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

@forcealignargpointer

@asyncsignalsafe

@see libc/runtime/abort.S

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

@see libc/sock/accept.c

access

Checks if effective user can access path in particular ways.

@param

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

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see libc/tinymath/acos.S

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.S

acosh

Returns inverse hyperbolic cosine of 𝑥.

@param

double x

@return

double

@see libc/tinymath/acosh.c

acoshf

Returns inverse hyperbolic cosine of 𝑥.

@param

float x

@return

float

@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(abs(sqrt((1-𝑥)*(1+𝑥))),𝑥)

@domain -1 ≤ 𝑥 ≤ 1

@mode long,legacy

@see libc/tinymath/acosl.S

AddressBirthAction

@param

void* addr

@return

void*

@see third_party/dlmalloc/mtrace.c

AddressDeathAction

@param

void* addr

@return

void*

@see third_party/dlmalloc/mtrace.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/time/alarm.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/runtime/arememoryintervalsok.c

asctime

Converts date time to string.

@param

ANONYMOUS-STRUCT* date

@return

char*: date time string in statically allocated buffer

@see asctime_r for reentrant version

@see libc/time/asctime.c

asctime_r

Converts date time to string.

@param

struct tm* date
char* buf: needs to have 64 bytes

@return

char*: pointer to buf

@see asctime_r for reentrant version

@see libc/time/asctime_r.c

asin

Returns arc sine of 𝑥.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@see libc/tinymath/asin.S

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.S

asinh

Returns inverse hyperbolic sine of 𝑥.

@param

double x

@return

double

@see libc/tinymath/asinh.c

asinhf

Returns inverse hyperbolic sine of 𝑥.

@param

float x

@return

float

@see libc/tinymath/asinhf.c

asinhl

Returns inverse hyperbolic sine of 𝑥.

@param

long double x

@return

long double

@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

@mode long,legacy

@see libc/tinymath/asinl.S

asprintf

Formats string, allocating needed memory.

@param

char** strp
char* fmt
...

@return

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

@see xasprintf() for a better API

@see libc/mem/asprintf.c

__assert_fail

Handles failure of assert() macro.

@param

char* expr
char* file
int line

@noreturn

@see libc/runtime/assertfail.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.S

atan2

Returns arc tangent of 𝑦/𝑥.

@param

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

@return

: double scalar in low half of %xmm0

@note the greatest of all libm functions

@see libc/tinymath/atan2.S

atan2f

Returns arc tangent of 𝑦/𝑥.

@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/atan2f.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.S

atanh

Returns inverse hyperbolic tangent of 𝑥.

@param

double x

@return

double

@see libc/tinymath/atanh.c

atanhf

Returns inverse hyperbolic tangent of 𝑥.

@param

float x

@return

float

@see libc/tinymath/atanhf.c

atanhl

Returns inverse hyperbolic tangent of 𝑥.

@param

long double x

@return

long double

@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/runtime/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

char* s

@return

double

@see third_party/gdtoa/atof.c

atoi

Decodes decimal number from ASCII string.

@param

char* s: is a non-null NUL-terminated string

@return

int: the decoded signed saturated number

@note calling strtoimax() directly with base 0 permits greater flexibility in terms of inputs

@see libc/fmt/atoi.c

atol

@param

char* s

@return

long

@see libc/fmt/atol.c

atoll

@param

char* s

@return

long

@see libc/fmt/atoll.c

atomic_load

Atomically loads value.

This macro is intended to prevent things like compiler load tearing optimizations.

@param

void* p
unsigned long n

@return

long

@see libc/bits/atomic_load.c

atomic_store

Atomically stores value.

This macro is intended to prevent things like compiler store tearing optimizations.

@param

void* p
long x
unsigned long n

@return

long

@see libc/bits/atomic_store.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.

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 NUL-terminated UTF-8 path

@return

char*: pointer inside path or path itself

@see libc/fmt/basename.c

basename_n

Returns pointer to last filename component in path.

