigned short* work

@return

int

@see third_party/zlib/inftrees.c

inflateBack

inflateBack() does a raw inflate with a single call using a call-back interface for input and output. This is potentially more efficient than inflate() for file i/o applications, in that it avoids copying between the output and the sliding window by simply making the window itself the output buffer. inflate() can be faster on modern CPUs when used with large buffers. inflateBack() trusts the application to not change the output buffer passed by the output function, at least until inflateBack() returns.

inflateBackInit() must be called first to allocate the internal state and to initialize the state with the user-provided window buffer. inflateBack() may then be used multiple times to inflate a complete, raw deflate stream with each call. inflateBackEnd() is then called to free the allocated state.

A raw deflate stream is one with no zlib or gzip header or trailer. This routine would normally be used in a utility that reads zip or gzip files and writes out uncompressed files. The utility would decode the header and process the trailer on its own, hence this routine expects only the raw deflate stream to decompress. This is different from the default behavior of inflate(), which expects a zlib header and trailer around the deflate stream.

inflateBack() uses two subroutines supplied by the caller that are then called by inflateBack() for input and output. inflateBack() calls those routines until it reads a complete deflate stream and writes out all of the uncompressed data, or until it encounters an error. The function's parameters and return types are defined above in the in_func and out_func typedefs. inflateBack() will call in(in_desc, &buf) which should return the number of bytes of provided input, and a pointer to that input in buf. If there is no input available, in() must return zero -- buf is ignored in that case -- and inflateBack() will return a buffer error. inflateBack() will call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. out() should return zero on success, or non-zero on failure. If out() returns non-zero, inflateBack() will return with an error. Neither in() nor out() are permitted to change the contents of the window provided to inflateBackInit(), which is also the buffer that out() uses to write from. The length written by out() will be at most the window size. Any non-zero amount of input may be provided by in().

For convenience, inflateBack() can be provided input on the first call by setting strm->next_in and strm->avail_in. If that input is exhausted, then in() will be called. Therefore strm->next_in must be initialized before calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in must also be initialized, and then if strm->avail_in is not zero, input will initially be taken from strm->next_in[0 .. strm->avail_in - 1].

The in_desc and out_desc parameters of inflateBack() is passed as the first parameter of in() and out() respectively when they are called. These descriptors can be optionally used to pass any information that the caller- supplied in() and out() functions need to do their job.

On return, inflateBack() will set strm->next_in and strm->avail_in to pass back any unused input that was provided by the last in() call. The return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR if in() or out() returned an error, Z_DATA_ERROR if there was a format error in the deflate stream (in which case strm->msg is set to indicate the nature of the error), or Z_STREAM_ERROR if the stream was not properly initialized. In the case of Z_BUF_ERROR, an input or output error can be distinguished using strm->next_in which will be Z_NULL only if in() returned an error. If strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning non-zero. (in() will always be called before out(), so strm->next_in is assured to be defined if out() returns non-zero.) Note that inflateBack() cannot return Z_OK.

@return

int

@see third_party/zlib/zlib.h

inflateBackEnd

All memory allocated by inflateBackInit() is freed.

@return

int: Z_OK on success, or Z_STREAM_ERROR if the stream state was inconsistent.

@see third_party/zlib/zlib.h

inflateBackInit

Initialize internal stream state for decompression using inflateBack() calls. The fields zalloc, zfree and opaque in strm must be initialized before the call. If zalloc and zfree are Z_NULL, then the default library- derived memory allocation routines are used. windowBits is the base two logarithm of the window size, in the range 8..15. window is a caller supplied buffer of that size. Except for special applications where it is assured that deflate was used with small window sizes, windowBits must be 15 and a 32K byte window must be supplied to be able to decompress general deflate streams.

See inflateBack() for the usage of these routines.

@return

int: Z_OK on success, Z_STREAM_ERROR if any of the parameters are invalid, or Z_MEM_ERROR if the internal state could not be allocated.

@see third_party/zlib/zlib.h

inflateCopy

Sets the destination stream as a complete copy of the source stream.

This function can be useful when randomly accessing a large stream. The first pass through the stream can periodically record the inflate state, allowing restarting inflate at those points when randomly accessing the stream.

@return

int: Z_OK if success, Z_MEM_ERROR if there was not enough memory, Z_STREAM_ERROR if the source stream state was inconsistent (such as zalloc being Z_NULL). msg is left unchanged in both source and destination.

@see third_party/zlib/zlib.h

inflateEnd

All dynamically allocated data structures for this stream are freed. This function discards any unprocessed input and does not flush any pending output.

@return

int: Z_OK or Z_STREAM_ERROR if stream state inconsistent

@see third_party/zlib/zlib.h

inflateGetDictionary

Returns the sliding dictionary being maintained by inflate. dictLength is set to the number of bytes in the dictionary, and that many bytes are copied to dictionary. dictionary must have enough space, where 32768 bytes is always enough. If inflateGetDictionary() is called with dictionary equal to Z_NULL, then only the dictionary length is returned, and nothing is copied. Similary, if dictLength is Z_NULL, then it is not set.

@return

int: Z_OK on success, or Z_STREAM_ERROR if the stream state is inconsistent.

@see third_party/zlib/zlib.h

inflateGetHeader

inflateGetHeader() requests that gzip header information be stored in the provided gz_header structure. inflateGetHeader() may be called after inflateInit2() or inflateReset(), and before the first call of inflate(). As inflate() processes the gzip stream, head->done is zero until the header is completed, at which time head->done is set to one. If a zlib stream is being decoded, then head->done is set to -1 to indicate that there will be no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be used to force inflate() to return immediately after header processing is complete and before any actual data is decompressed.

The text, time, xflags, and os fields are filled in with the gzip header contents. hcrc is set to true if there is a header CRC. (The header CRC was valid if done is set to one.) If extra is not Z_NULL, then extra_max contains the maximum number of bytes to write to extra. Once done is true, extra_len contains the actual extra field length, and extra contains the extra field, or that field truncated if extra_max is less than extra_len. If name is not Z_NULL, then up to name_max characters are written there, terminated with a zero unless the length is greater than name_max. If comment is not Z_NULL, then up to comm_max characters are written there, terminated with a zero unless the length is greater than comm_max. When any of extra, name, or comment are not Z_NULL and the respective field is not present in the header, then that field is set to Z_NULL to signal its absence. This allows the use of deflateSetHeader() with the returned structure to duplicate the header. However if those fields are set to allocated memory, then the application will need to save those pointers elsewhere so that they can be eventually freed.

If inflateGetHeader is not used, then the header information is simply discarded. The header is always checked for validity, including the header CRC if present. inflateReset() will reset the process to discard the header information. The application would need to call inflateGetHeader() again to retrieve the header from the next gzip stream.

@return

int: Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent.

@see third_party/zlib/zlib.h

inflateInit

Initializes the internal stream state for decompression. The fields next_in, avail_in, zalloc, zfree and opaque must be initialized before by the caller. In the current version of inflate, the provided input is not read or consumed. The allocation of a sliding window will be deferred to the first call of inflate (if the decompression does not complete on the first call). If zalloc and zfree are set to Z_NULL, inflateInit updates them to use default allocation functions.

@return

int: Z_OK if success, Z_MEM_ERROR if there was not enough memory, or Z_STREAM_ERROR if the parameters are invalid, such as a null pointer to the structure. msg is set to null if there is no error message. inflateInit does not perform any decompression. Actual decompression will be done by inflate(). So next_in, and avail_in, next_out, and avail_out are unused and unchanged. The current implementation of inflateInit() does not process any header information -- that is deferred until inflate() is called.

@see third_party/zlib/zlib.h

inflateInit2

This is another version of inflateInit with an extra parameter. The fields next_in, avail_in, zalloc, zfree and opaque must be initialized before by the caller.

The windowBits parameter is the base two logarithm of the maximum window size (the size of the history buffer). It should be in the range 8..15 for this version of the library. The default value is 15 if inflateInit is used instead. windowBits must be greater than or equal to the windowBits value provided to deflateInit2() while compressing, or it must be equal to 15 if deflateInit2() was not used. If a compressed stream with a larger window size is given as input, inflate() will return with the error code Z_DATA_ERROR instead of trying to allocate a larger window.

windowBits can also be zero to request that inflate use the window size in the zlib header of the compressed stream.

windowBits can also be -8..-15 for raw inflate. In this case, -windowBits determines the window size. inflate() will then process raw deflate data, not looking for a zlib or gzip header, not generating a check value, and not looking for any check values for comparison at the end of the stream. This is for use with other formats that use the deflate compressed data format such as zip. Those formats provide their own check values. If a custom format is developed using the raw deflate format for compressed data, it is recommended that a check value such as an Adler-32 or a CRC-32 be applied to the uncompressed data as is done in the zlib, gzip, and zip formats. For most applications, the zlib format should be used as is. Note that comments above on the use in deflateInit2() applies to the magnitude of windowBits.

windowBits can also be greater than 15 for optional gzip decoding. Add 32 to windowBits to enable zlib and gzip decoding with automatic header detection, or add 16 to decode only the gzip format (the zlib format will return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see below), inflate() will not automatically decode concatenated gzip streams. inflate() will return Z_STREAM_END at the end of the gzip stream. The state would need to be reset to continue decoding a subsequent gzip stream.

@return

int: Z_OK if success, Z_MEM_ERROR if there was not enough memory, or Z_STREAM_ERROR if the parameters are invalid, such as a null pointer to the structure. msg is set to null if there is no error message. inflateInit2 does not perform any decompression apart from possibly reading the zlib header if present: actual decompression will be done by inflate(). (So next_in and avail_in may be modified, but next_out and avail_out are unused and unchanged.) The current implementation of inflateInit2() does not process any header information -- that is deferred until inflate() is called.

@see third_party/zlib/zlib.h

inflateMark

Returns two values, one in the lower 16 bits of the return value, and the other in the remaining upper bits, obtained by shifting the return value down 16 bits. If the upper value is -1 and the lower value is zero, then inflate() is currently decoding information outside of a block. If the upper value is -1 and the lower value is non-zero, then inflate is in the middle of a stored block, with the lower value equaling the number of bytes from the input remaining to copy. If the upper value is not -1, then it is the number of bits back from the current bit position in the input of the code (literal or length/distance pair) currently being processed. In that case the lower value is the number of bytes already emitted for that code.

A code is being processed if inflate is waiting for more input to complete decoding of the code, or if it has completed decoding but is waiting for more output space to write the literal or match data.

inflateMark() is used to mark locations in the input data for random access, which may be at bit positions, and to note those cases where the output of a code may span boundaries of random access blocks. The current location in the input stream can be determined from avail_in and data_type as noted in the description for the Z_BLOCK flush parameter for inflate.

@return

long: the value noted above, or -65536 if the provided source stream state was inconsistent.

@see third_party/zlib/zlib.h

inflatePrime

This function inserts bits in the inflate input stream. The intent is that this function is used to start inflating at a bit position in the middle of a byte. The provided bits will be used before any bytes are used from next_in. This function should only be used with raw inflate, and should be used before the first inflate() call after inflateInit2() or inflateReset(). bits must be less than or equal to 16, and that many of the least significant bits of value will be inserted in the input.

If bits is negative, then the input stream bit buffer is emptied. Then inflatePrime() can be called again to put bits in the buffer. This is used to clear out bits leftover after feeding inflate a block description prior to feeding inflate codes.

@return

int: Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent.

@see third_party/zlib/zlib.h

inflateReset

This function is equivalent to inflateEnd followed by inflateInit, but does not free and reallocate the internal decompression state. The stream will keep attributes that may have been set by inflateInit2.

@return

int: Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent (such as zalloc or state being Z_NULL).

@see third_party/zlib/zlib.h

inflateReset2

This function is the same as inflateReset, but it also permits changing the wrap and window size requests. The windowBits parameter is interpreted the same as it is for inflateInit2. If the window size is changed, then the memory allocated for the window is freed, and the window will be reallocated by inflate() if needed.

@return

int: Z_OK if success, or Z_STREAM_ERROR if the source stream state was inconsistent (such as zalloc or state being Z_NULL), or if the windowBits parameter is invalid.

@see third_party/zlib/zlib.h

inflateSetDictionary

Initializes the decompression dictionary from the given uncompressed byte sequence. This function must be called immediately after a call of inflate, if that call returned Z_NEED_DICT. The dictionary chosen by the compressor can be determined from the Adler-32 value returned by that call of inflate. The compressor and decompressor must use exactly the same dictionary (see deflateSetDictionary). For raw inflate, this function can be called at any time to set the dictionary. If the provided dictionary is smaller than the window and there is already data in the window, then the provided dictionary will amend what's there. The application must insure that the dictionary that was used for compression is provided.

@return

int: Z_OK if success, Z_STREAM_ERROR if a parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the expected one (incorrect Adler-32 value). inflateSetDictionary does not perform any decompression: this will be done by subsequent calls of inflate().

@see third_party/zlib/zlib.h

inflateSync

Skips invalid compressed data until a possible full flush point (see above for the description of deflate with Z_FULL_FLUSH) can be found, or until all available input is skipped. No output is provided.

inflateSync searches for a 00 00 FF FF pattern in the compressed data. All full flush points have this pattern, but not all occurrences of this pattern are full flush points.

@return

int: Z_OK if a possible full flush point has been found, Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point has been found, or Z_STREAM_ERROR if the stream structure was inconsistent. In the success case, the application may save the current current value of total_in which indicates where valid compressed data was found. In the error case, the application may repeatedly call inflateSync, providing more input each time, until success or end of the input data.

@see third_party/zlib/zlib.h

_init

Decentralized function for process initialization.

Modules may inject cheap data structure initialization code into this function using the .init.start and .init.end macros. That code can use the LODS and STOS instructions to initialize memory that's restricted to read-only after initialization by PIRO.

This is fast, since the linker is able to roll-up initialization for large codebases comprised of many modules, into a perfectly linear order. It also enables a common pattern we use, which we call “Referencing Is Initialization” (RII).

C/C++ code should favor using ordinary constructors, since under normal circumstances the compiler will clobber RDI and RSI which are granted special meanings within this function.

@param

r12: is argc (still callee saved)
r13: is argv (still callee saved)
r14: is envp (still callee saved)
r15: is envp (still callee saved)

@return

@note rdi is __init_bss_start (callee monotonic lockstep)

@note rsi is __init_rodata_start (callee monotonic lockstep)

@see .init.start & .init.end (libc/macros.internal.inc)

@see ape/ape.lds

@see libc/runtime/init.S

__init_bss_start

Decentralized section for unpacked data structures.

Data in this section becomes read-only after initialization.

@return

@see .piro.bss.init (libc/macros.internal.inc)

@see libc/runtime/piro.c

@see ape/ape.lds

@see libc/runtime/init.S

__init_rodata_start

Decentralized section for packed data structures & initializers.

@return

@see .initro (libc/macros.internal.inc)

@see ape/ape.lds

@see libc/runtime/init.S

InitHttpMessage

Initializes HTTP message parser.

@param

struct HttpMessage* r
int type

@return

void

@see net/http/parsehttpmessage.c

InitializeFileDescriptors

@return

void

@see libc/intrin/g_fds.c

initstate

@param

unsigned int seed
char* state
unsigned long size

@return

char*

@see libc/rand/random.c

insertionsort

Sorts array of signed 32-bit integers.

@param

int* a
unsigned long n

@return

void

@see djbsort()

@see libc/str/insertionsort.greg.c

int128toarray_radix10

Converts signed 128-bit integer to string.

@param

__int128 i
char* a: needs at least 41 bytes

@return

unsigned long: bytes written w/o nul

@see libc/fmt/itoa128radix10.greg.c

int64toarray

@param

long i
char* a
int r

@return

unsigned long

@see libc/fmt/itoa64.c

interruptiblecall

Calls function that may be cancelled by a signal.

@param

struct InterruptibleCall* icall
long(*)() callback
long p1
long p2
long p3
long p4

@return

long: the value returned by callback or -1 on interrupt; they may be differentiated using the state→returnval filed, which is only modified by this function when callbacks succeed

@see libc/runtime/interruptiblecall.c

ioctl

Controls settings on device.

@param

int fd
unsigned long request
...

@return

int

@restartable

@vforksafe

@see libc/calls/ioctl.c

ioctl_default

@param

int fd
unsigned long request
...

@return

int

@see libc/calls/ioctl_default.c

ioctl_fioclex

Sets "close on exec" on file descriptor the fast way.

@param

int fd
int req

@return

int

@see ioctl(fd, FIOCLEX, 0) dispatches here

@see libc/calls/ioctl_fioclex.c

ioctl_siocgifaddr

@param

int fd
...

@return

int

@see libc/calls/ioctl_siocgifconf.c

ioctl_siocgifaddr_nt

Returns unicast addresses.

@param

int fd
struct ifreq* ifr

@return

int

@see libc/calls/ioctl_siocgifconf-nt.c

ioctl_siocgifbrdaddr

@param

int fd
...

@return

int

@see libc/calls/ioctl_siocgifconf.c

ioctl_siocgifbrdaddr_nt

Returns broadcast address.

@param

int fd
struct ifreq* ifr

@return

int

@see libc/calls/ioctl_siocgifconf-nt.c

ioctl_siocgifconf

Returns information about network interfaces.

@param

int fd
...

@return

int

@see ioctl(fd, SIOCGIFCONF, tio) dispatches here

@see libc/calls/ioctl_siocgifconf.c

ioctl_siocgifconf_nt

@param

int fd
struct ifconf* ifc

@return

int

@see libc/calls/ioctl_siocgifconf-nt.c

ioctl_siocgifdstaddr

@param

int fd
...

@return

int

@see libc/calls/ioctl_siocgifconf.c

ioctl_siocgifflags

@param

int fd
...

@return

int

@see libc/calls/ioctl_siocgifconf.c

ioctl_siocgifflags_nt

@param

int fd
struct ifreq* ifr

@return

int

@see libc/calls/ioctl_siocgifconf-nt.c

ioctl_siocgifnetmask

@param

int fd
...

@return

int

@see libc/calls/ioctl_siocgifconf.c

ioctl_siocgifnetmask_nt

@param

int fd
struct ifreq* ifr

@return

int

@see libc/calls/ioctl_siocgifconf-nt.c

ioctl_tcgets

Returns information about terminal.

@param

int fd
...

@return

int

@see tcgetattr(fd, tio) dispatches here

@see ioctl(fd, TCGETS, tio) dispatches here

@see ioctl(fd, TIOCGETA, tio) dispatches here

@see libc/calls/ioctl_tcgets.c

ioctl_tcgets_nt

@param

int ignored
struct termios* tio

@return

int

@see libc/calls/ioctl_tcgets-nt.c

ioctl_tcsets

Changes terminal behavior.

@param

int fd
unsigned long request
...

@return

int

@see tcsetattr(fd, TCSA{NOW,DRAIN,FLUSH}, tio) dispatches here

@see ioctl(fd, TCSETS{,W,F}, tio) dispatches here

@see ioctl(fd, TIOCGETA{,W,F}, tio) dispatches here

@see libc/calls/ioctl_tcsets.c

ioctl_tcsets_nt

@param

int ignored
unsigned long request
struct linux* tio

@return

int

@see libc/calls/ioctl_tcsets-nt.c

ioctl_tiocgwinsz

Returns width and height of terminal.

@param

int fd
...

@return

int

@see ioctl(fd, TIOCGWINSZ, ws) dispatches here

@see libc/calls/ioctl_tiocgwinsz.c

ioctl_tiocgwinsz_nt

@param

struct Fd* fd
struct winsize* ws

@return

int

@see libc/calls/ioctl_tiocgwinsz-nt.c

ioctl_tiocswinsz

Sets width and height of terminal.

@param

int fd
...

@return

int

@see ioctl(fd, TIOCSWINSZ, ws) dispatches here

@see libc/calls/ioctl_tiocswinsz.c

ioctl_tiocswinsz_nt

@param

int fd
struct winsize* ws

@return

int

@see libc/calls/ioctl_tiocswinsz-nt.c

__iovec2nt

Converts I/O vector from System Five to WIN32 ABI.

@param

struct ProviderSpecific* iovnt
struct iovec* iov
unsigned long iovlen

@return

unsigned long: effective iovlen

@see IOV_MAX

@see libc/sock/iovec2nt.c

_isabspath

Returns true if pathname is considered absolute.

/home/jart/foo.txt is absolute
C:/Users/jart/foo.txt is absolute on Windows
C:\Users\jart\foo.txt is absolute on Windows
\??\C:\Users\jart\foo.txt is absolute on Windows
\\.\C:\Users\jart\foo.txt is absolute on Windows
/Users/jart/foo.txt is effectively absolute on Windows
\Users\jart\foo.txt is effectively absolute on Windows

@param

const char* path

@return

_Bool

@see libc/str/isabspath.c

IsAcceptableHost

Returns true if host seems legit.

This function may be called after ParseUrl() or ParseHost() has already handled things like percent encoding. There's currently no support for IPv6 and IPv7.

Here's examples of permitted inputs:

""
1.2.3.4
1.2.3.4.arpa
localservice
hello.example
_hello.example
-hello.example
hi-there.example

Here's some examples of forbidden inputs:

::1
1.2.3
1.2.3.4.5
.hi.example
hi..example

@param

const char* s
unsigned long n: if -1 implies strlen

@return

_Bool

@see net/http/isacceptablehost.c

IsAcceptablePath

Returns true if path seems legit.

The substring "//" is disallowed.
We won't serve hidden files (segment starts with '.'). The only exception is /.well-known/.
We won't serve paths with segments equal to "." or "..".

It is assumed that the URI parser already took care of percent escape decoding as well as ISO-8859-1 decoding. The input needs to be a UTF-8 string. This function takes overlong encodings into consideration, so you don't need to call Underlong() beforehand.

@param

const char* data
unsigned long size: if -1 implies strlen

@return

_Bool

@see IsReasonablePath()

@see net/http/isacceptablepath.c

IsAcceptablePort

Returns true if port seems legit.

Here's examples of permitted inputs:

""
0
65535

Here's some examples of forbidden inputs:

-1
65536
https

@param

const char* s
unsigned long n: if -1 implies strlen

@return

_Bool

@see net/http/isacceptableport.c

IsAfrinicIp

Returns true if IPv4 address is managed by AFRINIC.

@param

unsigned int x

@return

_Bool

@see net/http/isafrinicip.c

isalnum

Returns nonzero if c is lower, alpha, or digit.

@param

int c

@return

int

@see libc/str/isalnum.c

isalpha

Returns nonzero if c is upper or lower.

@param

int c

@return

int

@see libc/str/isalpha.c

IsAnonymousIp

Returns true if IPv4 address is anonymous proxy provider.

@param

unsigned int x

@return

_Bool

@see net/http/isanonymousip.c

IsApnicIp

Returns true if IPv4 address is managed by APNIC.

@param

unsigned int x

@return

_Bool

@see net/http/isapnicip.c

IsArinIp

Returns true if IPv4 address is managed by ARIN.

@param

unsigned int x

@return

_Bool

@see net/http/isarinip.c

isascii

Returns nonzero if c is ascii.

@param

int c

@return

int

@see libc/str/isascii.c

IsAtLeastWindows10

Returns true if we're running at least Windows 10.

This function may only be called if IsWindows() is true.

@return

_Bool

@see libc/intrin/isatleastwindows10.greg.c

isatty

Tells if file descriptor is a terminal.

@param

int fd: is file descriptor

@return

int: 1 if is terminal, otherwise 0 w/ errno

@raise EBADF if fd isn't a valid file descriptor

@raise ENOTTY if fd is something other than a terminal

@raise EPERM if pledge() was used without tty

@see libc/calls/isatty.c

isblank

Returns nonzero if c is space or tab.

@param

int c

@return

int

@see libc/str/isblank.c

ischardev

Returns true if file descriptor is backed by character i/o.

This function is equivalent to:

struct stat st;
return stat(path, &st) != -1 && S_ISCHR(st.st_mode);

Except faster and with fewer dependencies.

@param

int fd

@return

int

@see isregularfile(), isdirectory(), issymlink(), fileexists()

@see libc/calls/ischardev.c

iscntrl

Returns nonzero if c is C0 ASCII control code or DEL.

@param

int c

@return

int

@see libc/str/iscntrl.c

IsDebuggerPresent

Determines if gdb, strace, windbg, etc. is controlling process.

@param

_Bool force

@return

int: non-zero if attached, otherwise 0

@see libc/intrin/isdebuggerpresent.c

isdigit

Returns nonzero if c is decimal digit.

@param

int c

@return

int

@see libc/str/isdigit.c

isdigit_l

@param

int c
struct __locale_struct* l

@return

int

@see libc/unicode/isdigit_l.c

isdirectory

Returns true if file exists and is a directory.

This function is equivalent to:

struct stat st;
return fstatat(AT_FDCWD, path, &st, AT_SYMLINK_NOFOLLOW) != -1 &&
       S_ISDIR(st.st_mode);

Except faster, with fewer dependencies, and less errno clobbering.

@param

const char* path

@return

_Bool

@see isregularfile(), issymlink(), ischardev()

@see libc/calls/isdirectory.c

isdirectory_nt

Returns true if file exists and is a directory on Windows NT.

@param

const char* path

@return

_Bool

@see libc/calls/isdirectory-nt.c

_isdirsep

Returns true if character is directory separator slash.

@param

int c

@return

_Bool

@see libc/str/isdirsep.c

IsDodIp

Returns true if IP is owned by the U.S. Department of Defense.

@param

unsigned int x

@return

_Bool

@see net/http/isdodip.c

IsElf64Binary

@param

struct Elf64_Ehdr* elf
unsigned long mapsize

@return

_Bool

@see libc/elf/iself64binary.c

IsElfSymbolContent

@param

struct Elf64_Sym* sym

@return

_Bool

@see libc/elf/iselfsymbolcontent.c

isexecutable

Returns true if file exists and is executable.

@param

const char* path

@return

_Bool

@see access(exe, X_OK) which is more accurate on NT

@asyncsignalsafe

@vforksafe

@see libc/calls/isexecutable.c

isgraph

Returns nonzero if c is printable ascii that isn't space.

@param

int c

@return

int

@see libc/str/isgraph.c

_isheap

Returns true if address isn't stack and was malloc'd or mmap'd.

@param

void* p

@return

_Bool

@assume stack addresses are always greater than heap addresses

@assume stack memory isn't stored beneath %rsp (-mno-red-zone)

@see libc/runtime/isheap.c

IsLacnicIp

Returns true if IPv4 address is managed by LACNIC.

@param

unsigned int x

@return

_Bool

@see net/http/islacnicip.c

IsLoopbackIp

Returns true if IPv4 address is used for localhost.

@param

unsigned int x

@return

_Bool

@see net/http/isloopbackip.c

islower

Returns nonzero if c is lowercase alpha ascii character.

@param

int c

@return

int

@see libc/str/islower.c

islower_l

@param

int c
struct __locale_struct* l

@return

int

@see libc/unicode/islower_l.c

IsMemtracked

@param

int x
int y

@return

_Bool

@see libc/runtime/ismemtracked.greg.c

IsMimeType

Returns true if content-type 𝑡 has mime-type 𝑠.

@param

const char* t
unsigned long n
const char* s

@return

_Bool

@see net/http/ismimetype.c

IsMulticastIp

Returns true if IPv4 address is used for multicast.

@param

unsigned int x

@return

_Bool

@see net/http/ismulticastip.c

iso8601

Converts timestamp to ISO-8601 formatted string.

@param

char* p
struct tm* tm

@return

char*

@see libc/time/iso8601.c

isprint

Returns nonzero if c is printable ascii including space.

@param

int c

@return

int

@see libc/str/isprint.c

IsPrivateIp

Returns true if IPv4 address is intended for private networks.

@param

unsigned int x

@return

_Bool

@see net/http/isprivateip.c

IsPublicIp

Returns true if IPv4 address is Globally Reachable.

We intentionally omit TEST-NET here which can be used to simulate public Internet traffic using non-Internet IPs.

@param

unsigned int x

@return

_Bool: true 92.4499% of the time

@see IANA IPv4 Special-Purpose Address Registry

@see libc/sock/ispublicip.c

ispunct

Returns nonzero if c ∈ !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~

@param

int c

@return

int

@see libc/str/ispunct.c

IsReasonablePath

Returns true if path doesn't contain "." or ".." segments.

@param

const char* data
unsigned long size: if -1 implies strlen

@return

_Bool

@see IsAcceptablePath()

@see net/http/isreasonablepath.c

isregularfile

Returns true if file exists and is a regular file.

This function is equivalent to:

return fstatat(AT_FDCWD, path, &st, AT_SYMLINK_NOFOLLOW) != -1 &&
       S_ISREG(st.st_mode);

Except faster, with fewer dependencies, and less errno clobbering.

@param

const char* path

@return

_Bool

@see isdirectory(), ischardev(), issymlink()

@see libc/calls/isregularfile.c

isregularfile_nt

Returns true if file exists and is a regular file on Windows NT.

@param

const char* path

@return

_Bool

@see libc/calls/isregularfile-nt.c

IsRipeIp

Returns true if IPv4 address is managed by RIPE NCC.

@param

unsigned int x

@return

_Bool

@see net/http/isripeip.c

IsRunningUnderMake

Returns true if current process was spawned by GNU Make.

@return

_Bool

@see libc/intrin/isrunningundermake.c

issetugid

Determines if process is tainted.

This function returns 1 if process was launched as a result of an execve() call on a binary that had the setuid or setgid bits set. FreeBSD defines tainted as including processes that changed their effective user / group ids at some point.

@return

int: always successful, 1 if yes, 0 if no

@see libc/calls/issetugid.c

isspace

Returns nonzero if c is space, \t, \r, \n, \f, or \v.

@param

int c

@return

int

@see isblank()

@see libc/str/isspace.c

issymlink

Returns true if file exists and is a symbolic link.

This function is equivalent to:

struct stat st;
return fstatat(AT_FDCWD, path, &st, AT_SYMLINK_NOFOLLOW) != -1 &&
       S_ISLNK(st.st_mode);

Except faster and with fewer dependencies.

@param

const char* path

@return

_Bool

@see isregularfile(), isdirectory(), fileexists(), ischardev()

@see libc/calls/issymlink.c

issymlink_nt

Returns true if file exists and is a symbolic link on Windows NT.

@param

const char* path

@return

_Bool

@see libc/calls/issymlink-nt.c

IsTestnetIp

Returns true if IPv4 address is intended for documentation.

@param

unsigned int x

@return

_Bool

@see RFC5737

@see net/http/istestnetip.c

_istext

Returns true if buffer is most likely plaintext.

@param

void* data
unsigned long size

@return

_Bool

@see libc/str/istext.c

isupper

Returns nonzero if c is uppercase alpha ascii character.

@param

int c

@return

int

@see libc/str/isupper.c

isupper_l

@param

int c
struct __locale_struct* l

@return

int

@see libc/unicode/isupper_l.c

IsValidCookieValue

Returns true if string is a valid cookie value (any ASCII excluding control char, whitespace, double quotes, comma, semicolon, and backslash).

@param

const char* s
unsigned long n: if -1 implies strlen

@return

_Bool

@see net/http/isvalidcookievalue.c

IsValidHttpToken

Returns true if string is ASCII without delimiters.

@param

const char* s
unsigned long n: if -1 implies strlen

@return

_Bool

@see net/http/isvalidhttptoken.c

iswalnum

Returns nonzero if c is lower, alpha, or digit.

@param

unsigned int c

@return

int

@see libc/str/iswalnum.c

iswalpha

Returns nonzero if c is alphabetical.

@param

unsigned int c

@return

int

@see libc/str/iswalpha.c

iswalpha_l

@param

unsigned int c
struct __locale_struct* l

@return

int

@see libc/unicode/iswalpha_l.c

iswblank

Returns nonzero if c is space or tab.

@param

unsigned int c

@return

int

@see libc/str/iswblank.c

iswblank_l

@param

unsigned int c
struct __locale_struct* l

@return

int

@see libc/unicode/iswblank_l.c

iswcntrl

Returns nonzero if c is C0 or C1 control code.

@param

unsigned int c

@return

int

@see libc/str/iswcntrl.c

iswcntrl_l

@param

unsigned int c
struct __locale_struct* l

@return

int

@see libc/unicode/iswcntrl_l.c

iswctype

Returns nonzero if c has property.

@param

unsigned int c
unsigned int t: is number returned by wctype

@return

int

@see libc/str/iswctype.c

iswdigit

Returns nonzero if c is decimal digit.

@param

unsigned int c

@return

int

@see libc/str/iswdigit.c

iswdigit_l

@param

unsigned int c
struct __locale_struct* l

@return

int

@see libc/unicode/iswdigit_l.c

iswgraph

Returns nonzero if c is printable and not a space.

@param

unsigned int c

@return

int

@see libc/str/iswgraph.c

iswlower

Returns nonzero if c is lowercase letter.

@param

unsigned int c

@return

int

@see libc/str/iswlower.c

iswlower_l

@param

unsigned int c
struct __locale_struct* l

@return

int

@see libc/unicode/iswlower_l.c

__isworker

Indicates if current execution context is a worker task.

Setting this to true on things like the forked process of a web server is a good idea since it'll ask the C runtime to not pull magical stunts like attaching GDB to the process on crash.

@type

_Bool

@see libc/intrin/isworker.c

iswprint

Returns nonzero if c is printable.

@param

unsigned int c

@return

int

@see libc/str/iswprint.c

iswprint_l

@param

unsigned int c
struct __locale_struct* l

@return

int

@see libc/unicode/iswprint_l.c

iswpunct

Returns nonzero if c is punctuation mark.

@param

unsigned int c

@return

int

@see libc/str/iswpunct.c

iswpunct_l

@param

unsigned int c
struct __locale_struct* l

@return

int

@see libc/unicode/iswpunct_l.c

iswseparator

Returns nonzero if 𝑐 isn't alphanumeric.

Line reading interfaces generally define this operation as UNICODE characters that aren't in the letter category (Lu, Ll, Lt, Lm, Lo) and aren't in the number categorie (Nd, Nl, No). We also add a few other things like blocks and emoji (So).

@param

unsigned int c

@return

int

@see libc/str/iswseparator.c

iswspace

Returns nonzero if c is space character.

We define this as invisible characters which move the cursor. That means \t\r\n\f\v and unicodes whose category begins with Z but not ogham since it's not invisible and non-breaking spaces neither since they're not invisible to emacs users.

@param

unsigned int c

@return

int

@see libc/str/iswspace.c

iswspace_l

@param

unsigned int c
struct __locale_struct* l

@return

int

@see libc/unicode/iswspace_l.c

iswupper

Returns nonzero if c is uppercase letter.

@param

unsigned int c

@return

int

@see libc/str/iswupper.c

iswupper_l

@param

unsigned int c
struct __locale_struct* l

@return

int

@see libc/unicode/iswupper_l.c

iswxdigit

Returns nonzero if c is ascii hex digit.

@param

unsigned int c

@return

int

@see libc/str/iswxdigit.c

iswxdigit_l

@param

unsigned int c
struct __locale_struct* l

@return

int

@see libc/unicode/iswxdigit_l.c

isxdigit

Returns true if c is hexadecimal digit.

@param

int c

@return

int

@see libc/str/isxdigit.c

isxdigit_l

@param

int c
struct __locale_struct* l

@return

int

@see libc/unicode/isxdigit_l.c

IsZipCdir32

Returns true if zip end of central directory header seems legit.

@param

const unsigned char* p
unsigned long n
unsigned long i

@return

_Bool

@see libc/str/iszipcdir32.c

IsZipCdir64

Returns true if zip64 end of central directory header seems legit.

@param

const unsigned char* p
unsigned long n
unsigned long i

@return

_Bool

@see libc/str/iszipcdir64.c

itoa

@param

int value
char* str
int radix

@return

char*

@see libc/fmt/itoa.c

_jmpstack

Switches stack.

@param

rdi: is new rsp, passed as malloc(size) + size
rsi: is function to call in new stack space
rdx,rcx,r8,r9: get passed as args to rsi

@noreturn

@see libc/runtime/jmpstack.S

_join

Waits for thread created by _spawn() to terminate.

This will free your thread's stack and tls memory too.

@param

struct ths* th

@return

int

@see libc/thread/spawn.c

_joinpaths

Joins paths, e.g.

0    + 0    → 0
""   + ""   → ""
"a"  + 0    → "a"
"a"  + ""   → "a/"
0    + "b"  → "b"
""   + "b"  → "b"
"."  + "b"  → "./b"
"b"  + "."  → "b/."
"a"  + "b"  → "a/b"
"a/" + "b"  → "a/b"
"a"  + "b/" → "a/b/"
"a"  + "/b" → "/b"

@param

char* buf
unsigned long size
const char* path
const char* other

@return

char*: joined path, which may be buf, path, or other, or null if (1) buf didn't have enough space, or (2) both path and other were null

@see libc/fmt/joinpaths.c

kappendf

Appends formatted string to buffer w/ kprintf, e.g.

char *b = 0;
kappendf(&b, "hello %d\n", 123);
free(b);

@param

char** b
const char* fmt
...

@return

long: bytes appended or -1 if ENOMEM

@see appendz(b).i to get buffer length

@note O(1) amortized buffer growth

@see kprintf()

@see libc/stdio/kappendf.c

kConsoleHandles

@type

const char[3]

@see libc/intrin/restorewintty.c

kCp437

ibm cp437 unicode table w/ string literal safety

        ░▄██▒▄█ ▐██ ░░░     ▀▀████▒▀█▄
       ▐███▓██░ ██▌            ▀████▄■█▄
      ▐█▓███▀█░██▀   ░          ░▀█████▓▄
     ▐█▓██▀▄█▒██▀  ▄▄░  ▄▄▄ ░░░   ░▀████▒▄
    ▐████▀▄█■█▀      ▀▀             ░█████░
   ▐█▓█▀████▀          ░             ▐▓███▒
   █░███▀▀     ░░░    ▄█       ░░░    █████
  ▐█▓█░▀▀  ░░▄█▄▄▄▄▄  ▀▄ ▌▄▄▄░▄▄▄▄▄   ▐████░
  ▐███▌   ▄▀█████████▄ ▌▐▄████████▄   ▐▓███░
  ▐███░░░▀▄█▀▄▄████▄▀░  ▐████████▒ ▀   ░███░
  ░████░ ▓▀ ▄███████▀▌   ▀▄■████▀▀█▀   ██▀█
   ▓███░ ░▄▀▀░░░ ▀  ░░▌   ▄▀▀▄░░▀░▄▀▄ ▐██▀▄
   ░███░  ▄▓▓▄▄░▀▀█▀█ ▌░░  ▀█▀█▀▀     ▐██▀
 █▀▄▐██   ▀░░   ▄▀ ▐ █    ▀ ▄▄▄░     ░▀▄█▄▀█
 ▌▄  █▓ ▒      ░  █▄█▄▀▄▄▄███▄▀▄ ░░   ░ ▀  █▌
  █▌▄░▌      ░░░▄▀█▀███████▄▀▄▀▄▀▀▄▄▄  █▀█░▐
   ██▄     ░░░▄█▄▀██▄█■██████▄█▄█▄■▀█░  ▐░▐
    ▀██░   ░▄██████████████████▄█▄█ ░█ ░ ▄▀
    ▀▓█▄▓░░  ▒█▀█████████████████████▒ ██▀
     ▀███ ▓▒   ██████████████▀▀▀▀█▄▀ ░▄█▒
      ▀███ ▀█▄▀▄█████▀▀  ▓▓▓▄░   ▐  ░▄██
        ▀██ ▄███████▄████████▀░░   ░▄██
  ▄██▀▀▄ █▄▀▄██▒▒███████████▀▀▀▄░ ░███░
▄██▀▄▄░░▀▐▄████▄ █████▀▄░░█▀▄▀░░  ▄██░
█████▄▄▄███▀░█▌██▄▀▀█████▄▄░░░▄▄███▀██▄ ▄▀▀▀▄▄
 ▀██████▀■▄█▄▄ ░▀███████████████▓▓░░▄██▀▄████▄▄▀▄

█▀█ █  █▀█ █▀█ █▄▀ ▐▀█▀▌█▀█ █▀█ █▄ █ ▀█▀ █▀█ █▀▀
█▀▄ █  █ █ █   █ ▀▄  █  █▀▄ █ █ █ ▀█  █  █   ▀▀█
█▄█ █▄▌█▄█ █▄█ █  █  █  █ █ █▄█ █  █ ▄█▄ █▄█ █▄█

THERE WILL BE BLOCKS               march 01 2017

@return

@see libc/str/str.h

@see kCp437i[]

@see libc/nexgen32e/kcp437.S

kCpuids

Globally precomputed CPUID.

This module lets us check CPUID in 0.06ns rather than 51.00ns. If every piece of native software linked this module, then the world would be a much better place; since all the alternatives are quite toilsome.

@return

@see www.felixcloutier.com/x86/cpuid

@see libc/nexgen32e/kcpuids.S

kCrashSigs

@type

int[8]

@see libc/log/oncrash.c

kDos2Errno

data structure for __dos2errno()

@return

@see libc/intrin/kdos2errno.S

kHexToInt

@type

const char[256]

@see libc/str/khextoint.c

kHttpMethod

@type

const char[8][18]

@see net/http/khttpmethod.c

kHttpRepeatable

Set of standard comma-separate HTTP headers that may span lines.

These headers may specified on multiple lines, e.g.

Allow: GET
Allow: POST

Is the same as:

Allow: GET, POST

Standard headers that aren't part of this set will be overwritten in the event that they're specified multiple times. For example,

Content-Type: application/octet-stream
Content-Type: text/plain; charset=utf-8

Is the same as:

Content-Type: text/plain; charset=utf-8

This set exists to optimize header lookups and parsing. The existence of standard headers that aren't in this set is an O(1) operation. The repeatable headers in this list require an O(1) operation if they are not present, otherwise the extended headers list needs to be crawled.

Please note non-standard headers exist, e.g. Cookie, that may span multiple lines, even though they're not comma-delimited. For those headers we simply don't add them to the perfect hash table.

@type

_Bool[87]

@note we choose to not recognize this grammar for kHttpConnection

@note grep '[A-Z][a-z]*".*":"' rfc2616

@note grep ':.*#' rfc2616

@see RFC7230 § 4.2

@see net/http/khttprepeatable.c

kHttpToken

generated by: o//tool/build/xlat.com -TiC ' ()<>@,;:\"/[]?={}' -iskHttpToken

present            absent
────────────────   ────────────────
                   ∅☺☻♥♦♣♠•◘○◙♂♀♪♫☼   0x00
                   ►◄↕‼¶§▬↨↑↓→←∟↔▲▼   0x10
 ! #$%&‘  *+ -.    ␠ “     ()  ,  /   0x20
0123456789                   :;<=>⁇   0x30
 ABCDEFGHIJKLMNO   @                  0x40
PQRSTUVWXYZ   ^_              [⭝]     0x50
`abcdefghijklmno                      0x60
pqrstuvwxyz | ~               { } ⌂   0x70
                   ÇüéâäàåçêëèïîìÄÅ   0x80
                   ÉæÆôöòûùÿÖÜ¢£¥€ƒ   0x90
                   áíóúñÑªº¿⌐¬½¼¡«»   0xa0
                   ░▒▓│┤╡╢╖╕╣║╗╝╜╛┐   0xb0
                   └┴┬├─┼╞╟╚╔╩╦╠═╬╧   0xc0
                   ╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀   0xd0
                   αßΓπΣσμτΦΘΩδ∞φε∩   0xe0
                   ≡±≥≤⌠⌡÷≈°∙×√ⁿ²■λ   0xf0

const char kHttpToken[256] = { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0x00 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0x10 0, 1, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, // 0x20 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, // 0x30 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 0x40 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, // 0x50 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 0x60 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0, // 0x70 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0x80 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0x90 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0xa0 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0xb0 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0xc0 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0xd0 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0xe0 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0xf0 };

@return

@see RFC2616 CHAR = <any US-ASCII character (octets 0 - 127)> SP = <US-ASCII SP, space (32)> HT = <US-ASCII HT, horizontal-tab (9)> CTL = <any US-ASCII control character

         (octets 0 - 31) and DEL (127)>

token = 1*<any CHAR except CTLs or separators> separators = "(" | ")" | "<" | ">" | "@"

       | "," | ";" | ":" | "\" | <">
       | "/" | "[" | "]" | "?" | "="
       | "{" | "}" | SP | HT

@see net/http/khttptoken.S

kill

Sends signal to process.

The impact of this action can be terminating the process, or interrupting it to request something happen.

@param

int pid: can be: >0 signals one process by id =0 signals all processes in current process group -1 signals all processes possible (except init) <-1 signals all processes in -pid process group
int sig: can be: >0 can be SIGINT, SIGTERM, SIGKILL, SIGUSR1, etc. =0 checks both if pid exists and we can signal it

@return

int: 0 if something was accomplished, or -1 w/ errno

@asyncsignalsafe

@see libc/calls/kill.c

killpg

Sends signal to process group.

@param

int pgrp
int sig

@return

int

@see libc/calls/killpg.c

kisdangerous

@param

void* p

@return

_Bool

@see libc/intrin/kprintf.greg.c

kMbBittab

@type

const unsigned int[51]

@see libc/str/mb.c

kNtSystemDirectory

RII constant holding 'C:/WINDOWS/SYSTEM32' directory.

@return

@note guarantees trailing slash if non-empty

@see libc/calls/kntsystemdirectory.S

kNtWindowsDirectory

RII constant holding 'C:/WINDOWS' directory.

@return

@note guarantees trailing slash if non-empty

@see libc/calls/kntwindowsdirectory.S

kNtWsaData

Information about underlying Windows Sockets implementation.

Cosmopolitan automatically calls YOINK() on this symbol when its Berkeley Socket wrappers are linked. The latest version of Winsock was introduced alongside x64, so this should never fail.

@type

struct kNtWsaData

@see libc/sock/kntwsadata.c

kprintf

Privileged printf().

This function is intended for crash reporting. It's designed to be as unbreakable as possible, so that error messages can always be printed even when the rest of the runtime is broken. As such, it has continue on error semantics, doesn't support buffering between invocations and floating point is not supported. Output is also truncated if the line gets too long, but care is taken to preserve your newline characters. Your errno and GetLastError() state will not be clobbered, and ftrace and other runtime magic won't be invoked, since all the runtime magic depends on this function.

Directives:

%[FLAGS][WIDTH|*][.[PRECISION|*]][TYPE]SPECIFIER

Specifiers:

c char
o octal
b binary
s string
t symbol
p pointer
d decimal
n newline
u unsigned
r carriage
m strerror
G strsignal
X uppercase
T timestamp
x hexadecimal
P PID (or TID if TLS is enabled)

Types:

hhh bool
hh char or cp437
h short or char16_t
l long or wchar_t
ll long long

Flags:

0 zero padding
- flip alignment
! bypass memory safety
, thousands grouping w/ comma
' thousands grouping w/ apostrophe
_ thousands grouping w/ underscore
+ plus leftpad if positive (aligns w/ negatives)
space leftpad if positive (aligns w/ negatives)
# represent value with literal syntax, e.g. 0x, 0b, quotes
^ uppercasing w/ towupper() if linked, otherwise toupper()

Error numbers:

%m formats error (if strerror_wr if is linked)
%m formats errno number (if strerror_wr isn't linked)
% m formats error with leading space if errno isn't zero
%lm means favor WSAGetLastError() over GetLastError() if linked

You need to link and load the symbol table before %t will work. You can do that by calling GetSymbolTable(). If that hasn't happened it will print &hexnumber instead.

@param

const char* fmt
...

@return

void

@asyncsignalsafe

@vforksafe

@see libc/intrin/kprintf.greg.c

ksnprintf

Privileged snprintf().

@param

char* b: is buffer, and guaranteed a NUL-terminator if n>0
unsigned long n: is number of bytes available in buffer
const char* fmt
...

@return

unsigned long: length of output excluding NUL, which may exceed n

@see kprintf() for documentation

@asyncsignalsafe

@vforksafe

@see libc/intrin/kprintf.greg.c

kStartTsc

Timestamp of process start.

@type

unsigned long

@see libc/runtime/winmain.greg.h

@see libc/crt/crt.S

@see libc/intrin/kstarttsc.c

kTmpPath

RII constant holding temporary file directory.

The order of precedence is:

$TMPDIR/
GetTempPath()
/tmp/

This guarantees trailing slash.

@type

char[1024]

@see libc/calls/ktmppath.c

kToLower

ASCII uppercase → lowercase translation tables.

char kToLower[256];

@return

@see kToUpper

@see libc/nexgen32e/ktolower.S

kToUpper

ASCII lowercase → uppercase translation tables.

char kToUpper[256];

@return

@see kToLower

@see libc/nexgen32e/ktoupper.S

kvappendf

Appends formatted string to buffer.

This is an alternative to vappendf() that uses the kprintf() formatting facility. This has some advantages in terms of performance, code size, and memory safety. There's also disadvantages, such as lack of floating-point directives.

@param

char** b
const char* f
struct __va_list* v

@return

long

@see kprintf()

@see libc/stdio/kvappendf.c

kvprintf

Privileged vprintf.

@param

const char* fmt
struct __va_list* v

@return

void

@see kprintf() for documentation

@asyncsignalsafe

@vforksafe

@see libc/intrin/kprintf.greg.c

kvsnprintf

Privileged vsnprintf().

@param

char* b: is buffer, and guaranteed a NUL-terminator if n>0
unsigned long n: is number of bytes available in buffer
const char* fmt
struct __va_list* v

@return

unsigned long: length of output excluding NUL, which may exceed n

@see kprintf() for documentation

@asyncsignalsafe

@vforksafe

@see libc/intrin/kprintf.greg.c

kX86GradeNames

@type

struct IdName[10]

@see libc/intrin/x86gradenames.c

kX86MarchNames

@type

struct IdName[23]

@see libc/intrin/x86marchnames.c

kXedChipFeatures

Mapping of enum XedChip -> bitset<enum XedIsaSet>.

See related APIs, e.g. xed_isa_set_is_valid_for_chip().

This information can be reproduced by building Xed and running the C preprocessor on xed-chip-features-table.c (see xed-chips.txt) which turns several thousand lines of non-evolving code into fifty. For example, 0x2800000ul was calculated as: 1UL<<(XED_ISA_SET_I86-64) | 1UL<<(XED_ISA_SET_LAHF-64).

@type

const unsigned long[3][53]

@see third_party/xed/x86features.c

kXedEamode

@type

const unsigned char[3][2]

@see third_party/xed/eamode.c

kXedErrorNames

Xed error code names.

puts(IndexDoubleNulString(kXedErrorNames, xedd->op.error));

@type

const char[338]

@see XedError

@see third_party/xed/xederror.c

l64a

Converts 32-bit integer to base64, the posix way.

@param

long x

@return

char*

@see a64l() for inverse

@see EncodeBase64()

@see libc/str/l64a.c

labs

Returns absolute value of long integer.

@param

long x

@return

long

@note labs(LONG_MIN) returns LONG_MIN unless -ftrapv

@note consider ABS() to avoid narrowing

@see libc/fmt/labs.c

landlock_add_rule

Adds new rule to Landlock ruleset.

@param

int fd
enum rule_type rule_type
void* rule_attr
unsigned int flags

@return

int

@error ENOSYS if Landlock isn't supported

@error EPERM if Landlock supported but SECCOMP BPF shut it down

@error EOPNOTSUPP if Landlock supported but disabled at boot time

@error EINVAL if flags not 0, or inconsistent access in the rule, i.e. landlock_path_beneath_attr::allowed_access is not a subset of the ruleset handled accesses

@error ENOMSG empty allowed_access

@error EBADF fd is not a file descriptor for current thread, or member of rule_attr is not a file descriptor as expected

@error EBADFD fd is not a ruleset file descriptor, or a member of rule_attr is not the expected file descriptor type

@error EPERM fd has no write access to the underlying ruleset

@error EFAULT rule_attr inconsistency

@see libc/calls/landlock_add_rule.c

landlock_create_ruleset

Create new Landlock filesystem sandboxing ruleset.

You may also use this function to query the current ABI version:

landlock_create_ruleset(0, 0, LANDLOCK_CREATE_RULESET_VERSION);

@param

struct landlock_ruleset_attr* attr
unsigned long size
unsigned int flags

@return

int: close exec file descriptor for new ruleset

@error ENOSYS if not running Linux 5.13+

@error EPERM if pledge() or seccomp bpf shut it down

@error EOPNOTSUPP Landlock supported but disabled at boot

@error EINVAL unknown flags, or unknown access, or too small size

@error E2BIG attr or size inconsistencies

@error EFAULT attr or size inconsistencies

@error ENOMSG empty landlock_ruleset_attr::handled_access_fs

@see libc/calls/landlock_create_ruleset.c

landlock_restrict_self

Enforces Landlock ruleset on calling thread.

@param

int fd
unsigned int flags

@return

int

@error EOPNOTSUPP if Landlock supported but disabled at boot time

@error EINVAL if flags isn't zero

@error EBADF if fd isn't file descriptor for the current thread

@error EBADFD if fd is not a ruleset file descriptor

@error EPERM if fd has no read access to underlying ruleset, or current thread is not running with no_new_privs, or it doesn’t have CAP_SYS_ADMIN in its namespace

@error E2BIG if the maximum number of stacked rulesets is reached for current thread

@see libc/calls/landlock_restrict_self.c

lchown

Changes owner and/or group of pathname, w/o dereferencing symlinks.

@param

const char* pathname
unsigned int uid: is user id, or -1u to not change
unsigned int gid: is group id, or -1u to not change

@return

int: 0 on success, or -1 w/ errno

@see chown() which dereferences symbolic links

@see /etc/passwd for user ids

@see /etc/group for group ids

@see libc/calls/lchown.c

ldexp

Returns 𝑥 × 2ʸ.

@param

double x
int n

@return

double

@see libc/tinymath/ldexp.c

ldexpf

Returns 𝑥 × 2ʸ.

@param

float x
int n

@return

float

@see libc/tinymath/ldexpf.c

ldexpl

Returns 𝑥 × 2ʸ.

@param

𝑥: is long double passed on stack
𝑦: is exponent via %edi

@return

: result in %st0

@see libc/tinymath/ldexpl.S

ldiv

@param

long num
long den

@return

struct ldiv_t

@see libc/fmt/ldiv.c

LengthInt64

Returns len(str(x)) where x is a signed 64-bit integer.

@param

long x

@return

unsigned int

@see libc/fmt/lengthuint64.c

LengthInt64Thousands

Returns decimal string length of int64 w/ thousands separators.

@param

long x

@return

unsigned int

@see libc/fmt/lengthuint64.c

LengthUint64

Returns len(str(x)) where x is an unsigned 64-bit integer.

@param

unsigned long x

@return

unsigned int

@see libc/fmt/lengthuint64.c

LengthUint64Thousands

Returns decimal string length of uint64 w/ thousands separators.

@param

unsigned long x

@return

unsigned int

@see libc/fmt/lengthuint64.c

lgamma

Returns natural logarithm of absolute value of gamma function.

@param

double x

@return

double

@see libc/tinymath/lgamma.c

lgamma_r

@param

double x
int* signgamp

@return

double

@see libc/tinymath/gamma.c

lgammaf

@param

float x

@return

float

@see libc/tinymath/lgammaf.c

lgammaf_r

Returns natural logarithm of absolute value of Gamma function.

@param

float x
int* signgamp

@return

float

@see libc/tinymath/lgammaf_r.c

link

Creates hard filesystem link.

This allows two names to point to the same file data on disk. They can only be differentiated by examining the inode number.

@param

const char* existingpath
const char* newpath

@return

int: 0 on success, or -1 w/ errno

@asyncsignalsafe

@see libc/calls/link.c

linkat

Creates hard filesystem link.

This allows two names to point to the same file data on disk. They can only be differentiated by examining the inode number.

@param

int olddirfd
const char* oldpath
int newdirfd
const char* newpath
int flags: can have AT_EMPTY_PATH or AT_SYMLINK_NOFOLLOW

@return

int: 0 on success, or -1 w/ errno

@asyncsignalsafe

@see libc/calls/linkat.c

listen

Asks system to accept incoming connections on socket.

The socket() and bind() functions need to be called beforehand. Once this function is called, accept() is used to wait for connections. Using this on connectionless sockets will allow it to receive packets on a designated address.

@param

int fd
int backlog: <= SOMAXCONN

@return

int: 0 on success or -1 w/ errno

@see libc/sock/listen.c

llabs

Returns absolute value of long long integer.

@param

long x

@return

long

@note llabs(LONG_LONG_MIN) returns LONG_LONG_MIN unless -ftrapv

@note consider ABS() to avoid narrowing

@see libc/fmt/llabs.c

lldiv

@param

long num
long den

@return

struct lldiv_t

@see libc/fmt/lldiv.c

llround

Rounds to nearest integer, away from zero.

@param

𝑥: is double scalar in low half of %xmm0

@return

: 64-bit signed integer in %rax

@see round(), lrint()

@see libc/tinymath/lround.S

llroundf

Rounds to nearest integer, away from zero.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: 64-bit signed integer in %rax

@see round()

@see libc/tinymath/lroundf.S

_loadxmm

Loads XMM registers from buffer.

@param

%rdi: points to &(forcealign(16) uint8_t[256])[128]

@return

@note modern cpus have out-of-order execution engines

@see libc/nexgen32e/loadxmm.S

localeconv

@return

struct lconv*

@see libc/unicode/localeconv.c

localtime

@param

const long* timep

@return

struct alttm*

@see libc/time/localtime.c

localtime_lock

@return

int

@see libc/time/localtime.c

localtime_r

@param

const long* timep
struct alttm* tmp

@return

struct alttm*

@see libc/time/localtime.c

localtime_unlock

@return

void

@see libc/time/localtime.c

_lockcmpxchg

Compares and exchanges w/ lock prefix.

@param

void* ifthing: is uint𝑘_t[hasatleast 1] where 𝑘 ∈ {8,16,32,64}
long isequaltome
long replaceitwithme
unsigned long size: is automatically supplied by macro wrapper

@return

_Bool: true if value was exchanged, otherwise false

@see cmpxchg() if only written by one thread

@see libc/intrin/lockcmpxchg.c

_lockxadd

Compares and exchanges w/ lock prefix.

@param

void* ifthing: is uint𝑘_t[hasatleast 1] where 𝑘 ∈ {8,16,32,64}
long replaceitwithme
unsigned long size: is automatically supplied by macro wrapper

@return

long: value at location *ifthing *before* addition

@see InterlockedAdd() for a very similar API

@see xadd() if only written by one thread

@see libc/intrin/lockxadd.c

lockxchg

Compares and exchanges w/ lock prefix.

@param

void* memory: is uint𝑘_t[hasatleast 1] where 𝑘 ∈ {8,16,32,64}
void* localvar
unsigned long size: is automatically supplied by macro wrapper

@return

long: true if value was exchanged, otherwise false

@see xchg()

@see libc/intrin/lockxchg.c

log

Returns natural logarithm of 𝑥.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see libc/tinymath/log-tiny.S

log10

Calculates log₁₀𝑥.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see libc/tinymath/log10-tiny.S

log10f

Calculates log₁₀𝑥.

@param

𝑥: is double scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/log10f.S

log10l

Calculates log₁₀𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result in %st

@see libc/tinymath/log10l.S

log1p

Returns log(𝟷+𝑥).

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see libc/tinymath/log1p-tiny.S

log1pf

Returns log(𝟷+𝑥).

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/log1pf.S

log1pl

Returns log(𝟷+𝑥).

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result of exponentiation on FPU stack in %st

@see libc/tinymath/log1pl.S

log2

Calculates log₂𝑥.

@param

𝑥: is a double passed in the lower quadword of %xmm0

@return

: result in lower quadword of %xmm0

@see libc/tinymath/log2-tiny.S

log2f

Calculates log₂𝑥.

@param

𝑥: is a float passed in the lower quarter of %xmm0

@return

: result in lower quarter of %xmm0

@see libc/tinymath/log2f-tiny.S

log2l

Calculates log₂𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result in %st

@see ilogbl()

@see libc/tinymath/log2l.S

__log_file

Log level for compile-time DCE.

@type

struct FILE*

@see libc/log/log.h

logb

Returns log₂ₓ exponent part of double.

@param

𝑥: is double passed in %xmm0

@return

: result in %xmm0

@see libc/tinymath/logb.S

logbf

Returns log₂ₓ exponent part of float.

@param

𝑥: is float passed in %xmm0

@return

: result in %xmm0

@see libc/tinymath/logbf.S

logbl

Returns log₂ₓ exponent part of long double.

@param

𝑥: is long double passed on stack

@return

: result in %st0

@see libc/tinymath/logbl.S

logf

Returns natural logarithm of 𝑥.

@param

𝑥: is double scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/logf.S

logl

Returns natural logarithm of 𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result on FPU stack in %st

@see libc/tinymath/logl.S

longerjmp

Loads previously saved processor state.

@param

rdi: points to the jmp_buf
rsi: is returned by setlongerjmp() invocation

@noreturn

@see libc/nexgen32e/longerjmp.S

longjmp

Loads previously saved processor state.

@param

rdi: points to the jmp_buf
esi: is returned by setjmp() invocation (coerced nonzero)

@noreturn

@assume system five nexgen32e abi conformant

@note code built w/ microsoft abi compiler can't call this

@see _gclongjmp() unwinds _gc() destructors

@see libc/nexgen32e/longjmp.S

_longjmp

Loads previously saved processor state.

@param

rdi: points to the jmp_buf
esi: is returned by setjmp() invocation (coerced nonzero)

@noreturn

@assume system five nexgen32e abi conformant

@note code built w/ microsoft abi compiler can't call this

@see _gclongjmp() unwinds _gc() destructors

@see libc/nexgen32e/longjmp.S

longsort

Sorting algorithm for longs that doesn't take long.

"What disorder is this? Give me my long sort!"
                          -Lord Capulet

@param

long* x
unsigned long n

@return

void

@see libc/str/longsort.c

LookupProtoByName

Opens and searches /etc/protocols to find number for a given name.

@param

const char* protoname

is a NULL-terminated string

char* buf

is a buffer to store the official name of the protocol

unsigned long bufsize

is the size of buf

const char* filepath

is the location of protocols file

 (if NULL, uses /etc/protocols)

@return

int

-1 on error, or

 positive protocol number

@note aliases are read from file for comparison, but not returned.

@see LookupProtoByNumber

@see libc/dns/lookupprotobyname.c

LookupProtoByNumber

Opens and searches /etc/protocols to find name for a given number.

The format of /etc/protocols is like this:

# comment
# NAME           PROTOCOL        ALIASES
ip               0               IP
icmp             1               ICMP

@param

const int protonum

is the protocol number

char* buf

is a buffer to store the official name of the protocol

unsigned long bufsize

is the size of buf

const char* filepath

is the location of the protocols file

 (if NULL, uses /etc/protocols)

@return

int: 0 on success, -1 on error

@note aliases are not read from the file.

@see libc/dns/lookupprotobynumber.c

LookupServicesByName

Opens and searches /etc/services to find port for a given name.

@param

const char* servname

is a NULL-terminated string

char* servproto

is a NULL-terminated string (eg "tcp", "udp")

 (if servproto is an empty string,
  if is filled with the first matching
  protocol)

unsigned long servprotolen

the size of servproto

char* buf

is a buffer to store the official name of the service

 (if NULL, the official name is not stored)

unsigned long bufsize

is the size of buf

const char* filepath

is the location of services file

 (if NULL, uses /etc/services)

@return

int: -1 on error, or positive port number

@note aliases are read from file for comparison, but not returned.

@see LookupServicesByPort

@threadsafe

@see libc/dns/lookupservicesbyname.c

LookupServicesByPort

Opens and searches /etc/services to find name for a given port.

The format of /etc/services is like this:

# comment
# NAME       PORT/PROTOCOL       ALIASES
ftp          21/tcp
fsp          21/udp              fspd
ssh          22/tcp

@param

const int servport

is the port number

char* servproto

is a NULL-terminated string (eg "tcp", "udp")

 (if servproto is an empty string,
  if is filled with the first matching
  protocol)

unsigned long servprotolen

the size of servproto

char* buf

is a buffer to store the official name of the service

unsigned long bufsize

is the size of buf

const char* filepath

is the location of the services file

 (if NULL, uses /etc/services)

@return

int: 0 on success, -1 on error

@note aliases are not read from the file.

@see libc/dns/lookupservicesbyport.c

lround

Rounds to nearest integer, away from zero.

@param

𝑥: is double scalar in low half of %xmm0

@return

: 64-bit signed integer in %rax

@see round(), lrint()

@see libc/tinymath/lround.S

lroundf

Rounds to nearest integer, away from zero.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: 64-bit signed integer in %rax

@see round()

@see libc/tinymath/lroundf.S

lseek

Changes current position of file descriptor/handle.

@param

int fd: is a number returned by open()
long offset: is the relative byte count
unsigned int whence: can be SEEK_SET, SEEK_CUR, or SEEK_END

@return

long: new position relative to beginning, or -1 on error

@asyncsignalsafe

@see libc/calls/lseek.c

lstat

Returns information about file, w/o traversing symlinks.

@param

const char* pathname
struct stat* st

@return

int

@asyncsignalsafe

@see libc/calls/lstat.c

lutimes

Changes file timestamps, the legacy way.

@param

const char* filename
struct it_value* tv

@return

int

@see libc/calls/lutimes.c

lz4check

@param

void* data

@return

const unsigned char*

@see libc/str/lz4check.c

lz4cpy

Decompresses LZ4 block.

This is a 103 byte implementation of the LZ4 algorithm. Please note LZ4 files are comprised of multiple frames, which may be decoded together using the wrapper function lz4decode().

@param

void* dest
void* blockdata
unsigned long blocksize

@return

void*

@see rldecode() for a 16-byte decompressor

@see libc/str/lz4cpy.c

lz4decode

Decompresses LZ4 file.

We assume (1) the file is mmap()'d or was copied into into memory beforehand; and (2) folks handling untrustworthy data shall place 64kb of guard pages on the ends of each buffer, see mapanon(). We don't intend to support XXHASH; we recommend folks needing checks against data corruption consider crc32c(), or gzip since it's the best at file recovery. Dictionaries are supported; by convention, they are passed in the ≤64kb bytes preceding src.

@param

void* dest
void* src

@return

void*: pointer to end of decoded data, similar to mempcpy()

@see _mapanon(), lz4check()

@see libc/str/lz4decode.c

madvise

Drops hints to O/S about intended access patterns of mmap()'d memory.

@param

void* addr
unsigned long length
int advice: can be MADV_WILLNEED, MADV_SEQUENTIAL, MADV_FREE, etc.

@return

int: 0 on success, or -1 w/ errno

@see libc/sysv/consts.sh

@see fadvise()

@see libc/calls/madvise.c

major

@param

unsigned long x

@return

unsigned int

@see libc/calls/major.c

makedev

@param

unsigned int x
unsigned int y

@return

unsigned long

@see libc/calls/makedev.c

makedirs

Recursively creates directory a.k.a. folder.

This function won't fail if the directory already exists.

@param

const char* path: is a UTF-8 string, preferably relative w/ forward slashes
unsigned int mode: can be, for example, 0755

@return

int: 0 on success or -1 w/ errno

@see mkdir()

@see libc/x/makedirs.c

mallinfo

@param

struct mallinfo*

@return

struct mallinfo

@see libc/mem/mallinfo.c

malloc

Allocates uninitialized memory.

Returns a pointer to a newly allocated chunk of at least n bytes, or null if no space is available, in which case errno is set to ENOMEM on ANSI C systems.

If n is zero, malloc returns a minimum-sized chunk. (The minimum size is 32 bytes on 64bit systems.) Note that size_t is an unsigned type, so calls with arguments that would be negative if signed are interpreted as requests for huge amounts of space, which will often fail. The maximum supported value of n differs across systems, but is in all cases less than the maximum representable value of a size_t.

@param

rdi: is number of bytes needed, coerced to 1+

@return

: new memory, or NULL w/ errno

@threadsafe

@see libc/mem/malloc.S

malloc_inspect_all

@param

void(*)() handler
void* arg

@return

void

@see libc/mem/malloc_inspect_all.c

malloc_stats

@return

void

@see libc/log/malloc_stats.c

malloc_trim

Releases freed memory back to system.

@param

rdi: specifies bytes of memory to leave available

@return

: 1 if it actually released any memory, else 0

@see libc/mem/malloc_trim.S

malloc_usable_size

Returns the number of bytes you can actually use in an allocated chunk, which may be more than you requested (although often not) due to alignment and minimum size constraints.

You can use this many bytes without worrying about overwriting other allocated objects. This is not a particularly great programming practice. malloc_usable_size can be more useful in debugging and assertions, for example:

p = malloc(n)
assert(malloc_usable_size(p) >= 256)

@param

rdi: is address of allocation

@return

: rax is total number of bytes

@see dlmalloc_usable_size()

@threadsafe

@see libc/mem/malloc_usable_size.S

__map_phdrs

Maps APE-defined ELF program headers into memory and clears BSS.

@param

struct mman* mm
unsigned long* pml4t
unsigned long b

@return

void

@see libc/calls/mman.greg.c

_mapanon

Helper function for allocating anonymous mapping.

This function is equivalent to:

mmap(NULL, mapsize, PROT_READ | PROT_WRITE,
     MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);

If mmap() fails, possibly because the parent process did this:

if (!vfork()) {
  setrlimit(RLIMIT_AS, &(struct rlimit){maxbytes, maxbytes});
  execv(prog, (char *const[]){prog, 0});
}
wait(0);

Then this function will call:

__oom_hook(size);

If it's linked. The LIBC_TESTLIB library provides an implementation, which can be installed as follows:

int main() {
    InstallQuotaHandlers();
    // ...
}

That is performed automatically for unit test executables.

@param

unsigned long size

@return

void*: memory map address on success, or null w/ errno

@see libc/runtime/mapanon.c

_mapshared

Creates anonymous shared memory mapping.

@param

unsigned long size

@return

void*: memory map address on success, or null w/ errno

@see libc/runtime/mapshared.c

_mapstack

Allocates stack.

The size of your returned stack is always GetStackSize().

The bottom 4096 bytes of your stack can't be used, since it's always reserved for a read-only guard page. With ASAN it'll be poisoned too.

The top 16 bytes of a stack can't be used due to openbsd:stackbound and those bytes are also poisoned under ASAN build modes.

@return

void*: stack bottom address on success, or null w/ errrno

@see libc/runtime/mapstack.c

MapViewOfFileEx

Maps view of file mapping into memory on the New Technology.

@param

long hFileMappingObject: was returned by CreateFileMapping()
unsigned int dwDesiredAccess: has kNtFileMap... flags
unsigned int dwFileOffsetHigh
unsigned int dwFileOffsetLow
unsigned long dwNumberOfBytesToMap
void* opt_lpDesiredBaseAddress: may be NULL to let o/s choose

@return

void*: base address, or NULL on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/mapviewoffileex.c

MapViewOfFileExNuma

Maps view of file mapping into memory on the New Technology.

@param

long hFileMappingObject: was returned by CreateFileMapping()
unsigned int dwDesiredAccess: has kNtFileMap... flags
unsigned int dwFileOffsetHigh
unsigned int dwFileOffsetLow
unsigned long dwNumberOfBytesToMap
void* opt_lpDesiredBaseAddress: may be NULL to let o/s choose
unsigned int nndDesiredNumaNode

@return

void*: base address, or NULL on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/mapviewoffileexnuma.c

MarsagliaXorshift32

@param

unsigned int* state

@return

unsigned int

@see libc/rand/xorshift32.c

MarsagliaXorshift64

@param

unsigned long* state

@return

unsigned long

@see libc/rand/xorshift64.c

mblen

@param

const char* s
unsigned long n

@return

int

@see libc/str/mblen.c

mbrlen

@param

const char* s
unsigned long n
unsigned int* t

@return

unsigned long

@see libc/str/mbrlen.c

mbrtoc16

@param

unsigned short* pc16
const char* s
unsigned long n
unsigned int* ps

@return

unsigned long

@see libc/str/mbrtoc16.c

mbrtoc32

@param

unsigned int* pc32
const char* s
unsigned long n
unsigned int* ps

@return

unsigned long

@see libc/str/mbrtoc32.c

mbrtowc

@param

int* wc
const char* src
unsigned long n
unsigned int* st

@return

unsigned long

@see libc/str/mbrtowc.c

mbsinit

@param

const unsigned int* t

@return

int

@see libc/str/mbsinit.c

mbsnrtowcs

@param

int* wcs
const char** src
unsigned long n
unsigned long wn
unsigned int* st

@return

unsigned long

@see libc/str/mbsnrtowcs.c

mbsrtowcs

@param

int* ws
const char** src
unsigned long wn
unsigned int* st

@return

unsigned long

@see libc/str/mbsrtowcs.c

mbstowcs

@param

int* pwc
const char* s
unsigned long wn

@return

unsigned long

@see libc/str/mbstowcs.c

mbtowc

@param

int* wc
const char* src
unsigned long n

@return

int

@see libc/str/mbtowc.c

MeasureEntropy

Returns Shannon entropy of array.

This gives you an idea of the density of information. Cryptographic random should be in the ballpark of 7.9 whereas plaintext will be more like 4.5.

@param

const char* p: is treated as binary octets
unsigned long n: should be at least 1000

@return

double: number between 0 and 8

@see libc/rand/measureentropy.c

memalign

Allocates aligned memory.

Returns a pointer to a newly allocated chunk of n bytes, aligned in accord with the alignment argument. The alignment argument shall be rounded up to the nearest two power and higher 2 powers may be used if the allocator imposes a minimum alignment requirement.

@param

rdi: is alignment in bytes, coerced to 1+ w/ 2-power roundup
rsi: is number of bytes needed, coerced to 1+

@return

: rax is memory address, or NULL w/ errno

@see valloc(), pvalloc()

@threadsafe

@see libc/mem/memalign.S

memcasecmp

Compares memory case-insensitively.

memcasecmp n=0                     992 picoseconds
memcasecmp n=1                       1 ns/byte            590 mb/s
memcasecmp n=2                       1 ns/byte            843 mb/s
memcasecmp n=3                       1 ns/byte            885 mb/s
memcasecmp n=4                       1 ns/byte            843 mb/s
memcasecmp n=5                       1 ns/byte            820 mb/s
memcasecmp n=6                       1 ns/byte            770 mb/s
memcasecmp n=7                       1 ns/byte            765 mb/s
memcasecmp n=8                     206 ps/byte          4,724 mb/s
memcasecmp n=9                     220 ps/byte          4,428 mb/s
memcasecmp n=15                    617 ps/byte          1,581 mb/s
memcasecmp n=16                    124 ps/byte          7,873 mb/s
memcasecmp n=17                    155 ps/byte          6,274 mb/s
memcasecmp n=31                    341 ps/byte          2,860 mb/s
memcasecmp n=32                     82 ps/byte         11,810 mb/s
memcasecmp n=33                    100 ps/byte          9,743 mb/s
memcasecmp n=80                     53 ps/byte         18,169 mb/s
memcasecmp n=128                    49 ps/byte         19,890 mb/s
memcasecmp n=256                    45 ps/byte         21,595 mb/s
memcasecmp n=16384                  42 ps/byte         22,721 mb/s
memcasecmp n=32768                  40 ps/byte         24,266 mb/s
memcasecmp n=131072                 40 ps/byte         24,337 mb/s

@param

void* p
void* q
unsigned long n

@return

int: is <0, 0, or >0 based on uint8_t comparison

@see libc/str/memcasecmp.c

memccpy

Copies at most N bytes from SRC to DST until 𝑐 is encountered.

This is little-known C Standard Library approach, dating back to the Fourth Edition of System Five, for copying a C strings to fixed-width buffers, with added generality.

For example, strictly:

char buf[16];
CHECK_NOTNULL(memccpy(buf, s, '\0', sizeof(buf)));

Or unstrictly:

if (!memccpy(buf, s, '\0', sizeof(buf))) strcpy(buf, "?");

Are usually more sensible than the following:

char cstrbuf[16];
snprintf(cstrbuf, sizeof(cstrbuf), "%s", CSTR);

@param

void* dst
void* src
int c: is search character and is masked with 255
unsigned long n

@return

void*: DST + idx(c) + 1, or NULL if 𝑐 ∉ 𝑠₀․․ₙ₋₁

@note DST and SRC can't overlap

@asyncsignalsafe

@see libc/str/memccpy.c

memchr16

Returns pointer to first instance of character in range.

@param

rdi: is a non-null pointer to memory
esi: is the search word
rdx: is length of memory in shorts

@return

: rax points to word if found or NULL

@asyncsignalsafe

@see libc/nexgen32e/strsak16.S

memfrob

Memfrob implements a crypto algorithm proven to be unbreakable, without meeting its requirements concerning secrecy or length.

@param

void* buf
unsigned long size

@return

void*

@see libc/str/memfrob.c

meminfo

Prints memory mappings.

@param

int fd

@return

void

@see libc/log/meminfo.c

memjmpinit

Initializes jump table for memset() and memcpy().

@param

!ZF: if required cpu vector extensions are available
rdi: is address of 64-bit jump table
rsi: is address of 8-bit jump initializers
rdx: is address of indirect branch
ecx: is size of jump table

@return

@see libc/nexgen32e/memjmpinit.S

memmove

Copies memory.

memmove n=0                        661 picoseconds
memmove n=1                        661 ps/byte          1,476 mb/s
memmove n=2                        330 ps/byte          2,952 mb/s
memmove n=3                        330 ps/byte          2,952 mb/s
memmove n=4                        165 ps/byte          5,904 mb/s
memmove n=7                        141 ps/byte          6,888 mb/s
memmove n=8                         82 ps/byte             11 GB/s
memmove n=15                        44 ps/byte             21 GB/s
memmove n=16                        41 ps/byte             23 GB/s
memmove n=31                        32 ps/byte             29 GB/s
memmove n=32                        31 ps/byte             30 GB/s
memmove n=63                        21 ps/byte             45 GB/s
memmove n=64                        15 ps/byte             61 GB/s
memmove n=127                       13 ps/byte             73 GB/s
memmove n=128                       31 ps/byte             30 GB/s
memmove n=255                       20 ps/byte             45 GB/s
memmove n=256                       19 ps/byte             49 GB/s
memmove n=511                       16 ps/byte             56 GB/s
memmove n=512                       17 ps/byte             54 GB/s
memmove n=1023                      18 ps/byte             52 GB/s
memmove n=1024                      13 ps/byte             72 GB/s
memmove n=2047                       9 ps/byte             96 GB/s
memmove n=2048                       9 ps/byte             98 GB/s
memmove n=4095                       8 ps/byte            112 GB/s
memmove n=4096                       8 ps/byte            109 GB/s
memmove n=8191                       7 ps/byte            124 GB/s
memmove n=8192                       7 ps/byte            125 GB/s
memmove n=16383                      7 ps/byte            134 GB/s
memmove n=16384                      7 ps/byte            134 GB/s
memmove n=32767                     13 ps/byte             72 GB/s
memmove n=32768                     13 ps/byte             72 GB/s
memmove n=65535                     13 ps/byte             68 GB/s
memmove n=65536                     14 ps/byte             67 GB/s
memmove n=131071                    14 ps/byte             65 GB/s
memmove n=131072                    14 ps/byte             64 GB/s
memmove n=262143                    15 ps/byte             63 GB/s
memmove n=262144                    15 ps/byte             63 GB/s
memmove n=524287                    15 ps/byte             61 GB/s
memmove n=524288                    15 ps/byte             61 GB/s
memmove n=1048575                   15 ps/byte             61 GB/s
memmove n=1048576                   15 ps/byte             61 GB/s
memmove n=2097151                   19 ps/byte             48 GB/s
memmove n=2097152                   27 ps/byte             35 GB/s
memmove n=4194303                   28 ps/byte             33 GB/s
memmove n=4194304                   28 ps/byte             33 GB/s
memmove n=8388607                   28 ps/byte             33 GB/s
memmove n=8388608                   28 ps/byte             33 GB/s

DST and SRC may overlap.

@param

void* dst: is destination
void* src: is memory to copy
unsigned long n: is number of bytes to copy

@return

void*: dst

@asyncsignalsafe

@see libc/intrin/memmove.c

mempcpy

@param

void* dst
void* src
unsigned long n

@return

void*

@see libc/intrin/mempcpy.c

memset16

Sets wide memory.

@param

unsigned short* p
unsigned short c
unsigned long n

@return

unsigned short*

@asyncsignalsafe

@see libc/str/memset16.c

memsummary

@param

int fd

@return

void

@see libc/log/memsummary.c

MetalPrintf

Prints string to serial port.

This only supports %d and %s. It'll will work even if .rodata hasn't been loaded into memory yet.

@param

const char* fmt
...

@return

void

@see libc/runtime/metalprintf.greg.c

mincore

Tells you which pages are resident in memory.

@param

void* addr
unsigned long length
unsigned char* vec

@return

int

@see libc/calls/mincore.c

minor

@param

unsigned long x

@return

unsigned int

@see libc/calls/minor.c

mkdir

Creates directory a.k.a. folder.

mkdir o               →  0
mkdir o/yo/yo/yo      → -1 w/ ENOENT
if o/yo is file       → -1 w/ ENOTDIR
if o/yo/yo/yo is dir  → -1 w/ EEXIST
if o/yo/yo/yo is file → -1 w/ EEXIST

@param

const char* path: is a UTF-8 string, preferably relative w/ forward slashes
unsigned int mode: can be, for example, 0755

@return

int: 0 on success or -1 w/ errno

@error ENAMETOOLONG if >246 characters on NT

@asyncsignalsafe

@see makedirs()

@see libc/calls/mkdir.c

mkdirat

Creates directory a.k.a. folder.

@param

int dirfd: is normally AT_FDCWD but if it's an open directory and path is relative, then path becomes relative to dirfd
const char* path: is a UTF-8 string, preferably relative w/ forward slashes
unsigned int mode: can be, for example, 0755

@return

int: 0 on success or -1 w/ errno

@error EEXIST, ENOTDIR, ENAMETOOLONG, EACCES, ENOENT

@asyncsignalsafe

@see makedirs()

@see libc/calls/mkdirat.c

mkdtemp

Creates temporary directory.

@param

char* template: must end with XXXXXX which is replaced with nondeterministic base36 random data

@return

char*: pointer to template on success, or NULL w/ errno

@raise EINVAL if template didn't end with XXXXXX

@see libc/stdio/mkdtemp.c

mkfifo

Creates named pipe.

@param

const char* pathname
unsigned int mode: is octal, e.g. 0600 for owner-only read/write

@return

int

@asyncsignalsafe

@see libc/calls/mkfifo.c

mknod

Creates filesystem inode.

@param

const char* path
unsigned int mode: is octal mode, e.g. 0600; needs to be or'd with one of: S_IFDIR: directory S_IFIFO: named pipe S_IFREG: regular file S_IFSOCK: named socket S_IFBLK: block device (root has authorization) S_IFCHR: character device (root has authorization)
unsigned long dev: it's complicated

@return

int: 0 on success, or -1 w/ errno

@asyncsignalsafe

@see libc/calls/mknod.c

mkntcmdline

Converts System V argv to Windows-style command line.

Escaping is performed and it's designed to round-trip with GetDosArgv() or GetDosArgv(). This function does NOT escape command interpreter syntax, e.g. $VAR (sh), %VAR% (cmd).

@param

unsigned short* cmdline: is output buffer
const char* prog: is used as argv[0]
char** argv: is an a NULL-terminated array of UTF-8 strings

@return

int: freshly allocated lpCommandLine or NULL w/ errno

@see libc/runtime/dosargv.c

@see libc/calls/mkntcmdline.c

mkntenvblock

Copies sorted environment variable block for Windows.

This is designed to meet the requirements of CreateProcess().

@param

unsigned short* envvars: receives sorted double-NUL terminated string list
char** envp: is an a NULL-terminated array of UTF-8 strings
const char* extravar: is a VAR=val string we consider part of envp or NULL
char* buf

@return

int: 0 on success, or -1 w/ errno

@error E2BIG if total number of shorts exceeded ARG_MAX/2 (32767)

@see libc/calls/mkntenvblock.c

__mkntpath2

Copies path for Windows NT.

This entails (1) UTF-8 to UTF-16 conversion; (2) replacing forward-slashes with backslashes; and (3) remapping several well-known paths (e.g. /dev/null → NUL) for convenience.

@param

const char* path
unsigned short* path16: is shortened so caller can prefix, e.g. \\.\pipe\, and due to a plethora of special-cases throughout the Win32 API
int flags: is used by open()

@return

int: short count excluding NUL on success, or -1 w/ errno

@error ENAMETOOLONG

@see libc/calls/mkntpath.c

mkostemp

@param

char* template
unsigned int flags

@return

int

@see libc/stdio/mkostemp.c

mkostemps

Delegates to mkotempsm() w/ owner-only non-execute access.

@param

char* template
int suffixlen
unsigned int flags

@return

int

@see libc/stdio/mkostemps.c

mkostempsm

Opens unique temporary file.

The substring XXXXXX is replaced with a pseudorandom number that's seeded automatically and grants 30 bits of randomness to each value. Retries are made in the unlikely event of collisions.

@param

char* template: is a pathname relative to current directory by default, that needs to have "XXXXXX" at the end of the string
int suffixlen: may be nonzero to permit characters after the XXXXXX
unsigned int flags: can have O_APPEND, O_CLOEXEC, etc.
int mode: is conventionally 0600, for owner-only non-exec access

@return

int: exclusive open file descriptor for generated pathname, or -1 w/ errno

@see kTmpPath

@see libc/stdio/mkostempsm.c

mkostempsmi

@param

char* tpl
int slen
unsigned int flags
unsigned long* rando
int mode
int(*)() openit

@return

int

@see libc/stdio/mkostempsm.c

mkstemp

@param

char* template

@return

int

@see libc/stdio/mkstemp.c

mkstemps

@param

char* template
int suffixlen

@return

int

@see libc/stdio/mkstemps.c

mktemp

Generates unique filename.

This function is usually frowned upon, since it's been known to create nasty opportunities for race conditions. Our implementation reflects that; consider using mkostemps().

@param

char* template

@return

char*

@see libc/stdio/mktemp.c

mktime

@param

struct alttm* tmp

@return

long

@see libc/time/localtime.c

_mktls

Allocates thread-local storage memory for new thread.

@param

char** out_tib

@return

char*: buffer that must be released with free()

@see libc/thread/mktls.c

mmap

Beseeches system for page-table entries, e.g.

char *m;
m = mmap(NULL, FRAMESIZE, PROT_READ | PROT_WRITE,
         MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
munmap(m, FRAMESIZE);

@param

void* addr

should be 0 to let your memory manager choose address; unless MAP_FIXED or MAP_FIXED_NOREPLACE are specified in flags in which case this function will do precicely as you ask, even if p=0 (in which you need -fno-delete-null-pointer-checks); it needs to be 64kb aligned because it's a wise choice that sadly needs to be made mandatory because of Windows although you can use __sys_mmap() to circumvent it on System Five in which case runtime support services, e.g. asan memory safety, could break

unsigned long size

must be >0 and needn't be a multiple of FRAMESIZE, but will be rounded up to FRAMESIZE automatically if MAP_ANONYMOUS is specified

int prot

can have PROT_READ/PROT_WRITE/PROT_EXEC/PROT_NONE/etc.

int flags

should have one of the following masked by MAP_TYPE

MAP_FILE in which case fd != -1 should be the case
MAP_PRIVATE for copy-on-write behavior of writeable pages
MAP_SHARED to create shared memory between processes
MAP_STACK to create a grows-down alloc, where a guard page is automatically protected at the bottom: FreeBSD's behavior is polyfilled across platforms; uses MAP_GROWSDOWN on Linux too for extra oomph (do not use MAP_GROWSDOWN!) and this is completely mandatory on OpenBSD but helps perf elsewhere if you need to create 10,000 threads. This flag is the reason why STACK_FRAME_UNLIMITED toil is important, because this only allocates a 4096-byte guard page, thus we need the GCC compile-time checks to ensure some char[8192] vars will not create an undetectable overflow into another thread's stack

Your flags may optionally bitwise or any of the following:

MAP_ANONYMOUS in which case fd == -1 should be the case
MAP_FIXED in which case addr becomes more than a hint
MAP_FIXED_NOREPLACE to protect existing mappings; this is always polyfilled by mmap() which tracks its own memory and removed before passing to the kernel, in order to support old versions; if you believe mappings exist which only the kernel knows, then this flag may be passed to sys_mmap() on Linux 4.17+ and FreeBSD (where it has multiple bits)
MAP_CONCEAL is FreeBSD/NetBSD/OpenBSD-only
MAP_NORESERVE is Linux/XNU/NetBSD-only
MAP_POPULATE is Linux/FreeBSD-only
MAP_NONBLOCK is Linux-only
MAP_NOSYNC is FreeBSD-only
MAP_INHERIT is NetBSD-only
MAP_LOCKED is Linux-only

int fd

is an open()'d file descriptor, whose contents shall be made available w/ automatic reading at the chosen address and must be -1 if MAP_ANONYMOUS is specified

long off

specifies absolute byte index of fd's file for mapping, should be zero if MAP_ANONYMOUS is specified, and sadly needs to be 64kb aligned too

@return

void*: virtual base address of new mapping, or MAP_FAILED w/ errno

@see libc/runtime/mmap.c

modf

@param

double x
double* iptr

@return

double

@see libc/tinymath/modf.c

modff

@param

float x
float* iptr

@return

float

@see libc/tinymath/modff.c

__morph_begin

Begins code morphing executable.