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 path
unsigned long size: is byte length of path

@return

char*: pointer inside path or path itself

@see libc/fmt/basename_n.c

bcmp

Compares memory.

This API was thought to be nearly extinct until recent versions of Clang (c. 2019) started generating synthetic calls to it.

@param

void* a
void* b
unsigned long n

@return

int: 0 if a and b have equal contents, otherwise non-zero

@asyncsignalsafe

@see libc/str/bcmp.c

bcopy

Copies memory the legacy way.

@param

void* dst
void* src
unsigned long n

@return

void*

@see libc/str/bcopy.c

bfree

Frees memory return by balloc().

@param

struct GuardedBuffer* b

@return

void

@deprecated

@see libc/mem/bfree.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

unsigned short x

@return

unsigned short

@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

unsigned char x

@return

unsigned char

@see libc/bits/bitreverse8.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

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

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

bsrmax

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/bsrmax.S

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

bulk_free

Frees and clears (sets to NULL) each non-null pointer in the given array. This is likely to be faster than freeing them one-by-one. If footers are used, pointers that have been allocated in different mspaces are not freed or cleared, and the count of all such pointers is returned. For large arrays of pointers with poor locality, it may be worthwhile to sort this array before calling bulk_free.

@param

void** array
unsigned long nelem

@return

unsigned long

@see third_party/dlmalloc/bulk_free.c

bzero

Sets memory to zero.

C code should always favor memset(), since that's the one we've prototyped with the best optimizations. This definition is used by old code and sometimes code generators, as a thunk.

@param

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

@return

@see memset(), explicit_bzero()

@see libc/nexgen32e/bzero.S

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

callexitontermination

Installs default handlers for friendly kill signals.

@param

struct kSigsetEmpty* 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()

@see libc/mem/calloc.S

cancolor

Returns true if ANSI terminal colors are appropriate.

We take an optimistic approach here. We use colors, unless we see the environment variable TERM=dumb, which is set by software like Emacs. It's a common antipattern to check isatty(STDERR_FILENO), since that usually makes colors harder to get than they are to remove:

 sed 's/\x1b\[[;[:digit:]]*m//g' <color.txt >uncolor.txt

Ideally, all software should be updated to understand color, since it's been formally standardized nearly as long as ASCII. Even old MS-DOS supports it (but Windows didn't until Windows 10) yet even tools like less may need wrapper scripts, e.g.:

 #!/bin/sh
 LESSCHARSET=UTF-8 exec /usr/bin/less -RS "$@"

It's that easy fam.

@return

_Bool

@see libc/log/cancolor.c

carsort100

Sorts int32 key-value arrays of trivial size.

@param

unsigned long n
UNKNOWN a

@return

void

@see test/libc/alg/carsort_test.c

@see carsort1000() if larger

@see libc/runtime/carsort100.c

carsort1000

Sorts int32 key-value arrays of nontrivial size.

@param

unsigned long n
UNKNOWN A

@return

void

@see test/libc/alg/carsort_test.c

@see carsort100() if smaller

@see libc/runtime/carsort1000.c

cbrt

Returns cube root of 𝑥.

@param

%xmm0: holds binary64 number

@return

: %xmm0 holds binary64 result

@see libc/tinymath/cbrt.S

__cbrt

Returns cube root of 𝑥.

@param

double x

@return

double

@see libc/tinymath/cbrtc.c

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

chdir

Sets current directory.

@param

char* path

@return

int

@asyncsignalsafe

@see fchdir()

@see libc/calls/chdir.c

__check_fail

Handles failure of CHECK_xx() macros.

@param

char* suffix
char* opstr
unsigned long want
char* wantstr
unsigned long got
char* gotstr
char* file
int line
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
char* opchar

@return

void

@see libc/log/thunks/__check_fail_ndebug.S

@see libc/log/checkfail_ndebug.c

CheckElfAddress

@param

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

@return

void

@see libc/elf/checkelfaddress.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

This works on Windows NT if you ignore the error ;-)

@param

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

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

clearenv

Removes all environment variables.