@return

void: 0 on success, or -1 w/ errno

@see libc/runtime/morph.greg.c

__morph_end

Begins code morphing executable.

@return

void

@see libc/runtime/morph.greg.c

morton

Interleaves bits.

@param

unsigned long y
unsigned long x

@return

unsigned long

@see https://en.wikipedia.org/wiki/Z-order_curve

@see unmorton()

@see libc/bits/morton.c

mount

Mounts file system.

The following flags may be specified:

MS_RDONLY (mount read-only)
MS_NOSUID (don't honor S_ISUID bit)
MS_NODEV (disallow special files)
MS_NOEXEC (disallow program execution)
MS_SYNCHRONOUS (writes are synced at once)
MS_NOATIME (do not update access times)
MS_REMOUNT (tune existing mounting)

The following flags may also be used, but could be set to zero at runtime if the underlying kernel doesn't support them.

MNT_ASYNC (xnu, freebsd, openbsd, netbsd)
MNT_RELOAD (xnu, freebsd, openbsd, netbsd)
MS_STRICTATIME (linux, xnu)
MS_RELATIME (linux, netbsd)
MNT_SNAPSHOT (xnu, freebsd)
MS_MANDLOCK (linux)
MS_DIRSYNC (linux)
MS_NODIRATIME (linux)
MS_BIND (linux)
MS_MOVE (linux)
MS_REC (linux)
MS_SILENT (linux)
MS_POSIXACL (linux)
MS_UNBINDABLE (linux)
MS_PRIVATE (linux)
MS_SLAVE (linux)
MS_SHARED (linux)
MS_KERNMOUNT (linux)
MS_I_VERSION (linux)
MS_LAZYTIME (linux)
MS_ACTIVE (linux)
MS_NOUSER (linux)
MS_RMT_MASK (linux)
MNT_SUIDDIR (freebsd)
MNT_NOCLUSTERR (freebsd)
MNT_NOCLUSTERW (freebsd)

Some example values for the type parameter:

"nfs"
"vfat"
"tmpfs"
"iso8601"

@param

const char* source
const char* target
const char* type
unsigned long flags
void* data

@return

int

@see libc/calls/mount.c

MoveFileEx

Deletes existing empty directory.

@param

const unsigned short* lpExistingFileName
const unsigned short* lpNewFileName
int dwFlags

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/movefileex.c

mprotect

Modifies restrictions on virtual memory address range.

@param

void* addr: needs to be 4kb aligned
unsigned long size
int prot: can have PROT_{NONE,READ,WRITE,EXEC,GROWSDOWN,GROWSUP}

@return

int: 0 on success, or -1 w/ errno

@see mmap()

@see libc/runtime/mprotect.c

mpsadbw

Computes multiple sum of absolute differences.

This appears to be intended for video encoding motion estimation. It can be combined with phminposuw. That allows us to search for an int overlapping inside 𝑏 that's nearest to an aligned int in 𝑎.

@param

unsigned short* c
const unsigned char* b
const unsigned char* a
unsigned char control

@return

void

@note goes fast w/ sse4 cf. core c. 2006 cf. bulldozer c. 2011

@mayalias

@see libc/intrin/mpsadbw.c

__mpsadbws

Jump table for mpsadbw() with non-constexpr immediate parameter.

@return

@note needs sse4 cf. core c. 2006 cf. bulldozer c. 2011

@see mpsadbw()

@see libc/intrin/mpsadbws.S

mremap

Extends and/or relocates memory pages.

@param

void* p: is old address
unsigned long n: is old size
unsigned long m: is new size
int f: should have MREMAP_MAYMOVE and may have MAP_FIXED
...

@return

void*

@see libc/runtime/mremap.c

msync

Synchronize memory mapping changes to disk.

Without this, there's no guarantee memory is written back to disk. Particularly on RHEL5, OpenBSD, and Windows NT.

@param

void* addr: needs to be 4096-byte page aligned
unsigned long size
int flags: needs MS_ASYNC or MS_SYNC and can have MS_INVALIDATE

@return

int: 0 on success or -1 w/ errno

@see libc/runtime/msync.c

_mt19937

Generates random integer on [0, 2^64)-interval.

This uses the Mersenne Twister pseudorandom number generator.

@return

unsigned long

@see smt19937(), Smt19937()

@see libc/rand/mt19937.c

Mul4x4Adx

Computes 512-bit product of 256-bit and 256-bit numbers.

Instructions: 88 Total Cycles: 36 Total uOps: 120 uOps Per Cycle: 3.33 IPC: 2.44 Block RThroughput: 20.0

@param

rdi: receives 8 quadword result
rsi: is left hand side which must have 4 quadwords
rdx: is right hand side which must have 4 quadwords

@return

@note words are host endian while array is little endian

@mayalias

@see libc/nexgen32e/mul4x4adx.S

Mul6x6Adx

Computes 768-bit product of 384-bit and 384-bit numbers.

Instructions: 152 Total Cycles: 65 Total uOps: 260 uOps Per Cycle: 4.00 IPC: 2.34 Block RThroughput: 43.3

@param

rdi: receives 8 quadword result
rsi: is left hand side which must have 4 quadwords
rdx: is right hand side which must have 4 quadwords

@return

@note words are host endian while array is little endian

@mayalias

@see libc/nexgen32e/mul6x6adx.S

Mul8x8Adx

Computes 1024-bit product of 512-bit and 512-bit numbers.

Instructions: 260 Total Cycles: 98 Total uOps: 452 uOps Per Cycle: 4.61 IPC: 2.65 Block RThroughput: 75.3

@param

rdi: receives 16 quadword result
rsi: is left hand side which must have 8 quadwords
rdx: is right hand side which must have 8 quadwords

@return

@note words are host endian while array is little endian

@mayalias

@see libc/nexgen32e/mul8x8adx.S

__mulvdi3

Returns 𝑥*𝑦, aborting on overflow.

@param

rdi: is int64 𝑥
rdi: is int64 𝑥

@return

: rax is 𝑥*𝑦

@see -ftrapv

@see libc/intrin/mulvdi3.S

__mulvsi3

Returns 𝑥*𝑦, aborting on overflow.

@param

edi: is int32 𝑥
esi: is int32 𝑦

@return

: eax is 𝑥*𝑦

@see -ftrapv

@see libc/intrin/mulvsi3.S

__mulvti3

Returns 𝑥*𝑦, aborting on overflow.

@param

rdi:rsi: is int128 𝑥
rdx:rcx: is int128 𝑦

@return

: rdx:rax is 𝑥*𝑦

@see -ftrapv

@see libc/intrin/mulvti3.S

munmap

Releases memory pages.

@param

void* p: is the beginning of the memory region to unmap
unsigned long n: is the number of bytes to be unmapped

@return

int: 0 on success, or -1 w/ errno

@raises EINVAL if n == 0

@raises EINVAL if n isn't 48-bit

@raises EINVAL if p+(n-1) isn't 48-bit

@raises EINVAL if p isn't 65536-byte aligned

@see libc/runtime/munmap.c

nan

@param

const char* s

@return

double

@see libc/tinymath/nan.c

nanf

@param

const char* s

@return

float

@see libc/tinymath/nanf.c

nanl

@param

const char* s

@return

long double

@see libc/tinymath/nanl.c

_nanos

Returns nanoseconds since UNIX epoch.

@param

int timer

@return

__int128

@see libc/calls/nanos.c

nanosleep

Sleeps for a particular amount of time.

@param

struct st_birthtim* req: is the duration of time we should sleep
struct st_birthtim* rem: if non-NULL will receive the amount of time that wasn't slept because a signal was delivered. If no signal's delivered then this value will be set to {0, 0}. It's also fine to set this value to the same pointer as req.

@return

int: 0 on success, or -1 w/ errno

@raise EINVAL if req->tv_nsec ∉ [0,1000000000)

@raise EINTR if a signal was delivered, and rem is updated

@raise EFAULT if req is NULL or req / rem is a bad pointer

@raise ENOSYS on bare metal

@note POSIX.1 specifies nanosleep() measures against CLOCK_REALTIME however Linux measures uses CLOCK_MONOTONIC. This shouldn't matter, since POSIX.1 further specifies that discontinuous changes in CLOCK_REALTIME shouldn't impact nanosleep()

@norestart

@see libc/calls/nanosleep.c

__negvdi2

Returns -𝑥, aborting on overflow (two's complement bane).

@param

rdi: is int64 𝑥

@return

: rax is -𝑥

@see -ftrapv

@see libc/intrin/negvdi2.S

__negvsi2

Returns -𝑥, aborting on overflow (two's complement bane).

@param

edi: is int32 𝑥

@return

: eax is -𝑥

@see -ftrapv

@see libc/intrin/negvsi2.S

__negvti2

Returns -𝑥, aborting on overflow.

@param

rdi:rsi: is int128 𝑥

@return

: rdx:rax is -𝑥

@see -ftrapv

@see libc/intrin/negvti2.S

__new_page

Allocates new page of physical memory.

@param

struct mman* mm

@return

unsigned long

@see libc/calls/mman.greg.c

newaddrinfo

@param

unsigned short port

@return

struct addrinfo*

@see libc/dns/newaddrinfo.c

newlocale

@param

int catmask
const char* locale
struct __locale_struct* base

@return

struct __locale_struct*

@see libc/unicode/newlocale.c

nextafter

@param

double x
double y

@return

double

@see libc/tinymath/nextafter.c

nextafterf

@param

float x
float y

@return

float

@see libc/tinymath/nextafterf.c

nextafterl

@param

long double x
long double y

@return

long double

@see libc/tinymath/nextafterl.c

nexttoward

@param

double x
long double y

@return

double

@see libc/tinymath/nexttoward.c

nexttowardf

@param

float x
long double y

@return

float

@see libc/tinymath/nexttowardf.c

nexttowardl

@param

long double x
long double y

@return

long double

@see libc/tinymath/nexttowardl.c

nftw

Walks file tree.

@param

const char* path
int(*)() fn
int fd_limit
int flags

@return

int

@see examples/walk.c for example

@see third_party/musl/nftw.c

nice

Changes process priority.

@param

int delta: is added to current priority w/ clamping

@return

int: new priority, or -1 w/ errno

@see Linux claims ioprio_set() is tuned automatically by this

@see libc/calls/nice.c

nl_langinfo

@param

int item

@return

char*

@see libc/unicode/langinfo.c

nl_langinfo_l

@param

int item
struct __locale_struct* loc

@return

char*

@see libc/unicode/langinfo.c

__nocolor

Indicates if ANSI terminal colors are inappropriate.

Normally this variable should be false. We only set it to true if we're running on an old version of Windows or the environment variable TERM is set to dumb.

We think colors should be the norm, since most software is usually too conservative about removing them. Rather than using isatty consider using sed for instances where color must be removed:

 sed 's/\x1b\[[;[:digit:]]*m//g' <color.txt >uncolor.txt

For some reason, important software is configured by default in many operating systems, to not only disable colors, but utf-8 too! Here's an example of how a wrapper script can fix that for less.

 #!/bin/sh
 LESSCHARSET=UTF-8 exec /usr/bin/less -RS "$@"

Thank you for using colors!

@type

_Bool

@see libc/intrin/nocolor.c

__nosync

Tunes sync system call availability.

If this value is set to 0x5453455454534146, then the system calls sync(), fsync(), and fdatasync() system calls will do nothing and return success. This is intended to be used for things like making things like Python unit tests go faster because fsync is extremely slow and using tmpfs requires root privileges.

@type

unsigned long

@see libc/calls/nosync.c

nowl_setup

@return

long double

@see libc/calls/now.c

__nt2sysv

Translates function call from code built w/ MS-style compiler.

This wraps WinMain() and callback functions passed to Win32 API. Please note an intermediary jump slot is needed to set %rax.

@param

%rax: is function address

@return

: %rax,%xmm0

@note slower than __sysv2nt

@see NT2SYSV() macro

@see libc/nexgen32e/nt2sysv.S

ntaccesscheck

Asks Microsoft if we're authorized to use a folder or file.

Implementation Details: MSDN documentation imposes no limit on the internal size of SECURITY_DESCRIPTOR, which we are responsible for allocating. We've selected 1024 which shall hopefully be adequate.

@param

const unsigned short* pathname
unsigned int flags: can have R_OK, W_OK, X_OK, etc.

@return

int: 0 if authorized, or -1 w/ errno

@kudos Aaron Ballman for teaching this

@see libc/sysv/consts.sh

@see libc/calls/ntaccesscheck.c

NtGetVersion

Returns New Technology version, e.g.

This can only be called on Windows.

@return

int

@see IsAtLeastWindows10()

@see libc/intrin/ntgetversion.c

ntreturn

Exitpoint for Windows NT system calls.

@param

unsigned int status

@return

long

@see libc/calls/ntreturn.c

ntsetprivilege

Sets NT permission thing, e.g.

int64_t htoken;
if (OpenProcessToken(GetCurrentProcess(),
                     kNtTokenAdjustPrivileges | kNtTokenQuery,
                     &htoken)) {
  ntsetprivilege(htoken, u"SeManageVolumePrivilege",
                 kNtSePrivilegeEnabled);
  CloseHandle(htoken);
}

@param

long token
const unsigned short* name
unsigned int attrs

@return

int

@see libc/calls/ntsetprivilege.c

ntspawn

Spawns process on Windows NT.

This function delegates to CreateProcess() with UTF-8 → UTF-16 translation and argv escaping. Please note this will NOT escape command interpreter syntax.

@param

const char* prog: won't be PATH searched
char** argv: specifies prog arguments
char** envp
const char* extravar: is added to envp to avoid setenv() in caller
struct NtSecurityAttributes* opt_lpProcessAttributes
struct NtSecurityAttributes* opt_lpThreadAttributes
int bInheritHandles: means handles already marked inheritable will be inherited; which, assuming the System V wrapper functions are being used, should mean (1) all files and sockets that weren't opened with O_CLOEXEC; and (2) all memory mappings
unsigned int dwCreationFlags
const unsigned short* opt_lpCurrentDirectory
struct NtStartupInfo* lpStartupInfo
struct NtProcessInformation* opt_out_lpProcessInformation: can be used to return process and thread IDs to parent, as well as open handles that need close()

@return

int: 0 on success, or -1 w/ errno

@see spawnve() which abstracts this function

@see libc/calls/ntspawn.c

__on_arithmetic_overflow

Arithmetic overflow handler.

@return

@see -ftrapv

@see libc/intrin/onarithmeticoverflow.S

__oncrash

Crashes in a developer-friendly human-centric way.

We first try to launch GDB if it's an interactive development session. Otherwise we show a really good crash report, sort of like Python, that includes filenames and line numbers. Many editors, e.g. Emacs, will even recognize its syntax for quick hopping to the failing line. That's only possible if the the .com.dbg file is in the same folder. If the concomitant debug binary can't be found, we simply print addresses which may be cross-referenced using objdump.

This function never returns, except for traps w/ human supervision.

@param

int sig
struct siginfo_t* si
struct ucontext_t* ctx

@return

void

@threadsafe

@vforksafe

@see libc/log/oncrash.c

__onfork

Triggers callbacks registered by atfork().

@return

void

@note only fork() should call this

@asyncsignalsafe

@see libc/calls/atfork.c

open

Opens file.

@param

const char* file: is a UTF-8 string, preferably relative w/ forward slashes
int flags: should be O_RDONLY, O_WRONLY, or O_RDWR, and can be or'd with O_CREAT, O_TRUNC, O_APPEND, O_EXCL, O_CLOEXEC, O_TMPFILE
...

@return

int: number needing close(), or -1 w/ errno

@asyncsignalsafe (zip files may have issues)

@vforksafe (raises error if zip file)

@restartable

@threadsafe

@see libc/calls/open.c

openat

Opens file.

@param

int dirfd: is normally AT_FDCWD but if it's an open directory and file is a relative path, then file is opened relative to dirfd
const char* file: is a UTF-8 string, preferably relative w/ forward slashes
int flags: should be O_RDONLY, O_WRONLY, or O_RDWR, and can be or'd with O_CREAT, O_TRUNC, O_APPEND, O_EXCL, O_CLOEXEC, O_TMPFILE
...

@return

int: number needing close(), or -1 w/ errno

@asyncsignalsafe (zip files may have issues)

@vforksafe (raises error if zip file)

@threadsafe

@see libc/calls/openat.c

opendir

Opens directory, e.g.

DIR *d;
struct dirent *e;
CHECK((d = opendir(path)));
while ((e = readdir(d))) {
  printf("%s/%s\n", path, e->d_name);
}
LOGIFNEG1(closedir(d));

@param

const char* name

@return

struct dirstream*

@returns newly allocated DIR object, or NULL w/ errno

@errors ENOENT, ENOTDIR, EACCES, EMFILE, ENFILE, ENOMEM

@see glob()

@see libc/stdio/dirstream.c

OpenExecutable

Opens executable in O_RDWR mode.

To avoid ETXTBSY we need to unmap the running executable first, then open the file, and finally load the code back into memory.

@return

: file descriptor

@note only works on .com binary (not .com.dbg)

@note only supports linux, freebsd, openbsd, and netbsd

@see libc/runtime/openexecutable.S

openlog

Opens a connection to the system logger

Calling this function before calling syslog() is optional and only allow customizing the identity, options and facility of the messages logged.

@param

const char* ident

a string that prepends every logged message. If it set to NULL, the program name is used.

int opt

specifies flags which control the operation of openlog(). Only the following flags are supported:

LOG_CONS = Write directly to the system console if there is
           an error while sending to the system logger.
LOG_NDELAY = Open the connection with the system logger
             immediately instead of waiting for the first
             message to be logged.
LOG_ODELAY = The converse of LOG_NDELAY.
LOG_PERROR = Also log the message to stderr.
LOG_PID = Include the caller's PID with each message

int facility

specifies the default facitlity value that defines what kind of program is logging the message. Possible values are: LOG_AUTH, LOG_AUTHPRIV, LOG_CRON, LOG_DAEMON, LOG_FTP, LOG_LOCAL0 through LOG_LOCAL7, LOG_LPR, LOG_MAIL, LOG_NEWS, LOG_SYSLOG, LOG_USER (default), LOG_UUCP.

@return

void

@asyncsignalsafe

@see libc/sock/syslog.c

OpenProcess

Creates file mapping object on the New Technology.

@param

unsigned int dwDesiredAccess: should be kNtProcess... combination
int bInheritHandle
unsigned int dwProcessId

@return

long: ehandle, or 0 on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see MapViewOfFileEx()

@see libc/intrin/openprocess.c

openpty

Opens new pseudo teletypewriter.

@param

int* mfd: receives controlling tty rw fd on success
int* sfd: receives subordinate tty rw fd on success
char* name
struct termios* tio: may be passed to tune a century of legacy behaviors
struct winsize* wsz: may be passed to set terminal display dimensions

@return

int: 0 on success, or -1 w/ errno

@params flags is usually O_RDWR|O_NOCTTY

@see libc/calls/openpty.c

OpenSymbolTable

Maps debuggable binary into memory and indexes symbol addresses.

@param

const char* filename

@return

struct SymbolTable*: object freeable with CloseSymbolTable(), or NULL w/ errno

@see libc/runtime/opensymboltable.greg.c

optarg

Argument associated with option.

@type

char*

@see getopt()

@see third_party/getopt/getopt.c

opterr

If error message should be printed.

@type

int

@see getopt()

@see third_party/getopt/getopt.c

optind

Index into parent argv vector.

@type

int

@see getopt()

@see third_party/getopt/getopt.c

optopt

Character checked for validity.

@type

int

@see getopt()

@see third_party/getopt/getopt.c

optreset

Reset getopt.

@type

int

@see getopt()

@see third_party/getopt/getopt.c

pabsb

Converts signed bytes to absolute values, 𝑎ᵢ ← |𝑏ᵢ|.

@param

unsigned char* a
const char* b

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@see libc/intrin/pabsb.c

pabsd

Converts shorts to absolute values, 𝑎ᵢ ← |𝑏ᵢ|.

@param

unsigned int* a
const int* b

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@see libc/intrin/pabsd.c

pabsw

Converts shorts to absolute values, 𝑎ᵢ ← |𝑏ᵢ|.

@param

unsigned short* a
const short* b

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@see libc/intrin/pabsw.c

packssdw

Casts ints to shorts w/ saturation.

@param

short* a
const int* b
const int* c

@return

void

@mayalias

@see libc/intrin/packssdw.c

packsswb

Casts shorts to signed chars w/ saturation.

𝑎 ← {CLAMP[𝑏ᵢ]|𝑖∈[0,4)} ║ {CLAMP[𝑐ᵢ]|𝑖∈[4,8)}

@param

char* a
const short* b
const short* c

@return

void

@see packuswb()

@mayalias

@see libc/intrin/packsswb.c

packusdw

Casts ints to shorts w/ saturation.

@param

unsigned short* a
const int* b
const int* c

@return

void

@mayalias

@see libc/intrin/packusdw.c

packuswb

Casts shorts to unsigned chars w/ saturation.

𝑎 ← {CLAMP[𝑏ᵢ]|𝑖∈[0,4)} ║ {CLAMP[𝑐ᵢ]|𝑖∈[4,8)}

@param

unsigned char* a
const short* b
const short* c

@return

void

@see packsswb()

@mayalias

@see libc/intrin/packuswb.c

paddb

Adds 8-bit integers.

@param

char* a
const char* b
const char* c

@return

void

@mayalias

@see libc/intrin/paddb.c

paddd

Adds 32-bit integers.

@param

unsigned int* a
const unsigned int* b
const unsigned int* c

@return

void

@mayalias

@see libc/intrin/paddd.c

paddq

Adds 64-bit integers.

@param

unsigned long* a
const unsigned long* b
const unsigned long* c

@return

void

@mayalias

@see libc/intrin/paddq.c

paddsb

Adds signed 8-bit integers w/ saturation.

@param

char* a
const char* b
const char* c

@return

void

@mayalias

@see libc/intrin/paddsb.c

paddsw

Adds signed 16-bit integers w/ saturation.

@param

short* a
const short* b
const short* c

@return

void

@mayalias

@see libc/intrin/paddsw.c

paddusb

Adds unsigned 8-bit integers w/ saturation.

@param

unsigned char* a
const unsigned char* b
const unsigned char* c

@return

void

@mayalias

@see libc/intrin/paddusb.c

paddusw

Adds unsigned 16-bit integers w/ saturation.

@param

unsigned short* a
const unsigned short* b
const unsigned short* c

@return

void

@mayalias

@see libc/intrin/paddusw.c

paddw

Adds 16-bit integers.

@param

short* a
const short* b
const short* c

@return

void

@note shorts can't overflow so ubsan won't report it when it happens

@see paddsw()

@mayalias

@see libc/intrin/paddw.c

__paginate

Displays wall of text in terminal with pagination.

@param

int fd
const char* s

@return

void

@see libc/stdio/paginate.c

palignr

Overlaps vectors.

𝑖= 0 means 𝑐←𝑎

0<𝑖<16 means 𝑐←𝑎║𝑏

𝑖=16 means 𝑐←𝑏

16<𝑖<32 means 𝑐←𝑏║0

𝑖≥32 means 𝑐←0

@param

void* c
void* b
void* a
unsigned long i

@return

void

@note not compatible with mmx

@see pvalignr()

@mayalias

@see libc/intrin/palignr.c

__palignrs

Jump table for palignr() with non-constexpr immediate parameter.

@return

@note needs ssse3 cf. prescott c. 2004 cf. bulldozer c. 2011

@see palignr()

@see libc/intrin/palignrs.S

pand

Ands 128-bit integers.

@param

unsigned long* a
const unsigned long* b
const unsigned long* c

@return

void

@mayalias

@see libc/intrin/pand.c

pandn

Nands 128-bit integers.

@param

unsigned long* a
const unsigned long* b
const unsigned long* c

@return

void

@mayalias

@see libc/intrin/pandn.c

ParseContentLength

Parses Content-Length header.

@param

const char* s
unsigned long n

@return

long: -1 on invalid or overflow, otherwise >=0 value

@see net/http/parsecontentlength.c

ParseForwarded

Parses X-Forwarded-For.

This header is used by reverse proxies. For example:

X-Forwarded-For: 203.0.110.2, 203.0.113.42:31337

The port is optional and will be set to zero if absent.

@param

const char* s: is input data
unsigned long n: if -1 implies strlen
unsigned int* ip: receives last/right ip on success if not NULL
unsigned short* port: receives port on success if not NULL

@return

int: 0 on success or -1 on failure

@see RFC7239's poorly designed Forwarded header

@see net/http/parseforwarded.c

ParseHost

Parses HTTP Host header.

The input is ISO-8859-1 which is transcoded to UTF-8. Therefore we assume percent-encoded bytes are expressed as UTF-8. Returned values might contain things like NUL characters, C0, and C1 control codes. UTF-8 isn't checked for validity and may contain overlong values. Absent can be discerned from empty by checking if the pointer is set.

This function turns an HTTP header HOST[:PORT] into two strings, one for host and the other for port. You may then call IsAcceptableHost() and IsAcceptablePort() to see if they are valid values. After that a function like sscanf() can be used to do the thing you likely thought this function would do.

This function doesn't initialize h since it's assumed this will be called conditionally after ParseRequestUri() if the host is absent. Fields unrelated to authority won't be impacted by this function.

@param

const char* s: is value like 127.0.0.1 or foo.example:80
unsigned long n: is byte length and -1 implies strlen
struct Url* h: is needs to be initialized by caller

@return

char*: memory backing UrlView needing free

@see net/http/parseurl.c

ParseHostsTxt

Parses HOSTS.TXT contents.

Hostnames were invented by Peggy Karp; her format looks like this:

# this is a comment
# IP            CANON [ALT...]
203.0.113.1     lol.example. lol
203.0.113.2     cat.example. cat

@param

struct HostsTxt* ht
struct FILE* f: is the file content; see fopen() and fmemopen()

@return

int: 0 on success, or -1 w/ errno

@see hoststxtsort() which is the logical next step

@see libc/dns/parsehoststxt.c

ParseHttpDateTime

Parses HTTP timestamp, e.g.

Sun, 04 Oct 2020 19:50:10 GMT

@param

const char* p
unsigned long n: if -1 implies strlen

@return

long: seconds from unix epoch

@see FormatHttpDateTime()

@see net/http/parsehttpdatetime.c

ParseHttpMessage

Parses HTTP request or response.

This parser is responsible for determining the length of a message and slicing the strings inside it. Performance is attained using perfect hash tables. No memory allocation is performed for normal messages. Line folding is forbidden. State persists across calls so that fragmented messages can be handled efficiently. A limitation on message size is imposed to make the header data structures smaller.

This parser assumes ISO-8859-1 and guarantees no C0 or C1 control codes are present in message fields, with the exception of tab. Please note that fields like kHttpStateUri may use UTF-8 percent encoding. This parser doesn't care if you choose ASA X3.4-1963 or MULTICS newlines.

kHttpRepeatable defines which standard header fields are O(1) and which ones may have comma entries spilled over into xheaders. For most headers it's sufficient to simply check the static slice. If r->headers[kHttpFoo].a is zero then the header is totally absent.

This parser has linear complexity. Each character only needs to be considered a single time. That's the case even if messages are fragmented. If a message is valid but incomplete, this function will return zero so that it can be resumed as soon as more data arrives.

This parser takes about 400 nanoseconds to parse a 403 byte Chrome HTTP request under MODE=rel on a Core i9 which is about three cycles per byte or a gigabyte per second of throughput per core.

@param

struct HttpMessage* r
const char* p
unsigned long n

@return

int

@note we assume p points to a buffer that has >=SHRT_MAX bytes

@see HTTP/1.1 RFC2616 RFC2068

@see HTTP/1.0 RFC1945

@see net/http/parsehttpmessage.c

ParseHttpRange

Parses HTTP Range request header.

Here are some example values:

Range: bytes=0-                 (everything)
Range: bytes=0-499              (first 500 bytes)
Range: bytes=500-999            (second 500 bytes)
Range: bytes=-500               (final 500 bytes)
Range: bytes=0-0,-1             (first and last and always)
Range: bytes=500-600,601-999    (overlong but legal)

@param

const char* p
unsigned long n
long resourcelength
long* out_start
long* out_length

@return

_Bool

@see net/http/parsehttprange.c

ParseIp

Parse IPv4 address.

@param

const char* s
unsigned long n: if -1 implies strlen

@return

long: -1 on failure, otherwise 32-bit host-order unsigned integer

@see net/http/parseip.c

ParseParams

Parses HTTP POST key-value params.

These are similar to the parameters found in a Request-URI. The main difference is that + is translated into space here. The mime type for this is application/x-www-form-urlencoded.

This parser is charset agnostic. Returned values might contain things like NUL characters, NUL, control codes, and non-canonical encodings. Absent can be discerned from empty by checking if the pointer is set.

There's no failure condition for this routine. This is a permissive parser that doesn't impose character restrictions beyond what is necessary for parsing.

@param

const char* s: is value like foo=bar&x=y&z
unsigned long n: is byte length and -1 implies strlen
struct params* h: must be zeroed by caller and this appends if reused

@return

char*: UrlView memory with same n needing free (h.p needs free too)

@see net/http/parseurl.c

parseport

@param

const char* service

@return

int

@see libc/sock/parseport.c

ParseRequestUri

Parses HTTP Request-URI.

There's no failure condition for this routine. This is a permissive parser that doesn't impose character restrictions beyond what is necessary for parsing. This doesn't normalize path segments like . or ... Use IsAcceptablePath() to check for those.

@param

const char* s: is value like /hi?x=y&z or http://a.example/hi#x
unsigned long n: is byte length and -1 implies strlen
struct Url* h: is assumed to be uninitialized

@return

char*: memory backing UrlView needing free (and h.params.p too)

@see net/http/parseurl.c

ParseResolvConf

Parses /etc/resolv.conf file.

The content of the file usually looks like this:

nameserver 8.8.8.8
nameserver 8.8.4.4

@param

struct ResolvConf* resolv: points to a ResolvConf object, which should be zero initialized by the caller; or if it already contains items, this function will append
struct FILE* f: is an open stream with file content

@return

int: number of nameservers appended, or -1 w/ errno

@see libc/dns/parseresolvconf.c

ParseUrl

Parses URL.

This parser is charset agnostic. Percent encoded bytes are decoded for all fields (with the exception of scheme). Returned values might contain things like NUL characters, spaces, control codes, and non-canonical encodings. Absent can be discerned from empty by checking if the pointer is set.

There's no failure condition for this routine. This is a permissive parser. This doesn't normalize path segments like . or .. so use IsAcceptablePath() to check for those. No restrictions are imposed beyond that which is strictly necessary for parsing. All the s that is provided will be consumed to the one of the fields. Strict conformance is enforced on some fields more than others, like scheme, since it's the most non-deterministically defined field of them all.

Please note this is a URL parser, not a URI parser. Which means we support everything everything the URI spec says we should do except for the things we won't do, like tokenizing path segments into an array and then nesting another array beneath each of those for storing semicolon parameters. So this parser won't make SIP easy. What it can do is parse HTTP URLs and most URIs like s:opaque, better in fact than most things which claim to be URI parsers.

@param

const char* s: is value like /hi?x=y&z or http://a.example/hi#x
unsigned long n: is byte length and -1 implies strlen
struct Url* h: is assumed to be uninitialized

@return

char*: memory backing UrlView needing free (and h.params.p too)

@see URI Generic Syntax RFC3986 RFC2396

@see EncodeUrl()

@see net/http/parseurl.c

PascalifyDnsName

Writes dotted hostname to DNS message wire.

The wire format is basically a sequence of Pascal strings, for each label in the name. We only do enough validation to maintain protocol invariants.

@param

unsigned char* buf
unsigned long size
const char* name: is a dotted NUL-terminated hostname string

@return

int: bytes written (excluding NUL) or -1 w/ errno

@see libc/dns/pascalifydnsname.c

pause

Waits for signal.

This suspends execution until an unmasked signal is delivered. If the signal delivery kills the process, this won't return. The signal mask of the current thread is used. If a signal handler exists, this shall return after it's been invoked.

This function is equivalent to:

select(0, 0, 0, 0, 0);

However this has a tinier footprint and better logging.

@return

int: -1 w/ errno set to EINTR

@see sigsuspend()

@norestart

@see libc/calls/pause.c

pavgb

Averages packed 8-bit unsigned integers w/ rounding.

@param

unsigned char* a
const unsigned char* b
const unsigned char* c

@return

void

@mayalias

@see libc/intrin/pavgb.c

pavgw

Averages packed 16-bit unsigned integers w/ rounding.

@param

unsigned short* a
const unsigned short* b
const unsigned short* c

@return

void

@mayalias

@see libc/intrin/pavgw.c

pclose

Closes stream created by popen().

@param

struct FILE* f

@return

int: termination status of subprocess, or -1 w/ ECHILD

@see libc/stdio/pclose.c

pcmpeqb

Compares signed 8-bit integers w/ equal to predicate.

@param

unsigned char* a
const unsigned char* b
const unsigned char* c

@return

void

@mayalias

@see libc/intrin/pcmpeqb.c

pcmpeqd

Compares signed 32-bit integers w/ equal to predicate.

@param

int* a
const int* b
const int* c

@return

void

@mayalias

@see libc/intrin/pcmpeqd.c

pcmpeqw

Compares signed 16-bit integers w/ equal to predicate.

@param

short* a
const short* b
const short* c

@return

void

@mayalias

@see libc/intrin/pcmpeqw.c

pcmpgtb

Compares signed 8-bit integers w/ greater than predicate.

Note that operands can be xor'd with 0x80 for unsigned compares.

@param

char* a
const char* b
const char* c

@return

void

@mayalias

@see libc/intrin/pcmpgtb.c

pcmpgtd

Compares signed 32-bit integers w/ greater than predicate.

@param

int* a
const int* b
const int* c

@return

void

@mayalias

@see libc/intrin/pcmpgtd.c

pcmpgtw

Compares signed 16-bit integers w/ greater than predicate.

@param

short* a
const short* b
const short* c

@return

void

@mayalias

@see libc/intrin/pcmpgtw.c

pdep

Parallel bit deposit.

@param

unsigned long x
unsigned long mask

@return

unsigned long

@see libc/intrin/pdep.c

perror

Writes error messages to standard error.

@param

const char* message

@return

void

@see libc/log/perror.c

pext

Parallel bit extract.

@param

unsigned long x
unsigned long mask

@return

unsigned long

@see libc/intrin/pext.c

phaddd

Adds adjacent 32-bit integers.

@param

unsigned int* a
const unsigned int* b
const unsigned int* c

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@mayalias

@see libc/intrin/phaddd.c

phaddsw

Adds adjacent shorts w/ saturation.

@param

short* a
const short* b
const short* c

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@mayalias

@see libc/intrin/phaddsw.c

phaddw

Adds adjacent 16-bit integers.

@param

short* a
const short* b
const short* c

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@mayalias

@see libc/intrin/phaddw.c

phsubd

Subtracts adjacent 32-bit integers.

@param

unsigned int* a
const unsigned int* b
const unsigned int* c

@return

void

@note goes fast w/ ssse3

@mayalias

@see libc/intrin/phsubd.c

phsubsw

Subtracts adjacent shorts w/ saturation.

@param

short* a
const short* b
const short* c

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@mayalias

@see libc/intrin/phsubsw.c

phsubw

Subtracts adjacent 16-bit integers.

@param

short* a
const short* b
const short* c

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@mayalias

@see libc/intrin/phsubw.c

pipe

Creates file-less file descriptors for interprocess communication.

@param

int* pipefd

@return

int: 0 on success or -1 w/ errno

@raise EFAULT if pipefd is NULL or an invalid address

@raise EMFILE if RLIMIT_NOFILE is exceedde

@asyncsignalsafe

@see pipe2()

@see libc/calls/pipe.c

pipe2

Creates file-less file descriptors for interprocess communication.

@param

int* pipefd: is used to return (reader, writer) file descriptors
int flags: can have O_CLOEXEC or O_DIRECT or O_NONBLOCK

@return

int: 0 on success, or -1 w/ errno and pipefd isn't modified

@see libc/calls/pipe2.c

pmaddubsw

Multiplies bytes and adds adjacent results w/ short saturation.

𝑤ᵢ ← CLAMP[ 𝑏₂ᵢ𝑐₂ᵢ + 𝑏₍₂ᵢ₊₁₎𝑐₍₂ᵢ₊₁₎ ]

@param

short* w
const unsigned char* b
const char* c

@return

void

@note SSSE3 w/ Prescott c. 2004, Bulldozer c. 2011

@note greatest simd op, like, ever

@mayalias

@see libc/intrin/pmaddubsw.c

pmaddwd

Multiplies 16-bit signed integers and adds adjacent results.

@param

int* a
const short* b
const short* c

@return

void

@mayalias

@see libc/intrin/pmaddwd.c

pmaxsw

Gets maximum of signed 16-bit integers.

@param

short* a
const short* b
const short* c

@return

void

@mayalias

@see libc/intrin/pmaxsw.c

pmaxub

Returns minimum of 8-bit unsigned integers.

@param

unsigned char* a
const unsigned char* b
const unsigned char* c

@return

void

@mayalias

@see libc/intrin/pmaxub.c

pminsw

Gets minimum of signed 16-bit integers.

@param

short* a
const short* b
const short* c

@return

void

@mayalias

@see libc/intrin/pminsw.c

pminub

Returns minimum of 8-bit unsigned integers.

@param

unsigned char* a
const unsigned char* b
const unsigned char* c

@return

void

@mayalias

@see libc/intrin/pminub.c

pmovmskb

Turns result of byte comparison into bitmask.

@param

const unsigned char* p

@return

unsigned int

@see pcmpeqb(), bsf(), etc.

@see libc/intrin/pmovmskb.c

pmulhrsw

Multiplies Q15 numbers.

@param

short* a
const short* b
const short* c

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@note a.k.a. packed multiply high w/ round & scale

@see Q2F(15,𝑥), F2Q(15,𝑥)

@mayalias

@see libc/intrin/pmulhrsw.c

pmulhuw

Multiplies 16-bit unsigned integers and stores high word.

@param

unsigned short* a
const unsigned short* b
const unsigned short* c

@return

void

@mayalias

@see libc/intrin/pmulhuw.c

pmulhw

Multiplies 16-bit signed integers and stores high word.

@param

short* a
const short* b
const short* c

@return

void

@mayalias

@see libc/intrin/pmulhw.c

pmulld

Multiplies 32-bit integers.

@param

unsigned int* a
const unsigned int* b
const unsigned int* c

@return

void

@see pmuludq()

@mayalias

@see libc/intrin/pmulld.c

pmullw

Multiplies 16-bit signed integers.

@param

short* a
const short* b
const short* c

@return

void

@mayalias

@see libc/intrin/pmullw.c

pmuludq

Multiplies 32-bit unsigned integers w/ promotion.

@param

unsigned long* a
const unsigned int* b
const unsigned int* c

@return

void

@see pmulld()

@mayalias

@see libc/intrin/pmuludq.c

pochisq

@param

const double ax
const int df

@return

double

@see libc/rand/poz.c

poll

Waits for something to happen on multiple file descriptors at once.

Warning: XNU has an inconsistency with other platforms. If you have pollfds with fd≥0 and none of the meaningful events flags are added e.g. POLLIN then XNU won't check for POLLNVAL. This matters because one of the use-cases for poll() is quickly checking for open files.

Note: Polling works best on Windows for sockets. We're able to poll input on named pipes. But for anything that isn't a socket, or pipe with POLLIN, (e.g. regular file) then POLLIN/POLLOUT are always set into revents if they're requested, provided they were opened with a mode that permits reading and/or writing.

Note: Windows has a limit of 64 file descriptors and ENOMEM with -1 is returned if that limit is exceeded. In practice the limit is not this low. For example, pollfds with fd<0 don't count. So the caller could flip the sign bit with a short timeout, to poll a larger set.

@param

struct pollfd* fds
unsigned long nfds
int timeout_ms: if 0 means don't wait and -1 means wait forever

@return

int: number of items fds whose revents field has been set to nonzero to describe its events, or 0 if the timeout elapsed, or -1 w/ errno; fds[𝑖].revents is always zero initializaed and then will be populated with POLL{IN,OUT,PRI,HUP,ERR,NVAL} if something was determined about the file descriptor

@asyncsignalsafe

@threadsafe

@norestart

@see libc/calls/poll.c

popcnt

Returns number of bits set in integer.

@param

unsigned long x

@return

unsigned long

@see libc/intrin/popcnt.c

popen

Spawns subprocess and returns pipe stream.

@param

const char* cmdline
const char* mode

@return

struct FILE*

@see pclose()

@see libc/stdio/popen.c

por

Ors 128-bit integers.

@param

unsigned long* a
const unsigned long* b
const unsigned long* c

@return

void

@mayalias

@see libc/intrin/por.c

posix_fadvise

@param

int fd
unsigned long offset
unsigned long len
int advice

@return

int

@see libc/calls/posix_fadvise.c

posix_madvise

@param

void* addr
unsigned long len
int advice

@return

int

@see libc/calls/posix_madvise.c

posix_memalign

Allocates aligned memory, the POSIX way.

Allocates a chunk of n bytes, aligned in accord with the alignment argument. Differs from memalign() only in that it:

Assigns the allocated memory to *pp rather than returning it
Fails and returns EINVAL if the alignment is not a power of two
Fails and returns ENOMEM if memory cannot be allocated

@param

void** pp: receives pointer, only on success
unsigned long alignment: must be 2-power multiple of sizeof(void *)
unsigned long bytes: is number of bytes to allocate

@return

int: return 0 or EINVAL or ENOMEM w/o setting errno

@see memalign()

@threadsafe

@see libc/mem/posix_memalign.c

posix_openpt

Opens new pseudo teletypewriter.

@param

int flags

@return

int: file descriptor, or -1 w/ errno

@params flags is usually O_RDWR|O_NOCTTY

@see libc/calls/posix_openpt.c

posix_spawn

Spawns process the POSIX way.

@param

int* pid: is non-NULL and will be set to child pid in parent
const char* path: of executable that is not PATH searched
char** file_actions
struct _posix_spawnattr* attrp
char** argv
char** envp

@return

int: 0 on success or error number on failure

@see libc/stdio/spawn.c

posix_spawn_file_actions_addclose

Add a close action to object.

@param

char** file_actions
int fildes

@return

int

@see libc/stdio/spawnf.c

posix_spawn_file_actions_adddup2

Add a dup2 action to object.

@param

char** file_actions
int fildes
int newfildes

@return

int

@see libc/stdio/spawnf.c

posix_spawn_file_actions_addopen

Add an open action to object.

@param

char** file_actions
int fildes
const char* path
int oflag
unsigned int mode

@return

int

@see libc/stdio/spawnf.c

posix_spawn_file_actions_destroy

Frees object storage and make invalid.

@param

char** file_actions

@return

int

@see libc/stdio/spawnf.c

posix_spawn_file_actions_init

Creates object with no actions.

@param

char** file_actions

@return

int

@see libc/stdio/spawnf.c

posix_spawnattr_destroy

@param

struct _posix_spawnattr* attr

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_getflags

@param

struct _posix_spawnattr* attr
short* flags

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_getpgroup

@param

struct _posix_spawnattr* attr
int* pgroup

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_getschedparam

@param

struct _posix_spawnattr* attr
struct posix_attr_schedparam* schedparam

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_getschedpolicy

@param

struct _posix_spawnattr* attr
int* schedpolicy

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_getsigdefault

@param

struct _posix_spawnattr* attr
struct posix_attr_sigdefault* sigdefault

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_getsigmask

@param

struct _posix_spawnattr* attr
struct posix_attr_sigdefault* sigmask

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_init

Initialize object with default values.

@param

struct _posix_spawnattr* attr

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_setflags

@param

struct _posix_spawnattr* attr
short flags

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_setpgroup

@param

struct _posix_spawnattr* attr
int pgroup

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_setschedparam

@param

struct _posix_spawnattr* attr
struct posix_attr_schedparam* schedparam

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_setschedpolicy

@param

struct _posix_spawnattr* attr
int schedpolicy

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_setsigdefault

@param

struct _posix_spawnattr* attr
struct posix_attr_sigdefault* sigdefault

@return

int

@see libc/stdio/spawna.c

posix_spawnattr_setsigmask

@param

struct _posix_spawnattr* attr
struct posix_attr_sigdefault* sigmask

@return

int

@see libc/stdio/spawna.c

posix_spawnp

Spawns process the POSIX way w/ PATH search.

@param

int* pid: is non-NULL and will be set to child pid in parent
const char* path: of executable is PATH searched unless it contains a slash
char** file_actions
struct posix_spawnattr_t* attrp
char** argv
char** envp

@return

int: 0 on success or error number on failure

@see libc/stdio/spawnp.c

pow

Returns 𝑥^𝑦.

@param

𝑥: is double scalar in low half of %xmm0
𝑦: is double scalar in low half of %xmm1

@return

: double scalar in low half of %xmm0

@see libc/tinymath/pow-tiny.S

pow10

Returns 10^x.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see pow(), exp()

@see libc/tinymath/exp10.S

pow10f

Returns 10^x.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/exp10f.S

pow10l

Returns 10^x.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result of exponentiation on FPU stack in %st

@see libc/tinymath/exp10l.S

powf

Returns 𝑥^𝑦.

@param

𝑦: is float scalar in low quarter of %xmm0
𝑥: is float scalar in low quarter of %xmm1

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/powf-tiny.S

powi

Returns 𝑥^𝑦.

@param

𝑥: is double scalar in low half of %xmm0
𝑦: is int passed in %edi

@return

: double scalar in low half of %xmm0

@see libc/tinymath/powi.S

powif

Returns 𝑥^𝑦.

@param

𝑥: is float scalar in low quarter of %xmm0
𝑦: is int passed in %edi

@return

: double scalar in low half of %xmm0

@see libc/tinymath/powif.S

powil

Returns 𝑥^𝑦.

@param

𝑥: is long double passed on stack
𝑦: is int passed in %edi

@return

: %st

@see libc/tinymath/powil.S

prctl

Tunes process on Linux.

@param

int operation
...

@return

int

@raise ENOSYS on non-Linux

@see libc/calls/prctl.c

pread

Reads from file at offset, thus avoiding superfluous lseek().

@param

int fd: is something open()'d earlier, noting pipes might not work
void* buf: is copied into, cf. copy_file_range(), sendfile(), etc.
unsigned long size: in range [1..0x7ffff000] is reasonable
long offset: is bytes from start of file at which read begins

@return

long: [1..size] bytes on success, 0 on EOF, or -1 w/ errno; with exception of size==0, in which case return zero means no error

@see pwrite(), write()

@asyncsignalsafe

@vforksafe

@see libc/calls/pread.c

preadv

Reads with maximum generality.

@param

int fd
struct iovec* iov
int iovlen
long off

@return

long: number of bytes actually read, or -1 w/ errno

@asyncsignalsafe

@vforksafe

@see libc/calls/preadv.c

__print_maps

Prints memory mappings to stderr.

@return

void

@see libc/runtime/printmaps.c

__printargs

Prints lots of information about this process, e.g.

__printargs("");

This is called automatically in MODE=dbg if --strace is used.

@param

const char* prologue: needs to be a .rodata kprintf string

@return

void

@see libc/runtime/printargs.c

PrintBacktraceUsingSymbols

Prints stack frames with symbols.

PrintBacktraceUsingSymbols(STDOUT_FILENO, NULL, GetSymbolTable());

@param

int fd
struct StackFrame* bp: is rbp which can be NULL to detect automatically
struct SymbolTable* st: is open symbol table for current executable

@return

int: -1 w/ errno if error happened

@see libc/log/backtrace3.c

printf

Formats and writes text to stdout.

Cosmopolitan supports most of the standard formatting behaviors described by man 3 printf, in addition to the following

%jjd, %jjx, etc. are {,u}int128_t (cosmopolitan only)
%'d or %,d may be used to insert thousands separators. The prior is consistent with C; the latter is consistent with Python.
%m inserts strerror(errno) into the formatted output. This is consistent with glibc, musl, and uclibc.
%hs converts UTF-16/UCS-2 → UTF-8, which can be helpful on Windows. Formatting (e.g. %-10hs) will use monospace display width rather than string length or codepoint count.
%ls (or %Ls) converts UTF-32 → UTF-8. Formatting (e.g. %-10ls) will use monospace display width rather than string length.
The %#s and %#c alternate forms display values using the standard IBM standard 256-letter alphabet. Using %#.*s to specify length will allow true binary (i.e. with NULs) to be formatted.
The %'s and %'c alternate forms are Cosmopolitan extensions for escaping string literals for C/C++ and Python. The outer quotation marks can be added automatically using %`s. If constexpr format strings are used, we can avoid linking cescapec() too.
The backtick modifier (%`s and %`c) and repr() directive (%r) both ask the formatting machine to represent values as real code rather than using arbitrary traditions for displaying values. This means it implies the quoting modifier, wraps the value with {,u,L}['"] quotes, displays NULL as "NULL" rather than "(null)".

@param

const char* fmt
...

@return

int

@see __fmt() for intuitive reference documentation

@see {,v}{,s{,n},{,{,x}as},f,d}printf

@see libc/stdio/printf.c

PrintGarbage

Prints list of deferred operations on shadow stack.

@return

void

@see libc/log/printgarbage.c

PrintGarbageNumeric

Prints list of deferred operations on shadow stack w/o symbols.

@param

struct FILE* f

@return

void

@see libc/log/printgarbagenumeric.c

PrintMemoryIntervals

@param

int fd
struct _mmi* mm

@return

void

@see libc/runtime/printmemoryintervals.c

PrintSystemMappings

@param

int outfd

@return

void

@see libc/intrin/printsystemmappings.greg.c

program_executable_name

@type

char[1024]

@see libc/calls/getprogramexecutablename.greg.c

program_invocation_name

Supplies argv[0] the GNU way.

If argv[0] isn't supplied, this value will be null.

@return

@see program_invocation_short_name

@see GetProgramExecutableName()

@see libc/nexgen32e/program_invocation_name.S

program_invocation_short_name

Supplies basename(argv[0]) The GNU Way.

If argv[0] isn't supplied, this value will be null.

@return

@see GetProgramExecutableName()

@see program_invocation_name

@see libc/runtime/program_invocation_short_name.S

psadbw

Computes sum of absolute differences.

@param

unsigned long* a
const unsigned char* b
const unsigned char* c

@return

void

@mayalias

@see libc/intrin/psadbw.c

pselect

Does what poll() does except with bitset API.

This system call is supported on all platforms. It's like select() except that it atomically changes the sigprocmask() during the op.

@param

int nfds
struct fd_set* readfds
struct fd_set* writefds
struct fd_set* exceptfds
struct st_birthtim* timeout
struct sa_mask* sigmask

@return

int

@see libc/sock/pselect.c

pshufb

Shuffles and/or clears 8-bit integers.

@param

unsigned char* a
const unsigned char* b
const unsigned char* c

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@note doesn't perfectly emulate mmx

@mayalias

@see libc/intrin/pshufb.c

pshufd

Shuffles int vector.

@param

int* b
const int* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/pshufd.c

pshufhw

Shuffles lower half of word vector.

@param

short* b
const short* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/pshufhw.c

pshuflw

Shuffles lower half of word vector.

@param

short* b
const short* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/pshuflw.c

pshufw

Shuffles mmx vector.

@param

short* b
const short* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/pshufw.c

psignb

Conditionally negates or zeroes signed bytes.

@param

char* a
const char* b
const char* c

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@see libc/intrin/psignb.c

psignd

Conditionally negates or zeroes ints.

@param

int* a
const int* b
const int* c

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@see libc/intrin/psignd.c

psignw

Conditionally negates or zeroes shorts.

@param

short* a
const short* b
const short* c

@return

void

@note goes fast w/ ssse3 (intel c. 2004, amd c. 2011)

@see libc/intrin/psignw.c

pslld

Multiplies ints by two power.

@param

unsigned int* a
const unsigned int* b
unsigned char c

@return

void

@note c needs to be a literal, asmconstexpr, or linkconstsym

@mayalias

@see libc/intrin/pslld.c

pslldq

Shifts vector left by n bytes w/ zero-fill.

@param

unsigned char* b: receives output
const unsigned char* a: is input vector
unsigned long n

@return

void

@mayalias

@see libc/intrin/pslldq.c

pslldv

Multiplies ints by two power.

@param

unsigned int* a
const unsigned int* b
const unsigned long* c

@return

void

@mayalias

@see libc/intrin/pslldv.c

psllq

Multiplies longs by two power.

@param

unsigned long* a
const unsigned long* b
unsigned char c

@return

void

@note c needs to be a literal, asmconstexpr, or linkconstsym

@mayalias

@see libc/intrin/psllq.c

psllqv

Multiplies longs by two power.

@param

unsigned long* a
const unsigned long* b
const unsigned long* c

@return

void

@mayalias

@see libc/intrin/psllqv.c

psllw

Multiplies shorts by two power.

@param

unsigned short* a
const unsigned short* b
unsigned char c

@return

void

@note c needs to be a literal, asmconstexpr, or linkconstsym

@mayalias

@see libc/intrin/psllw.c

psllwv

Multiplies shorts by two power.

@param

unsigned short* a
const unsigned short* b
const unsigned long* c

@return

void

@mayalias

@see libc/intrin/psllwv.c

psrad

Divides ints by two power.

@param

int* a
const int* b
unsigned char k

@return

void

@note c needs to be a literal, asmconstexpr, or linkconstsym

@note arithmetic shift right will sign extend negatives

@mayalias

@see libc/intrin/psrad.c

psradv

Divides shorts by two powers.

@param

int* a
const int* b
const unsigned long* c

@return

void

@note arithmetic shift right will sign extend negatives

@mayalias

@see libc/intrin/psradv.c

psraw

Divides shorts by two power.

@param

short* a
const short* b
unsigned char k

@return

void

@note c needs to be a literal, asmconstexpr, or linkconstsym

@note arithmetic shift right will sign extend negatives

@mayalias

@see libc/intrin/psraw.c

psrawv

Divides shorts by two power.

@param

short* a
const short* b
const unsigned long* c

@return

void

@note arithmetic shift right will sign extend negatives

@mayalias

@see libc/intrin/psrawv.c

psrld

Divides unsigned ints by two power.

@param

unsigned int* a
const unsigned int* b
unsigned char c

@return

void

@note c needs to be a literal, asmconstexpr, or linkconstsym

@note logical shift does not sign extend negatives

@mayalias

@see libc/intrin/psrld.c

psrldq

Shifts vector left by n bytes w/ zero-fill.

@param

unsigned char* b: receives output
const unsigned char* a: is input vector
unsigned long n

@return

void

@mayalias

@see libc/intrin/psrldq.c

psrldv

Divides ints by two power.

@param

unsigned int* a
const unsigned int* b
const unsigned long* c

@return

void

@note logical shift does not sign extend negatives

@mayalias

@see libc/intrin/psrldv.c

psrlq

Divides unsigned longs by two power.

@param

unsigned long* a
const unsigned long* b
unsigned char c

@return

void

@note c needs to be a literal, asmconstexpr, or linkconstsym

@note logical shift does not sign extend negatives

@mayalias

@see libc/intrin/psrlq.c

psrlqv

Divides unsigned longs by two power.

@param

unsigned long* a
const unsigned long* b
const unsigned long* c

@return

void

@note logical shift does not sign extend negatives

@mayalias

@see libc/intrin/psrlqv.c

psrlw

Divides unsigned shorts by two power.

@param

unsigned short* a
const unsigned short* b
unsigned char c

@return

void

@note c needs to be a literal, asmconstexpr, or linkconstsym

@note logical shift does not sign extend negatives

@mayalias

@see libc/intrin/psrlw.c

psrlwv

Divides unsigned shorts by two power.

@param

unsigned short* a
const unsigned short* b
const unsigned long* c

@return

void

@note logical shift does not sign extend negatives

@mayalias

@see libc/intrin/psrlwv.c

psubb

Subtracts 8-bit integers.

@param

unsigned char* a
const unsigned char* b
const unsigned char* c

@return

void

@mayalias

@see libc/intrin/psubb.c

psubd

Subtracts 32-bit integers.

@param

unsigned int* a
const unsigned int* b
const unsigned int* c

@return

void

@mayalias

@see libc/intrin/psubd.c

psubq

Subtracts 64-bit integers.

@param

unsigned long* a
const unsigned long* b
const unsigned long* c

@return

void

@mayalias

@see libc/intrin/psubq.c

psubsb

Subtracts signed 8-bit integers w/ saturation.

@param

char* a
const char* b
const char* c

@return

void

@mayalias

@see libc/intrin/psubsb.c

psubsw

Subtracts signed 16-bit integers w/ saturation.

@param

short* a
const short* b
const short* c

@return

void

@mayalias

@see libc/intrin/psubsw.c

psubusb

Subtracts unsigned 8-bit integers w/ saturation.

@param

unsigned char* a
const unsigned char* b
const unsigned char* c

@return

void

@mayalias

@see libc/intrin/psubusb.c

psubusw

Subtracts unsigned 16-bit integers w/ saturation.

@param

unsigned short* a
const unsigned short* b
const unsigned short* c

@return

void

@mayalias

@see libc/intrin/psubusw.c

psubw

Subtracts 16-bit integers.

@param

short* a
const short* b
const short* c

@return

void

@mayalias

@see libc/intrin/psubw.c

pthread_cancel

@param

unsigned long* thread

@return

int

@see libc/intrin/pthread.c

pthread_getspecific

Gets value of TLS slot for current thread.

@param

unsigned int key

@return

void*

@see libc/thread/pthread_getspecific.c

pthread_key_create

Allocates TLS slot.

@param

unsigned int* key
void(*)() dtor

@return

int

@see libc/thread/pthread_key_create.c

pthread_key_delete

Deletes TLS slot.

@param

unsigned int key

@return

int

@see libc/thread/pthread_key_delete.c

pthread_mutex_destroy

Destroys mutex.

@param

struct pthread_mutex_t* mutex

@return

int: 0 on success, or error number on failure

@see libc/intrin/pthread_mutex_destroy.c

pthread_mutex_init

Initializes mutex.

@param

struct pthread_mutex_t* mutex
struct pthread_mutexattr_t* attr: may be NULL

@return

int: 0 on success, or error number on failure

@see libc/intrin/pthread_mutex_init.c

pthread_mutex_lock

Locks mutex.

_spinlock()         l:   181,570c    58,646ns
mutex normal        l:   297,965c    96,241ns
mutex recursive     l: 1,112,166c   359,223ns
mutex errorcheck    l: 1,449,723c   468,252ns

@param

struct pthread_mutex_t* mutex

@return

int: 0 on success, or error number on failure

@see libc/intrin/pthread_mutex_lock.c

pthread_mutex_trylock

Tries to acquire mutex.

@param

struct pthread_mutex_t* mutex

@return

int

@see libc/intrin/pthread_mutex_trylock.c

pthread_mutex_unlock

Releases mutex.

@param

struct pthread_mutex_t* mutex

@return

int: 0 on success or error number on failure

@raises EPERM if in error check mode and not owned by caller

@see libc/intrin/pthread_mutex_unlock.c

pthread_mutexattr_destroy

Destroys mutex attr.

@param

struct pthread_mutexattr_t* attr

@return

int: 0 on success, or error number on failure

@see libc/intrin/pthread_mutexattr_destroy.c

pthread_mutexattr_gettype

Gets mutex type.

@param

struct pthread_mutexattr_t* attr

int* type

will be set to one of these on success

PTHREAD_MUTEX_NORMAL
PTHREAD_MUTEX_DEFAULT
PTHREAD_MUTEX_RECURSIVE
PTHREAD_MUTEX_ERRORCHECK

@return

int: 0 on success, or error on failure

@see libc/intrin/pthread_mutexattr_gettype.c

pthread_mutexattr_init

Initializes mutex attr.

@param

struct pthread_mutexattr_t* attr

@return

int: 0 on success, or error number on failure

@see libc/intrin/pthread_mutexattr_init.c

pthread_mutexattr_settype

Sets mutex type.

@param

struct pthread_mutexattr_t* attr

int type

can be one of

PTHREAD_MUTEX_NORMAL
PTHREAD_MUTEX_DEFAULT
PTHREAD_MUTEX_RECURSIVE
PTHREAD_MUTEX_ERRORCHECK

@return

int: 0 on success, or error on failure

@raises EINVAL if type is invalid

@see libc/intrin/pthread_mutexattr_settype.c

pthread_once

@param

int* once
void(*)() init

@return

int

@see libc/intrin/pthread_once.c

pthread_setspecific

Sets value of TLS slot for current thread.

@param

unsigned int key
void* val

@return

int

@see libc/thread/pthread_setspecific.c

ptrace

Traces process.

@param

int request: can be PTRACE_xxx
...

@return

long

@note de facto linux only atm

@vforksafe

@see libc/calls/ptrace.c

ptsname

@param

int fd

@return

char*

@see libc/calls/ptsname.c

ptsname_r

@param

int fd
char* buf
unsigned long size

@return

int

@see libc/calls/ptsname_r.c

puff

@param

unsigned char* dest
unsigned long* destlen
const unsigned char* source
unsigned long* sourcelen

@return

int

@see third_party/zlib/puff.c

punpckhbw

Interleaves high bytes.

@param

unsigned char* a
const unsigned char* b
const unsigned char* c

@return

void

@mayalias

@see libc/intrin/punpckhbw.c

punpckhdq

Interleaves high doublewords.

     0    1    2    3
  B  aaaa bbbb CCCC DDDD
  C  eeee ffff GGGG HHHH
               └┬─┘ └─┬┘
           ┌────┘     │
     ┌─────┴─┐ ┌──────┴┐
→ A  CCCC GGGG DDDD HHHH

@param

unsigned int* a
const unsigned int* b
const unsigned int* c

@return

void

@mayalias

@see libc/intrin/punpckhdq.c

punpckhqdq

Interleaves high quadwords.

@param

unsigned long* a
const unsigned long* b
const unsigned long* c

@return

void

@mayalias

@see libc/intrin/punpckhqdq.c

punpckhwd

Interleaves high words.

     0  1  2  3  4  5  6  7
  B  aa bb cc dd EE FF GG HH
  C  ii jj kk ll MM NN OO PP
                 └┤ └┤ └┤ └┤
         ┌────────┘  │  │  │
         │     ┌─────┘  │  │
         │     │     ┌──┘  │
     ┌───┤ ┌───┤ ┌───┤ ┌───┤
→ A  EE MM FF NN GG OO HH PP

@param

unsigned short* a
const unsigned short* b
const unsigned short* c

@return

void

@mayalias

@see libc/intrin/punpckhwd.c

punpcklbw

Interleaves low bytes.

     0 1 2 3 4 5 6 7 8 9 A B C D E F
  B  A B C D E F G H i j k l m n o p
  C  Q R S T U V W X y z α σ π μ τ ε
     │ │ │ │ │ │ │ │
     │ │ │ └─────┐
     │ │ └───┐   │  etc...
     │ └─┐   │   │
     ├─┐ ├─┐ ├─┐ ├─┐
→ A  A Q B R C S D T E U F V G W H X

@param

unsigned char* a
const unsigned char* b
const unsigned char* c

@return

void

@mayalias

@see libc/intrin/punpcklbw.c

punpckldq

Interleaves low doublewords.

     0    1    2    3
  B  AAAA BBBB cccc dddd
  C  EEEE FFFF gggg hhhh
     └┬─┘ └─┬┘
      │     └───┐
     ┌┴──────┐ ┌┴──────┐
→ A  AAAA EEEE BBBB FFFF

@param

unsigned int* a
const unsigned int* b
const unsigned int* c

@return

void

@mayalias

@see libc/intrin/punpckldq.c

punpcklqdq

Interleaves low quadwords.

@param

unsigned long* a
const unsigned long* b
const unsigned long* c

@return

void

@mayalias

@see libc/intrin/punpcklqdq.c

punpcklwd

Interleaves low words.

     0  1  2  3  4  5  6  7
  B  AA BB CC DD ee ff gg hh
  C  II JJ KK LL mm nn oo pp
     ├┘ ├┘ ├┘ ├┘
     │  │  │  └────────┐
     │  │  └─────┐     │
     │  └──┐     │     │
     ├───┐ ├───┐ ├───┐ ├───┐
→ A  AA II BB JJ CC KK DD LL

@param

unsigned short* a
const unsigned short* b
const unsigned short* c

@return

void

@mayalias

@see libc/intrin/punpcklwd.c

putc

Writes byte to stream.

@param

int c: is byte to buffer or write, which is masked
struct FILE* f

@return

int: c as unsigned char if written or -1 w/ errno

@threadsafe

@see libc/stdio/putc.c

putc_unlocked

Writes byte to stream.

@param

int c: is byte to buffer or write, which is masked
struct FILE* f

@return

int: c as unsigned char if written or -1 w/ errno

@see libc/stdio/putc_unlocked.c

putchar

Writes byte to stdout.

@param

int c

@return

int: c (as unsigned char) if written or -1 w/ errno

@threadsafe

@see libc/stdio/putchar.c

putchar_unlocked

Writes byte to stdout.

@param

int c

@return

int: c (as unsigned char) if written or -1 w/ errno

@see libc/stdio/putchar_unlocked.c

putenv

Emplaces environment key=value.

@param

char* s

@return

int: 0 on success or non-zero on error

@see setenv(), getenv()

@see libc/mem/putenv.c

PutEnvImpl

@param

char* s
_Bool overwrite

@return

int

@see libc/mem/putenv.c

puts

Writes string w/ trailing newline to stdout.

@param

const char* s

@return

int: non-negative number on success, or EOF on error with errno set and the ferror(stdout) state is updated

@see libc/stdio/puts.c

pututf16

Encodes character to string as UTF-16.

Implementation Details: The header macro should ensure this function is only called for truly huge codepoints. Plus this function makes a promise to not clobber any registers but %rax.

@param

unsigned short* s: is what ch gets encoded to
unsigned long size: is the number of shorts available in s
unsigned int wc
_Bool awesome: enables numbers the IETF unilaterally banned

@return

int: number of shorts written or -1 w/ errno

@todo delete

@see libc/str/pututf16.ncabi.c

putwc

Writes wide character to stream.

@param

int wc
struct FILE* f

@return

unsigned int: wc if written or -1 w/ errno

@threadsafe

@see libc/stdio/putwc.c

putwc_unlocked

Writes wide character to stream.

@param

int wc
struct FILE* f

@return

unsigned int: wc if written or -1 w/ errno

@see libc/stdio/putwc_unlocked.c

putwchar

Writes wide character to stdout.

@param

int wc

@return

unsigned int: wc if written or -1 w/ errno

@threadsafe

@see libc/stdio/putwchar.c

putwchar_unlocked

Writes wide character to stdout.

@param

int wc

@return

unsigned int: wc if written or -1 w/ errno

@see libc/stdio/putwchar_unlocked.c

pvalloc

Equivalent to memalign(PAGESIZE, ROUNDUP(n, PAGESIZE)).

@param

unsigned long n: number of bytes needed

@return

void*: memory address, or NULL w/ errno

@see valloc()

@threadsafe

@see libc/mem/pvalloc.c

pwrite

Writes to file at offset, thus avoiding superfluous lseek().

@param

int fd: is something open()'d earlier, noting pipes might not work
void* buf: is copied from, cf. copy_file_range(), sendfile(), etc.
unsigned long size: in range [1..0x7ffff000] is reasonable
long offset: is bytes from start of file at which write begins, which can exceed or overlap the end of file, in which case your file will be extended

@return

long: [1..size] bytes on success, or -1 w/ errno; noting zero is impossible unless size was passed as zero to do an error check

@see pread(), write()

@asyncsignalsafe

@vforksafe

@see libc/calls/pwrite.c

pwritev

Writes data from multiple buffers to offset.

Please note that it's not an error for a short write to happen. This can happen in the kernel if EINTR happens after some of the write has been committed. It can also happen if we need to polyfill this system call using pwrite().

@param

int fd
struct iovec* iov
int iovlen
long off

@return

long: number of bytes actually sent, or -1 w/ errno

@asyncsignalsafe

@vforksafe

@see libc/calls/pwritev.c

pxor

Xors 128-bit integers.

@param

unsigned long* a
const unsigned long* b
const unsigned long* c

@return

void

@mayalias

@see libc/intrin/pxor.c

qsort

Sorts array.

@param

void* base: points to an array to sort in-place
unsigned long count: is the item count
unsigned long width: is the size of each item
int(*)() cmp: is a callback returning <0, 0, or >0

@return

void

@see longsort(), djbsort()

@see libc/str/qsort.c

qsort_r

Sorts array.

@param

void* base: points to an array to sort in-place
unsigned long count: is the item count
unsigned long width: is the size of each item
int(*)() cmp: is a callback returning <0, 0, or >0
void* arg: will optionally be passed as the third argument to cmp

@return

void

@see qsort()

@see libc/str/qsort.c

quick_exit

Exits process faster.

@param

int exitcode: is masked with 255

@noreturn

@see libc/intrin/quick_exit.c

raise

Sends signal to this process.

@param

int sig: can be SIGALRM, SIGINT, SIGTERM, SIGKILL, etc.

@return

int: 0 on success or -1 w/ errno

@asyncsignalsafe

@see libc/calls/raise.c

rand

Returns 31-bit linear congruential pseudorandom number, e.g.

int x = rand();
assert(x >= 0);

This function always returns a positive number. If srand() isn't called, then it'll return the same sequence each time your program runs. Faster and more modern alternatives exist to this function.

This function is not thread safe in the sense that multiple threads might simultaneously generate the same random values.

@return

int

@note this function does well on bigcrush and practrand

@note this function is not intended for cryptography

@see lemur64(), rand64(), rdrand()

@see libc/rand/rand.c

rand64

Returns nondeterministic random data.

This function is similar to lemur64() except that it doesn't produce the same sequences of numbers each time your program is run. This is the case even across forks and threads, whose sequences will differ.

@return

unsigned long

@see rdseed(), rdrand(), rand(), random(), rngset()

@note this function takes 5 cycles (30 if __threaded)

@note this function is not intended for cryptography

@note this function passes bigcrush and practrand

@asyncsignalsafe

@threadsafe

@vforksafe

@see libc/rand/rand64.c

random

@return

long

@see libc/rand/random.c

rawmemchr16

Returns pointer to first instance of character in range.

@param

rdi: is a non-null pointer to memory
esi: is the search word

@return

: rax points to word if found, or else undefined behavior

@see libc/nexgen32e/strsak16.S

rawwmemchr

Returns pointer to first instance of character in range.

@param

rdi: is a non-null pointer to memory
esi: is the search word

@return

: rax points to word if found, or else undefined behavior

@see libc/nexgen32e/strsak32.S

rdrand

Retrieves 64-bits of hardware random data from RDRAND instruction.

If RDRAND isn't available (we check CPUID and we also disable it automatically for microarchitectures where it's slow or buggy) then we try getrandom(), RtlGenRandom(), or sysctl(KERN_ARND). If those aren't available then we try /dev/urandom and if that fails, we try getauxval(AT_RANDOM), and if not we finally use RDTSC and getpid().

@return

unsigned long

@note this function could block a nontrivial time on old computers

@note this function is indeed intended for cryptography

@note this function takes around 300 cycles

@see rngset(), rdseed(), rand64()

@asyncsignalsafe

@vforksafe

@see libc/rand/rdrand.c

rdrand_init

@param

int argc
char** argv
char** envp
long* auxv

@return

void

@see libc/rand/rdrand_init.c

rdseed

Retrieves 64-bits of true random data from RDSEED instruction.

If RDSEED isn't available, we'll try RDRAND (which we automatically disable for microarchitectures where it's known to be slow or buggy). If RDRAND isn't available then we try getrandom(), RtlGenRandom(), or sysctl(KERN_ARND). If those aren't available then we try /dev/urandom and if that fails, we use RDTSC and getpid().

@return

unsigned long

@note this function could block a nontrivial time on old computers

@note this function is indeed intended for cryptography

@note this function takes around 800 cycles

@see rngset(), rdrand(), rand64()

@asyncsignalsafe

@vforksafe

@see libc/rand/rdseed.c

read

Reads data from file descriptor.

@param

int fd: is something open()'d earlier
void* buf: is copied into, cf. copy_file_range(), sendfile(), etc.
unsigned long size: in range [1..0x7ffff000] is reasonable

@return

long: [1..size] bytes on success, 0 on EOF, or -1 w/ errno; with exception of size==0, in which case return zero means no error

@see write(), pread(), readv()

@asyncsignalsafe

@restartable

@see libc/calls/read.c

readansi

Reads single keystroke or control sequence from character device.

When reading ANSI UTF-8 text streams, characters and control codes are oftentimes encoded as multi-byte sequences. This function knows how long each sequence is, so that each read consumes a single thing from the underlying file descriptor, e.g.

"a"               ALFA
"\316\261"        ALPHA
"\e[38;5;202m"    ORANGERED
"\e[A"            UP
"\e\e[A"          ALT-UP
"\001"            CTRL-ALFA
"\e\001"          ALT-CTRL-ALFA
"\eOP"            PF1
"\000"            NUL
"\e]rm -rf /\e\\" OSC
"\302\233A"       UP
"\300\200"        NUL

This routine generalizes to ascii, utf-8, chorded modifier keys, function keys, color codes, c0/c1 control codes, cursor movement, mouse movement, etc.

Userspace buffering isn't required, since ANSI escape sequences and UTF-8 are decoded without peeking. Noncanonical overlong encodings can cause the stream to go out of sync. This function recovers such events by ignoring continuation bytes at the beginning of each read.

@param

int fd
char* p: is guaranteed to receive a NUL terminator if n>0
unsigned long n

@return

long: number of bytes read (helps differentiate "\0" vs. "")

@see examples/ttyinfo.c

@see ANSI X3.64-1979

@see ISO/IEC 6429

@see FIPS-86

@see ECMA-48

@see libc/calls/readansi.c

readdir

Reads next entry from directory stream.

This API doesn't define any particular ordering.

@param

struct dirstream* dir: is the object opendir() or fdopendir() returned

@return

struct ent*: next entry or NULL on end or error, which can be differentiated by setting errno to 0 beforehand

@see libc/stdio/dirstream.c

readlink

Reads symbolic link.

@param

const char* path: must be a symbolic link pathname
char* buf: will receive symbolic link contents, and won't be modified unless the function succeeds (with the exception of no-malloc nt) and this buffer will *not* be nul-terminated
unsigned long bufsiz

@return

long: number of bytes written to buf, or -1 w/ errno; if the return is equal to bufsiz then truncation may have occurred

@see readlinkat(AT_FDCWD, ...) for modern version of this

@error EINVAL if path isn't a symbolic link

@asyncsignalsafe

@see libc/calls/readlink.c

readlinkat

Reads symbolic link.

This does *not* nul-terminate the buffer.

@param

int dirfd: is normally AT_FDCWD but if it's an open directory and file is a relative path, then file is opened relative to dirfd
const char* path: must be a symbolic link pathname
char* buf: will receive symbolic link contents, and won't be modified unless the function succeeds (with the exception of no-malloc nt) and this buffer will *not* be nul-terminated
unsigned long bufsiz

@return

long: number of bytes written to buf, or -1 w/ errno; if the return is equal to bufsiz then truncation may have occurred

@error EINVAL if path isn't a symbolic link

@asyncsignalsafe

@see libc/calls/readlinkat.c

readv

Reads data to multiple buffers.

This is the same thing as read() except it has multiple buffers. This yields a performance boost in situations where it'd be expensive to stitch data together using memcpy() or issuing multiple syscalls. This wrapper is implemented so that readv() calls where iovlen<2 may be passed to the kernel as read() instead. This yields a 100 cycle performance boost in the case of a single small iovec.

@param

int fd
struct iovec* iov
int iovlen

@return

long: number of bytes actually read, or -1 w/ errno

@restartable

@see libc/calls/readv.c

_real1

Generates number on [0,1]-real-interval, e.g.

double x = _real1(lemur64())

@param

unsigned long x

@return

double

@see lemur64(), mt19937()

@see libc/rand/real1.c

_real2

Generates number on [0,1)-real-interval, e.g.

double x = _real2(lemur64())

@param

unsigned long x

@return

double

@see lemur64(), mt19937()

@see libc/rand/real2.c

_real3

Generates number on (0,1)-real-interval, e.g.

double x = _real3(lemur64())

@param

unsigned long x

@return

double

@see lemur64(), mt19937()

@see libc/rand/real3.c

realloc

Allocates / resizes / frees memory, e.g.

Returns a pointer to a chunk of size n that contains the same data as does chunk p up to the minimum of (n, p's size) bytes, or null if no space is available.

If p is NULL, realloc is equivalent to malloc. If p is not NULL and n is 0, realloc is equivalent to free.

The returned pointer may or may not be the same as p. The algorithm prefers extending p in most cases when possible, otherwise it employs the equivalent of a malloc-copy-free sequence.

Please note that p is NOT free()'d should realloc() fail, thus:

if ((p2 = realloc(p, n2))) {
  p = p2;
  ...
} else {
  ...
}

if n is for fewer bytes than already held by p, the newly unused space is lopped off and freed if possible.

The old unix realloc convention of allowing the last-free'd chunk to be used as an argument to realloc is not supported.

@param

rdi: (p) is address of current allocation or NULL
rsi: (n) is number of bytes needed

@return

: rax is result, or NULL w/ errno w/o free(p)

@note realloc(p=0, n=0) → malloc(32)

@note realloc(p≠0, n=0) → free(p)

@see dlrealloc()

@threadsafe

@see libc/mem/realloc.S

realloc_in_place

Resizes the space allocated for p to size n, only if this can be done without moving p (i.e., only if there is adjacent space available if n is greater than p's current allocated size, or n is less than or equal to p's size). This may be used instead of plain realloc if an alternative allocation strategy is needed upon failure to expand space, for example, reallocation of a buffer that must be memory-aligned or cleared. You can use realloc_in_place to trigger these alternatives only when needed.

@param

rdi: (p) is address of current allocation
rsi: (newsize) is number of bytes needed

@return

: rax is result, or NULL w/ errno

@see dlrealloc_in_place()

@threadsafe

@see libc/mem/realloc_in_place.S

reallocarray

Manages array memory, the BSD way.

@param

void* ptr: may be NULL for malloc() behavior
unsigned long nmemb: may be 0 for free() behavior; shrinking is promised too
unsigned long itemsize

@return

void*: new address or NULL w/ errno and ptr is NOT free()'d

@threadsafe

@see libc/mem/reallocarray.c

realpath

Returns absolute pathname.

This function removes /./ and /../ components. IF the path is a symbolic link then it's resolved.

@param

const char* filename
char* resolved: needs PATH_MAX bytes or NULL to use malloc()

@return

char*: resolved or NULL w/ errno

@see libc/calls/realpath.c

reboot

Reboots system.

The howto argument may be one of the following:

RB_AUTOBOOT
RB_POWER_OFF
RB_HALT_SYSTEM
RB_SW_SUSPEND (linux and windows only)
RB_KEXEC (linux only)
RB_ENABLE_CAD (linux only)
RB_DISABLE_CAD (linux only)

There's an implicit sync() operation before the reboot happens. This can be prevented by or'ing howto with RB_NOSYNC. Setting this option will also prevent apps on Windows from having time to close themselves.

@param

int howto

@return

int

@see libc/calls/reboot.c

recv

Receives data from network socket.

@param

int fd: is the file descriptor returned by socket()
void* buf: is where received network data gets copied
unsigned long size: is the byte capacity of buf
int flags: can have MSG_{WAITALL,PEEK,OOB}, etc.

@return

long: number of bytes received, 0 on remote close, or -1 w/ errno

@error EINTR, EHOSTUNREACH, ECONNRESET (UDP ICMP Port Unreachable), EPIPE (if MSG_NOSIGNAL), EMSGSIZE, ENOTSOCK, EFAULT, etc.

@asyncsignalsafe

@restartable (unless SO_RCVTIMEO)

@see libc/sock/recv.c

recvfrom

Receives data from network.

This function blocks unless MSG_DONTWAIT is passed.

@param

int fd: is the file descriptor returned by socket()
void* buf: is where received network data gets copied
unsigned long size: is the byte capacity of buf
unsigned int flags: can have MSG_{WAITALL,DONTROUTE,PEEK,OOB}, etc.
void* opt_out_srcaddr: receives the binary ip:port of the data's origin
unsigned int* opt_inout_srcaddrsize: is srcaddr capacity which gets updated

@return

long: number of bytes received, 0 on remote close, or -1 w/ errno

@error EINTR, EHOSTUNREACH, ECONNRESET (UDP ICMP Port Unreachable), EPIPE (if MSG_NOSIGNAL), EMSGSIZE, ENOTSOCK, EFAULT, etc.

@asyncsignalsafe

@restartable (unless SO_RCVTIMEO)

@see libc/sock/recvfrom.c

recvmsg

Sends a message from a socket.

@param

int fd

is the file descriptor returned by socket()

struct msg2* msg

is a pointer to a struct msghdr containing all the allocated

   buffers where to store incoming data.

int flags

MSG_OOB, MSG_DONTROUTE, MSG_PARTIAL, MSG_NOSIGNAL, etc.

@return

long: number of bytes received, or -1 w/ errno

@error EINTR, EHOSTUNREACH, ECONNRESET (UDP ICMP Port Unreachable), EPIPE (if MSG_NOSIGNAL), EMSGSIZE, ENOTSOCK, EFAULT, etc.

@asyncsignalsafe

@restartable (unless SO_RCVTIMEO)

@see libc/sock/recvmsg.c

RefreshTime

@return

void

@see libc/calls/now.c

regcomp

Compiles regular expression, e.g.

regex_t rx;
CHECK_EQ(REG_OK, regcomp(&rx, "^[A-Za-z]{2}$", REG_EXTENDED));
CHECK_EQ(REG_OK, regexec(&rx, "→A", 0, NULL, 0));
regfree(&rx);

@param

struct regex_t* preg: points to caller allocated memory that's used to store your regular expression. This memory needn't be initialized. If this function succeeds, then preg must be passed to regfree() later on, to free its associated resources
const char* regex: is utf-8 regular expression nul-terminated string
int cflags: can have REG_EXTENDED, REG_ICASE, REG_NEWLINE, REG_NOSUB

@return

int: REG_OK, REG_NOMATCH, REG_BADPAT, etc.

@see regexec(), regfree(), regerror()

@see third_party/regex/regcomp.c

regerror

Converts regular expression error code to string.

@param

int e: is error code
struct regex_t* preg
char* buf
unsigned long size

@return

unsigned long: number of bytes needed to hold entire string

@see third_party/regex/regerror.c

regexec

Executes regular expression.

@param

struct regex_t* preg: is state object previously made by regcomp()
const char* string
unsigned long nmatch
struct regmatch_t* pmatch
int eflags: can have REG_NOTBOL, REG_NOTEOL

@return

int: 0 or REG_NOMATCH

@see third_party/regex/regexec.c

regfree

Frees any memory allocated by regcomp().

The same object may be destroyed by regfree() multiple times, in which case subsequent calls do nothing. Once a regex is freed, it may be passed to regcomp() to reinitialize it.

@param

struct regex_t* preg

@return

void

@see third_party/regex/regcomp.c

ReleaseMemoryIntervals

@param

struct _mmi* mm
int x
int y
void(*)() wf

@return

int

@see libc/calls/memtrack.greg.c

ReleaseMemoryNt

@param

struct _mmi* mm
int l
int r

@return

void

@see libc/runtime/memtracknt.c

remainder

remainder(𝑥,𝑦) means (𝑥 rem 𝑦) w/ rint()-style rounding.

@param

𝑥: is double passed in lower half of %xmm0
𝑦: is double passed in lower half of %xmm1

@return

: remainder ∈ (-|𝑦|,|𝑦|) in %xmm0

@define 𝑥-rint(𝑥/𝑦)*𝑦

@see fmod(), emod(), operator%

@see libc/tinymath/remainder.S

remove

Deletes "file" or empty directory associtaed with name.

@param

const char* name

@return

int: 0 on success or -1 w/ errno

@see unlink() and rmdir() which this abstracts

@see libc/calls/remove.c

RemoveDirectory

Deletes existing empty directory on the New Technology.

@param

const unsigned short* lpPathName

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/removedirectory.c

remquo

Computes remainder and part of quotient.

@param

double x
double y
int* quo

@return

double

@see libc/tinymath/remquo.c

remquof

Computes remainder and part of quotient.

@param

float x
float y
int* quo

@return

float

@see libc/tinymath/remquof.c

remquol

Computes remainder and part of quotient.

@param

long double x
long double y
int* quo

@return

long double

@see libc/tinymath/remquol.c

rename

Moves file the Unix way.

This is generally an atomic operation with the file system, since all it's doing is changing a name associated with an inode. However, that means rename() doesn't permit your oldpathname and newpathname to be on separate file systems, in which case this returns EXDEV. That's also the case on Windows.

@param

const char* oldpathname
const char* newpathname

@return

int: 0 on success or -1 w/ errno

@asyncsignalsafe

@see libc/calls/rename.c

renameat

Renames files relative to directories.

@param

int olddirfd: is normally AT_FDCWD but if it's an open directory and oldpath is relative, then oldpath become relative to dirfd
const char* oldpath
int newdirfd: is normally AT_FDCWD but if it's an open directory and newpath is relative, then newpath become relative to dirfd
const char* newpath

@return

int: 0 on success, or -1 w/ errno

@see libc/calls/renameat.c

ReOpenFile

Reopens file on the New Technology.

@param

long hOriginalFile
unsigned int dwDesiredAccess
unsigned int dwShareMode
unsigned int dwFlagsAndAttributes

@return

long: handle, or -1 on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/reopenfile.c

replacestr

Replaces all instances of NEEDLE in S with REPLACEMENT.

@param

const char* s
const char* needle: can't be empty
const char* replacement

@return

char*: newly allocated memory that must be free()'d or NULL w/ errno

@error ENOMEM, EINVAL

@see libc/alg/replacestr.c

replaceuser

Replaces tilde in path w/ user home folder.

@param

const char* path: is NULL propagating

@return

char*: must be free()'d

@see libc/x/replaceuser.c

__replmode

Controls ANSI prefix for log emissions.

This should be true in raw tty mode repls.

@type

char

@see kprintf(), vflogf(), linenoise()

@see libc/intrin/nomultics.c

__reservefd

Finds open file descriptor slot.

@param

int start

@return

int

@asyncsignalsafe

@threadsafe

@see libc/calls/reservefd.c

__reservefd_unlocked

Finds open file descriptor slot.

@param

int start

@return

int

@asyncsignalsafe

@see libc/calls/reservefd.c

ResolveDns

Queries Domain Name System for address associated with name.

@param

struct ResolvConf* resolvconf: can be GetResolvConf()
int af: can be AF_INET, AF_UNSPEC
const char* name: can be a local or fully-qualified hostname
struct sa* addr: should point to a struct sockaddr_in; if this function succeeds, its sin_family and sin_addr fields will be modified
unsigned int addrsize: is the byte size of addr

@return

int: number of matches found, or -1 w/ errno

@error EAFNOSUPPORT. ENETDOWN, ENAMETOOLONG, EBADMSG

@see libc/dns/resolvedns.c

ResolveDnsReverse

Performs reverse DNS lookup with IP address.

@param

struct ResolvConf* resolvconf: can be GetResolvConf()
int af: can be AF_INET, AF_UNSPEC
const char* name: is a reversed IP address string ending with .in-addr.arpa
char* buf: to store the obtained hostname if any
unsigned long bufsize: is size of buf

@return

int: 0 on success, or -1 w/ errno

@error EAFNOSUPPORT, ENETDOWN, ENAMETOOLONG, EBADMSG

@see libc/dns/resolvednsreverse.c

ResolveHostsReverse

Finds name associated with address in HOSTS.TXT table.

@param

struct HostsTxt* ht: can be GetHostsTxt()
int af: can be AF_INET
const unsigned char* ip: is IP address in binary (sin_addr)
char* buf: is buffer to store the name
unsigned long bufsize: is length of buf

@return

int: 1 if found, 0 if not found, or -1 w/ errno

@error EAFNOSUPPORT

@see libc/dns/resolvehostsreverse.c

ResolveHostsTxt

Finds address associated with name in HOSTS.TXT table.

@param

struct HostsTxt* ht: can be GetHostsTxt()
int af: can be AF_INET, AF_UNSPEC
const char* name: can be a local or fully-qualified hostname
struct sockaddr* addr: should point to a struct sockaddr_in; if this function succeeds, its sin_family and sin_addr fields will be modified
unsigned int addrsize: is the byte size of addr
const char** canon: be used to return a pointer to the canonical name

@return

int: number of matches found, or -1 w/ errno

@error EAFNOSUPPORT

@see libc/dns/resolvehoststxt.c

RestoreDefaultCrashSignalHandlers

@return

void

@see libc/log/showcrashreports.c

__restorewintty

Puts cmd.exe gui back the way it was.