@return

int

@see libc/runtime/clearenv.c

clearerr

@param

struct FILE* f

@return

void

@see libc/stdio/clearerr.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_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.

@param

int clockid: can be CLOCK_REALTIME, CLOCK_MONOTONIC, etc. noting that on Linux CLOCK_MONOTONIC is redefined to use the monotonic clock that's actually monotonic lool
ANONYMOUS-STRUCT* ts: is where the result is stored

@return

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

@error ENOSYS if clockid isn't available; in which case this function guarantees an ordinary timestamp is still stored to ts; and errno isn't restored to its original value, to detect prec. loss

@see strftime(), gettimeofday()

@asyncsignalsafe

@see libc/calls/clock_gettime.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

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/bits/cmpxchg.c

commandv

Resolves full pathname of executable.

@param

char* name
char* pathbuf

@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

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

@return

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

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

_construct

Calls global initialization functions.

@param

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

@return

@see libc/runtime/construct.S

convertmicros

@param

struct it_value* tv
long tick

@return

long

@see libc/fmt/convertmicros.c

ConvertTicksToNanos

@param

unsigned long ticks

@return

long double

@see libc/calls/now.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

copyfile

Copies file.

@param

char* src
char* dst
int flags

@return

int

@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

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

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

@see libc/tinymath/cos.S

cosf

Returns cosine 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/cosf.S

cosh

Returns hyperbolic cosine of 𝑥.

@param

double x

@return

double

@see libc/tinymath/cosh.c

coshf

Returns hyperbolic cosine of 𝑥.

@param

float x

@return

float

@see libc/tinymath/coshf.c

coshl

Returns hyperbolic cosine of 𝑥.

@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

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)

@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

edi: is the initial hash value (0 is fine)
rsi: points to the data
rdx: is the byte size of data

@return

: eax is the new hash value

@note Used by ISCSI, TensorFlow, etc.

@see libc/str/crc32c.S

crc32c_pure

Computes Castagnoli CRC-32 on old computers.

@param

unsigned int init
void* data
unsigned long size

@return

unsigned int

@see libc/str/crc32c-pure.c

crc32c_sse42

Hashes data with hardware acceleration at 10GBps.

@param

unsigned int init
void* data
unsigned long n

@return

unsigned int

@note needs Nehalem+ c. 2008 or Bulldozer+ c. 2011

@see libc/str/crc32c-sse42.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

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

critbit0_allprefixed

Invokes callback for all items with prefix.

@param

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

@return

_Bool: true if 𝑡 was mutated

@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
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
char* u: NUL-terminated string

@return

_Bool: true if 𝑡 was mutated

@note h/t djb and agl

@see libc/alg/critbit0_insert.c

ctime

@param

long* timep

@return

char*

@see libc/time/ctime.c

ctime_r

@param

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/runtime/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/runtime/cxaatexit.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

__defer

Calls FN(ARG) when function returns.

@param

struct StackFrame* frame
void* fn
void* arg

@return

void

@see libc/runtime/gc.h

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

describeos

@param

char* buf
unsigned long size

@return

char*

@see libc/runtime/describeos.c

deserializednsheader

Serializes DNS message header to wire.

@param

struct header* header
unsigned char* buf
unsigned long size

@return

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

@see libc/dns/dnsheader.c

devrand

Reads random bytes from system pseudo random number api.

@param

void* buf
unsigned long size

@return

int: 0 on success or -1 w/ errno

@see libc/rand/devrand.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 x
long y

@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.

@param

char* s: is mutated

@return

char*

@see libc/fmt/dirname.c

div

@param

int num
int den

@return

struct div_t

@see libc/fmt/div.c

div1000000000int64

Divides 64-bit signed integer by 1,000,000,000.

@param

rdi: is number to divide

@return

: quotient

@see libc/nexgen32e/div1000000000int64.S

div1000000int64

Divides 64-bit signed integer by 1,000,000.

@param

rdi: is number to divide

@return

: quotient

@see libc/nexgen32e/div1000000int64.S

div10000int64

Divides 64-bit signed integer by 10,000.

@param

rdi: is number to divide

@return

: truncated quotient

@see libc/nexgen32e/div10000int64.S

div1000int64

Divides 64-bit signed integer by 1,000.

@param

rdi: is number to divide

@return

: quotient

@see libc/nexgen32e/div1000int64.S

div100int64

Divides 64-bit signed integer by 100.

@param

rdi: is number to divide

@return

: rax has quotient

@see libc/nexgen32e/div100int64.S

div10int64

Divides 64-bit signed integer by 10.

@param

rdi: is number to divide

@return

: quotient

@see libc/nexgen32e/div10int64.S

__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

dlcalloc

@param

unsigned long n_elements
unsigned long elem_size

@return

void*

@see third_party/dlmalloc/dlcalloc.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

independent_calloc(size_t n_elements, size_t element_size, void* chunks[]);

independent_calloc is similar to calloc, but instead of returning a single cleared space, it returns an array of pointers to n_elements independent elements that can hold contents of size elem_size, each of which starts out cleared, and can be independently freed, realloc'ed etc. The elements are guaranteed to be adjacently allocated (this is not guaranteed to occur with multiple callocs or mallocs), which may also improve cache locality in some applications.

The "chunks" argument is optional (i.e., may be null, which is probably the most typical usage). If it is null, the returned array is itself dynamically allocated and should also be freed when it is no longer needed. Otherwise, the chunks array must be of at least n_elements in length. It is filled in with the pointers to the chunks.

In either case, independent_calloc returns this pointer array, or null if the allocation failed. * If n_elements is zero and "chunks" is null, it returns a chunk representing an array with zero elements (which should be freed if not wanted).

Each element must be freed when it is no longer needed. This can be done all at once using bulk_free.

independent_calloc simplifies and speeds up implementations of many kinds of pools. * It may also be useful when constructing large data structures that initially have a fixed number of fixed-sized nodes, but the number is not known at compile time, and some of the nodes may later need to be freed. For example:

struct Node { int item; struct Node* next; };
struct Node* build_list() {
  struct Node **pool;
  int n = read_number_of_nodes_needed();
  if (n <= 0) return 0;
  pool = (struct Node**)(independent_calloc(n, sizeof(struct Node), 0);
  if (pool == 0) __die();
  // organize into a linked list...
  struct Node* first = pool[0];
  for (i = 0; i < n-1; ++i)
  pool[i]->next = pool[i+1];
  free(pool); * // Can now free the array (or not, if it is needed later)
  return first;
}

@param

unsigned long n_elements
unsigned long elem_size
void** chunks

@return

void**

@see third_party/dlmalloc/dlindependent_calloc.c

dlindependent_comalloc

independent_comalloc(size_t n_elements, size_t sizes[], void* chunks[]);

independent_comalloc allocates, all at once, a set of n_elements chunks with sizes indicated in the "sizes" array. It returns an array of pointers to these elements, each of which can be independently freed, realloc'ed etc. The elements are guaranteed to be adjacently allocated (this is not guaranteed to occur with multiple callocs or mallocs), which may also improve cache locality in some applications.

The "chunks" argument is optional (i.e., may be null). If it is null the returned array is itself dynamically allocated and should also be freed when it is no longer needed. Otherwise, the chunks array must be of at least n_elements in length. It is filled in with the pointers to the chunks.

In either case, independent_comalloc returns this pointer array, or null if the allocation failed. If n_elements is zero and chunks is null, it returns a chunk representing an array with zero elements (which should be freed if not wanted).