@return

void

@see libc/intrin/restorewintty.c

rewind

Moves standard i/o stream to beginning of file.

Like fseek(), this function can be used to restore a stream from the EOF state, without reopening it.

@param

struct FILE* f

@return

void

@see libc/stdio/rewind.c

rewinddir

Seeks to beginning of directory stream.

@param

struct dirstream* dir

@return

void

@see libc/stdio/dirstream.c

rindex

Returns pointer to last instance of character the BSD way.

@param

rdi: is a non-null NUL-terminated string pointer
esi: is the search byte

@return

: rax points to result, or NULL if not found

@see libc/str/rindex.S

rint

Rounds to nearest integer.

@param

is: double passed in %xmm0

@return

: double in %xmm0

@note rounding behavior can be changed in mxcsr

@see libc/tinymath/rint.S

rintl

Rounds to nearest integer.

@param

is: long double passed on stack

@return

: long double in %st

@note rounding behavior can be changed in control word

@see libc/tinymath/rintl.S

rldecode

Thirteen byte decompressor.

@param

di: points to output buffer
si: points to uint8_t {len₁,byte₁}, ..., {0,0}

@return

@mode long,legacy,real

@see libc/nexgen32e/rldecode.S

rldecode2

@param

void* d
struct RlDecode* r

@return

void

@see libc/str/rldecode2.c

rmdir

Deletes empty directory.

@param

const char* path

@return

int: 0 on success or -1 w/ errno on error

@see libc/calls/rmdir.c

rmrf

Recursively removes file or directory.

@param

const char* path

@return

int

@see libc/x/rmrf.c

rngset

Fills memory with random bytes, e.g.

char buf[512];
rngset(buf, sizeof(buf), 0, 0);

If reseed is zero then the internal PRNG is disabled and bytes are simply copied in little-endian order from the seed function. If seed is NULL then the reseed parameter is used as the seed value for the internal PRNG. If seed!=NULL and reseed>8 then reseed is the number of bytes after which the seed() function should be called again, to freshen up the PRNG.

The main advantage of this generator is that it produces data at 13 gigabytes per second since Vigna's Algorithm vectorizes better than alternatives, going even faster than xorshift.

@param

void* b
unsigned long n
unsigned long(*)() seed
unsigned long reseed

@return

void*: original buf

@see libc/rand/rngset.c

round

Rounds to nearest integer, away from zero.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@define round(𝑥) = copysign(trunc(fabs(𝑥)+.5),𝑥) round(𝑥) = trunc(𝑥+copysign(.5,𝑥))

@see libc/tinymath/round.S

rounddown2pow

Returns 𝑥 rounded down to previous two power.

@param

unsigned long x

@return

unsigned long

@define (𝑥>0→2^⌊log₂𝑥⌋, x=0→0, 𝑇→⊥)

@see roundup2pow()

@see libc/bits/rounddown2pow.c

roundf

Rounds to nearest integer, away from zero.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@see libc/tinymath/roundf.S

roundl

Rounds to nearest integer, away from zero.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result of exponentiation on FPU stack in %st

@see libc/tinymath/roundl.S

roundup2log

Returns 𝑥 rounded up to next two power and log'd.

@param

unsigned long x

@return

unsigned long

@see roundup2pow()

@see libc/bits/roundup2log.c

roundup2pow

Returns 𝑥 rounded up to next two power.

@param

unsigned long x

@return

unsigned long

@define (𝑥>0→2^⌈log₂x⌉, x=0→0, 𝑇→⊥)

@see rounddown2pow()

@see libc/bits/roundup2pow.c

rt_add

@param

void* buf
int bufl

@return

void

@see libc/rand/randtest.c

rt_end

@param

double* r_ent
double* r_chisq
double* r_mean
double* r_montepicalc
double* r_scc

@return

void

@see libc/rand/randtest.c

rt_init

@param

int binmode

@return

void

@see libc/rand/randtest.c

__sample_pids

Returns handles of windows pids being tracked.

We return 64 at most because Windows can't await on a larger number of things at the same time. If we have a lot of subprocesses, then we choose a subgroup to monitor at random.

@param

int* pids
long* handles
_Bool exploratory

@return

int: number of items returned in pids and handles

@see libc/calls/samplepids.c

_savexmm

Stores XMM registers to buffer.

@param

%rdi: points to &(forcealign(16) uint8_t[256])[128]

@return

@note modern cpus have out-of-order execution engines

@see libc/nexgen32e/savexmm.S

sbrk

Adjusts end of data section.

This shrinks or increases the program break by delta bytes. On success, the previous program break is returned. It's possible to pass zero to this function to get the current program break

@param

long delta

@return

void*: old break on success or -1 w/ errno

@see mmap(), brk(), _end

@see libc/runtime/brk.c

scalb

Returns 𝑥 × 2ʸ.

@param

𝑥: is double passed in %xmm0
𝑦: is double passed in %xmm1, which is truncated

@return

: result in %xmm0

@see ldexp()

@see libc/tinymath/scalb.S

scalbf

Returns 𝑥 × 2ʸ.

@param

𝑥: is float passed in %xmm0
𝑦: is float passed in %xmm1, which is truncated

@return

: result in %xmm0

@see ldexpf()

@see libc/tinymath/scalbf.S

scalbl

Returns 𝑥 × 2ʸ.

@param

𝑥: is long double passed on stack
𝑦: is long double passed on stack

@return

: result in %st0

@see ldexpl()

@see libc/tinymath/scalbl.S

scalbln

Returns 𝑥 × 2ʸ.

@param

double x
long n

@return

double

@see libc/tinymath/scalbln.c

scalblnf

Returns 𝑥 × 2ʸ.

@param

float x
long n

@return

float

@see libc/tinymath/scalblnf.c

scalblnl

Returns 𝑥 × 2ʸ.

@param

𝑥: is long double passed on stack
𝑦: is exponent via %edi

@return

: result in %st0

@see libc/tinymath/ldexpl.S

scalbn

Returns 𝑥 × 2ʸ.

@param

double x
int n

@return

double

@see libc/tinymath/scalbn.c

scalbnf

Returns 𝑥 × 2ʸ.

@param

float x
int n

@return

float

@see libc/tinymath/scalbnf.c

scalbnl

Returns 𝑥 × 2ʸ.

@param

𝑥: is long double passed on stack
𝑦: is exponent via %edi

@return

: result in %st0

@see libc/tinymath/ldexpl.S

scanf

Standard input decoder.

@param

const char* fmt
...

@return

int

@see libc/fmt/vcscanf.h

@see libc/stdio/scanf.c

sched_get_priority_max

Returns maximum sched_param::sched_priority for policy.

@param

int policy

@return

int: priority, or -1 w/ errno

@raise ENOSYS on XNU, Windows, OpenBSD

@raise EINVAL if policy is invalid

@see libc/calls/sched_get_priority_max.c

sched_get_priority_min

Returns minimum sched_param::sched_priority for policy.

@param

int policy

@return

int: priority, or -1 w/ errno

@raise ENOSYS on XNU, Windows, OpenBSD

@raise EINVAL if policy is invalid

@see libc/calls/sched_get_priority_min.c

sched_getaffinity

Gets kernel scheduling for particular CPUs.

@param

int tid
unsigned long size: is byte length of bitset
void* bitset: receives bitset and should be uint64_t[16] in order to work on older versions of Linux

@return

int: 0 on success, or -1 w/ errno

@raise ENOSYS on non-Linux

@see libc/calls/sched_getaffinity.c

sched_getparam

Gets scheduler policy parameter.

@param

int pid
struct sched_param* param

@return

int: 0 on success, or -1 w/ errno

@raise ENOSYS on XNU, Windows

@see libc/calls/sched_getparam.c

sched_getscheduler

Gets scheduler policy for pid.

@param

int pid: is the id of the process whose scheduling policy should be queried. Setting pid to zero means the same thing as getpid(). This applies to all threads associated with the process. Linux is special; the kernel treats this as a thread id (noting that getpid() == gettid() is always the case on Linux for the main thread) and will only take effect for the specified tid. Therefore this function is POSIX-compliant iif !__threaded.

@return

int: scheduler policy, or -1 w/ errno

@error ESRCH if pid not found

@error EPERM if not permitted

@error EINVAL if pid is negative on Linux

@see libc/calls/sched_getscheduler.c

sched_rr_get_interval

Returns round-robin SCHED_RR quantum for pid.

@param

int pid: is id of process (where 0 is same as getpid())
struct st_birthtim* tp: receives output interval

@return

int: 0 on success, or -1 w/ errno

@error ENOSYS if not Linux or FreeBSD

@error EFAULT if tp memory is invalid

@error EINVAL if invalid pid

@error ESRCH if could not find pid

@see libc/calls/sched_rr_get_interval.c

sched_setaffinity

Asks kernel to only schedule process on particular CPUs.

@param

int tid: is the process or thread id (or 0 for caller)
unsigned long bitsetsize: is byte length of bitset
void* bitset

@return

int: 0 on success, or -1 w/ errno

@raise ENOSYS if not Linux or Windows

@see libc/calls/sched_setaffinity.c

sched_setparam

Sets scheduler policy parameter.

@param

int pid
struct sched_param* param

@return

int

@raise ENOSYS on XNU, Windows

@see libc/calls/sched_setparam.c

sched_setscheduler

Sets scheduling policy of process, e.g.

struct sched_param p = {sched_get_priority_max(SCHED_OTHER)};
LOGIFNEG1(sched_setscheduler(0, SCHED_OTHER, &p));

Processes with numerically higher priority values are scheduled before processes with numerically lower priority values.

@param

int pid

is the id of the process whose scheduling policy should be changed. Setting pid to zero means the same thing as getpid(). This applies to all threads associated with the process. Linux is special; the kernel treats this as a thread id (noting that getpid() == gettid() is always the case on Linux for the main thread) and will only take effect for the specified tid. Therefore this function is POSIX-compliant iif !__threaded.

int policy

specifies the kernel's timesharing strategy.

The policy must have one of:

SCHED_OTHER (or SCHED_NORMAL) for the default policy
SCHED_RR for real-time round-robin scheduling
SCHED_FIFO for real-time first-in first-out scheduling
SCHED_BATCH for "batch" style execution of processes if supported (Linux), otherwise it's treated as SCHED_OTHER
SCHED_IDLE for running very low priority background jobs if it's supported (Linux), otherwise this is SCHED_OTHER. Pledging away scheduling privilege is permanent for your process; if a subsequent attempt is made to restore the SCHED_OTHER policy then this system call will EPERM (but on older kernels like RHEL7 this isn't the case). This policy isn't available on old Linux kernels like RHEL5, where it'll raise EINVAL.

The policy may optionally bitwise-or any one of:

SCHED_RESET_ON_FORK will cause the scheduling policy to be automatically reset to SCHED_NORMAL upon fork() if supported; otherwise this flag is polyfilled as zero, so that it may be safely used (without having to check if the o/s is Linux).

struct sched_param* param

must be set to the scheduler parameter, which should be greater than or equal to sched_get_priority_min(policy) and less than or equal to sched_get_priority_max(policy). Linux allows the static priority range 1 to 99 for the SCHED_FIFO and SCHED_RR policies, and the priority 0 is used for the remaining policies. You should still consider calling the function, because on NetBSD the correct priority might be -1.

@return

int: the former scheduling policy of the specified process. If this function fails, then the scheduling policy is not changed, and -1 w/ errno is returned.

@raise ENOSYS on XNU, Windows, OpenBSD

@raise EPERM if not authorized to use scheduler in question (e.g. trying to use a real-time scheduler as non-root on Linux) or possibly because pledge() was used and isn't allowing this

@raise EINVAL if param is NULL

@raise EINVAL if policy is invalid

@raise EINVAL if param has value out of ranges defined by policy

@see libc/calls/sched_setscheduler.c

sched_yield

Asks kernel to let other threads be scheduled.

@return

: 0 on success, or non-zero on failure

@norestart

@see libc/intrin/sched_yield.S

seccomp

Tunes Linux security policy.

This system call was first introduced in Linux 3.17. We polyfill automatically features like SECCOMP_SET_MODE_STRICT, for kernels dating back to 2.6.23, whenever possible.

@param

unsigned int operation
unsigned int flags
void* args

@return

int

@raise ENOSYS on non-Linux.

@see libc/calls/seccomp.c

seekdir

Seeks in directory stream.

@param

struct dirstream* dir
long off

@return

void

@see libc/stdio/dirstream.c

select

Does what poll() does except with bitset API.

This system call is supported on all platforms. However, on Windows, this is polyfilled to translate into poll(). So it's recommended that poll() be used instead.

@param

int nfds
struct fd_set* readfds
struct fd_set* writefds
struct fd_set* exceptfds
ANONYMOUS-STRUCT* timeout

@return

int

@see libc/sock/select.c

send

Sends data to network socket.

@param

int fd: is the file descriptor returned by socket()
void* buf: is the data to send, which we'll copy if necessary
unsigned long size: is the byte-length of buf
int flags: MSG_OOB, MSG_DONTROUTE, MSG_PARTIAL, MSG_NOSIGNAL, etc.

@return

long: number of bytes transmitted, or -1 w/ errno

@error EINTR, EHOSTUNREACH, ECONNRESET (UDP ICMP Port Unreachable), EPIPE (if MSG_NOSIGNAL), EMSGSIZE, ENOTSOCK, EFAULT, etc.

@asyncsignalsafe

@restartable (unless SO_RCVTIMEO)

@see libc/sock/send.c

sendfile

Transfers data from file to network.

@param

int outfd: needs to be a socket
int infd: needs to be a file
long* inout_opt_inoffset: may be specified for pread()-like behavior
unsigned long uptobytes: is usually the number of bytes remaining in file; it can't exceed INT_MAX-1; some platforms block until everything's sent, whereas others won't; zero isn't allowed

@return

long: number of bytes transmitted which may be fewer than requested

@see copy_file_range() for file ↔ file

@see splice() for fd ↔ pipe

@see libc/sock/sendfile.c

sendmsg

Sends a message on a socket.

@param

int fd

is the file descriptor returned by socket()

struct msghdr* msg

is a pointer to a struct msghdr containing all the required

   parameters (the destination address, buffers, ...)

int flags

MSG_OOB, MSG_DONTROUTE, MSG_PARTIAL, MSG_NOSIGNAL, etc.

@return

long: number of bytes transmitted, or -1 w/ errno

@error EINTR, EHOSTUNREACH, ECONNRESET (UDP ICMP Port Unreachable), EPIPE (if MSG_NOSIGNAL), EMSGSIZE, ENOTSOCK, EFAULT, etc.

@asyncsignalsafe

@restartable (unless SO_RCVTIMEO)

@see libc/sock/sendmsg.c

sendto

Sends data over network.

This function blocks unless MSG_DONTWAIT is passed. In that case, the non-error EWOULDBLOCK might be returned. It basically means we didn't wait around to learn an amount of bytes were written that we know in advance are guaranteed to be atomic.

@param

int fd: is the file descriptor returned by socket()
void* buf: is the data to send, which we'll copy if necessary
unsigned long size: is the byte-length of buf
unsigned int flags: MSG_OOB, MSG_DONTROUTE, MSG_PARTIAL, MSG_NOSIGNAL, etc.
void* opt_addr: is a binary ip:port destination override, which is mandatory for UDP if connect() wasn't called
unsigned int addrsize: is the byte-length of addr's true polymorphic form

@return

long: number of bytes transmitted, or -1 w/ errno

@error EINTR, EHOSTUNREACH, ECONNRESET (UDP ICMP Port Unreachable), EPIPE (if MSG_NOSIGNAL), EMSGSIZE, ENOTSOCK, EFAULT, etc.

@asyncsignalsafe

@restartable (unless SO_RCVTIMEO)

@see libc/sock/sendto.c

SerializeDnsHeader

Serializes DNS message h to wire.

@param

unsigned char* p
struct DnsHeader* h

@return

void: number of bytes written (always 12) or -1 w/ errno

@see pascalifydnsname()

@see libc/dns/dnsheader.c

SerializeDnsQuestion

Serializes DNS question record to wire.

@param

unsigned char* buf
unsigned long size
struct DnsQuestion* dq

@return

int: number of bytes written

@see pascalifydnsname()

@see libc/dns/serializednsquestion.c

setbuf

Sets buffer on stdio stream.

@param

struct FILE* f
char* buf

@return

void

@see libc/stdio/setbuf.c

setbuffer

Sets buffer on stdio stream.

@param

struct FILE* f
char* buf: may optionally be non-NULL to set the stream's underlying buffer, which the stream will own, but won't free
unsigned long size: is ignored if buf is NULL

@return

void

@see libc/stdio/setbuffer.c

setcontext

Sets machine state.

@return

@note please use longerjmp() and setlongerjmp() for fibers

@note currently only sets general registers

@see getcontext()

@see libc/calls/setcontext.S

SetCurrentDirectory

Sets current directory.

@param

const unsigned short* lpPathName

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/setcurrentdirectory.c

setegid

Sets effective group ID.

@param

unsigned int egid

@return

int: 0 on success, or -1 w/ errno

@raise EINVAL if euid not in legal range

@raise EPERM if lack privileges

@see libc/calls/setegid.c

setenv

Copies variable to environment.

@param

const char* name
const char* value
int overwrite

@return

int: 0 on success, or -1 w/ errno

@see putenv(), getenv()

@see libc/mem/setenv.c

seteuid

Sets effective user ID.

@param

unsigned int euid

@return

int: 0 on success, or -1 w/ errno

@raise EINVAL if euid not in legal range

@raise EPERM if lack privileges

@see libc/calls/seteuid.c

setfsgid

Sets user id of current process for file system ops.

@param

int gid

@return

int: previous filesystem gid

@see libc/calls/setfsgid.c

setfsuid

Sets user id of current process for file system ops.

@param

int uid

@return

int: previous filesystem uid

@see libc/calls/setfsuid.c

setgid

Sets group id of current process.

@param

int gid

@return

int: 0 on success, or -1 w/ errno

@raise EINVAL if gid not in legal range

@raise EPERM if lack privileges

@see libc/calls/setgid.c

setgrent

@return

void

@see third_party/musl/grp.c

sethostent

@param

int stayopen

@return

void

@see libc/dns/hostent.c

setitimer

Schedules delivery of one-shot or intermittent interrupt signal, e.g.

Raise SIGALRM every 1.5s:

CHECK_NE(-1, sigaction(SIGALRM,
                       &(struct sigaction){.sa_sigaction = missingno},
                       NULL));
CHECK_NE(-1, setitimer(ITIMER_REAL,
                       &(const struct itimerval){{1, 500000},
                                                 {1, 500000}},
                       NULL));

Set single-shot 50ms timer callback to interrupt laggy connect():

CHECK_NE(-1, sigaction(SIGALRM,
                       &(struct sigaction){.sa_sigaction = missingno,
                                           .sa_flags = SA_RESETHAND},
                       NULL));
CHECK_NE(-1, setitimer(ITIMER_REAL,
                       &(const struct itimerval){{0, 0}, {0, 50000}},
                       NULL));
if (connect(...) == -1 && errno == EINTR) { ... }

Disarm timer:

CHECK_NE(-1, setitimer(ITIMER_REAL, &(const struct itimerval){0}, NULL));

Be sure to check for EINTR on your i/o calls, for best low latency.

Timers are not inherited across fork.

@param

int which: can be ITIMER_REAL, ITIMER_VIRTUAL, etc.
struct itimerval* newvalue: specifies the interval ({0,0} means one-shot) and duration ({0,0} means disarm) in microseconds ∈ [0,999999] and if this parameter is NULL, we'll polyfill getitimer() behavior
struct itimerval* oldvalue

@return

int: 0 on success or -1 w/ errno

@see libc/calls/setitimer.c

setjmp

Saves caller CPU state to cacheline.

@param

rdi: points to jmp_buf

@return

: rax 0 when set and !0 when longjmp'd

@returnstwice

@assume system five nexgen32e abi conformant

@note code built w/ microsoft abi compiler can't call this

@see longjmp(), _gclongjmp()

@see libc/nexgen32e/setjmp.S

_setjmp

Saves caller CPU state to cacheline.

@param

rdi: points to jmp_buf

@return

: rax 0 when set and !0 when longjmp'd

@returnstwice

@assume system five nexgen32e abi conformant

@note code built w/ microsoft abi compiler can't call this

@see longjmp(), _gclongjmp()

@see libc/nexgen32e/setjmp.S

setkey

@param

const char* key

@return

void

@see third_party/musl/encrypt.c

setlinebuf

Puts stream in line-buffering mode.

@param

struct FILE* f

@return

void

@see libc/stdio/setlinebuf.c

setlocale

Sets program locale.

Cosmopolitan only supports the C or POSIX locale.

@param

int category
const char* locale

@return

char*

@see libc/unicode/setlocale.c

setlogmask

Sets log priority mask

Modifies the log priority mask that determines which calls to syslog() may be logged. Log priority values are LOG_EMERG, LOG_ALERT, LOG_CRIT, LOG_ERR, LOG_WARNING, LOG_NOTICE, LOG_INFO, and LOG_DEBUG.

@param

int maskpri

@return

int: the previous log priority mask

@asyncsignalsafe

@see libc/sock/syslog.c

setlongerjmp

Saves caller CPU state to cacheline.

@param

rdi: points to jmp_buf

@return

: eax contains 0 when set, and 1 if jumped; rdx contains value passed to longerjmp()

@returnstwice

@see libc/nexgen32e/setlongerjmp.S

setnetent

@param

int stayopen

@return

void

@see libc/dns/netent.c

setpgid

Changes process group for process.

@param

int pid
int pgid

@return

int

@vforksafe

@see libc/calls/setpgid.c

setpgrp

Sets the process group ID.

@return

int

@see libc/calls/setpgrp.c

setpriority

Sets nice value of thing.

@param

int which: can be PRIO_PROCESS, PRIO_PGRP, PRIO_USER
unsigned int who: is the pid, pgid, or uid, 0 meaning current
int value: ∈ [-NZERO,NZERO) which is clamped automatically

@return

int: 0 on success or -1 w/ errno

@error EACCES if lower that RLIMIT_NICE

@error EACCES on Linux without CAP_SYS_NICE

@see getpriority(), nice()

@see libc/calls/setpriority.c

setprotoent

@param

int stayopen

@return

void

@see libc/dns/protoent.c

setpwent

@return

void

@see third_party/musl/pwd.c

setregid

Sets real and/or effective group ids.

@param

unsigned int rgid: is real group id or -1 to leave it unchanged
unsigned int egid: is effective group id or -1 to leave it unchanged

@return

int: 0 on success or -1 w/ errno

@see libc/calls/setregid.c

setresgid

Sets real, effective, and "saved" group ids.

@param

unsigned int real: sets real group id or -1 to do nothing
unsigned int effective: sets effective group id or -1 to do nothing
unsigned int saved: sets saved group id or -1 to do nothing

@return

int

@see setresuid(), getauxval(AT_SECURE)

@raise ENOSYS on Windows NT

@see libc/calls/setresgid.c

setresuid

Sets real, effective, and "saved" user ids.

@param

unsigned int real: sets real user id or -1 to do nothing
unsigned int effective: sets effective user id or -1 to do nothing
unsigned int saved: sets saved user id or -1 to do nothing

@return

int

@see setresgid(), getauxval(AT_SECURE)

@raise ENOSYS on Windows NT

@see libc/calls/setresuid.c

setreuid

Sets real and/or effective user ids.

@param

unsigned int ruid: is real user id or -1 to leave it unchanged
unsigned int euid: is effective user id or -1 to leave it unchanged

@return

int: 0 on success or -1 w/ errno

@see libc/calls/setreuid.c

setrlimit

Sets resource limit for current process.

The following resources are recommended:

RLIMIT_AS limits the size of the virtual address space. This will work on all platforms. It's emulated on XNU and Windows which means it won't propagate across execve() currently.
RLIMIT_CPU causes SIGXCPU to be sent to the process when the soft limit on CPU time is exceeded, and the process is destroyed when the hard limit is exceeded. It works everywhere but Windows where it should be possible to poll getrusage() with setitimer()
RLIMIT_FSIZE causes SIGXFSZ to sent to the process when the soft limit on file size is exceeded and the process is destroyed when the hard limit is exceeded. It works everywhere but Windows
RLIMIT_NPROC limits the number of simultaneous processes and it should work on all platforms except Windows. Please be advised it limits the process, with respect to the activities of the user id as a whole.
RLIMIT_NOFILE limits the number of open file descriptors and it should work on all platforms except Windows (TODO)

The rlimit magnums differ for each platform but occupy the interval zero through RLIM_NLIMITS. Usually they're set to RLIM_INFINITY which is -1 on Linux/Windows, and LONG_MAX on BSDs. In any case they're both very large numbers under the Cosmopolitan unsigned ABI because struct rlimit uses uint64_t. The special magnum 127 is used for constant values that aren't supported by the host platform.

@param

int resource
struct rlimit* rlim: specifies new resource limit

@return

int: 0 on success or -1 w/ errno

@see libc/sysv/consts.sh

@vforksafe

@see libc/calls/setrlimit.c

setservent

@param

int stayopen

@return

void

@see libc/dns/servent.c

setsid

Creates session and sets the process group id.

@return

int: new session id, or -1 w/ errno

@see libc/calls/setsid.c

setsockopt

Modifies socket settings.

This function is the ultimate rabbit hole. Basic usage:

int yes = 1; setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &yes, sizeof(yes));

@param

int fd
int level: can be SOL_SOCKET, SOL_IP, SOL_TCP, etc.
int optname: can be SO_{REUSE{PORT,ADDR},KEEPALIVE,etc.} etc.
void* optval
unsigned int optlen

@return

int: 0 on success, or -1 w/ errno

@error ENOPROTOOPT for unknown (level,optname)

@error EINVAL if optlen is invalid somehow

@error ENOTSOCK if fd is valid but not a socket

@error EBADF if fd isn't valid

@error EFAULT if optval memory isn't valid

@see libc/sysv/consts.sh for tuning catalogue

@see getsockopt()

@see libc/sock/setsockopt.c

_setstack

Switches stack.

@param

rdi: is new rsp, passed as malloc(size) + size
rsi: is function to call in new stack space
rdx,rcx,r8,r9: get passed as args to rsi

@return

: rax and happens on original stack

@see libc/runtime/setstack.S

setstate

@param

char* state

@return

char*

@see libc/rand/random.c

setuid

Sets user id of current process.

@param

int uid

@return

int: 0 on success, or -1 w/ errno

@raise EINVAL if uid not in legal range

@raise EAGAIN on temporary failure

@raise EAGAIN change would cause RLIMIT_NPROC to be exceeded

@raise EPERM if lack privileges

@see libc/calls/setuid.c

SetUp

User-defined test setup function.

The test runner will call this function before each TEST() if it's defined by the linkage.

@return

void

@see libc/testlib/testlib.h

setvbuf

Tunes buffering settings for an stdio stream.

@param

struct FILE* f
char* buf: may optionally be non-NULL to set the stream's underlying buffer which the caller still owns and won't free, otherwise the existing buffer is used
int mode: may be _IOFBF, _IOLBF, or _IONBF
unsigned long size: is ignored if buf is NULL

@return

int: 0 on success or -1 on error

@see libc/stdio/setvbuf.c

sha1_transform_avx2

Performs Intel® AVX2™ optimized SHA-1 update.

This implementation is based on the previous SSSE3 release: Visit http://software.intel.com/en-us/articles/ and refer to improving-the-performance-of-the-secure-hash-algorithm-1/

Updates 20-byte SHA-1 record at start of 'state', from 'input', for even number of 'blocks' consecutive 64-byte blocks.

void sha1_transform_avx2(struct sha1_state *state,
                         const uint8_t *input,
                         int blocks);

@param

%rdi: points to output digest
%rsi: points to input data
%rdx: is number of 64-byte blocks to process

@return

@see X86_HAVE(SHA)

@see libc/nexgen32e/sha1.S

sha1_transform_ni

Performs Intel® SHA-NI™ optimized SHA-1 update.

The function takes a pointer to the current hash values, a pointer to the input data, and a number of 64 byte blocks to process. Once all blocks have been processed, the digest pointer is updated with the resulting hash value. The function only processes complete blocks, there is no functionality to store partial blocks. All message padding and hash value initialization must be done outside the update function.

The indented lines in the loop are instructions related to rounds processing. The non-indented lines are instructions related to the message schedule.

void sha1_transform_ni(uint32_t digest[static 5],
                       const void *data,
                       uint32_t numBlocks);

@param

%rdi: points to output digest
%rsi: points to input data
%rdx: is number of 64-byte blocks to process

@return

@see X86_HAVE(SHA)

@see libc/nexgen32e/sha1ni.S

sha256_transform_ni

Performs Intel® SHA-NI™ optimized SHA-256 update.

The indented lines in the loop are instructions related to rounds processing. The non-indented lines are instructions related to the message schedule.

void sha256_transform_ni(uint32_t digest[static 8],
                         const void *data,
                         int32_t numBlocks);

@param

%rdi: points to output digest
%rsi: points to input data
%rdx: is number of blocks to process

@return

@see X86_HAVE(SHA)

@see libc/nexgen32e/sha256ni.S

ShowBacktrace

@param

int fd
struct StackFrame* bp

@return

void

@see libc/log/backtrace2.c

ShowCrashReport

@param

int err
int sig
struct siginfo_t* si
struct ucontext_t* ctx

@return

void

@see libc/log/oncrash.c

ShowCrashReports

Installs crash signal handlers.

Normally, only functions calling die() will print backtraces. This function may be called at program startup to install handlers that will display similar information, for most types of crashes.

Backtraces
CPU state printout
Automatic debugger attachment

Another trick this function enables, is you can press CTRL+\ to open the debugger GUI at any point while the program is running. It can be useful, for example, if a program is caught in an infinite loop.

@return

void

@see callexitontermination()

@see libc/log/showcrashreports.c

shufpd

Shuffles double vector.

@param

double* c
const double* b
const double* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/shufpd.c

shufps

Shuffles float vector.

@param

float* c
const float* b
const float* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/shufps.c

shutdown

Disables sends or receives on a socket, without closing.

@param

int fd: is the open file descriptor for the socket
int how: can be SHUT_RD, SHUT_WR, or SHUT_RDWR

@return

int: 0 on success or -1 on error

@asyncsignalsafe

@see libc/sock/shutdown.c

__sig_add

Enqueues generic signal for delivery on New Technology.

@param

int sig
int si_code

@return

int: 0 on success, otherwise -1 w/ errno

@threadsafe

@see libc/calls/sig2.c

__sig_check

Enqueues generic signal for delivery on New Technology.

@param

_Bool restartable: is for functions like read() but not poll()

@return

_Bool: true if EINTR should be returned by caller

@note called from main thread

@threadsafe

@see libc/calls/sig2.c

__sig_handle

Handles signal.

@param

_Bool restartable: can be used to suppress true return if SA_RESTART
int sig
int si_code
struct ucontext_t* ctx

@return

_Bool: true if signal was delivered

@see libc/calls/sig2.c

__sig_mask

Changes signal mask for main thread.

@param

int how
struct mask* neu
struct mask* old

@return

int: 0 on success, or -1 w/ errno

@see libc/calls/sig.c

__sig_raise

Handles signal immediately if not blocked.

@param

int sig
int si_code

@return

int: true if EINTR should be returned by caller; 1 if delivered, 0 if enqueued, otherwise -1 w/ errno

@note called from main thread

@threadsafe

@see libc/calls/sig2.c

sigaction

Installs handler for kernel interrupt, e.g.:

void GotCtrlC(int sig, siginfo_t *si, ucontext_t *ctx);
struct sigaction sa = {.sa_sigaction = GotCtrlC,
                       .sa_flags = SA_RESETHAND|SA_RESTART|SA_SIGINFO};
CHECK_NE(-1, sigaction(SIGINT, &sa, NULL));

The following flags are supported across platforms:

SA_SIGINFO: Causes the siginfo_t and ucontext_t parameters to be passed. This not only gives you more information about the signal, but also allows your signal handler to change the CPU registers. That's useful for recovering from crashes. If you don't use this attribute, then signal delivery will go a little faster.
SA_RESTART: Enables BSD signal handling semantics. Normally i/o entrypoints check for pending signals to deliver. If one gets delivered during an i/o call, the normal behavior is to cancel the i/o operation and return -1 with EINTR in errno. If you use the SA_RESTART flag then that behavior changes, so that any function that's been annotated with @restartable will not return EINTR and will instead resume the i/o operation. This makes coding easier but it can be an anti-pattern if not used carefully, since poor usage can easily result in latency issues. It also requires one to do more work in signal handlers, so special care needs to be given to which C library functions are @asyncsignalsafe.
SA_RESETHAND: Causes signal handler to be single-shot. This means that, upon entry of delivery to a signal handler, it's reset to the SIG_DFL handler automatically. You may use the alias SA_ONESHOT for this flag, which means the same thing.
SA_NODEFER: Disables the reentrancy safety check on your signal handler. Normally that's a good thing, since for instance if your SIGSEGV signal handler happens to segfault, you're going to want your process to just crash rather than looping endlessly. But in some cases it's desirable to use SA_NODEFER instead, such as at times when you wish to longjmp() out of your signal handler and back into your program. This is only safe to do across platforms for non-crashing signals such as SIGCHLD and SIGINT. Crash handlers should use Xed instead to recover execution, because on Windows a SIGSEGV or SIGTRAP crash handler might happen on a separate stack and/or a separate thread. You may use the alias SA_NOMASK for this flag, which means the same thing.
SA_NOCLDWAIT: Changes SIGCHLD so the zombie is gone and you can't call wait() anymore; similar but may still deliver the SIGCHLD.
SA_NOCLDSTOP: Lets you set SIGCHLD handler that's only notified on exit/termination and not notified on SIGSTOP, SIGTSTP, SIGTTIN, SIGTTOU, or SIGCONT.

Here's an example of the most professional way to handle signals in an i/o event loop. It's generally a best practice to have signal handlers do the fewest number of things possible. The trick is to have your signals work hand-in-glove with the EINTR errno. This obfuscates the need for having to worry about @asyncsignalsafe.

static volatile bool gotctrlc;

void OnCtrlC(int sig) {
  gotctrlc = true;
}

int main() {
  size_t got;
  ssize_t rc;
  char buf[1];
  struct sigaction oldint;
  struct sigaction saint = {.sa_handler = GotCtrlC};
  if (sigaction(SIGINT, &saint, &oldint) == -1) {
    perror("sigaction");
    exit(1);
  }
  for (;;) {
    rc = read(0, buf, sizeof(buf));
    if (rc == -1) {
      if (errno == EINTR) {
        if (gotctrlc) {
          break;
        }
      } else {
        perror("read");
        exit(2);
      }
    }
    if (!(got = rc)) {
      break;
    }
    for (;;) {
      rc = write(1, buf, got);
      if (rc != -1) {
        assert(rc == 1);
        break;
      } else if (errno != EINTR) {
        perror("write");
        exit(3);
      }
    }
  }
  sigaction(SIGINT, &oldint, 0);
}

Please note that you can't do the above if you use SA_RESTART. Since the purpose of SA_RESTART is to restart i/o operations whose docs say that they're @restartable and read() is one such function. Here's some even better news: if you don't install any signal handlers at all, then your i/o calls will never be interrupted!

Here's an example of the most professional way to recover from SIGSEGV, SIGFPE, and SIGILL.

void ContinueOnCrash(void);

void SkipOverFaultingInstruction(struct ucontext *ctx) {
  struct XedDecodedInst xedd;
  xed_decoded_inst_zero_set_mode(&xedd, XED_MACHINE_MODE_LONG_64);
  xed_instruction_length_decode(&xedd, (void *)ctx->uc_mcontext.rip, 15);
  ctx->uc_mcontext.rip += xedd.length;
}

void OnCrash(int sig, struct siginfo *si, struct ucontext *ctx) {
  SkipOverFaultingInstruction(ctx);
  ContinueOnCrash();  // reinstall here in case *rip faults
}

void ContinueOnCrash(void) {
  struct sigaction sa = {.sa_handler = OnSigSegv,
                         .sa_flags = SA_SIGINFO | SA_RESETHAND};
  sigaction(SIGSEGV, &sa, 0);
  sigaction(SIGFPE, &sa, 0);
  sigaction(SIGILL, &sa, 0);
}

int main() {
  ContinueOnCrash();
  // ...
}

You may also edit any other CPU registers during the handler. For example, you can use the above technique so that division by zero becomes defined to a specific value of your choosing!

Please note that Xed isn't needed to recover from SIGTRAP which can be raised at any time by embedding DebugBreak() or asm("int3") in your program code. Your signal handler will automatically skip over the interrupt instruction, assuming your signal handler returns.

The important signals supported across all platforms are:

SIGINT: When you press Ctrl-C this signal gets broadcasted to your process session group. This is the normal way to terminate console applications.
SIGQUIT: When you press CTRL-\ this signal gets broadcasted to your process session group. This is the irregular way to kill an application in cases where maybe your SIGINT handler is broken although, Cosmopolitan Libc ShowCrashReports() should program it such as to attach a debugger to the process if possible, or else show a crash report. Also note that in New Technology you should press CTRL+BREAK rather than CTRL+\ to get this signal.
SIGHUP: This gets sent to your non-daemon processes when you close your terminal session.
SIGTERM is what the kill command sends by default. It's the choice signal for terminating daemons.
SIGUSR1 and SIGUSR2 can be anything you want. Their default action is to kill the process. By convention SIGUSR1 is usually used by daemons to reload the config file.
SIGCHLD is sent when a process terminates and it takes a certain degree of UNIX mastery to address sanely.
SIGALRM is invoked by setitimer() and alarm(). It can be useful for interrupting i/o operations like connect().
SIGTRAP: This happens when an INT3 instruction is encountered.
SIGILL happens on illegal instructions, e.g. UD2.
SIGABRT happens when you call abort().
SIGFPE happens when you divide ints by zero, among other things.
SIGSEGV and SIGBUS indicate memory access errors and they have inconsistent semantics across platforms like FreeBSD.
SIGWINCH is sent when your terminal window is resized.
SIGXCPU and SIGXFSZ may be raised if you run out of resources, which can happen if your process, or the parent process that spawned your process, happened to call setrlimit(). Doing this is a wonderful idea.

@param

int sig
struct copy* act
struct copy* oldact

@return

int: 0 on success or -1 w/ errno

@see xsigaction() for a much better api

@asyncsignalsafe

@vforksafe

@see libc/calls/sigaction.c

sigaddset

Adds signal to set.

@param

struct sigset_t* set
int sig

@return

int: 0 on success, or -1 w/ errno

@raises EINVAL if 1 ≤ sig ≤ NSIG isn't the case

@asyncsignalsafe

@see libc/intrin/sigaddset.c

sigaltstack

Sets and/or gets alternate signal stack, e.g.

struct sigaction sa;
struct sigaltstack ss;
ss.ss_flags = 0;
ss.ss_size = GetStackSize();
ss.ss_sp = mmap(0, GetStackSize(), PROT_READ | PROT_WRITE,
                MAP_STACK | MAP_ANONYMOUS, -1, 0);
sa.sa_flags = SA_ONSTACK;
sa.sa_handler = OnStackOverflow;
__cxa_atexit(free, ss[0].ss_sp, 0);
sigemptyset(&sa.ss_mask);
sigaltstack(&ss, 0);
sigaction(SIGSEGV, &sa, 0);

It's strongly recommended that you allocate a stack with the same size as GetStackSize() and that it have GetStackSize() alignment. Otherwise some of your runtime support code (e.g. ftrace stack use logging, kprintf() memory safety) won't be able to work as well.

@param

struct uc_stack* neu: if non-null will install new signal alt stack
struct uc_stack* old: if non-null will receive current signal alt stack

@return

int: 0 on success, or -1 w/ errno

@see libc/calls/sigaltstack.c

sigdelset

Removes signal from set.

@param

struct sigset_t* set
int sig

@return

int: 0 on success, or -1 w/ errno

@raises EINVAL if 1 ≤ sig ≤ NSIG isn't the case

@asyncsignalsafe

@see libc/intrin/sigdelset.c

sigemptyset

Removes all signals from set.

@param

struct sigset_t* set

@return

int: 0 on success, or -1 w/ errno

@asyncsignalsafe

@see libc/intrin/sigemptyset.c

sigfillset

Adds all signals to set.

@param

struct sigset_t* set

@return

int: 0 on success, or -1 w/ errno

@asyncsignalsafe

@vforksafe

@see libc/intrin/sigfillset.c

sigignore

Configures process to ignore signal.

@param

int sig

@return

int

@see libc/calls/sigignore.c

siginterrupt

Tunes whether signal can interrupt restartable system calls.

@param

int sig
int flag

@return

int

@see libc/calls/siginterrupt.c

sigismember

Returns true if signal is member of set.

@param

struct sigset_t* set
int sig

@return

int: 1 if set, 0 if not set, or -1 w/ errno

@raises EINVAL if 1 ≤ sig ≤ NSIG isn't the case

@asyncsignalsafe

@vforksafe

@see libc/intrin/sigismember.c

signal

Installs kernel interrupt handler, e.g.

void GotCtrlC(int sig) { ... }
CHECK_NE(SIG_ERR, signal(SIGINT, GotCtrlC));

@param

int sig
void(*)() func

@return

void(*)(): old signal handler on success or SIG_ERR w/ errno

@note this function has BSD semantics, i.e. SA_RESTART

@see sigaction() which has more features and docs

@see libc/calls/signal.c

sigprocmask

Changes signal blocking state of calling thread, e.g.:

sigset_t neu,old;
sigfillset(&neu);
sigprocmask(SIG_BLOCK, &neu, &old);
sigprocmask(SIG_SETMASK, &old, NULL);

@param

int how: can be SIG_BLOCK (U), SIG_UNBLOCK (/), SIG_SETMASK (=)
struct sa_mask* opt_set
struct old* opt_out_oldset

@return

int: 0 on success, or -1 w/ errno

@asyncsignalsafe

@restartable

@vforksafe

@see libc/calls/sigprocmask.c

sigqueue

Sends signal to process, with data.

The impact of this action can be terminating the process, or interrupting it to request something happen.

@param

int pid: can be: >0 signals one process by id =0 signals all processes in current process group -1 signals all processes possible (except init) <-1 signals all processes in -pid process group
int sig: can be: >0 can be SIGINT, SIGTERM, SIGKILL, SIGUSR1, etc. =0 checks both if pid exists and we can signal it
union value value

@return

int: 0 if something was accomplished, or -1 w/ errno

@note this isn't supported on OpenBSD

@asyncsignalsafe

@see libc/calls/sigqueue.c

sigsuspend

Blocks until SIG ∉ MASK is delivered to process.

This temporarily replaces the signal mask until a signal that it doesn't contain is delivered.

@param

struct sa_mask* ignore: is a bitset of signals to block temporarily, which if NULL is equivalent to passing an empty signal set

@return

int: -1 w/ EINTR (or possibly EFAULT)

@asyncsignalsafe

@norestart

@see libc/calls/sigsuspend.c

sin

Returns sine of 𝑥.

@param

double x

@return

double

@note should take ~5ns

@see libc/tinymath/sin.c

sincos

Returns sine and cosine of 𝑥.

@param

double x
double* sin
double* cos

@return

void

@note should take ~10ns

@see libc/tinymath/sincos.c

sincosf

Returns sine and cosine of 𝑥.

@param

𝑥: is float scalar in low quarter of %xmm0
%rdi: is float *out_sin
%rsi: is float *out_cos

@return

@domain -(3π/8) < 𝑥 < 3π/8 for best accuracy

@see libc/tinymath/sincosf.S

sincosl

Returns sine and cosine of 𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes
%rdi: is long double *out_sin
%rsi: is long double *out_cos

@return

@domain -(3π/8) < 𝑥 < 3π/8 for best accuracy

@see libc/tinymath/sincosl.S

sinh

Returns hyperbolic sine of 𝑥.

sinh(x) = (exp(x) - 1/exp(x))/2
        = (exp(x)-1 + (exp(x)-1)/exp(x))/2
        = x + x^3/6 + o(x^5)

@param

double x

@return

double

@see libc/tinymath/sinh.c

sinhf

Returns hyperbolic sine of 𝑥.

sinh(x) = (exp(x) - 1/exp(x))/2
        = (exp(x)-1 + (exp(x)-1)/exp(x))/2
        = x + x^3/6 + o(x^5)

@param

float x

@return

float

@see libc/tinymath/sinhf.c

sinhl

Returns hyperbolic sine of 𝑥.

sinh(x) = (exp(x) - 1/exp(x))/2
        = (exp(x)-1 + (exp(x)-1)/exp(x))/2
        = x + x^3/6 + o(x^5)

@param

long double x

@return

long double

@see libc/tinymath/sinhl.c

sinl

Returns sine of 𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: %st stores result

@domain -(3π/8) < 𝑥 < 3π/8 for best accuracy

@see libc/tinymath/sinl.S

sizetol

Converts size string to long.