Each element must be freed when it is no longer needed. This can be done all at once using bulk_free.

independent_comallac differs from independent_calloc in that each element may have a different size, and also that it does not automatically clear elements.

independent_comalloc can be used to speed up allocation in cases where several structs or objects must always be allocated at the same time. For example:

struct Head { ... }
struct Foot { ... }
void send_message(char* msg) {
  int msglen = strlen(msg);
  size_t sizes[3] = { sizeof(struct Head), msglen, sizeof(struct Foot) };
  void* chunks[3];
  if (independent_comalloc(3, sizes, chunks) == 0) __die();
  struct Head* head = (struct Head*)(chunks[0]);
  char*        body = (char*)(chunks[1]);
  struct Foot* foot = (struct Foot*)(chunks[2]);
  // ...
}

In general though, independent_comalloc is worth using only for larger values of n_elements. For small values, you probably won't detect enough difference from series of malloc calls to bother.

Overuse of independent_comalloc can increase overall memory usage, since it cannot reuse existing noncontiguous small chunks that might be available for some of the elements.

@param

unsigned long n_elements
unsigned long* sizes
void** chunks

@return

void**

@see third_party/dlmalloc/dlindependent_calloc.c

dlmalloc

@param

unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_dispose_chunk

@param

struct MallocState* m
struct mchunk* p
unsigned long psize

@return

void

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_init

@return

void

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_stats

Prints on stderr the amount of space obtained from the system (both via sbrk and mmap), the maximum amount (which may be more than current if malloc_trim and/or munmap got called), and the current number of bytes allocated via malloc (or realloc, etc) but not yet freed. Note that this is the number of bytes allocated, not the number requested. It will be larger than the number requested because of alignment and bookkeeping overhead. Because it includes alignment wastage as being in use, this figure may be greater than zero even when no user-level chunks are allocated.

The reported current and maximum system memory can be inaccurate if a program makes other calls to system memory allocation functions (normally sbrk) outside of malloc.

malloc_stats prints only the most commonly interesting statistics. More information can be obtained by calling mallinfo.

@param

struct res*
struct MallocState* m

@return

struct res

@see third_party/dlmalloc/dlmalloc_stats.c

dlmalloc_sys_trim

@param

struct MallocState* m
unsigned long pad

@return

int

@see third_party/dlmalloc/dlmalloc.c

dlmalloc_trim

If possible, gives memory back to the system (via negative arguments to sbrk) if there is unused memory at the high end of the malloc pool or in unused MMAP segments. You can call this after freeing large blocks of memory to potentially reduce the system-level memory requirements of a program. However, it cannot guarantee to reduce memory. Under some allocation patterns, some large free blocks of memory will be locked between two used chunks, so they cannot be given back to the system.

The pad argument to malloc_trim represents the amount of free trailing space to leave untrimmed. If this argument is zero, only the minimum amount of memory to maintain internal data structures will be left. Non-zero arguments can be supplied to maintain enough trailing space to service future expected allocations without having to re-obtain memory from the system.

@param

unsigned long pad

@return

int: 1 if it actually released any memory, else 0

@see third_party/dlmalloc/malloc_trim.c

dlmalloc_try_realloc_chunk

@param

struct MallocState* m
struct mchunk* p
unsigned long nb
int can_move

@return

struct mchunk*

@see third_party/dlmalloc/dlmalloc_try_realloc_chunk.c

dlmalloc_usable_size

@param

void* mem

@return

unsigned long

@see third_party/dlmalloc/dlmalloc.c

dlmemalign

@param

unsigned long alignment
unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlmalloc.c

dlopen

@param

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/dlposix_memalign.c

dlpvalloc

@param

unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlpvalloc.c

dlrealloc

@param

void* oldmem
unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlrealloc.c

dlrealloc_in_place

@param

void* oldmem
unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlrealloc_in_place.c

dlsym

@param

void* handle
char* name

@return

void*

@see libc/runtime/ldso.c

dlvalloc

@param

unsigned long bytes

@return

void*

@see third_party/dlmalloc/dlvalloc.c

dnsnamecmp

Compares DNS hostnames in reverse lexicographical asciibetical order.