The following unit suffixes may be used

k or K for kilo (multiply by 𝑏¹)
m or M for mega (multiply by 𝑏²)
g or G for giga (multiply by 𝑏³)
t or T for tera (multiply by 𝑏⁴)
p or P for peta (multiply by 𝑏⁵)
e or E for exa (multiply by 𝑏⁶)

If a permitted alpha character is supplied, then any additional characters after it (e.g. kbit, Mibit, TiB) are ignored. Spaces before the integer are ignored, and overflows will be detected.

@param

const char* s: is non-null nul-terminated input string
long b: is multiplier which should be 1000 or 1024

@return

long: size greater than or equal 0 or -1 on error

@see libc/fmt/sizetol.c

sleb128

Encodes signed leb128 integer.

@param

char* p
__int128 x

@return

char*

@see libc/fmt/sleb128.c

sleb64

Encodes signed integer to array.

uleb64 INT64_MAX    l:        10𝑐         3𝑛𝑠
zleb64 INT64_MAX    l:        13𝑐         4𝑛𝑠
sleb64 INT64_MAX    l:        16𝑐         5𝑛𝑠
uleb128 INT64_MAX   l:        18𝑐         6𝑛𝑠
zleb128 INT64_MAX   l:        18𝑐         6𝑛𝑠
sleb128 INT64_MAX   l:        24𝑐         8𝑛𝑠
zleb64 INT64_MIN    l:        13𝑐         4𝑛𝑠
sleb64 INT64_MIN    l:        16𝑐         5𝑛𝑠
zleb128 INT64_MIN   l:        19𝑐         6𝑛𝑠
sleb128 INT64_MIN   l:        24𝑐         8𝑛𝑠

@param

char* p: is output array
long x: is number

@return

char*: p + i

@see libc/fmt/sleb64.c

sleep

Sleeps for particular number of seconds.

@param

unsigned int seconds

@return

unsigned int: 0 if the full time elapsed, otherwise we assume an interrupt was delivered, in which case the errno condition is ignored, and this function shall return the number of unslept seconds rounded using the ceiling function

@see nanosleep(), usleep()

@asyncsignalsafe

@norestart

@see libc/calls/sleep.c

_smt19937

Initializes mt[NN] with small seed value.

@param

unsigned long seed

@return

void

@see mt19937(), Smt19937()

@see libc/rand/mt19937.c

_Smt19937

Initializes mt[NN] with array.

@param

unsigned long* K: is the array for initializing keys
unsigned long n: is its length

@return

void

@see mt19937(), smt19937()

@see libc/rand/mt19937.c

snprintf

Formats string to buffer.

@param

char* buf
unsigned long count
const char* fmt
...

@return

int: number of bytes written, excluding the NUL terminator; or, if the output buffer wasn't passed, or was too short, then the number of characters that *would* have been written is returned

@see __fmt() and printf() for detailed documentation

@asyncsignalsafe

@vforksafe

@see libc/fmt/snprintf.c

sockaddr2bsd

Converts sockaddr (Linux/Windows) → sockaddr_bsd (XNU/BSD).

@param

void* addr
unsigned int addrsize
union sockaddr_storage_bsd* out_addr
unsigned int* out_addrsize

@return

int

@see libc/sock/sockaddr2bsd.c

sockaddr2linux

Converts sockaddr_bsd (XNU/BSD) → sockaddr (Linux/Windows).

@param

union sockaddr_storage_bsd* addr
unsigned int addrsize
union sockaddr_storage_linux* out_addr
unsigned int* inout_addrsize

@return

void

@see libc/sock/sockaddr2linux.c

socket

Creates new system resource for network communication, e.g.

int fd = socket(AF_INET, SOCK_STREAM, IPPROTO_TCP);

@param

int family: can be AF_UNIX, AF_INET, etc.
int type: can be SOCK_STREAM (for TCP), SOCK_DGRAM (e.g. UDP), or SOCK_RAW (IP) so long as IP_HDRINCL was passed to setsockopt(); and additionally, may be or'd with SOCK_NONBLOCK, SOCK_CLOEXEC
int protocol: can be IPPROTO_TCP, IPPROTO_UDP, or IPPROTO_ICMP

@return

int: socket file descriptor or -1 w/ errno

@error ENETDOWN, EPFNOSUPPORT, etc.

@see libc/sysv/consts.sh

@asyncsignalsafe

@see libc/sock/socket.c

socketpair

Creates bidirectional pipe, e.g.

int sv[2];
socketpair(AF_UNIX, SOCK_STREAM, 0, sv);

@param

int family: should be AF_UNIX or synonymously AF_LOCAL
int type: can be SOCK_STREAM or SOCK_DGRAM and additionally, may be or'd with SOCK_NONBLOCK, SOCK_CLOEXEC
int protocol
int* sv: a vector of 2 integers to store the created sockets

@return

int: 0 if success, -1 in case of error

@error EFAULT, EPFNOSUPPORT, etc.

@see libc/sysv/consts.sh

@asyncsignalsafe

@see libc/sock/socketpair.c

_spawn

Spawns thread, e.g.

int worker(void *arg, int tid) {
  const char *s = arg;
  printf("%s\n", s);
  return 0;
}

int main() {
  struct spawn th;
  _spawn(worker, "hi", &th);
  _join(&th);
}

@param

int(*)() fun: is thread worker callback, which receives arg and ctid
void* arg: shall be passed to fun
struct ths* opt_out_thread: needn't be initialiized and is always clobbered except when it isn't specified, in which case, the thread is kind of detached and will (currently) just leak the stack / tls memory

@return

int: 0 on success, or -1 w/ errno

@see libc/thread/spawn.c

splice

Transfers data to/from pipe.

@param

int infd
long* inopt_out_inoffset
int outfd
long* inopt_out_outoffset
unsigned long uptobytes
unsigned int flags: can have SPLICE_F_{MOVE,NONBLOCK,MORE,GIFT}

@return

long: number of bytes transferred, 0 on input end, or -1 w/ errno

@see copy_file_range() for file ↔ file

@see sendfile() for seekable → socket

@see libc/calls/splice.c

sprintf

Formats string to buffer that's hopefully large enough.

@param

char* buf
const char* fmt
...

@return

int

@see __fmt() and printf() for detailed documentation

@see snprintf() for same w/ buf size param

@asyncsignalsafe

@vforksafe

@see libc/fmt/sprintf.c

sqrt

Returns square root of 𝑥.

@param

𝑥: is an double passed in %xmm0

@return

: result in %xmm0

@see libc/tinymath/sqrt.S

sqrtf

Returns square root of 𝑥.

@param

𝑥: is an float passed in %xmm0

@return

: result in %xmm0

@see libc/tinymath/sqrtf.S

sqrtl

Returns square root of 𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: result on FPU stack in %st

@see libc/tinymath/sqrtl.S

srand

Seeds random number generator that's used by rand().

@param

unsigned long seed

@return

void

@see libc/rand/srand.c

srandom

@param

unsigned int seed

@return

void

@see libc/rand/random.c

sscanf

String decoder.

@param

const char* str
const char* fmt
...

@return

int

@see libc/fmt/vcscanf.h (for docs and implementation)

@see libc/fmt/sscanf.c

__start_fatal

Prints initial part of fatal message.

@param

const char* file
int line

@return

void

@note this is support code for __check_fail(), __assert_fail(), etc.

@see libc/log/startfatal.c

startswith

Returns true if s has prefix.

@param

const char* s: is a NUL-terminated string
const char* prefix: is also NUL-terminated

@return

_Bool

@see libc/str/startswith.c

startswith16

Returns true if s has prefix.

@param

const unsigned short* s: is a NUL-terminated string
const unsigned short* prefix: is also NUL-terminated

@return

_Bool

@see libc/str/startswith16.c

startswithi

@param

const char* s
const char* prefix

@return

_Bool

@see libc/str/startswithi.c

stat

Returns information about thing.

@param

const char* path
struct stat* st: is where result is stored

@return

int

@see S_ISDIR(st.st_mode), S_ISREG(), etc.

@raise EACCES if denied access to component in path prefix

@raise EIO if i/o error occurred while reading from filesystem

@raise ELOOP if a symbolic link loop exists in path

@raise ENAMETOOLONG if a component in path exceeds NAME_MAX

@raise ENOENT on empty string or if component in path doesn't exist

@raise ENOTDIR if a parent component existed that wasn't a directory

@raise EOVERFLOW shouldn't be possible on 64-bit systems

@raise ELOOP may ahappen if SYMLOOP_MAX symlinks were dereferenced

@raise ENAMETOOLONG may happen if path exceeded PATH_MAX

@asyncsignalsafe

@see libc/calls/stat.c

stderr

Pointer to standard error stream.

@type

struct __stderr*

@see libc/stdio/stderr.c

stdin

Pointer to standard input stream.

@type

struct __stdin*

@see libc/stdio/stdin.c

stdout

Pointer to standard output stream.

@type

struct __stdout*

@see libc/stdio/stdout.c

stpcpy

Copies bytes from 𝑠 to 𝑑 until a NUL is encountered.

@param

char* d
const char* s

@return

char*: pointer to nul byte

@note 𝑑 and 𝑠 can't overlap

@asyncsignalsafe

@see libc/intrin/stpcpy.c

stpncpy

Prepares static search buffer.

If SRC is too long, it's truncated and *not* NUL-terminated.
If SRC is too short, the remainder is zero-filled.

Please note this function isn't designed to prevent untrustworthy data from modifying memory without authorization. Consider trying memccpy() for that purpose.

@param

char* dest
const char* src
unsigned long stride

@return

char*: dest + stride

@see stncpy(), memccpy()

@asyncsignalsafe

@see libc/str/stpncpy.c

__strace

System call logging enabled state.

If Cosmopolitan was compiled with the SYSDEBUG macro (this is the default behavior, except in tiny and release modes) then __strace shall control whether or not system calls are logged to fd 2. If it's greater than zero, syscalls are logged. Otherwise, they're aren't.

By convention, functions wishing to disable syscall tracing for a short time period should say:

void foo() {
  --__strace;
  bar();
  ++__strace;
}

This way you still have some flexibility to force syscall tracing, by setting __strace to a higher number like 2 or 200. Even though under normal circumstances, __strace should only be either zero or one.

@type

_Atomic int

@see libc/sysv/strace.greg.c

__strace_init

Enables plaintext system call logging if --strace flag is passed.

@param

int argc
char** argv
char** envp
long* auxv

@return

int

@see libc/runtime/straceinit.greg.c

strcasecmp

Compares NUL-terminated strings ascii case-insensitively.

@param

const char* a: is first non-null nul-terminated string pointer
const char* b: is second non-null nul-terminated string pointer

@return

int: is <0, 0, or >0 based on tolower(uint8_t) comparison

@asyncsignalsafe

@see libc/str/strcasecmp.c

strcasecmp16

Compares NUL-terminated UCS-2 strings case-insensitively.

@param

const unsigned short* l
const unsigned short* r

@return

int: is <0, 0, or >0 based on uint16_t comparison

@asyncsignalsafe

@see libc/str/strcasecmp16.c

strcasecmp16to8

@param

const unsigned short* s1
const char* s2

@return

int

@see libc/str/strcasecmp8to16.c

strcasecmp8to16

Compares UTF-8 and UTF-16 strings, ignoring case.

@param

const char* s1
const unsigned short* s2

@return

int

@see libc/str/strcasecmp8to16.c

strcat

Appends 𝑠 to 𝑑.

@param

char* d
const char* s

@return

char*: 𝑑

@asyncsignalsafe

@see libc/str/strcat.c

strcat16

Appends 𝑠 to 𝑑.

@param

unsigned short* d
const unsigned short* s

@return

unsigned short*: 𝑑

@asyncsignalsafe

@see libc/str/strcat16.c

strchr16

Returns pointer to first instance of character.

@param

rdi: is a non-null NUL-terminated char16_t string pointer
esi: is the search word

@return

: rax points to first result, or NULL if not found

@note this won't return NULL if search character is NUL

@asyncsignalsafe

@see libc/nexgen32e/strsak16.S

strchrnul16

Returns pointer to first instance of character.

@param

rdi: is a non-null NUL-terminated char16_t string pointer
esi: is the search word

@return

: rax points to character, or to NUL word if not found

@note this won't return NULL if search character is NUL

@see libc/nexgen32e/strsak16.S

strclen

Returns number of characters in UTF-8 string.

@param

const char* s

@return

unsigned long

@see libc/str/strclen.c

strclen16

Returns number of characters in UTF-16 or UCS-2 string.

@param

const unsigned short* s

@return

unsigned long

@see libc/str/strclen16.c

strcmp

Compares NUL-terminated strings.

@param

const char* a: is first non-null NUL-terminated string pointer
const char* b: is second non-null NUL-terminated string pointer

@return

int: is <0, 0, or >0 based on uint8_t comparison

@asyncsignalsafe

@see libc/str/strcmp.c

strcmp16

Compares NUL-terminated UCS-2 strings.

@param

const unsigned short* l
const unsigned short* r

@return

int: is <0, 0, or >0 based on uint16_t comparison

@asyncsignalsafe

@see libc/str/strcmp16.c

strcmp16to8

@param

const unsigned short* s1
const char* s2

@return

int

@see libc/str/strcmp8to16.c

strcmp8to16

Compares UTF-8 and UTF-16 strings.

@param

const char* s1
const unsigned short* s2

@return

int

@see libc/str/strcmp8to16.c

strcoll

Compares strings in the C locale.

@param

const char* p
const char* q

@return

int

@see libc/str/strcoll.c

strcoll_l

@param

const char* p
const char* q
struct __locale_struct* l

@return

int

@see libc/unicode/strcoll_l.c

strcpy

Copies bytes from 𝑠 to 𝑑 until a NUL is encountered.

@param

char* d
const char* s

@return

char*: original dest

@note 𝑑 and 𝑠 can't overlap

@asyncsignalsafe

@see libc/intrin/strcpy.c

strcpy16

Copies NUL-terminated UCS-2 or UTF-16 string.

DEST and SRC must not overlap unless DEST ≤ SRC.

@param

unsigned short* dest: is destination memory
const unsigned short* src: is a NUL-terminated 16-bit string

@return

unsigned short*: original dest

@see libc/str/strcpy16.c

strcspn

Returns prefix length, consisting of chars not in reject. a.k.a. Return index of first byte that's in charset.

@param

const char* s
const char* reject: is nul-terminated character set

@return

unsigned long

@see strspn(), strtok_r()

@asyncsignalsafe

@see libc/str/strcspn.c

strcspn16

Returns prefix length, consisting of chars not in reject. a.k.a. Return index of first byte that's in charset.

@param

const unsigned short* s
const unsigned short* reject: is nul-terminated character set

@return

unsigned long

@see strspn(), strtok_r()

@asyncsignalsafe

@see libc/str/strcspn16.c

strdup

Allocates new copy of string.

@param

const char* s: is a NUL-terminated byte string

@return

char*: new string or NULL w/ errno

@error ENOMEM

@threadsafe

@see libc/mem/strdup.c

strerdoc

Converts errno value to descriptive sentence.

@param

int x

@return

char*: non-null rodata string or null if not found

@see libc/intrin/strerdoc.greg.c

strerrno

Converts errno value to symbolic name.

@param

int x

@return

char*: non-null rodata string or null if not found

@see libc/intrin/strerrno.greg.c

strerror

Converts errno value to string non-reentrantly.

@param

int err

@return

char*

@see strerror_r()

@see libc/fmt/strerror.c

strerror_r

Converts errno value to string.

@param

int err: is error number or zero if unknown
char* buf
unsigned long size

@return

int: 0 on success, or error code

@see libc/fmt/strerror_r.c

strerror_wr

Converts errno value to string with explicit windows errno too.

@param

int err: is error number or zero if unknown
unsigned int winerr
char* buf
unsigned long size

@return

int: 0 on success, or error code

@see libc/intrin/strerror_wr.greg.c

strfry

Jumbles up string.

@param

char* s

@return

char*

@see libc/rand/strfry.c

strftime

Converts time to string, e.g.

char b[64];
int64_t sec;
struct tm tm;
time(&sec);
localtime_r(&sec, &tm);
strftime(b, sizeof(b), "%Y-%m-%dT%H:%M:%S%z", &tm);       // ISO8601
strftime(b, sizeof(b), "%a, %d %b %Y %H:%M:%S %Z", &tm);  // RFC1123

@param

char* s
unsigned long maxsize
const char* format
struct tm_1* t

@return

unsigned long: bytes copied excluding nul, or 0 on error

@see FormatHttpDateTime()

@see libc/time/strftime.c

strftime_l

@param

char* s
unsigned long maxsize
const char* format
struct tm_1* t
struct __locale_struct* locale

@return

unsigned long

@see libc/time/strftime.c

stripext

Removes file extension.

@param

char* s: is mutated

@return

char*: s

@see libc/fmt/stripext.c

stripexts

Removes file extensions.

@param

char* s: is mutated

@return

char*: s

@see libc/fmt/stripexts.c

strlcat

Appends string SRC to DEST, the BSD way.

@param

char* dest: is a buffer holding a NUL-terminated string
const char* src: is a NUL-terminated string
unsigned long size: is byte capacity of dest

@return

unsigned long: strlen(dest) + strlen(src)

@note dest and src can't overlap

@see strncat()

@see libc/str/strlcat.c

strlcpy

Copies string, the BSD way.

@param

char* d: is buffer which needn't be initialized
const char* s: is a NUL-terminated string
unsigned long n: is byte capacity of d

@return

unsigned long: strlen(s)

@note d and s can't overlap

@note we prefer memccpy()

@see libc/str/strlcpy.c

strlen

Returns length of NUL-terminated string.

@param

const char* s: is non-null NUL-terminated string pointer

@return

unsigned long: number of bytes (excluding NUL)

@asyncsignalsafe

@see libc/intrin/strlen.c

strlen16

Returns length of NUL-terminated utf-16 string.

@param

const unsigned short* s: is non-null NUL-terminated string pointer

@return

unsigned long: number of shorts (excluding NUL)

@asyncsignalsafe

@see libc/str/strlen16.c

strncasecmp

Compares NUL-terminated strings case-insensitively w/ limit.

@param

const char* a: is first non-null NUL-terminated string pointer
const char* b: is second non-null NUL-terminated string pointer
unsigned long n

@return

int: is <0, 0, or >0 based on uint8_t comparison

@asyncsignalsafe

@see libc/str/strncasecmp.c

strncasecmp16

Compares NUL-terminated UCS-2 strings case-insensitively w/ limit.

@param

const unsigned short* a: is first non-null NUL-terminated char16 string pointer
const unsigned short* b: is second non-null NUL-terminated char16 string pointer
unsigned long n

@return

int: is <0, 0, or >0 based on uint8_t comparison

@asyncsignalsafe

@see libc/str/strncasecmp16.c

strncasecmp16to8

@param

const unsigned short* s1
const char* s2
unsigned long n

@return

int

@see libc/str/strncasecmp8to16.c

strncasecmp8to16

Compares UTF-8 and UTF-16 strings, ignoring case, with limit.

@param

const char* s1
const unsigned short* s2
unsigned long n

@return

int

@see libc/str/strncasecmp8to16.c

strncat

Appends at most 𝑛 bytes from 𝑠 to 𝑑.

@param

char* d
const char* s
unsigned long n

@return

char*: 𝑑

@note 𝑑 and 𝑠 can't overlap

@asyncsignaslenafe

@see libc/str/strncat.c

strncat16

Appends at most 𝑛 shorts from 𝑠 to 𝑑.

@param

unsigned short* d
const unsigned short* s
unsigned long n

@return

unsigned short*: 𝑑

@note 𝑑 and 𝑠 can't overlap

@asyncsignaslenafe

@see libc/str/strncat16.c

strnclen

@param

const char* s
unsigned long n

@return

unsigned long

@see libc/str/strclen.c

strnclen16

@param

const unsigned short* p
unsigned long n

@return

unsigned long

@see libc/str/strclen16.c

strncmp

Compares NUL-terminated strings w/ limit.

@param

const char* a: is first non-null NUL-terminated string pointer
const char* b: is second non-null NUL-terminated string pointer
unsigned long n

@return

int: is <0, 0, or >0 based on uint8_t comparison

@asyncsignalsafe

@see libc/str/strncmp.c

strncmp16

Compares NUL-terminated UCS-2 strings w/ limit.

@param

const unsigned short* a: is first non-null NUL-terminated char16 string pointer
const unsigned short* b: is second non-null NUL-terminated char16 string pointer
unsigned long n

@return

int: is <0, 0, or >0 based on uint8_t comparison

@asyncsignalsafe

@see libc/str/strncmp16.c

strncmp16to8

@param

const unsigned short* s1
const char* s2
unsigned long n

@return

int

@see libc/str/strncmp8to16.c

strncmp8to16

Compares UTF-8 and UTF-16 strings, with limit.

@param

const char* s1
const unsigned short* s2
unsigned long n

@return

int

@see libc/str/strncmp8to16.c

strncpy

Prepares static search buffer.

If SRC is too long, it's truncated and *not* NUL-terminated.
If SRC is too short, the remainder is zero-filled.

Please note this function isn't designed to prevent untrustworthy data from modifying memory without authorization; the memccpy() function can be used for that purpose.

Here's an example of the only use case we know of for strncpy:

static const struct People {
  char name[8];
  int age;
} kPeople[] = {
    {"alice", 29},  //
    {"bob", 42},    //
};

int GetAge(const char *name) {
  char k[8];
  int m, l, r;
  l = 0;
  r = ARRAYLEN(kPeople) - 1;
  strncpy(k, name, 8);
  while (l <= r) {
    m = (l + r) >> 1;
    if (READ64BE(kPeople[m].name) < READ64BE(k)) {
      l = m + 1;
    } else if (READ64BE(kPeople[m].name) > READ64BE(k)) {
      r = m - 1;
    } else {
      return kPeople[m].age;
    }
  }
  return -1;
}

@param

char* dest
const char* src
unsigned long stride

@return

char*: dest

@see stpncpy(), memccpy()

@asyncsignalsafe

@see libc/str/strncpy.c

strndup

Allocates new copy of string, with byte limit.

@param

const char* s: is a NUL-terminated byte string
unsigned long n: if less than strlen(s) will truncate the string

@return

char*: new string or NULL w/ errno

@error ENOMEM

@threadsafe

@see libc/mem/strndup.c

strnlen

Returns length of NUL-terminated string w/ limit.

@param

const char* s: is string
unsigned long n: is max length

@return

unsigned long: byte length

@asyncsignalsafe

@see libc/str/strnlen.c

strnlen16

Returns length of NUL-terminated 16-bit string w/ limit.

@param

const unsigned short* s: is utf16 string pointer
unsigned long n: is max length in shorts

@return

unsigned long: number of shorts

@asyncsignalsafe

@see libc/str/strnlen16.c

strnlen16_s

Returns length of char16_t string w/ security blankets.

This is like strnlen() except it'll return 0 if (1) RDI is NULL or (2) a NUL-terminator wasn't found in the first RSI shorts.

@param

rdi: is a nullable NUL-terminated char16_t string pointer
rsi: is the maximum number of shorts to consider

@return

: rax is the number of shorts, excluding the NUL

@see libc/nexgen32e/strsak16.S

strnlen_s

Returns length of NUL-terminated string... securely.

This is like strnlen() except it'll return 0 if s is null. We also make the assumption for the purposes of ASAN that n is the size of the buffer if s is non-null.

@param

const char* s: is string
unsigned long n: is max length

@return

unsigned long: byte length

@asyncsignalsafe

@see libc/str/strnlen_s.c

strntolower

@param

char* s
unsigned long n

@return

char*

@see libc/str/strntolower.c

strntoupper

Mutates string to ASCII uppercase w/ limit.

@param

char* s
unsigned long n

@return

char*: string

@praam s is string

@praam n is max bytes to consider

@see libc/str/strntoupper.c

strnwidth

Returns monospace display width of UTF-8 string.

Control codes are discounted
ANSI escape sequences are discounted
East asian glyphs, emoji, etc. count as two

@param

const char* s: is NUL-terminated string
unsigned long n: is max bytes to consider
unsigned long o: is offset for doing tabs

@return

int: monospace display width

@see libc/unicode/strnwidth.c

strnwidth16

Returns monospace display width of UTF-16 or UCS-2 string.

@param

const unsigned short* p
unsigned long n
unsigned long o

@return

int

@see libc/unicode/strnwidth16.c

strpbrk

Returns pointer to first byte matching any in accept, or NULL.

@param

const char* s
const char* accept

@return

char*

@asyncsignalsafe

@see libc/str/strpbrk.c

strpbrk16

Returns pointer to first byte matching any in accept, or NULL.

@param

const unsigned short* s
const unsigned short* accept

@return

unsigned short*

@asyncsignalsafe

@see libc/str/strpbrk16.c

strptime

@param

const char* s
const char* f
struct tm* tm

@return

char*

@see libc/time/strptime.c

strrchr

Searches for last instance of character in string.

@param

const char* s: is NUL-terminated string to search
int c: is treated as unsigned char

@return

char*: address of last c in s, or NULL if not found

@asyncsignalsafe

@see libc/str/strrchr.c

strrchr16

Searches for last instance of char16_t in string.

@param

const unsigned short* s: is NUL-terminated char16_t string to search
int c: is treated as char16_t

@return

unsigned short*: address of last c in s, or NULL if not found

@asyncsignalsafe

@see libc/str/strrchr16.c

strsak16

Swiss Army Knife of string char16_t scanning. Sixteen fast functions in one.

@param

rdi: is non-null string memory
rsi: is max number of shorts to consider
dx: is search character #1
r11w: is search character #2
r8: is subtracted from result (for length vs. pointer)
r9: masks result if DH is found (for NUL vs. NULL)
r10: masks result on shorts exhausted (for length v. NULL)

@return

: rax end pointer after r8/r9/r10 modifications

@see libc/nexgen32e/strsak16.S

strsep

Tokenizes string.

This works by mutating the caller's pointer and the string itself. The returned value is the next available token, or NULL if we've reached the end. Upon each call, *str is updated to point past the terminator we inserted. Multiple delimiter bytes may be passed, which are treated as a set of characters, not a substring.

@param

char** str: on first call points to var holding string to be tokenized and is used by this function to track state on subsequent calls
const char* delim: is a set of characters that constitute separators

@return

char*: next token or NULL when we've reached the end or *str==NULL

@note unlike strtok() this does empty tokens and is re-entrant

@see libc/str/strsep.c

strsignal

Returns string describing signal code.

This returns SIGZERO for 0 which is the empty value. Textual names should be available for signals 1 through 32. Signals in the range 33 and 128 are returned as a SIG%03d string. Everything else is SIGWUT

This function is thread safe when sig is a known signal magnum. Otherwise a pointer to static memory is returned which is unsafe.

@param

int sig: is signal number which should be in range 1 through 128

@return

char*: pointer to static memory that mutates on subsequent calls

@see sigaction()

@threadsafe

@see libc/intrin/strsignal.c

strspn

Returns prefix length, consisting of chars in accept.

@param

const char* s
const char* accept: is nul-terminated character set

@return

unsigned long

@see strcspn(), strtok_r()

@asyncsignalsafe

@see libc/str/strspn.c

strspn16

Returns prefix length, consisting of chars in accept.

@param

const unsigned short* s
const unsigned short* accept: is nul-terminated character set

@return

unsigned long

@see strcspn(), strtok_r()

@asyncsignalsafe

@see libc/str/strspn16.c

strstr16

Searches for substring.

@param

const unsigned short* haystack: is the search area, as a NUL-terminated string
const unsigned short* needle: is the desired substring, also NUL-terminated

@return

unsigned short*: pointer to first substring within haystack, or NULL

@asyncsignalsafe

@see memmem()

@see libc/str/strstr16.c

strtod

@param

const char* s00
char** se

@return

double

@see third_party/gdtoa/strtod.c

strtod_l

@param

const char* s
char** endptr
struct __locale_struct* l

@return

double

@see third_party/gdtoa/strtod_l.c

strtodg

@param

const char* s00
char** se
struct FPI* fpi
int* exp
unsigned int* bits

@return

int

@see third_party/gdtoa/strtodg.c

strtodI

@param

const char* s
char** sp
double* dd

@return

int

@see third_party/gdtoa/strtodI.c

strtof

@param

const char* s
char** sp

@return

float

@see third_party/gdtoa/strtof.c

strtof_l

@param

const char* s
char** sp
struct __locale_struct* l

@return

float

@see third_party/gdtoa/strtof_l.c

strtoi128

Decodes 128-bit signed integer from ASCII string.

@param

const char* s: is a non-null nul-terminated string
char** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

__int128: decoded saturated integer

@see strtou128()

@see libc/fmt/strtoi128.c

strtoId

@param

const char* s
char** sp
double* f0
double* f1

@return

int

@see third_party/gdtoa/strtoId.c

strtoIdd

@param

const char* s
char** sp
double* f0
double* f1

@return

int

@see third_party/gdtoa/strtoIdd.c

strtoIf

@param

const char* s
char** sp
float* f0
float* f1

@return

int

@see third_party/gdtoa/strtoIf.c

strtoimax

Decodes intmax_t from ASCII string.

@param

const char* s: is a non-null nul-terminated string
char** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

long: decoded saturated integer

@see strtoumax()

@see libc/fmt/strtoimax.c

strtoIx

@param

const char* s
char** sp
void* a
void* b

@return

int

@see third_party/gdtoa/strtoIx.c

strtok

Extracts non-empty tokens from string.

@param

char* s: is mutated and should be NULL on subsequent calls
const char* sep: is a NUL-terminated set of bytes to consider separators

@return

char*: pointer to next token or NULL for end

@see strtok_r() and strsep() for superior functions

@notasyncsignalsafe

@see libc/str/strtok.c

strtok_r

Extracts non-empty tokens from string.

@param

char* s: is mutated and should be NULL on subsequent calls
const char* sep: is a NUL-terminated set of bytes to consider separators
char** state: tracks progress between calls

@return

char*: pointer to next token or NULL for end

@see strsep() which is similar

@asyncsignalsafe

@see libc/str/strtok_r.c

strtol

Decodes signed integer from ASCII string.

atoi 10⁸              22𝑐         7𝑛𝑠
strtol 10⁸            37𝑐        12𝑛𝑠
strtoul 10⁸           35𝑐        11𝑛𝑠
wcstol 10⁸            30𝑐        10𝑛𝑠
wcstoul 10⁸           30𝑐        10𝑛𝑠
strtoimax 10⁸         80𝑐        26𝑛𝑠
strtoumax 10⁸         78𝑐        25𝑛𝑠
wcstoimax 10⁸         77𝑐        25𝑛𝑠
wcstoumax 10⁸         76𝑐        25𝑛𝑠

@param

const char* s: is a non-null nul-terminated string
char** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

long: the decoded signed saturated number

@see libc/fmt/strtol.c

strtold

Converts string to long double.

@param

const char* s
char** endptr

@return

long double

@see third_party/gdtoa/strtold.c

strtold_l

Converts string to long double.

@param

const char* s
char** endptr
struct __locale_struct* l

@return

long double

@see third_party/gdtoa/strtold_l.c

strtoll

Decodes signed integer from ASCII string.

@param

const char* s: is a non-null nul-terminated string
char** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

long: decoded signed saturated integer

@see libc/fmt/strtoll.c

strtoll_l

@param

const char* nptr
char** endptr
int base
struct __locale_struct* l

@return

long

@see libc/fmt/strtoll_l.c

strtolower

Mutates string to ASCII lowercase.

@param

char* s

@return

char*: string

@praam s is string

@see libc/str/strtolower.c

strtonum

Converts string to integer, the BSD way.

@param

const char* nptr
long minval
long maxval
const char** errstr

@return

long

@see libc/fmt/strtonum.c

strtopd

@param

const char* s
char** sp
double* d

@return

int

@see third_party/gdtoa/strtopd.c

strtopdd

@param

const char* s
char** sp
double* dd

@return

int

@see third_party/gdtoa/strtopdd.c

strtopf

@param

const char* s
char** sp
float* f

@return

int

@see third_party/gdtoa/strtopf.c

strtopx

@param

const char* s
char** sp
void* V

@return

int

@see third_party/gdtoa/strtopx.c

strtord

@param

const char* s
char** sp
int rounding
double* d

@return

int

@see third_party/gdtoa/strtord.c

strtordd

@param

const char* s
char** sp
int rounding
double* dd

@return

int

@see third_party/gdtoa/strtordd.c

strtorf

@param

const char* s
char** sp
int rounding
float* f

@return

int

@see third_party/gdtoa/strtorf.c

strtorx

@param

const char* s
char** sp
int rounding
void* L

@return

int

@see third_party/gdtoa/strtorx.c

strtou128

Decodes 128-bit unsigned integer from ASCII string.

@param

const char* s: is a non-null nul-terminated string
char** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

unsigned __int128: decoded integer mod 2¹²⁸ negated if leading -

@see strtoi128()

@see libc/fmt/strtou128.c

strtoul

Decodes unsigned integer from ASCII string.

@param

const char* s: is a non-null nul-terminated string
char** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

unsigned long: decoded integer mod 2⁶⁴ negated if leading -

@see libc/fmt/strtoul.c

strtoull

Decodes unsigned integer from ASCII string.

@param

const char* s: is a non-null nul-terminated string
char** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

unsigned long: decoded integer mod 2⁶⁴ negated if leading -

@see libc/fmt/strtoull.c

strtoull_l

@param

const char* nptr
char** endptr
int base
struct __locale_struct* l

@return

unsigned long

@see libc/fmt/strtoull_l.c

strtoumax

Decodes uintmax_t from ASCII string.

@param

const char* s: is a non-null nul-terminated string
char** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

unsigned long: decoded integer mod 2¹²⁸ negated if leading -

@see strtoimax()

@see libc/fmt/strtoumax.c

strtoupper

Mutates string to ASCII uppercase.

@param

char* s

@return

char*: string

@praam s is string

@see libc/str/strtoupper.c

strverscmp

Compares two version strings.

@param

const char* l0
const char* r0

@return

int

@see libc/str/strverscmp.c

strwidth

Returns monospace display width of UTF-8 string.

Control codes are discounted
ANSI escape sequences are discounted
East asian glyphs, emoji, etc. count as two

@param

const char* s: is NUL-terminated string
unsigned long o: is string offset for computing tab widths

@return

int: monospace display width

@see libc/unicode/strwidth.c

strwidth16

Returns monospace display width of UTF-16 or UCS-2 string.

@param

const unsigned short* s
unsigned long o

@return

int

@see libc/unicode/strwidth16.c

strxfrm

Transforms strings into current C locale. calling strcmp() on two strxfrm()-ed strings is same as calling strcoll() on the originals.

@param

char* dest: is buffer which needn't be initialized
const char* src: is a NUL-terminated string
unsigned long count: is number of bytes to write to destination

@return

unsigned long: length of transformed string

@note dest and src can't overlap

@note dest array size should be greater than count

@note if dest is NULL, count has to be zero

@see libc/str/strxfrm.c

strxfrm_l

@param

char* dest
const char* src
unsigned long count
struct __locale_struct* l

@return

unsigned long

@see libc/unicode/strxfrm_l.c

__subvdi3

Returns 𝑥-𝑦, aborting on overflow.

@param

rdi: is int64 𝑥
rsi: is int64 𝑦

@return

: rax is 𝑥-𝑦

@see -ftrapv

@see libc/intrin/subvdi3.S

__subvsi3

Returns 𝑥-𝑦, aborting on overflow.

@param

edi: is int32 𝑥
esi: is int32 𝑦

@return

@see -ftrapv

@see libc/intrin/subvsi3.S

__subvti3

Returns 𝑥-𝑦, aborting on overflow.

@param

rdi:rsi: is int128 𝑥
rdx:rcx: is int128 𝑦

@return

: rdx:rax is 𝑥-𝑦

@see -ftrapv

@see libc/intrin/subvti3.S

svigna

Seeds vigna() pseudorandom number generator.

@param

unsigned long seed

@return

void

@see vigna(), vigna_r()

@see libc/rand/vigna.c

swprintf

@param

int* ws
unsigned long n
const int* format
...

@return

int

@see libc/fmt/swprintf.c

symlink

Creates symbolic link.

This is like link() but adds a tiny indirection to make the fact that the file is a link obvious. It also enables certain other features, like the ability to be broken.

@param

const char* target: can be relative and needn't exist
const char* linkpath: is what gets created

@return

int: 0 on success, or -1 w/ errno

@note Windows NT only lets admins do this

@asyncsignalsafe

@see libc/calls/symlink.c

symlinkat

Creates symbolic link.

This is like link() but adds a tiny indirection to make the fact that the file is a link obvious. It also enables certain other features, like the ability to be broken.

@param

const char* target: can be relative and needn't exist
int newdirfd
const char* linkpath: is what gets created

@return

int: 0 on success, or -1 w/ errno

@raise EPERM if a non-admin on Windows NT tries to use this

@asyncsignalsafe

@see libc/calls/symlinkat.c

sync

Flushes file system changes to disk by any means necessary.

@return

void

@see __nosync to secretly disable

@see libc/calls/sync.c

sync_file_range

Flushes subset of file to disk.

@param

int fd
long offset: is page rounded
long bytes: is page rounded; 0 means until EOF
unsigned int flags: can have SYNC_FILE_RANGE_{WAIT_BEFORE,WRITE,WAIT_AFTER}

@return

int

@note Linux documentation says this call is "dangerous"; for highest assurance of data recovery after crash, consider fsync() on both file and directory

@see fsync(), fdatasync(), PAGESIZE

@see libc/calls/sync_file_range.c

sys_accept

@param

int server
void* addr
unsigned int* addrsize

@return

int

@see libc/sock/accept-sysv.c

sys_accept4

@param

int server
void* addr
unsigned int* addrsize
int flags

@return

int

@see libc/sock/accept4-sysv.c

sys_accept_nt

@param

struct Fd* fd
void* addr
unsigned int* addrsize
int flags

@return

int

@see libc/sock/accept-nt.c

sys_bind

@param

int fd
void* addr
unsigned int addrsize

@return

int

@see libc/sock/bind-sysv.c

sys_bind_nt

@param

struct Fd* fd
void* addr
unsigned int addrsize

@return

int

@see libc/sock/bind-nt.c

sys_chdir_nt

@param

const char* path

@return

int

@see libc/calls/chdir-nt.c

sys_clock_gettime_mono

@param

struct res* ts

@return

int

@see libc/calls/clock_gettime-mono.c

sys_clock_gettime_nt

@param

int clock
ANONYMOUS-STRUCT* ts

@return

int

@see libc/calls/clock_gettime-nt.c

sys_clock_gettime_xnu

@param

int clock
struct st_birthtim* ts

@return

int

@see libc/calls/clock_gettime-xnu.c

sys_clone_linux

Invokes clone() system call on GNU/Systemd.

@param

rdi: is flags
rsi: is top of stack
rdx: is ptid
rcx: is ctid
r8: is tls
r9: is func(void*,int)→int
8(rsp): is arg

@return

: tid of child on success, or -1 w/ errno

@see libc/runtime/clone-linux.S

sys_close_epoll_nt

@param

int fd

@return

int

@see libc/sock/epoll.c

sys_close_nt

@param

struct Fd* fd

@return

int

@see libc/calls/close-nt.c

sys_closesocket_nt

Closes socket on Windows.

This function should only be called by close().

@param

struct Fd* fd

@return

int

@see libc/sock/closesocket-nt.c

sys_connect

@param

int fd
void* addr
unsigned int addrsize

@return

int

@see libc/sock/connect-sysv.c

sys_connect_nt

@param

struct Fd* fd
void* addr
unsigned int addrsize

@return

int

@see libc/sock/connect-nt.c

sys_dup3

@param

int oldfd
int newfd
int flags

@return

int

@see libc/calls/dup3-sysv.c

sys_dup_nt

Implements dup(), dup2(), dup3(), and F_DUPFD for Windows.

@param

int oldfd
int newfd
int flags
int start

@return

int

@see libc/calls/dup-nt.c

sys_execve

@param

const char* prog
char** argv
char** envp

@return

int

@see libc/calls/execve-sysv.c

sys_execve_nt

@param

const char* program
char** argv
char** envp

@return

int

@see libc/calls/execve-nt.greg.c

sys_faccessat_nt

@param

int dirfd
const char* path
int mode
unsigned int flags

@return

int

@see libc/calls/faccessat-nt.c

sys_fadvise_nt

@param

int fd
unsigned long offset
unsigned long len
int advice

@return

int

@see libc/calls/fadvise-nt.c

sys_fchdir_nt

@param

int dirfd

@return

int

@see libc/calls/fchdir-nt.c

sys_fchmodat_nt

@param

int dirfd
const char* path
unsigned int mode
int flags

@return

int

@see libc/calls/fchmodat-nt.c

sys_fcntl

@param

int fd
int cmd
unsigned long arg

@return

int

@see libc/calls/fcntl-sysv.c

sys_fcntl_nt

@param

int fd
int cmd
unsigned long arg

@return

int

@see libc/calls/fcntl-nt.c

sys_fdatasync_nt

@param

int fd

@return

int

@see libc/calls/fdatasync-nt.c

sys_flock_nt

@param

int fd
int op

@return

int

@see libc/calls/flock-nt.c

sys_fork_nt

@return

int

@see libc/runtime/fork-nt.c

sys_fstat

Supports fstat(), etc. implementations.

@param

int fd
struct cosmo* st

@return

int

@asyncsignalsafe

@see libc/calls/fstat-sysv.c

sys_fstat_metal

@param

int fd
struct cosmo* st

@return

int

@see libc/calls/fstat-metal.c

sys_fstat_nt

@param

long handle
struct stat* st

@return

int

@see libc/calls/fstat-nt.c

sys_fstatat

Supports stat(), lstat(), fstatat(), etc. implementations.

@param

int dirfd
const char* path
struct cosmo* st
int flags

@return

int

@asyncsignalsafe

@see libc/calls/fstatat-sysv.c

sys_fstatat_nt

@param

int dirfd
const char* path
struct cosmo* st
int flags

@return

int

@see libc/calls/fstatat-nt.c

sys_ftruncate_nt

@param

long handle
unsigned long length

@return

int

@see libc/calls/ftruncate-nt.c

sys_getcwd_nt

@param

char* buf
unsigned long size

@return

char*

@see libc/calls/getcwd-nt.greg.c

sys_getcwd_xnu

@param

char* res
unsigned long size

@return

char*

@see libc/calls/getcwd-xnu.greg.c

sys_getloadavg_nt

@param

double* a
int n

@return

int

@see libc/calls/getloadavg-nt.c

sys_getpeername

@param

int fd
void* out_addr
unsigned int* out_addrsize

@return

int

@see libc/sock/getpeername-sysv.c

sys_getpeername_nt

@param

struct Fd* fd
void* out_addr
unsigned int* out_addrsize

@return

int

@see libc/sock/getpeername-nt.c

sys_getppid_nt

@return

int

@see libc/calls/getppid-nt.c

sys_getpriority_nt

@param

int ignored

@return

int

@see libc/calls/getpriority-nt.c

sys_getrusage

Returns resource usage statistics.