@param

char* A
char* B

@return

int: <0, 0, or >0

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

@see libc/dns/dnsnamecmp.c

do_check_free_chunk

@param

struct MallocState* m
struct mchunk* p

@return

void

@see third_party/dlmalloc/dlmalloc-debug.c

do_check_inuse_chunk

@param

struct MallocState* m
struct mchunk* p

@return

void

@see third_party/dlmalloc/dlmalloc-debug.c

do_check_malloc_state

@param

struct MallocState* m

@return

void

@see third_party/dlmalloc/dlmalloc-debug.c

do_check_malloced_chunk

@param

struct MallocState* m
void* mem
unsigned long s

@return

void

@see third_party/dlmalloc/dlmalloc-debug.c

do_check_mmapped_chunk

@param

struct MallocState* m
struct mchunk* p

@return

void

@see third_party/dlmalloc/dlmalloc-debug.c

do_check_top_chunk

@param

struct MallocState* m
struct mchunk* p

@return

void

@see third_party/dlmalloc/dlmalloc-debug.c

__dos2errno

Translates Windows error using superset of consts.sh.

@param

unsigned int error

@return

int

@see libc/sock/mapdoserrortoerrno.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/fmt/dosdatetimetounix.c

dprintf

Formats string directly to file descriptor.

@param

int fd
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

dup

Duplicates file descriptor/handle.

@param

int fd: remains open afterwards

@return

int: some arbitrary new number for fd

@asyncsignalsafe

@vforksafe

@see libc/calls/dup.c

dup2

Duplicates file descriptor, granting it specific number.

@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

@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

@return

int

@flags can have O_CLOEXEC

@see dup(), dup2()

@see libc/calls/dup3.c

eai2str

Turns getaddrinfo() return code into string.

@param

int code

@return

char*

@see libc/dns/eai2str.c

ecvt

@param

double value
int ndigit
int* decpt
int* sign

@return

char*

@see libc/fmt/fcvt.c

endgrent

@return

void

@see third_party/musl/grp.c

endpwent

@return

void

@see third_party/musl/pwd.c

endswith

Returns true if s has suffix.

@param

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

@return

_Bool

@see libc/str/endswith.c

endswith16

Returns true if s has suffix.

@param

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

@return

_Bool

@see libc/str/endswith16.c

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

err

@param

int eval
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.

@return

@see libc/sysv/consts.sh

@see libc/sysv/errfuns.h

@see __errno_location() stable abi

@see libc/nexgen32e/errno.S

__errno_location

Returns address of errno variable.

@return

@note this isn't a universal definition

@see libc/nexgen32e/errnolocation.S

errx

@param

int eval
char* fmt
...

@noreturn

@see libc/log/errx.c

escapedos

Escapes command so DOS can run it.

@param

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

@return

_Bool

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

@see libc/str/escapedos.c

execl

Executes program, with current environment.

The current process is replaced with the executed one.

@param

char* exe
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

char* exe
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

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

char* exe
char** argv

@return

int

@asyncsignalsafe

@vforksafe

@see libc/calls/execv.c

execve

Replaces current process with program.

@param

char* program: will not be PATH searched, see commandv()
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

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

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

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

@noreturn

@asyncsignalsafe

@vforksafe

@see libc/runtime/exit2.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.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.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.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.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. This implementation also hoses every register the abi allows. A concomitant prototype (str.h) countermands compiler magic.

@param

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

@return

@see libc/nexgen32e/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
char* path: is a filename or directory
int mode: can be R_OK, W_OK, X_OK, F_OK
unsigned int flags: should be 0

@return

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

@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

favail

Returns number of bytes available in stream buffer.

@param

struct FILE* f

@return

unsigned int

@see libc/stdio/favail.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.