@param

int who: can be RUSAGE_{SELF,CHILDREN,THREAD}
struct rusage* usage

@return

int: 0 on success, or -1 w/ errno

@see libc/calls/getrusage-sysv.c

sys_getrusage_nt

@param

int who
struct rusage* usage

@return

int

@see libc/calls/getrusage-nt.c

sys_getsetpriority_nt

@param

int which
unsigned int who
int value
int(*)() impl

@return

int

@see libc/calls/getsetpriority-nt.c

sys_getsockname

@param

int fd
void* out_addr
unsigned int* out_addrsize

@return

int

@see libc/sock/getsockname-sysv.c

sys_getsockname_nt

@param

struct Fd* fd
void* out_addr
unsigned int* out_addrsize

@return

int

@see libc/sock/getsockname-nt.c

sys_getsockopt_nt

@param

struct Fd* fd
int level
int optname
void* out_opt_optval
unsigned int* inout_optlen

@return

int

@see libc/sock/getsockopt-nt.c

sys_gettid

@return

int

@see libc/intrin/sys_gettid.greg.c

sys_gettimeofday_metal

@param

struct ru_stime* tv
struct timezone* tz
void* wut

@return

struct axdx_t

@see libc/calls/gettimeofday-metal.c

sys_gettimeofday_nt

@param

ANONYMOUS-STRUCT* tv
struct timezone* tz
void* wut

@return

struct axdx_t

@see libc/calls/gettimeofday-nt.c

sys_gettimeofday_xnu

@param

struct ru_stime* tv
struct timezone* tz
void* wut

@return

struct ad

@see libc/calls/gettimeofday-xnu.c

sys_isatty_metal

@param

int fd

@return

int

@see libc/calls/isatty-metal.c

sys_isatty_nt

@param

int fd

@return

int

@see libc/calls/isatty-nt.c

sys_kill_nt

@param

int pid
int sig

@return

int

@see libc/calls/kill-nt.c

sys_linkat_nt

@param

int olddirfd
const char* oldpath
int newdirfd
const char* newpath

@return

int

@see libc/calls/linkat-nt.c

sys_listen_nt

@param

struct Fd* fd
int backlog

@return

int

@see libc/sock/listen-nt.c

sys_lseek_nt

@param

int fd
long offset
int whence

@return

long

@see libc/calls/lseek-nt.c

sys_madvise_nt

@param

void* addr
unsigned long length
int advice

@return

int

@see libc/calls/madvise-nt.c

sys_mkdirat_nt

@param

int dirfd
const char* path
unsigned int mode

@return

int

@see libc/calls/mkdirat-nt.c

sys_mmap

Obtains memory mapping directly from system.

The mmap() function needs to track memory mappings in order to support Windows NT and Address Sanitizer. That memory tracking can be bypassed by calling this function. However the caller is responsible for passing the magic memory handle on Windows NT to CloseHandle().

@param

void* addr
unsigned long size
int prot
int flags
int fd
long off

@return

struct d

@asyncsignalsafe

@threadsafe

@see libc/calls/directmap.c

sys_mmap_metal

@param

void* paddr
unsigned long size
int prot
int flags
int fd
long off

@return

struct res

@see libc/calls/directmap-metal.c

sys_mmap_nt

@param

void* addr
unsigned long size
int prot
int flags
int fd
long off

@return

struct dm

@see libc/calls/directmap-nt.c

sys_mprotect_nt

@param

void* addr
unsigned long size
int prot

@return

int

@see libc/runtime/mprotect-nt.greg.c

sys_msync_nt

@param

char* addr
unsigned long size
int flags

@return

int

@see libc/runtime/msync-nt.c

sys_munmap

Unmaps memory directly with system.

This function bypasses memtrack. Therefore it won't work on Windows, but it works on everything else including bare metal.

@param

void* p
unsigned long n

@return

int

@asyncsignalsafe

@threadsafe

@see libc/calls/munmap-sysv.c

sys_munmap_metal

@param

void* addr
unsigned long size

@return

int

@see libc/calls/munmap-metal.c

sys_nanosleep_nt

@param

struct st_birthtim* req
struct elapsed* rem

@return

int

@see libc/calls/nanosleep-nt.c

sys_nanosleep_xnu

@param

ANONYMOUS-STRUCT* req
struct elapsed* rem

@return

int

@see libc/calls/nanosleep-xnu.c

sys_open_nt

@param

int dirfd
const char* file
unsigned int flags
int mode

@return

int

@see libc/calls/open-nt.c

sys_openat

@param

int dirfd
const char* file
int flags
unsigned int mode

@return

int

@see libc/calls/openat-sysv.c

sys_openat_metal

@param

int dirfd
const char* file
int flags
unsigned int mode

@return

int

@see libc/calls/openat-metal.c

sys_pause_nt

@return

int

@see libc/calls/pause-nt.c

sys_pipe

@param

int* fds

@return

int

@see libc/calls/pipe-sysv.c

sys_pipe2

@param

int* pipefd
unsigned int flags

@return

int

@see libc/calls/pipe2-sysv.c

sys_pipe_nt

@param

int* pipefd
unsigned int flags

@return

int

@see libc/calls/pipe-nt.c

sys_poll_metal

@param

struct pollfd* fds
unsigned long nfds
unsigned int timeout_ms

@return

int

@see libc/calls/poll-metal.c

sys_poll_nt

Polls on the New Technology.

This function is used to implement poll() and select(). You may poll on both sockets and files at the same time. We also poll for signals while poll is polling.

@param

struct pollfd* fds
unsigned long nfds
unsigned long* ms

@return

int

@see libc/calls/poll-nt.c

sys_read_nt

@param

struct Fd* fd
struct iovec* iov
unsigned long iovlen
long opt_offset

@return

long

@see libc/calls/read-nt.c

sys_readlinkat_nt

@param

int dirfd
const char* path
char* buf
unsigned long bufsiz

@return

long

@see libc/calls/readlinkat-nt.c

sys_readv_metal

@param

struct Fd* fd
struct iovec* iov
int iovlen

@return

long

@see libc/calls/readv-metal.c

sys_readv_nt

@param

struct Fd* fd
struct iovec* iov
int iovlen

@return

long

@see libc/calls/readv-nt.c

sys_readv_serial

@param

struct Fd* fd
struct iovec* iov
int iovlen

@return

long

@see libc/calls/readv-serial.c

sys_recv_nt

Performs stream socket receive on New Technology.

@param

struct Fd* fd: must be a socket
struct iovec* iov
unsigned long iovlen
unsigned int flags

@return

long: number of bytes received, or -1 w/ errno

@see libc/sock/recv-nt.c

sys_recvfrom_nt

Performs datagram receive on New Technology.

@param

struct Fd* fd: must be a socket
struct iovec* iov
unsigned long iovlen
unsigned int flags
void* opt_out_srcaddr
unsigned int* opt_inout_srcaddrsize

@return

long: number of bytes received, or -1 w/ errno

@see libc/sock/recvfrom-nt.c

sys_renameat_nt

@param

int olddirfd
const char* oldpath
int newdirfd
const char* newpath

@return

int

@see libc/calls/renameat-nt.c

sys_sched_getscheduler_netbsd

@param

int pid

@return

int

@see libc/calls/sched_getscheduler-netbsd.c

sys_send_nt

Performs stream socket send on the New Technology.

@param

int fd: must be a socket
struct iovec* iov
unsigned long iovlen
unsigned int flags

@return

long: number of bytes handed off, or -1 w/ errno

@see libc/sock/send-nt.c

sys_sendto_nt

Performs datagram socket send on the New Technology.

@param

int fd: must be a socket
struct iovec* iov
unsigned long iovlen
unsigned int flags
void* opt_in_addr
unsigned int in_addrsize

@return

long: number of bytes handed off, or -1 w/ errno

@see libc/sock/sendto-nt.c

sys_setitimer_nt

@param

int which
struct itimerval* newvalue
struct itimerval* out_opt_oldvalue

@return

int

@see libc/calls/setitimer-nt.c

sys_setpriority_nt

@param

int nice

@return

int

@see libc/calls/setpriority-nt.c

sys_setsockopt_nt

@param

struct Fd* fd
int level
int optname
void* optval
unsigned int optlen

@return

int

@see libc/sock/setsockopt-nt.c

sys_shutdown_nt

@param

struct Fd* fd
int how

@return

int

@see libc/sock/shutdown-nt.c

sys_sigprocmask

@param

int how
struct uc_sigmask* opt_set
struct old* opt_out_oldset

@return

int

@see libc/calls/sigprocmask-sysv.greg.c

sys_socket

@param

int family
int type
int protocol

@return

int

@see libc/sock/socket-sysv.c

sys_socket_nt

@param

int family
int type
int protocol

@return

int

@see libc/sock/socket-nt.c

sys_socketpair

@param

int family
int type
int protocol
int* sv

@return

int

@see libc/sock/socketpair-sysv.c

sys_socketpair_nt

@param

int family
int type
int proto
int* sv

@return

int

@see libc/sock/socketpair-nt.c

sys_symlinkat_nt

@param

const char* target
int newdirfd
const char* linkpath

@return

int

@see libc/calls/symlinkat-nt.c

sys_sync_nt

Flushes all open file handles and, if possible, all disk drives.

@return

int

@see libc/calls/sync-nt.c

sys_sysinfo_nt

@param

struct sysinfo* info

@return

int

@see libc/calls/sysinfo-nt.c

sys_truncate_nt

@param

const char* path
unsigned long length

@return

int

@see libc/calls/truncate-nt.c

sys_unlinkat_nt

@param

int dirfd
const char* path
int flags

@return

int

@see libc/calls/unlinkat-nt.c

sys_unveil_linux

@param

const char* path
const char* permissions

@return

int

@see libc/calls/unveil.c

sys_utimensat

@param

int dirfd
const char* path
ANONYMOUS-STRUCT* ts
int flags

@return

int

@see libc/calls/utimensat-sysv.c

sys_utimensat_nt

@param

int dirfd
const char* path
ANONYMOUS-STRUCT* ts
int flags

@return

int

@see libc/calls/utimensat-nt.c

sys_utimensat_xnu

@param

int dirfd
const char* path
ANONYMOUS-STRUCT* ts
int flags

@return

int

@see libc/calls/utimensat-xnu.c

sys_utimes_nt

@param

const char* path
struct ru_stime* tv

@return

int

@see libc/calls/sys_utimes_nt.c

sys_wait4

@param

int pid
int* opt_out_wstatus
int options
struct rusage* opt_out_rusage

@return

int

@see libc/calls/wait4-sysv.c

sys_wait4_nt

@param

int pid
int* opt_out_wstatus
int options
struct rusage* opt_out_rusage

@return

int

@see libc/calls/wait4-nt.c

sys_write_nt

@param

int fd
struct iovec* iov
unsigned long iovlen
long opt_offset

@return

long

@see libc/calls/write-nt.c

sys_writev_metal

@param

struct Fd* fd
struct iovec* iov
int iovlen

@return

long

@see libc/calls/writev-metal.c

sys_writev_nt

@param

int fd
struct iovec* iov
int iovlen

@return

long

@see libc/calls/writev-nt.c

sys_writev_serial

@param

struct Fd* fd
struct iovec* iov
int iovlen

@return

long

@see libc/calls/writev-serial.c

sys_xinet_ntop

Formats internet address to string, or dies.

@param

int af: can be AF_INET, e.g. addr->sin_family
void* src: is the binary-encoded address, e.g. &addr->sin_addr

@return

char*: allocated IP address string, which must be free()'d

@see libc/sock/xinet_ntop.c

syscall

Performs raw System Five system call.

This function provides a direct path into system call support that's friendly to C code, since it doesn't need an intermediate thunk. It only supports arities up to six, since there's no way to do more safely; this isn't a problem with Linux, although certain BSD calls may not be available.

@param

%rdi: is system call ordinal, which isn't translated, and must be correct for the underlying host system
%rsi,%rdx,%rcx,%r8,%r9: may supply parameters 1 through 5
sixth: is optionally pushed on the stack before call

@return

: %rax has result, or -1 w/ errno on failure

@see libc/sysv/syscall.S

syscall

Invokes SYSCALL for libfatal forceinline asm() routines.

@param

rax: is ordinal
rdi: is arg1
rsi: is arg2
rdx: is arg3
rcx: is arg4
r8: is arg5
r9: is arg6
rsp: may contain more args

@return

: rdx:rax where rax holds -errno on error

@clob rax,rdx,memory,cc

@see libc/intrin/syscall.S

syscon_start

Sections for varint encoded magic numbers.

These sections are all ordered by (group_name, constant_name). They're populated by modules simply referencing the symbols.

@return

@see libc/sysv/consts.sh

@see libc/sysv/consts/syscon_h

@see libc/sysv/systemfive.S

sysconf

Returns configuration value about system.

The following parameters are supported:

_SC_CLK_TCK returns number of clock ticks per second
_SC_ARG_MAX currently always returns 32768 due to Windows
_SC_PAGESIZE currently always returns 65536 due to Windows
_SC_NPROCESSORS_ONLN returns number of CPUs in the system
_SC_OPEN_MAX returns maximum number of open files
_SC_CHILD_MAX returns maximum number of processes

@param

int name

@return

long

@see libc/runtime/sysconf.c

sysinfo

Returns amount of system ram, cores, etc.

@param

struct sysinfo* info

@return

int: 0 on success or -1 w/ errno

@error ENOSYS, EFAULT

@see libc/calls/sysinfo.c

syslog

Generates a log message which will be distributed by syslogd

Note: no errors are reported if an error occurred while logging

  the message.

@param

int priority: is a bitmask containing the facility value and the level value. If no facility value is ORed into priority, then the default value set by openlog() is used. it set to NULL, the program name is used. Level is one of LOG_EMERG, LOG_ALERT, LOG_CRIT, LOG_ERR, LOG_WARNING, LOG_NOTICE, LOG_INFO, LOG_DEBUG
const char* message: the message formatted using the same rules as printf()
...

@return

void

@asyncsignalsafe

@see libc/sock/syslog.c

system

Launches program with system command interpreter.

@param

const char* cmdline: is an interpreted Turing-complete command

@return

int: -1 if child process couldn't be created, otherwise a wait status that can be accessed using macros like WEXITSTATUS(s)

@see libc/stdio/system.c

systemexec

Executes system command replacing current process.

@param

const char* cmdline

@return

int

@vforksafe

@see libc/stdio/systemexec.c

__systemfive

Performs System Five System Call.

Cosmopolitan is designed to delegate all function calls into the Linux, FreeBSD, OpenBSD, and XNU kernels via this function, with few exceptions. This function should generally only be called by generated thunks in the libc/sysv/syscalls/ directory.

It's safe to call this function on Windows, where it will always return -1 with errno == ENOSYS. Further note that -1 is the only return value that means error, a common anti-pattern is to check for values less than 0 (which is more problematic on 32-bit).

It is important to consider that system calls are one order of a magnitude more expensive than normal function calls. For example getpid() on Linux usually takes 500ns, and cached i/o calls will take 1µs or more. So we don't need to inline them like Chromium.

Another thing to consider is that BSDs only loosely follow the System Five ABI for the SYSCALL instruction. For example Linux always follows the six argument limit but the FreeBSD sendfile system call accepts a seventh argument that is passed on stack and OpenBSD modifies functions like mmap so that the sixth arg is passed on the stack. There's also the carry flag convention that XNU, FreeBSD, and OpenBSD inherited from 386BSD aka Jolix

@param

%rax: function ordinal supplied by jump slot
%rdi,%rsi,%rdx,%rcx,%r8,%r9: and rest on stack

@return

: %rax:%rdx is result, or -1 w/ errno on error

@clob %rcx,%r10,%r11

@see syscalls.sh

@see libc/sysv/systemfive.S

tan

Returns tangent of x.

@param

double x

@return

double

@see libc/tinymath/tan.c

tanf

Returns tangent of 𝑥.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@domain -(3π/8) < 𝑥 < 3π/8 for best accuracy

@see libc/tinymath/tanf.S

tanh

Returns hyperbolic tangent of 𝑥.

tanh(x) = (exp(x) - exp(-x))/(exp(x) + exp(-x))
        = (exp(2*x) - 1)/(exp(2*x) - 1 + 2)
        = (1 - exp(-2*x))/(exp(-2*x) - 1 + 2)

@param

double x

@return

double

@see libc/tinymath/tanh.c

tanhf

Returns hyperbolic tangent of 𝑥.

tanh(x) = (exp(x) - exp(-x))/(exp(x) + exp(-x))
        = (exp(2*x) - 1)/(exp(2*x) - 1 + 2)
        = (1 - exp(-2*x))/(exp(-2*x) - 1 + 2)

@param

float x

@return

float

@see libc/tinymath/tanhf.c

tanhl

Returns hyperbolic tangent of 𝑥.

tanh(x) = (exp(x) - exp(-x))/(exp(x) + exp(-x))
        = (exp(2*x) - 1)/(exp(2*x) - 1 + 2)
        = (1 - exp(-2*x))/(exp(-2*x) - 1 + 2)

@param

long double x

@return

long double

@see libc/tinymath/tanhl.c

tanl

Returns tangent of 𝑥.

@param

𝑥: is an 80-bit long double passed on stack in 16-bytes

@return

: %st stores result

@see libc/tinymath/tanl.S

tarjan

Determines order of things in network and finds tangled clusters too.

@param

int vertex_count: is the number of items in the vertices array
const int[2]* edges: are grouped directed links between indices of vertices, which can be thought of as "edge[i][0] depends on edge[i][1]" or "edge[i][1] must come before edge[i][0]" in topological order
int edge_count: is the number of items in edges, which may be 0 if there aren't any connections between vertices in the graph
int* out_sorted: receives indices into the vertices array in topologically sorted order, and must be able to store vertex_count items, and that's always how many are stored
int* out_opt_components: receives indices into the out_sorted array, indicating where each strongly-connected component ends; must be able to store vertex_count items; and it may be NULL
int* out_opt_componentcount: receives the number of cycle indices written to out_opt_components, which will be vertex_count if there aren't any cycles in the graph; and may be NULL if out_opt_components is NULL

@return

int: 0 on success or -1 w/ errno

@error ENOMEM

@note Tarjan's Algorithm is O(|V|+|E|)

@see libc/alg/tarjan.c

tcdrain

@param

int fd

@return

int

@see libc/calls/tcdrain.c

tcflow

Changes flow of teletypewriter data.

TCOOFF suspends output
TCOON resumes output
TCIOFF transmits a STOP character
TCION transmits a START character

@param

int fd
int action

@return

int

@see libc/calls/tcflow.c

tcflush

Flushes teletypewriter data.

TCIFLUSH flushes data received but not read
TCOFLUSH flushes data written but not transmitted
TCIOFLUSH does both TCOFLUSH and TCIFLUSH

@param

int fd
int queue

@return

int

@see libc/calls/tcflush.c

tcgetattr

Obtains the termios struct.

Here are the general defaults you can expect across platforms:

c_iflag        = ICRNL IXON
c_oflag        = OPOST ONLCR NL0 CR0 TAB0 BS0 VT0 FF0
c_cflag        = ISIG CREAD CS8
c_lflag        = ISIG ICANON ECHO ECHOE ECHOK IEXTEN ECHOCTL ECHOKE
c_ispeed       = 38400
c_ospeed       = 38400
c_cc[VINTR]    = CTRL-C
c_cc[VQUIT]    = CTRL-\   # ignore this comment
c_cc[VERASE]   = CTRL-?
c_cc[VKILL]    = CTRL-U
c_cc[VEOF]     = CTRL-D
c_cc[VTIME]    = CTRL-@
c_cc[VMIN]     = CTRL-A
c_cc[VSTART]   = CTRL-Q
c_cc[VSTOP]    = CTRL-S
c_cc[VSUSP]    = CTRL-Z
c_cc[VEOL]     = CTRL-@
c_cc[VSWTC]    = CTRL-@
c_cc[VREPRINT] = CTRL-R
c_cc[VDISCARD] = CTRL-O
c_cc[VWERASE]  = CTRL-W
c_cc[VLNEXT]   = CTRL-V
c_cc[VEOL2]    = CTRL-@

@param

int fd: open file descriptor that isatty()
struct termios* tio: is where result is stored

@return

int: -1 w/ errno on error

@asyncsignalsafe

@see libc/calls/tcgetattr.c

tcgetpgrp

Returns which process group controls terminal.

@param

int fd

@return

int

@asyncsignalsafe

@see libc/calls/tcgetpgrp.c

tcgetsid

@param

int fd

@return

int

@see libc/calls/tcgetsid.c

tcsendbreak

@param

int fd
int len

@return

int

@see libc/calls/tcsendbreak.c

tcsetattr

Sets struct on teletypewriter w/ drains and flushes.

@param

int fd

open file descriptor that isatty()

int opt

can be:

TCSANOW: sets console settings
TCSADRAIN: drains output, and sets console settings
TCSAFLUSH: drops input, drains output, and sets console settings

struct termios* tio

@return

int: 0 on success, -1 w/ errno

@asyncsignalsafe

@see libc/calls/tcsetattr.c

tcsetpgrp

Puts process group in control of terminal.

@param

int fd
int pgrp

@return

int

@asyncsignalsafe

@see libc/calls/tcsetpgrp.c

TearDown

User-defined test cleanup function.

The test runner will call this function after each TEST() if it's defined by the linkage.

@return

void

@see libc/testlib/testlib.h

telldir

Returns offset into directory data.

@param

struct dirstream* dir

@return

long

@see libc/stdio/dirstream.c

tempnam

Creates name for temporary file.

@param

const char* dir
const char* pfx

@return

char*

@see third_party/musl/tempnam.c

TerminateProcess

Terminates the specified process and all of its threads.

@param

long hProcess
unsigned int uExitCode

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/terminateprocess.c

testlib_enable_tmp_setup_teardown

Enables setup and teardown of test directories.

If the linker says this symbol exists then, regardless of its value, a unique test directory will be created at the start of each test, the test will be run with that directory as its working directory, and if the test succeeds it'll be removed along with any contents.

@type

char

@see libc/testlib/testlib.h

__text_windows_start

Special area for Windows NT support code.

Isolating this code adds value for Windows users by minimizing page faults through improved locality. On System Five the PIRO runtime can unmap these pages.

@return

@see libc/runtime/piro.c

@see ape/ape.lds

@see libc/runtime/init.S

__tfork_thread

Creates thread on OpenBSD.

@param

rdi: is params
rsi: is size of params
rdx: is start function
rcx: is start parameter

@return

: thread id or negative errno

@see libc/runtime/clone-openbsd.S

tgamma

@param

double x

@return

double

@see libc/tinymath/tgamma.c

tgammaf

@param

float x

@return

float

@see libc/tinymath/tgammaf.c

tgkill

Kills thread group.

@param

int tgid
int tid
int sig

@return

int

@raises ENOSYS on non-Linux

@see tkill()

@see libc/calls/tgkill.c

__threaded

Contains TID of main thread or 0 if threading isn't enabled.

@type

int

@see libc/nexgen32e/threaded.c

time

Returns time as seconds from UNIX epoch.

@param

long* opt_out_ret: can receive return value on success

@return

long: seconds since epoch, or -1 w/ errno

@asyncsignalsafe

@see libc/calls/time.c

times

Returns accounting data for process on time-sharing system.

@param

struct tms* out_times

@return

long

@see libc/time/times.c

_timespec2timeval

Converts struct timespec to struct timeval.

This divides ts.tv_nsec by 1000 with upward rounding and overflow handling. Your ts.tv_nsec must be on the interval [0,1000000000) otherwise {-1, -1} is returned.

@param

struct ts ts

@return

ANONYMOUS-STRUCT: converted timeval whose tv_usec will be -1 on error

@see libc/intrin/timespec2timeval.c

_timespec_add

Adds two nanosecond timestamps.

@param

struct x x
struct y y

@return

struct y

@see libc/calls/timespec_add.c

_timespec_eq

Checks if 𝑥 = 𝑦.

@param

struct x x
struct y y

@return

_Bool

@see libc/calls/_timespec_eq.c

_timespec_frommicros

Converts timespec interval from microseconds.

@param

long x

@return

struct ts

@see libc/calls/_timespec_frommicros.c

_timespec_frommillis

Converts timespec interval from milliseconds.

@param

long x

@return

struct ts

@see libc/calls/_timespec_frommillis.c

_timespec_gt

Returns true if timespec x is greater than y.

@param

struct x x
struct y y

@return

_Bool

@see libc/calls/struct/timespec_gt.c

_timespec_gte

Checks if 𝑥 ≥ 𝑦.

@param

struct x x
struct y y

@return

_Bool

@see libc/calls/_timespec_gte.c

_timespec_sub

Subtracts two nanosecond timestamps.

@param

struct x x
struct y y

@return

struct y

@see libc/calls/timespec_sub.c

_timespec_tomicros

Converts timespec interval to microseconds.

@param

struct x x

@return

long

@see libc/calls/_timespec_tomicros.c

_timespec_tomillis

Converts timespec interval to milliseconds.

@param

struct x x

@return

long

@see libc/calls/_timespec_tomillis.c

TimeSpecToWindowsTime

@param

struct t t

@return

long

@see libc/str/timespectowindowstime.c

_timeval_add

Adds two microsecond timestamps.

@param

struct x x
struct y y

@return

struct y

@see libc/calls/addtimeval.c

TimeValToWindowsTime

@param

struct t t

@return

long

@see libc/str/timevaltowindowstime.c

timezone

@type

long

@see libc/time/timezone.c

timingsafe_memcmp

Lexicographically compares the first 𝑛 bytes in 𝑝 and 𝑞.

The following expression:

timingsafe_memcmp(p, q, n)

Is functionally equivalent to:

MAX(-1, MIN(1, memcmp(p, q, n)))

Running time is independent of the byte sequences compared, making this safe to use for comparing secret values such as cryptographic MACs. In contrast, memcmp() may short-circuit after finding the first differing byte.

timingsafe_memcmp n=0              661 picoseconds
timingsafe_memcmp n=1                1 ns/byte            590 mb/s
timingsafe_memcmp n=2                1 ns/byte            738 mb/s
timingsafe_memcmp n=3                1 ns/byte            805 mb/s
timingsafe_memcmp n=4                1 ns/byte            843 mb/s
timingsafe_memcmp n=5                1 ns/byte            922 mb/s
timingsafe_memcmp n=6                1 ns/byte            932 mb/s
timingsafe_memcmp n=7                1 ns/byte            939 mb/s
timingsafe_memcmp n=8              992 ps/byte            984 mb/s
timingsafe_memcmp n=9              992 ps/byte            984 mb/s
timingsafe_memcmp n=15             926 ps/byte          1,054 mb/s
timingsafe_memcmp n=16             950 ps/byte          1,026 mb/s
timingsafe_memcmp n=17             933 ps/byte          1,045 mb/s
timingsafe_memcmp n=31             896 ps/byte          1,089 mb/s
timingsafe_memcmp n=32             888 ps/byte          1,098 mb/s
timingsafe_memcmp n=33             972 ps/byte          1,004 mb/s
timingsafe_memcmp n=80             913 ps/byte          1,068 mb/s
timingsafe_memcmp n=128            891 ps/byte          1,095 mb/s
timingsafe_memcmp n=256            873 ps/byte          1,118 mb/s
timingsafe_memcmp n=16384          858 ps/byte          1,138 mb/s
timingsafe_memcmp n=32768          856 ps/byte          1,140 mb/s
timingsafe_memcmp n=131072         857 ps/byte          1,138 mb/s
bcmp ne n=256                        3 ps/byte            246 gb/s
bcmp eq n=256                       32 ps/byte         30,233 mb/s
memcmp ne n=256                      3 ps/byte            246 gb/s
memcmp eq n=256                     31 ps/byte         31,493 mb/s
timingsafe_bcmp ne n=256            27 ps/byte         35,992 mb/s
timingsafe_bcmp eq n=256            27 ps/byte         35,992 mb/s
timingsafe_memcmp ne n=256         877 ps/byte          1,113 mb/s
timingsafe_memcmp eq n=256         883 ps/byte          1,105 mb/s

@param

void* p
void* q
unsigned long n

@return

int: -1, 0, or 1 based on comparison

@note each byte is interpreted as unsigned char

@see timingsafe_bcmp() it's 100x faster

@asyncsignalsafe

@see libc/str/timingsafe_memcmp.c

tinydivsi

Support code for fast integer division by Si units.

Division by magnums is described in Hacker's Delight and is usually generated automatically by compilers, but sadly not when we optimize for size and idiv goes at least 10x slower so we do this which saves space while avoiding build tuning

@param

rdi: is number to divide
cl: is magnum #1
rdx: is magnum #2

@return

: quotient

@see libc/nexgen32e/tinydivsi.greg.S

tinywcslen

32-bit strlen that's tiny and near optimal if data's tiny.

@param

RDI: is wchar_t *s
EAX: is unsigned length

@return

@see libc/nexgen32e/strsak32.S

@see libc/nexgen32e/tinywcslen.greg.S

tinywcsnlen

32-bit strnlen that's tiny and near optimal if data's tiny.

@param

RDI: is wchar_t *s
RSI: is size_t n
EAX: is unsigned length

@return

@see libc/nexgen32e/strsak32.S

@see libc/nexgen32e/tinywcsnlen.greg.S

tkill

Kills thread.

@param

int tid: is thread id
int sig: does nothing on xnu

@return

int: 0 on success, or -1 w/ errno

@see libc/calls/tkill.c

tmpfile

Creates a temporary file.

@return

struct FILE*

@see mkostempsm(), kTmpPath

@see libc/stdio/tmpfile.c

tolower

Converts character to ascii lower case.

@param

int c

@return

int

@see libc/str/tolower.c

tolower_l

@param

int c
struct __locale_struct* l

@return

int

@see libc/unicode/tolower_l.c

touch

Creates new file or changes modified time on existing one.

@param

const char* file: is a UTF-8 string, which may or may not exist
unsigned int mode: is an octal user/group/other permission, e.g. 0755

@return

int: 0 on success, or -1 w/ errno

@see creat()

@see libc/calls/touch.c

toupper

Converts character to upper case.

@param

int c

@return

int

@see libc/str/toupper.c

toupper_l

@param

int c
struct __locale_struct* l

@return

int

@see libc/unicode/toupper_l.c

towctrans

@param

unsigned int c
const int* t

@return

unsigned int

@see libc/str/towctrans.c

towlower

Converts wide character to lower case.

@param

unsigned int c

@return

unsigned int

@see libc/str/towlower.c

towlower_l

@param

unsigned int c
struct __locale_struct* l

@return

unsigned int

@see libc/unicode/towlower_l.c

towupper

Converts wide character to upper case.

@param

unsigned int c

@return

unsigned int

@see libc/str/towupper.c

towupper_l

@param

unsigned int c
struct __locale_struct* l

@return

unsigned int

@see libc/unicode/towupper_l.c

tpdecode

Thompson-Pike Varint Decoder.

@param

const char* s: is a NUL-terminated string
unsigned int* out

@return

int: number of bytes successfully consumed or -1 w/ errno

@note synchronization is performed

@see libc/str/tpdecodecb.internal.h (for implementation)

@deprecated

@see libc/str/tpdecode.ncabi.c

tpenc

Encodes Thompson-Pike varint.

@param

edi: is int to encode

@return

: rax is word-encoded byte buffer

@note invented on a napkin in a new jersey diner

@see libc/intrin/tpenc.S

tpencode

Thompson-Pike Varint Encoder.

Implementation Details: The header macro should ensure this function is only called for non-ASCII, or DCE'd entirely. In addition to that this function makes a promise to not clobber any registers but %rax.

@param

char* p: is what ch gets encoded to
unsigned long size: is the number of bytes available in buf
unsigned int wc
int awesome: mode enables numbers the IETF unilaterally banned

@return

unsigned int: number of bytes written

@note this encoding was designed on a napkin in a new jersey diner

@deprecated

@see libc/str/tpencode.ncabi.c

tprecode16to8

Transcodes UTF-16 to UTF-8.

This is a low-level function intended for the core runtime. Use utf16toutf8() for a much better API that uses malloc().

@param

char* dst: is output buffer
unsigned long dstsize: is bytes in dst
const unsigned short* src: is NUL-terminated UTF-16 input string

@return

struct r: ax bytes written excluding nul; dx index of character after nul word in src

@see libc/str/tprecode16to8.c

tprecode8to16

Transcodes UTF-8 to UTF-16.

This is a low-level function intended for the core runtime. Use utf8toutf16() for a much better API that uses malloc().

@param

unsigned short* dst: is output buffer
unsigned long dstsize: is shorts in dst
const char* src: is NUL-terminated UTF-8 input string

@return

struct r: ax shorts written excluding nul; dx index of character after nul word in src

@see libc/str/tprecode8to16.c

traceme

@type

int

@see libc/log/traceme.c

TrackMemoryInterval

@param

struct _mmi* mm
int x
int y
long h
int prot
int flags
_Bool readonlyfile
_Bool iscow
long offset
long size

@return

int

@see libc/calls/memtrack.greg.c

trunc

Rounds to integer, towards zero.

@param

double x

@return

double

@see libc/tinymath/trunc.c

truncate

Reduces or extends underlying physical medium of file.

If file was originally larger, content >length is lost.

@param

const char* path: must exist
unsigned long length

@return

int: 0 on success or -1 w/ errno

@see ftruncate()

@error ENOENT

@see libc/calls/truncate.c

truncf

Rounds to integer, toward zero.

@param

𝑥: is float scalar in low quarter of %xmm0

@return

: float scalar in low quarter of %xmm0

@define trunc(𝑥+copysign(.5,𝑥))

@see round(),rint(),nearbyint()

@see roundss $_MM_FROUND_TO_ZERO|_MM_FROUND_NO_EXC,%xmm0,%xmm0

@see libc/tinymath/truncf.S

truncl

Rounds to integer, toward zero.

@param

𝑥: is long double passed on stack

@return

: long double in %st

@see libc/tinymath/truncl.S

ttyname

Returns name of terminal.

@param

int fd

@return

char*

@see libc/calls/ttyname.c

ttyname_r

Returns name of terminal, reentrantly.

@param

int fd
char* buf
unsigned long size

@return

int

@see libc/calls/ttyname_r.c

tzname

@type

char*[2]

@see libc/time/timezone.c

tzset

@return

void

@see libc/time/localtime.c

__udivmodti4

Performs 128-bit unsigned division and remainder.

@param

unsigned __int128 a: is dividend
unsigned __int128 b: is divisor
unsigned __int128* rem: receives remainder if not NULL

@return

unsigned __int128

@see third_party/compiler_rt/udivmodti4.c

uint128toarray_radix10

Converts unsigned 128-bit integer to string.

@param

unsigned __int128 i
char* a: needs at least 40 bytes

@return

unsigned long: bytes written w/o nul

@see libc/fmt/itoa128radix10.greg.c

uint64toarray

@param

unsigned long i
char* a
int r

@return

unsigned long

@see libc/fmt/itoa64.c

uint64toarray_fixed16

@param

unsigned long x
char* b
unsigned char k

@return

unsigned long

@see libc/fmt/itoa64fixed16.greg.c

uint64toarray_radix16

@param

unsigned long x
char* b

@return

unsigned long

@see libc/fmt/itoa64radix16.greg.c

uint64toarray_radix8

Converts unsigned 64-bit integer to octal string.

@param

unsigned long i
char* a: needs at least 24 bytes

@return

unsigned long: bytes written w/o nul

@see libc/fmt/itoa64radix8.c

uleb128

Encodes unsigned leb128 integer.

@param

char* p
unsigned __int128 x

@return

char*

@see libc/fmt/uleb128.c

uleb64

Encodes unsigned integer to array.

uleb64 INT64_MAX    l:        10𝑐         3𝑛𝑠
zleb64 INT64_MAX    l:        13𝑐         4𝑛𝑠
sleb64 INT64_MAX    l:        16𝑐         5𝑛𝑠
uleb128 INT64_MAX   l:        18𝑐         6𝑛𝑠
zleb128 INT64_MAX   l:        18𝑐         6𝑛𝑠
sleb128 INT64_MAX   l:        24𝑐         8𝑛𝑠
zleb64 INT64_MIN    l:        13𝑐         4𝑛𝑠
sleb64 INT64_MIN    l:        16𝑐         5𝑛𝑠
zleb128 INT64_MIN   l:        19𝑐         6𝑛𝑠
sleb128 INT64_MIN   l:        24𝑐         8𝑛𝑠

@param

char* p: is output array
unsigned long x: is number

@return

char*: p + i

@see libc/fmt/uleb64.c

umask

Sets file mode creation mask.

@param

int newmask

@return

int: previous mask

@note always succeeds

@see libc/calls/umask.c

uname

Asks kernel to give us the uname -a data.

@param

struct utsname* lool

@return

int: 0 on success, or -1 w/ errno

@see libc/calls/uname.c

unbing

Turns CP437 unicode glyph into its binary representation.

@param

int c: is a unicode character

@return

int: byte representation, or -1 if ch wasn't ibm cp437

@see bing()

@see libc/fmt/unbing.c

unbingbuf

Decodes human-readable CP437 glyphs into binary, e.g.

char binged[5];
char golden[5] = "\0\1\2\3\4";
unbingbuf(binged, sizeof(binged), u" ☺☻♥♦", -1);
CHECK_EQ(0, memcmp(binged, golden, 5));

@param

void* buf: is caller owned
unsigned long size: is byte length of buf
const unsigned short* glyphs: is UCS-2 encoded CP437 representation of binary data
int fill: if -1 will memset any remaining buffer space

@return

void*

@note no NUL terminator is added to end of buf

@see tunbing(), unbingstr(), unbing()

@see libc/x/unbingbuf.c

unbingstr

Decodes human-readable CP437 glyphs into binary, e.g.

CHECK_EQ(0, memcmp(gc(unbingstr(u" ☺☻♥♦")), "\0\1\2\3\4", 5));

@param

const unsigned short* s

@return

void*

@note no NUL terminator is added to end of buf

@see tunbing(), unbingbuf(), unbing()

@see libc/x/unbingstr.c

Unchunk

Removes chunk transfer encoding from message body in place.

@param

struct HttpUnchunker* u
char* p: is modified in place
unsigned long n
unsigned long* l: receives content length if not null

@return

long: bytes processed, 0 if need more data, or -1 on failure

@see net/http/unchunk.c

uncompress

Decompresses the source buffer into the destination buffer. sourceLen is the byte length of the source buffer. Upon entry, destLen is the total size of the destination buffer, which must be large enough to hold the entire uncompressed data. (The size of the uncompressed data must have been saved previously by the compressor and transmitted to the decompressor by some mechanism outside the scope of this compression library.) Upon exit, destLen is the actual size of the uncompressed data.

@return

int: Z_OK if success, Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR if there was not enough room in the output buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In the case where there is not enough room, uncompress() will fill the output buffer with the uncompressed data up to that point.

@see third_party/zlib/zlib.h

uncompress2

Same as uncompress, except that sourceLen is a pointer, where the length of the source is *sourceLen. On return, *sourceLen is the number of source bytes consumed.

@return

int

@see third_party/zlib/zlib.h

undeflate

Decompresses raw DEFLATE data.

This is 10x smaller and 10x slower than chromium zlib.

@param

void* output: should be followed by a single guard page, and have 36kb of guard pages preceding it too because buffer overflows are part of the design of this algorithm
unsigned long outputsize
void* input
unsigned long inputsize
struct DeflateState* ds

@return

long

@note h/t Phil Katz, David Huffman, Claude Shannon

@see libc/str/undeflate.c

Underlong

Canonicalizes overlong Thompson-Pike encodings.

Please note that the IETF banned these numbers, so if you want to enforce their ban you can simply strcmp() the result to check for the existence of banned numbers.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/underlong.c

ungetc

Pushes byte back to stream.

@param

int c
struct FILE* f

@return

int

@threadsafe

@see libc/stdio/ungetc.c

ungetc_unlocked

Pushes byte back to stream.

@param

int c
struct FILE* f

@return

int

@see libc/stdio/ungetc_unlocked.c

ungetwc

Pushes wide character back to stream.

@param

unsigned int c
struct FILE* f

@return

unsigned int

@threadsafe

@see libc/stdio/ungetwc.c

ungetwc_unlocked

Pushes wide character back to stream.

@param

unsigned int c
struct FILE* f

@return

unsigned int

@see libc/stdio/ungetwc_unlocked.c

ungray

Decodes gray code.

@param

unsigned int x

@return

unsigned int

@see https://en.wikipedia.org/wiki/Gray_code

@see gray()

@see libc/bits/ungray.c

unhexbuf

@param

void* buf
unsigned long size
const char* hexdigs

@return

void*

@see libc/fmt/unhexbuf.c

unhexstr

@param

const char* hexdigs

@return

void*

@see libc/mem/unhexstr.c

unhilbert

Decodes Hilbert space-filling curve.

@param

long n
long i

@return

struct m

@see https://en.wikipedia.org/wiki/Hilbert_curve

@see hilbert()

@see libc/bits/hilbert.c

unlink

Removes file.

This may be used to delete files but it can't be used to delete directories. The exception are symlinks, which this will delete however not the linked directory.

@param

const char* name

@return

int: 0 on success, or -1 w/ errno

@asyncsignalsafe

@see libc/calls/unlink.c

unlink_s

Deletes file.

The caller's variable is made NULL. Note that we define unlink(NULL) as a no-op.

@param

const char** namep

@return

int: 0 on success, or -1 w/ errno

@asyncsignalsafe

@see libc/calls/unlink_s.c

unlinkat

Deletes inode and maybe the file too.

This may be used to delete files and directories and symlinks.

@param

int dirfd: is normally AT_FDCWD but if it's an open directory and path is relative, then path becomes relative to dirfd
const char* path: is the thing to delete
int flags: can have AT_REMOVEDIR

@return

int: 0 on success, or -1 w/ errno

@see libc/calls/unlinkat.c

unlockpt

@param

int fd

@return

int

@see libc/calls/unlockpt.c

UnmapViewOfFile

Unmaps memory created by MapViewOfFileEx().

@param

void* lpBaseAddress

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/unmapviewoffile.c

unmorton

Deinterleaves bits.

@param

unsigned long i

@return

struct axdx_t: deinterleaved coordinate {ax := 𝑦, dx := 𝑥}

@see en.wikipedia.org/wiki/Z-order_curve

@see morton()

@see libc/bits/unmorton.c

unmount

Unmounts file system.

The following flags may be specified:

MNT_FORCE

The following flags may also be used, but could be set to zero at runtime if the underlying kernel doesn't support them.

MNT_DETACH
MNT_EXPIRE
UMOUNT_NOFOLLOW
MNT_BYFSID

@param

const char* target
int flags

@return

int

@see libc/calls/unmount.c

unsetenv

Removes environment variable.

@param

const char* s

@return

int

@see libc/calls/unsetenv.c

unsleb128

Decodes a GNU-style varint from a buffer.

The GNU Assembler is able to encode numbers this way, since it's used by the DWARF debug format.

@param

void* buf
unsigned long size
__int128* out

@return

int

@see libc/fmt/unsleb128.c

UntrackMemoryIntervals

@param

void* addr
unsigned long size

@return

int

@see libc/runtime/untrackmemoryintervals.c

unuleb64

Decodes unsigned integer from array.

@param

char* p: is input array
unsigned long n: is capacity of p
unsigned long* x: receives number number

@return

int: bytes decoded or -1 on error

@see libc/fmt/unuleb64.c

unveil

Restricts filesystem operations, e.g.

unveil(".", "r");     // current directory + children are visible
unveil("/etc", "r");  // make /etc readable too
unveil(0, 0);         // commit and lock policy

Unveiling restricts a view of the filesystem to a set of allowed paths with specific privileges.

Once you start using unveil(), the entire file system is considered hidden. You then specify, by repeatedly calling unveil(), which paths should become unhidden. When you're finished, you call unveil(0,0) which commits your policy.

There are some differences between unveil() on Linux versus OpenBSD.

Build your policy and lock it in one go. On OpenBSD, policies take effect immediately and may evolve as you continue to call unveil() but only in a more restrictive direction. On Linux, nothing will happen until you call unveil(0,0) which commits and locks.
Try not to overlap directory trees. On OpenBSD, if directory trees overlap, then the most restrictive policy will be used for a given file. On Linux overlapping may result in a less restrictive policy and possibly even undefined behavior.
OpenBSD and Linux disagree on error codes. On OpenBSD, accessing paths outside of the allowed set raises ENOENT, and accessing ones with incorrect permissions raises EACCES. On Linux, both these cases raise EACCES.
Unlike OpenBSD, Linux does nothing to conceal the existence of paths. Even with an unveil() policy in place, it's still possible to access the metadata of all files using functions like stat() and open(O_PATH), provided you know the path. A sandboxed process can always, for example, determine how many bytes of data are in /etc/passwd, even if the file isn't readable. But it's still not possible to use opendir() and go fishing for paths which weren't previously known.
Use ftruncate() rather than truncate(). One of the backdoors with Landlock is it currently can't restrict truncate() and setxattr() which permits certain kinds of modifications to files outside the sandbox. When your policy is committed, we install a SECCOMP BPF filter to disable those calls, however similar trickery may be possible through other unaddressed calls like ioctl(). Using the pledge() function in addition to unveil() will solve this, since it installs a strong system call access policy.
Set your process-wide policy at startup from the main thread. On OpenBSD unveil() will apply process-wide even when called from a child thread; whereas with Linux, calling unveil() from a thread will cause your ruleset to only apply to that thread in addition to any descendent threads it creates.
Always specify at least one path. OpenBSD has unclear semantics when unveil(0,0) is used without any previous calls.
On OpenBSD calling unveil(0,0) will prevent unveil() from being used again. On Linux this is allowed, because Landlock is able to do that securely, i.e. the second ruleset can only be a subset of the previous ones.

This system call is supported natively on OpenBSD and polyfilled on Linux using the Landlock LSM[1].

@param

const char* path

is the file or directory to unveil

const char* permissions

is a string consisting of zero or more of the following characters:

'r' makes path available for read-only path operations, corresponding to the pledge promise "rpath".
w makes path available for write operations, corresponding to the pledge promise "wpath".
x makes path available for execute operations, corresponding to the pledge promises "exec" and "execnative".
c allows path to be created and removed, corresponding to the pledge promise "cpath".

@return

int: 0 on success, or -1 w/ errno

@raise ENOSYS if host os isn't Linux or OpenBSD

@raise ENOSYS if Landlock isn't supported on this kernel

@raise EINVAL if one argument is set and the other is not

@raise EINVAL if an invalid character in permissions was found

@raise EPERM if unveil() is called after locking

@note on Linux this function requires Linux Kernel 5.13+

@see [1] https://docs.kernel.org/userspace-api/landlock.html

@threadsafe

@see libc/calls/unveil.c

unzleb64

Decodes array to signed integer w/ zig-zag encoding.

@param

const char* p: is array
unsigned long n: is byte length of array
long* o: optionally receives decoded integer

@return

int: bytes decoded or -1 on error

@see zleb64()

@see libc/fmt/unzleb64.c

uselocale

@param

struct __locale_struct* l

@return

struct __locale_struct*

@see libc/unicode/uselocale.c

usleep

Sleeps for particular number of microseconds.

@param

unsigned int micros

@return

int: 0 on success, or -1 w/ errno

@raise EINTR if a signal was delivered while sleeping

@see nanosleep(), sleep()

@norestart

@see libc/calls/usleep.c

utf16to32

Transcodes UTF-16 to UTF-32.

@param

const unsigned short* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

int*

@see libc/x/utf16to32.c

utf16toutf8

Transcodes UTF-16 to UTF-8.

@param

const unsigned short* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

char*

@see libc/x/utf16toutf8.c

utf8toutf32

Transcodes UTF-8 to UTF-32.

@param

const char* p: is input value
unsigned long n: if -1 implies strlen
unsigned long* z: if non-NULL receives output length

@return

int*

@see libc/x/utf8toutf32.c

utime

Changes last accessed/modified times on file.

@param

const char* path
struct utimbuf* times: if NULL means now

@return

int: 0 on success or -1 w/ errno

@asyncsignalsafe

@see libc/calls/utime.c

utimensat

Sets atime/mtime on file, the modern way.

This is two functions in one. If path is null then this function becomes the same as futimens(dirfd, ts).

XNU and RHEL5 only have microsecond accuracy and there's no dirfd relative support.

@param

int dirfd: should AT_FDCWD
const char* path
struct st_birthtim* ts: is atime/mtime, or null for current time
int flags: can have AT_SYMLINK_NOFOLLOW

@return

int

@raise ENOSYS on RHEL5 if path is NULL

@raise EINVAL if flags had unrecognized bits

@raise EINVAL if path is NULL and flags has AT_SYMLINK_NOFOLLOW

@raise EBADF if dirfd isn't a valid fd or AT_FDCWD

@raise EFAULT if path or ts memory was invalid

@raise EROFS if file system is read-only

@raise ENAMETOOLONG

@raise EPERM

@see futimens()

@asyncsignalsafe

@see libc/calls/utimensat.c

utimes

Changes last accessed/modified times on file.

@param

const char* path
struct ru_stime* tv

@return

int: 0 on success or -1 w/ errno

@asyncsignalsafe

@see stat()

@see libc/calls/utimes.c

valloc

Equivalent to memalign(PAGESIZE, n).

@param

unsigned long n: number of bytes needed

@return

void*: memory address, or NULL w/ errno

@see pvalloc()

@threadsafe

@see libc/mem/valloc.c

vappendf

Appends formatted string to buffer.

@param

char** b
const char* f
struct __va_list* v

@return

long

@see libc/stdio/vappendf.c

vasprintf

Formats string w/ dynamic memory allocation.

@param

char** strp
const char* fmt
struct __va_list* va

@return

int

@see xasprintf() for a better API

@threadsafe

@see libc/mem/vasprintf.c

vcscanf

String / file / stream decoder.

This scanf implementation is able to tokenize strings containing 8-bit through 128-bit integers (with validation), floating point numbers, etc. It can also be used to convert UTF-8 to UTF-16/32.

%d parses integer
%ms parses string allocating buffer assigning pointer

@param

int(*)() callback: supplies UTF-8 characters using -1 sentinel
int(*)() unget
void* arg
const char* fmt: is a computer program embedded inside a c string, written in a domain-specific programming language that, by design, lacks Turing-completeness
struct __va_list* va: points to the variadic argument state

@return

int

@see libc/fmt/pflink.h (dynamic memory is not a requirement)

@see libc/fmt/vcscanf.c

vdprintf

Formats string directly to system i/o device.

@param

int fd
const char* fmt
struct __va_list* va

@return

int

@asyncsignalsafe

@vforksafe

@see libc/calls/vdprintf.c

__vdsosym

Returns address of vDSO function.

@param

const char* version
const char* name

@return

void*

@see libc/calls/vdsofunc.greg.c

verr

@param

int eval
const char* fmt
struct __va_list* va

@noreturn

@see libc/log/verr.c

verrx

@param

int eval
const char* fmt
struct __va_list* va

@noreturn

@see libc/log/verrx.c

vflogf

Writes formatted message w/ timestamp to log.

Timestamps are hyphenated out when multiple events happen within the same second in the same process. When timestamps are crossed out, it will display microseconsd as a delta elapsed time. This is useful if you do something like:

INFOF("connecting to foo");
connect(...)
INFOF("connected to foo");

In that case, the second log entry will always display the amount of time that it took to connect. This is great in forking applications.

@param

unsigned int level
const char* file
int line
struct FILE* f
const char* fmt
struct __va_list* va

@return

void

@asyncsignalsafe

@threadsafe

@see libc/log/vflogf.c

vfork

Forks process without copying page tables.

This is the same as fork() except it's optimized for the case where the caller invokes execve() immediately afterwards. You can also call functions like close(), dup2(), etc. You cannot call read() safely but you can call pread(). Call _exit() but don't call exit(). Look for the vforksafe function annotation

Do not make the assumption that the parent is suspended until the child terminates since this impl calls fork() on Windows.

@return

: pid of child process or 0 if forked process

@returnstwice

@vforksafe

@see libc/runtime/vfork.S

vfprintf

Formats and writes text to stream.

@param

struct FILE* f
const char* fmt
struct __va_list* va

@return

int

@see printf() for further documentation

@see libc/stdio/vfprintf.c

vfprintf_unlocked

Formats and writes text to stream.

@param

struct FILE* f
const char* fmt
struct __va_list* va

@return

int

@see printf() for further documentation

@see libc/stdio/vfprintf_unlocked.c

vfscanf

Stream decoder.

@param

struct FILE* stream
const char* fmt
struct __va_list* ap

@return

int

@see libc/fmt/vcscanf.h

@see libc/stdio/vfscanf.c

vigna

Returns deterministic pseudorandom data, e.g.

uint64_t x = vigna();

You can generate different types of numbers as follows:

int64_t x = vigna() >> 1;    // make positive signed integer
double x = _real1(vigna());  // make float on [0,1]-interval

You can seed this random number generator using:

svigna(rdseed());

You may use the reentrant version of this function:

static uint64_t s = 0;
uint64_t x = svigna_r(&s);

If you want to fill a buffer with data then rngset() implements vigna's algorithm to do that extremely well:

char buf[4096];
rngset(buf, sizeof(buf), vigna, 0);

If you want a fast pseudorandom number generator that seeds itself automatically on startup and fork() then consider rand64(). If you want true random data then consider rdseed, rdrand, and getrandom.

@return

unsigned long: 64 bits of pseudorandom data

@note this function is not intended for cryptography

@note this function passes bigcrush and practrand

@note this function takes at minimum 4 cycles

@see libc/rand/vigna.c

vigna_r

Returns pseudorandom data.

@param

unsigned long* state

@return

unsigned long

@see vigna() for easy api

@see libc/rand/vigna.c

VirtualProtect

Protects memory on the New Technology.

@param

void* lpAddress
unsigned long dwSize
unsigned int flNewProtect
unsigned int* lpflOldProtect

@return

int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/virtualprotect.c

VisualizeControlCodes

Makes control codes and trojan source plainly viewable.

This is useful for logging data like HTTP messages, where we don't want full blown C string literal escaping, but we don't want things like raw ANSI control codes from untrusted devices in our terminals.

This function also canonicalizes overlong encodings. Therefore it isn't necessary to say VisualizeControlCodes(Underlong(𝑥))) since VisualizeControlCodes(𝑥) will do the same thing.

@param

const char* data: is input value
unsigned long size: if -1 implies strlen
unsigned long* out_size: if non-NULL receives output length

@return

char*: allocated NUL-terminated buffer, or NULL w/ errno

@see net/http/visualizecontrolcodes.c

vmsplice

Transfers memory to pipe.

@param

int fd
struct iovec* chunks
long count
unsigned int flags: can have SPLICE_F_{MOVE,NONBLOCK,MORE,GIFT}

@return

long: number of bytes actually transferred, or -1 w/ errno

@see libc/calls/vmsplice.c

vprintf

Formats and writes text to stdout.

@param

const char* fmt
struct __va_list* va

@return

int

@see printf() for further documentation

@see libc/stdio/vprintf.c

vscanf

String decoder.

@param

const char* fmt
struct __va_list* ap

@return

int

@see libc/fmt/vcscanf.h

@see libc/stdio/vscanf.c

vsnprintf

Formats string to buffer w/ preexisting vararg state.

@param

char* buf: stores output and a NUL-terminator is always written, provided buf!=NULL && size!=0
unsigned long size: is byte capacity buf
const char* fmt
struct __va_list* va

@return

int: number of bytes written, excluding the NUL terminator; or, if the output buffer wasn't passed, or was too short, then the number of characters that *would* have been written is returned

@see __fmt() and printf() for detailed documentation

@asyncsignalsafe

@vforksafe

@see libc/fmt/vsnprintf.c

vsprintf

Formats string to buffer hopefully large enough w/ vararg state.

@param

char* buf
const char* fmt
struct __va_list* va

@return

int

@see __fmt() and printf() for detailed documentation

@see vsnprintf() for modern alternative w/ buf size param

@see libc/fmt/vsprintf.c

vsscanf

Decodes string.

@param

const char* str
const char* fmt
struct __va_list* va

@return

int

@see libc/fmt/vcscanf.h (for docs and implementation)

@note to offer the best performance, we assume small codebases needing vsscanf() won't need sscanf() too; and as such, there's a small code size penalty to using both

@see libc/fmt/vsscanf.c

vsyslog

Generates a log message which will be distributed by syslogd

Note: no errors are reported if an error occurred while logging

  the message.

@param

int priority: is a bitmask containing the facility value and the level value. If no facility value is ORed into priority, then the default value set by openlog() is used. it set to NULL, the program name is used. Level is one of LOG_EMERG, LOG_ALERT, LOG_CRIT, LOG_ERR, LOG_WARNING, LOG_NOTICE, LOG_INFO, LOG_DEBUG
const char* message: the format of the message to be processed by vprintf()
struct __va_list* ap: the va_list of arguments to be applied to the message

@return

void

@asyncsignalsafe

@see libc/sock/syslog.c

vwarn

@param

const char* fmt
struct __va_list* va

@return

void

@see libc/log/vwarn.c

vwarnx

@param

const char* fmt
struct __va_list* va

@return

void

@see libc/log/vwarnx.c

wait

Waits for status to change on any child process.

@param

int* opt_out_wstatus: optionally returns status code, and *wstatus may be inspected using WEEXITSTATUS(), etc.

@return

int: process id of terminated child or -1 w/ errno

@asyncsignalsafe

@restartable

@vforksafe

@see libc/calls/wait.c

_wait0

Blocks until memory location becomes zero.

This is intended to be used on the child thread id, which is updated by the _spawn() system call when a thread terminates. The purpose of this operation is to know when it's safe to munmap() a threads stack

@param

const int* ctid

@return

void

@see libc/intrin/wait0.c

wait3

Waits for status to change on any child process.

@param

int* opt_out_wstatus: optionally returns status code, and *wstatus may be inspected using WEEXITSTATUS(), etc.
int options: can have WNOHANG, WUNTRACED, WCONTINUED, etc.
struct rusage* opt_out_rusage: optionally returns accounting data

@return

int: process id of terminated child or -1 w/ errno

@asyncsignalsafe

@restartable

@see libc/calls/wait3.c

wait4

Waits for status to change on process.

@param

int pid: >0 targets specific process, =0 means any proc in a group, -1 means any child process, <-1 means any proc in specific group
int* opt_out_wstatus: optionally returns status code, and *wstatus may be inspected using WEEXITSTATUS(), etc.
int options: can have WNOHANG, WUNTRACED, WCONTINUED, etc.
struct rusage* opt_out_rusage: optionally returns accounting data

@return

int: process id of terminated child or -1 w/ errno

@asyncsignalsafe

@restartable

@see libc/calls/wait4.c

WaitForMultipleObjects

Waits for handles to change status.

@param

unsigned int nCount
const long* lpHandles
int bWaitAll
unsigned int dwMilliseconds

@return

unsigned int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/waitformultipleobjects.c

WaitForSingleObject

Waits for handle to change status.

@param

long hHandle
unsigned int dwMilliseconds

@return

unsigned int

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/waitforsingleobject.c

waitpid

Waits for status to change on process.

@param

int pid: >0 targets specific process, =0 means any proc in a group, -1 means any child process, <-1 means any proc in specific group
int* opt_out_wstatus: optionally returns status code, and *wstatus may be inspected using WEXITSTATUS(), etc.
int options: can have WNOHANG, WUNTRACED, WCONTINUED, etc.

@return

int: process id of terminated child or -1 w/ errno

@asyncsignalsafe

@restartable

@see libc/calls/waitpid.c

warn

@param

const char* fmt
...

@return

void

@see libc/log/warn.c

warnx

@param

const char* fmt
...

@return

void

@see libc/log/warnx.c

_wchomp

Mutates line to remove line-ending characters.

@param

int* line: is NULL-propagating

@return

int*

@see getline

@see libc/str/wchomp.c

wcrtomb

@param

char* s
int wc
unsigned int* st

@return

unsigned long

@see libc/str/wcrtomb.c

wcscasecmp

Compares NUL-terminated wide strings case-insensitively.

@param

const int* a: is first non-null NUL-terminated string pointer
const int* b: is second non-null NUL-terminated string pointer

@return

int: is <0, 0, or >0 based on uint8_t comparison

@asyncsignalsafe

@see libc/str/wcscasecmp.c

wcscat

Appends 𝑠 to 𝑑.

@param

int* d
const int* s

@return

int*: 𝑑

@asyncsignalsafe

@see libc/str/wcscat.c

wcschr

Returns pointer to first instance of character.

@param

rdi: is a non-null NUL-terminated wchar_t string pointer
esi: is the search word

@return

: rax points to first result, or NULL if not found

@note this won't return NULL if search character is NUL

@asyncsignalsafe

@see libc/nexgen32e/strsak32.S

wcschrnul

Returns pointer to first instance of character.

@param

rdi: is a non-null NUL-terminated wchar_t string pointer
esi: is the search word

@return

: rax points to character, or to NUL word if not found

@note this won't return NULL if search character is NUL

@see libc/nexgen32e/strsak32.S

wcscmp

Compares NUL-terminated wide strings.

@param

const int* a: is first non-null NUL-terminated string pointer
const int* b: is second non-null NUL-terminated string pointer

@return

int: is <0, 0, or >0 based on uint8_t comparison

@asyncsignalsafe

@see libc/str/wcscmp.c

wcscoll_l

@param

const int* p
const int* q
struct __locale_struct* l

@return

int

@see libc/unicode/wcscoll_l.c

wcscpy

Copies NUL-terminated wide character string.

𝑑 and 𝑠 must not overlap unless 𝑑 ≤ 𝑠.

@param

int* d
const int* s

@return

int*: original dest

@asyncsignalsafe

@see libc/str/wcscpy.c

wcscspn

Returns prefix length, consisting of chars not in reject. a.k.a. Return index of first byte that's in charset.

@param

const int* s
const int* reject: is nul-terminated character set

@return

unsigned long

@see strspn(), strtok_r()

@asyncsignalsafe

@see libc/str/wcscspn.c

wcsdup

Allocates copy of wide string.

@param

const int* s

@return

int*

@threadsafe

@see libc/mem/wcsdup.c

wcsendswith

Returns true if s has suffix.

@param

const int* s: is a NUL-terminated string
const int* suffix: is also NUL-terminated

@return

_Bool

@see libc/str/wcsendswith.c

wcslen

Returns length of NUL-terminated wchar_t string.

@param

rdi: is non-null NUL-terminated wchar_t string pointer

@return

: rax is the number of chars, excluding the NUL

@asyncsignalsafe

@see libc/nexgen32e/strsak32.S

wcsncasecmp

Compares NUL-terminated wide strings case-insensitively w/ limit.

@param

const int* a: is first non-null NUL-terminated string pointer
const int* b: is second non-null NUL-terminated string pointer
unsigned long n

@return

int: is <0, 0, or >0 based on uint8_t comparison

@asyncsignalsafe

@see libc/str/wcsncasecmp.c

wcsncat

Appends at most 𝑛 wides from 𝑠 to 𝑑.

@param

int* d
const int* s
unsigned long n

@return

int*: 𝑑

@note 𝑑 and 𝑠 can't overlap

@asyncsignaslenafe

@see libc/str/wcsncat.c

wcsncmp

Compares NUL-terminated wide strings w/ limit.

@param

const int* a: is first non-null NUL-terminated string pointer
const int* b: is second non-null NUL-terminated string pointer
unsigned long n

@return

int: is <0, 0, or >0 based on uint8_t comparison

@asyncsignalsafe

@see libc/str/wcsncmp.c

wcsncpy

@param

int* d
const int* s
unsigned long n

@return

int*

@see libc/str/wcsncpy.c

wcsnlen

Returns length of NUL-terminated memory, with limit.

@param

rdi: is non-null memory
rsi: is the maximum number of chars to consider

@return

: rax is the number of chars, excluding the NUL

@asyncsignalsafe

@see libc/nexgen32e/strsak32.S

wcsnlen_s

Returns length of wchar_t string w/ security blankets.

This is like wcsnlen() except it'll return 0 if (1) RDI is NULL or (2) a NUL-terminator wasn't found in the first RSI chars.

@param

rdi: is a nullable NUL-terminated wchar_t string pointer
rsi: is the maximum number of chars to consider

@return

: rax is the number of chars, excluding the NUL

@see libc/nexgen32e/strsak32.S

wcsnrtombs

@param

char* dst
const int** wcs
unsigned long wn
unsigned long n
unsigned int* st

@return

unsigned long

@see libc/str/wcsnrtombs.c

wcsnwidth

Returns monospace display width of wide character string.

@param

const int* pwcs
unsigned long n
unsigned long o

@return

int

@see libc/unicode/wcsnwidth.c

wcspbrk

Returns pointer to first byte matching any in accept, or NULL.

@param

const int* s
const int* accept

@return

int*

@asyncsignalsafe

@see libc/str/wcspbrk.c

wcsrchr

Searches for last instance of wchar_t in string.

@param

const int* s: is NUL-terminated wchar_t string to search
int c: is the needle

@return

int*: address of last c in s, or NULL if not found

@asyncsignalsafe

@see libc/str/wcsrchr.c

wcsrtombs

@param

char* s
const int** ws
unsigned long n
unsigned int* st

@return

unsigned long

@see libc/str/wcsrtombs.c

wcssak

Swiss army knife of wchar_t string scanning. Seven fast functions in one.

@param

rdi: is non-null wchar_t string memory
rsi: is max number of chars to consider
edx: is search character #1
r11d: is search character #2
r8: is subtracted from result (for length vs. pointer)
r9: masks result if r11w is found (for NUL vs. NULL)
r10: masks result on chars exhausted (for length v. NULL)

@return

: rax end pointer after r8/r9/r10 modifications

@see libc/nexgen32e/strsak32.S

wcsspn

Returns prefix length, consisting of chars in accept.

@param

const int* s
const int* accept: is nul-terminated character set

@return

unsigned long

@see strcspn(), strtok_r()

@asyncsignalsafe

@see libc/str/wcsspn.c

wcsstartswith

Returns true if s has prefix.

@param

const int* s: is a NUL-terminated string
const int* prefix: is also NUL-terminated

@return

_Bool

@see libc/str/wcsstartswith.c

wcsstr

Searches for substring.

@param

const int* haystack: is the search area, as a NUL-terminated string
const int* needle: is the desired substring, also NUL-terminated

@return

int*: pointer to first substring within haystack, or NULL

@asyncsignalsafe

@see memmem()

@see libc/str/wcslen.c

wcstod

@param

const int* nptr
int** endptr

@return

double

@see third_party/gdtoa/wcstod.c

wcstof

@param

const int* nptr
int** endptr

@return

float

@see third_party/gdtoa/wcstof.c

wcstoi128

Decodes 128-bit signed integer from wide string.

@param

const int* s: is a non-null nul-terminated string
int** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

__int128: decoded saturated integer

@see strtou128()

@see libc/fmt/wcstoi128.c

wcstoimax

Decodes intmax_t from wide string.

@param

const int* s: is a non-null nul-terminated string
int** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

long: decoded saturated integer

@see strtoumax()

@see libc/fmt/wcstoimax.c

wcstok

Extracts non-empty tokens from string.

@param

int* s: is mutated and should be NULL on subsequent calls
const int* sep: is a NUL-terminated set of wchars to consider separators
int** state: tracks progress between calls

@return

int*: pointer to next token or NULL for end

@see libc/str/wcstok.c

wcstol

Decodes signed long integer from wide string.

@param

const int* s: is a non-null nul-terminated string
int** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

long: the decoded signed saturated number

@see libc/fmt/wcstol.c

wcstold

@param

const int* nptr
int** endptr

@return

long double

@see third_party/gdtoa/wcstold.c

wcstold_l

@param

const int* nptr
int** endptr
struct __locale_struct* l

@return

long double

@see third_party/gdtoa/wcstold_l.c

wcstoll

Decodes signed long long integer from wide string.

@param

const int* s: is a non-null nul-terminated string
int** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

long: the decoded signed saturated number

@see libc/fmt/wcstoll.c

wcstoll_l

@param

const int* nptr
int** endptr
int base
struct __locale_struct* l

@return

long

@see libc/fmt/wcstoll_l.c

wcstombs

@param

char* s
const int* ws
unsigned long n

@return

unsigned long

@see libc/str/wcstombs.c

wcstou128

Decodes 128-bit unsigned integer from wide string.

@param

const int* s: is a non-null nul-terminated string
int** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

unsigned __int128: decoded integer mod 2¹²⁸ negated if leading -

@see strtoi128()

@see libc/fmt/wcstou128.c

wcstoul

Decodes unsigned integer from wide string.

@param

const int* s: is a non-null nul-terminated string
int** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

unsigned long: decoded integer mod 2⁶⁴ negated if leading -

@see libc/fmt/wcstoul.c

wcstoull

Decodes unsigned long long integer from wide string.

@param

const int* s: is a non-null nul-terminated string
int** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

unsigned long: decoded integer mod 2⁶⁴ negated if leading -

@see libc/fmt/wcstoull.c

wcstoull_l

@param

const int* nptr
int** endptr
int base
struct __locale_struct* l

@return

unsigned long

@see libc/fmt/wcstoull_l.c

wcstoumax

Decodes uintmax_t from wide string.

@param

const int* s: is a non-null nul-terminated string
int** endptr: if non-null will always receive a pointer to the char following the last one this function processed, which is usually the NUL byte, or in the case of invalid strings, would point to the first invalid character
int base: can be anywhere between [2,36] or 0 to auto-detect based on the the prefixes 0 (octal), 0x (hexadecimal), 0b (binary), or decimal (base 10) by default

@return

unsigned long: decoded integer mod 2¹²⁸ negated if leading -

@see strtoimax()

@see libc/fmt/wcstoumax.c

wcswidth

Returns monospace display width of wide character string.

@param

const int* pwcs
unsigned long o

@return

int

@see libc/unicode/wcswidth.c

wcsxfrm

@param

int* d
const int* s
unsigned long n

@return

unsigned long

@see libc/str/wcsxfrm.c

wcsxfrm_l

@param

int* dest
const int* src
unsigned long count
struct __locale_struct* l

@return

unsigned long

@see libc/unicode/wcsxfrm_l.c

wctob

@param

unsigned int c

@return

int

@see libc/str/wctob.c

wctomb

@param

char* s
int wc

@return

int

@see libc/str/wctomb.c

wctrans

@param

const char* s

@return

const int*

@see libc/str/wctrans.c

wctype

Returns number representing character class name.

@param

const char* s: can be "alnum", "alpha", "blank", "cntrl", "digit", "graph", "lower", "print", "punct", "space", "upper", "xdigit"

@return

unsigned int: nonzero id or 0 if not found

@see libc/str/wctype.c

wcwidth

Returns cell width of monospace character.

@param

int c

@return

int

@see libc/unicode/wcwidth.c

_weakfree

Thunks free() if it's linked, otherwise do nothing.

@param

void* p

@return

void

@see libc/runtime/weakfree.c

WindowsDurationToTimeSpec

@param

long x

@return

ANONYMOUS-STRUCT

@see libc/str/windowsdurationtotimespec.c

WindowsDurationToTimeVal

@param

long x

@return

ANONYMOUS-STRUCT

@see libc/str/windowsdurationtotimeval.c

WindowsTimeToTimeSpec

Converts Windows COBOL timestamp to UNIX epoch in nanoseconds.

@param

long x

@return

ANONYMOUS-STRUCT

@see libc/str/windowstimetotimespec.c

WindowsTimeToTimeVal

Converts Windows COBOL timestamp to UNIX epoch in microseconds.

@param

long x

@return

ANONYMOUS-STRUCT

@see libc/str/windowstimetotimeval.c

__winerr

Return path for failed Win32 API calls.

@return

long: -1 w/ few exceptions

@note this is a code-size saving device

@see libc/intrin/winerr.greg.c

WinMain

Main function on Windows NT.

The Cosmopolitan Runtime provides the following services, which aim to bring Windows NT behavior closer in harmony with System Five:

We configure CMD.EXE for UTF-8 and enable ANSI colors on Win10.
Command line arguments are passed as a blob of UTF-16 text. We chop them up into an char *argv[] UTF-8 data structure, in accordance with the DOS conventions for argument quoting.
Environment variables are passed to us as a sorted UTF-16 double NUL terminated list. We translate this to char ** using UTF-8.
Allocates new stack at a high address. NT likes to choose a stack address that's beneath the program image. We want to be able to assume that stack addresses are located at higher addresses than heap and program memory.
Reconfigure x87 FPU so long double is actually long (80 bits).
Finally, we need fork. Since disagreeing with fork is axiomatic to Microsoft's engineering culture, we need to go to great lengths to have it anyway without breaking Microsoft's rules: using the WIN32 API (i.e. not NTDLL) to copy MAP_PRIVATE pages via a pipe. It'd go faster if the COW pages CreateFileMappingNuma claims to have turns out to be true. Until then we have a "PC Scale" and entirely legal workaround that they hopefully won't block using Windows Defender.

@param

long hInstance: call GetModuleHandle(NULL) from main if you need it
long hPrevInstance
const char* lpCmdLine
long nCmdShow

@return

long

@see libc/runtime/winmain.greg.c

WinMainForked

@return

void

@see libc/runtime/fork-nt.c

__winsockerr

Error return path for winsock wrappers.

@return

long

@see libc/calls/winsockerr.c

WinSockInit

@return

void

@see libc/sock/kntwsadata.c

WinThreadLaunch

Used by clone() on Windows to launch thread.

Windows owns the stack memory when we initially enter threads. This function switches us over, so that we can start using the runtime facilities.

@param

%rdi: is arg
%rsi: is tid
%rdx: is func
%rcx: is stack

@return

: %rax is exit code

@see clone()

@see libc/runtime/winthreadlaunch.S

wmemchr

Returns pointer to first instance of character in range.

@param

rdi: is a non-null pointer to memory
esi: is the int32_t search word (officially wchar_t)
rdx: is length of memory in chars

@return

: rax points to word if found or NULL

@asyncsignalsafe

@see libc/nexgen32e/strsak32.S

wmemcmp

Compares NUL-terminated wide strings w/ limit.

@param

const int* a: is first non-null NUL-terminated string pointer
const int* b: is second non-null NUL-terminated string pointer
unsigned long n

@return

int: is <0, 0, or >0 based on uint8_t comparison

@asyncsignalsafe

@see libc/str/wmemcmp.c

wmemcpy

@param

int* dest
const int* src
unsigned long count

@return

int*

@see libc/str/wmemcpy.c

wmemmove

@param

int* dest
const int* src
unsigned long count

@return

int*

@see libc/str/wmemmove.c

wmempcpy

@param

int* dest
const int* src
unsigned long count

@return

int*

@see libc/str/wmempcpy.c

write

Writes data to file descriptor.

@param

int fd: is something open()'d earlier
void* buf: is copied from, cf. copy_file_range(), sendfile(), etc.
unsigned long size: in range [1..0x7ffff000] is reasonable

@return

long: [1..size] bytes on success, or -1 w/ errno; noting zero is impossible unless size was passed as zero to do an error check

@see read(), pwrite(), writev(), SIGPIPE

@asyncsignalsafe

@restartable

@see libc/calls/write.c

writev

Writes data from multiple buffers.

This is the same thing as write() except it has multiple buffers. This yields a performance boost in situations where it'd be expensive to stitch data together using memcpy() or issuing multiple syscalls. This wrapper is implemented so that writev() calls where iovlen<2 may be passed to the kernel as write() instead. This yields a 100 cycle performance boost in the case of a single small iovec.

@param

int fd
struct iovec* iov
int iovlen

@return

long: number of bytes actually handed off, or -1 w/ errno

@restartable

@see libc/calls/writev.c

WritevUninterruptible

@param

int fd
struct iovec* iov
int iovlen

@return

long

@see libc/calls/writevuninterruptible.c

WSARecv

Receives data from Windows socket.

@param

unsigned long s
struct ProviderSpecific* inout_lpBuffers
unsigned int dwBufferCount
unsigned int* opt_out_lpNumberOfBytesRecvd
unsigned int* inout_lpFlags
struct NtOverlapped* opt_inout_lpOverlapped
void(*)() opt_lpCompletionRoutine

@return

int: 0 on success, or -1 on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/wsarecv.c

WSARecvFrom

Receives data from Windows socket.

@param

unsigned long s
struct ProviderSpecific* inout_lpBuffers
unsigned int dwBufferCount
unsigned int* opt_out_lpNumberOfBytesRecvd
unsigned int* inout_lpFlags
void* opt_out_fromsockaddr
unsigned int* opt_inout_fromsockaddrlen
struct NtOverlapped* opt_inout_lpOverlapped
void(*)() opt_lpCompletionRoutine

@return

int: 0 on success, or -1 on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/wsarecvfrom.c

WSAStartup

Winsock2 prototypes.

@return

int

@note Some of the functions exported by WS2_32.DLL, e.g. bind(), overlap with the names used by System V. Prototypes for these functions are declared within their respective wrappers.

@see libc/nt/winsock.h

WSAWaitForMultipleEvents

Waits for events on Windows sockets.

@param

unsigned int cEvents
const long* lphEvents
int fWaitAll
unsigned int dwTimeout_ms
int fAlertable

@return

unsigned int: 0 on success, or -1 on failure

@note this wrapper takes care of ABI, STRACE(), and __winerr()

@see libc/intrin/wsawaitformultipleevents.c

xasprintf

Returns dynamically formatted string.

@param

const char* fmt
...

@return

char*: must be free()'d or gc()'d

@note greatest of all C functions

@see libc/x/xasprintf.c

xbarf

Writes data to file.

@param

const char* path
void* data
unsigned long size: can be -1 to strlen(data)

@return

int: 0 on success or -1 w/ errno

@note this is uninterruptible

@see libc/x/xbarf.c

xcalloc

Allocates initialized memory, or dies.

@param

unsigned long count
unsigned long size

@return

void*

@see libc/x/xcalloc.c

xdie

@return

void

@see libc/x/xdie.c

xdirname

Returns directory portion of path.

@param

const char* path

@return

char*

@see libc/x/xdirname.c

xdtoa

Converts double to string the easy way.

@param

double d

@return

char*: string that needs to be free'd

@see libc/x/xdtoa.c

xdtoaf

Converts double to string w/ high-accuracy the easy way.

@param

float d

@return

char*: string that needs to be free'd

@see libc/x/xdtoaf.c

xdtoal

Converts double to string the easy way.

@param

long double d

@return

char*: string that needs to be free'd

@see libc/x/xdtoal.c

xed_decoded_inst_zero_set_mode

Clears instruction decoder state.

@param

struct XedDecodedInst* p
int mmode

@return

struct XedDecodedInst*

@see third_party/xed/x86ild.greg.c

xed_get_chip_features

@param

struct XedChipFeatures* p
int chip

@return

void

@see third_party/xed/x86isa.c

xed_instruction_length_decode

Decodes machine instruction length.

This function also decodes other useful attributes, such as the offsets of displacement, immediates, etc. It works for all ISAs from 1977 to 2020.

@param

struct XedDecodedInst* xedd
void* itext
unsigned long bytes

@return

int

@note binary footprint increases ~4kb if this is used

@see biggest code in gdb/clang/tensorflow binaries

@see third_party/xed/x86ild.greg.c

xed_isa_set_is_valid_for_chip

@param

int isa_set
int chip

@return

_Bool

@see third_party/xed/x86isa.c

xed_prefix_table_bit

Phash tables for instruction length decoding.

@return

@see build/rle.py for more context here

@see third_party/xed/x86tab.S

xed_test_chip_features

@param

struct XedChipFeatures* p
int isa_set

@return

_Bool

@see third_party/xed/x86isa.c

xfixpath

Fixes $PATH environment variable on Windows.

@return

void

@see libc/x/xfixpath.c

xgetline

Reads line from stream.

@param

struct FILE* f

@return

char*: allocated line that needs free() and usually _chomp() too, or NULL on ferror() or feof()

@see getdelim() for a more difficult api

@see _chomp()

@see libc/x/xgetline.c

xhomedir

Returns home directory.

@return

char*

@see libc/x/xhomedir.c

xiso8601ts

Returns allocated string representation of nanosecond timestamp.

@param

struct ts* opt_ts

@return

char*

@see libc/time/xiso8601.c

xiso8601tv

Returns allocated string representation of microsecond timestamp.

@param

struct ru_stime* opt_tv

@return

char*

@see libc/time/xiso8601.c

xjoinpaths

Joins paths, e.g.

"a"  + "b"  → "a/b"
"a/" + "b"  → "a/b"
"a"  + "b/" → "a/b/"
"a"  + "/b" → "/b"
"."  + "b"  → "b"
""   + "b"  → "b"

@param

const char* path
const char* other

@return

char*: newly allocated string of resulting path

@see libc/x/xjoinpaths.c

xload

Inflates data once atomically, e.g.

void *GetData(void) {
  static char once;
  static void *ptr;
  static const unsigned char rodata[] = {...};
  if (once) return ptr;
  return xload(&once, &ptr, rodata, 112, 1024);
}

The above is an example of how this helper may be used to have lazy loading of big infrequently accessed image data.

@param

_Bool* o: points to your static init guard
void** t: points to your static pointer holder
void* p: is read-only data compressed using raw deflate
unsigned long n: is byte length of deflated data
unsigned long m: is byte length of inflated data

@return

void*: pointer to inflated data

@threadsafe

@see libc/x/xload.c

xloadzd

Loads δzd encoded data once atomically.

@param

_Bool* o: points to your static init guard
void** t: points to your static pointer holder
void* p: is read-only data compressed using raw deflate
unsigned long n: is byte length of deflated data
unsigned long m: is byte length of inflated data
unsigned long c: is number of items in array
unsigned long z: is byte length of items
unsigned int s: is crc32 checksum

@return

void*: pointer to decoded data

@threadsafe

@see libc/x/xloadzd.c

xmalloc

Allocates uninitialized memory, or dies.

@param

unsigned long bytes

@return

void*

@see libc/x/xmalloc.c

xmemalign

Allocates aligned memory, or dies.

@param

unsigned long alignment
unsigned long bytes

@return

void*

@see libc/x/xmemalign.c

xmemalignzero

Allocates aligned cleared memory, or dies.

@param

unsigned long alignment
unsigned long bytes

@return

void*

@see libc/x/xmemalignzero.c

xreadlink

Reads symbolic link.

@param

const char* path

@return

char*: nul-terminated string, or null w/ errno

@see readlink()

@see libc/x/xreadlink.c

xreadlinkat

Reads symbolic link.

@param

int dirfd
const char* path

@return

char*: nul-terminated string, or null w/ errno

@see readlinkat()

@see libc/x/xreadlinkat.c

xrealloc

Allocates/expands/shrinks/frees memory, or die.

This API enables you to do the following:

p = xrealloc(p, n)

The standard behaviors for realloc() still apply:

!p means xmalloc (returns non-NULL)
p && n means resize (returns non-NULL)
p && !n means free (returns NULL)

The complexity of resizing is guaranteed to be amortized.

@param

void* p
unsigned long n

@return

void*

@see libc/x/xrealloc.c

xsigaction

Installs handler for kernel interrupt, e.g.:

onctrlc(sig) { exit(128+sig); }
CHECK_NE(-1, xsigaction(SIGINT, onctrlc, SA_RESETHAND, 0, 0));

@param

int sig: can be SIGINT, SIGTERM, etc.
void* handler: is SIG_DFL, SIG_IGN, or a pointer to a 0≤arity≤3 callback function passed (sig, siginfo_t *, ucontext_t *).
unsigned long flags: can have SA_RESETHAND, SA_RESTART, SA_SIGINFO, etc.
unsigned long mask: is 1ul«SIG₁[…|1ul«SIGₙ] bitset to block in handler
struct sa* old: optionally receives previous handler

@return

int: 0 on success, or -1 w/ errno

@see libc/sysv/consts.sh

@asyncsignalsafe

@vforksafe

@see libc/x/xsigaction.c

xslurp

Reads entire file into memory.

@param

const char* path
unsigned long* opt_out_size

@return

void*: NUL-terminated malloc'd contents, or NULL w/ errno

@note this is uninterruptible

@see libc/x/xslurp.c

xspawn

Spawns process using fork().

@param

struct rusage* r: if provided gets accounting data

@return

int: wstatus, or -2 on child, or -1 w/ errno

@see libc/x/xspawn.c

xstrcat

Concatenates strings / chars to newly allocated memory, e.g.

xstrcat("hi", ' ', "there")

Or without the C99 helper macro:

(xstrcat)("hi", ' ', "there", NULL)

This goes twice as fast as the more powerful xasprintf(). It's not quadratic like strcat(). It's much slower than high-effort stpcpy(), particularly with string literals.

@param

const char* s
...

@return

char*

@see gc()

@see libc/x/xstrcat.c

xstrdup

Allocates new copy of string, or dies.

@param

const char* s

@return

char*

@see libc/x/xstrdup.c

xstripext

Removes file extension.

@param

const char* s: is mutated

@return

char*: s

@see libc/x/xstripext.c

xstripexts

Removes file extensions.

@param

const char* s: is mutated

@return

char*: s

@see libc/x/xstripexts.c

xstrmul

Multiplies string.

@param

const char* s
unsigned long n

@return

char*

@see libc/x/xstrmul.c

xstrndup

Allocates new copy of string, with byte limit.

@param

const char* s: is a NUL-terminated byte string
unsigned long n: if less than strlen(s) will truncate the string

@return

char*: new string or NULL w/ errno

@error ENOMEM

@see libc/x/xstrndup.c

xunbing

Decodes CP437 glyphs to bounds-checked binary buffer, e.g.

char *mem = xunbing(u" ☺☻♥♦"); EXPECT_EQ(0, memcmp("\0\1\2\3\4", mem, 5)); tfree(mem);

@param

const unsigned short* binglyphs

@return

void*

@see xunbing(), unbingstr(), unbing()

@see libc/x/tunbing.c

xunbinga

Same as xunbing() w/ alignment guarantee.

@param

unsigned long a
const unsigned short* binglyphs

@return

void*

@see libc/x/tunbing.c

xvalloc

Allocates page-aligned memory, or dies.

@param

unsigned long size

@return

void*

@see libc/x/xvalloc.c

xvasprintf

Returns dynamically formatted string.

@param

const char* fmt
struct __va_list* va

@return

char*: fully formatted string, which must be free()'d

@see xasprintf()

@see libc/x/xvasprintf.c

xvspawn

Spawns process using vfork().

@param

void(*)() f: is child callback
void* ctx
struct rusage* r: if provided gets accounting data

@return

int: wstatus, or -1 w/ errno

@see libc/x/xvspawn.c

xwrite

Writes data uninterruptibly.

@param

int fd
void* p
unsigned long n

@return

int: 0 on success, or -1 w/ errno

@see libc/x/xwrite.c

z_errmsg

@type

const char*[10]

@see third_party/zlib/zutil.c

zcalloc

@param

void* opaque
unsigned long items
unsigned long size

@return

void*

@see third_party/zlib/zalloc.c

zcfree

@param

void* opaque
void* ptr

@return

void

@see third_party/zlib/zalloc.c

zError

Exported to allow conversion of error code to string for compress() and uncompress()

@param

int err

@return

const char*

@see third_party/zlib/zutil.c

__zipos_close

Closes compressed object.

@param

int fd: is vetted by close()

@return

int

@asyncsignalsafe

@threadsafe

@vforksafe

@see libc/zipos/close.c

__zipos_free

Frees ZipOS handle.

@param

struct Zipos* z
struct ZiposHandle* h

@return

void

@asyncsignalsafe

@threadsafe

@see libc/zipos/free.c

__zipos_fstat

Reads file metadata from αcτµαlly pδrταblε εxεcµταblε object store.

@param

struct ZiposHandle* h
ANONYMOUS-STRUCT* st

@return

int

@asyncsignalsafe

@see libc/zipos/fstat.c

__zipos_get

Returns pointer to zip central directory of current executable.

@return

struct zipos*

@asyncsignalsafe

@threadsafe

@see libc/zipos/get.c

__zipos_lseek

Changes current position of zip file handle.

@param

struct ZiposHandle* h
long offset: is the relative byte count
unsigned int whence: can be SEEK_SET, SEEK_CUR, or SEEK_END

@return

long: new position relative to beginning, or -1 on error

@asyncsignalsafe

@see libc/zipos/lseek.c

__zipos_open

Loads compressed file from αcτµαlly pδrταblε εxεcµταblε object store.

@param

struct ZiposUri* name
unsigned int flags
int mode

@return

int

@asyncsignalsafe (todo)

@threadsafe

@see libc/zipos/open.c

__zipos_parseuri

Extracts information about ZIP URI if it is one.

@param

const char* uri
struct ZiposUri* out

@return

long

@see libc/zipos/parseuri.c

__zipos_read

Reads data from zip store object.

@param

struct ZiposHandle* h
struct iovec* iov
unsigned long iovlen
long opt_offset

@return

long: [1..size] bytes on success, 0 on EOF, or -1 w/ errno; with exception of size==0, in which case return zero means no error

@asyncsignalsafe

@see libc/zipos/read.c

__zipos_stat

Reads file metadata from αcτµαlly pδrταblε εxεcµταblε object store.

@param

struct ZiposUri* name
ANONYMOUS-STRUCT* st

@return

int

@asyncsignalsafe

@see libc/zipos/stat.c

zleb128

Encodes signed integer to array.

@param

char* p
__int128 x

@return

char*

@see libc/fmt/zleb128.c

zleb64

Encodes signed integer to array w/ zig-zag encoding.

uleb64 INT64_MAX    l:        10𝑐         3𝑛𝑠
zleb64 INT64_MAX    l:        13𝑐         4𝑛𝑠
sleb64 INT64_MAX    l:        16𝑐         5𝑛𝑠
uleb128 INT64_MAX   l:        18𝑐         6𝑛𝑠
zleb128 INT64_MAX   l:        18𝑐         6𝑛𝑠
sleb128 INT64_MAX   l:        24𝑐         8𝑛𝑠

@param

char* p: is output array which should have 10 items
long x: is number

@return

char*: p + i

@see unzleb64()

@see libc/fmt/zleb64.c

zlibCompileFlags

@return

unsigned long

@see third_party/zlib/zutil.c

zlibVersion

The application can compare zlibVersion and ZLIB_VERSION for consistency. If the first character differs, the library code actually used is not compatible with the zlib.h header file used by the application. This check is automatically made by deflateInit and inflateInit.

@return

const char*

@see third_party/zlib/zlib.h