@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, 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 V 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

This works on Windows NT if you ignore the error ;-)

@param

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

@return

int

@errors ENOSYS

@asyncsignalsafe

@see chmod()

@see libc/calls/fchmod.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

@see libc/calls/fchown.c

fchownat

Changes owner and/or group of pathname.

@param

int dirfd: is open()'d relative-to directory, or AT_FDCWD, etc.
char* pathname
unsigned int uid: is user id, or -1 to not change
unsigned int gid: is group id, or -1 to not change
unsigned 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));

@param

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

@return

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

@asyncsignalsafe

@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 fsync(), sync_file_range()

@asyncsignalsafe

@see libc/calls/fdatasync.c

fdopen

Allocates stream object for already-opened file descriptor.

@param

int fd: existing file descriptor or -1 for plain old buffer
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

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

@return

int

@see libc/stdio/feof.c

ferror

Returns nonzero if stream is in error state.

@param

struct FILE* f

@return

int

@note EOF doesn't count

@see feof()

@see libc/stdio/ferror.c

fflush

Blocks until data from stream buffer is written out.

@param

struct FILE* f: is the stream handle

@return

int: number of bytes written or -1 on error

@see libc/stdio/fflush.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 uint8_t from stream.

@param

struct FILE* f

@return

int

@see libc/stdio/fgetc.c

fgetpos

@param

struct FILE* stream
unsigned long* pos

@return

int

@see libc/stdio/fgetpos.c

fgets

Reads content 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
int size
struct FILE* f

@return

char*

@see libc/stdio/fgets.c

fgetwc

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.c

fgetws

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

@param

int* s
int size
struct FILE* f

@return

int*

@see libc/stdio/fgetws.c

filecmp

Compares contents of files with memcmp().

@param

char* pathname1
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.

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

char* path

@return

_Bool

@see libc/calls/fileexists.c

fileno

Returns file descriptor associated with stream.

@param

struct FILE* f

@return

int

@see libc/stdio/fileno.c

filetimetotime

@param

struct ft ft

@return

long

@see libc/fmt/filetimetotime.c

FileTimeToTimeSpec

Converts Windows COBOL timestamp to UNIX epoch in nanoseconds.

@param

struct ft ft

@return

ANONYMOUS-STRUCT

@see libc/fmt/filetimetotimespec.c

FileTimeToTimeVal

@param

struct ru_stime* tv
struct ft ft

@return

void

@see libc/fmt/filetimetotimeval.c

FindComBinary

Returns path of binary without debug information, or null.

@return

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

@see libc/runtime/findcombinary.c

FindDebugBinary

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

@return

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

@see libc/runtime/finddebugbinary.c

FindMemoryInterval

@param

struct _mmi* mm
int x

@return

unsigned int

@see libc/runtime/findmemoryinterval.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

__flbf

Returns nonzero if stream is line buffered.

@param

struct FILE* f

@return

int

@see libc/stdio/flbf.c

flock

Acquires lock on file.

@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

@see libc/calls/flock.c

flockfile

Does nothing since Cosmopolitan currently doesn't support threads.

@param

struct FILE* f

@return

void

@see libc/stdio/flockfile.c

flogf

Writes formatted message w/ timestamp to log.

@param

unsigned int level
char* file
int line
struct FILE* f
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

_flushlbf

Flushes all line-buffered streams.

@return

void

@see libc/stdio/flushlbf.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
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/tinymath/fmodl.S

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

char* pat
char* str
int flags

@return

int

@see glob()

@see third_party/musl/fnmatch.c

fopen

Opens file as stream object.

@param

char* pathname: is a utf-8 ideally relative filename
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

char* mode

@return

int

@see libc/stdio/fopenflags.c

fork

Creates new process zygote style.

@return

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

@asyncsignalsafe

@see libc/runtime/fork.c

__fpending

Returns number of pending output bytes.

@param

struct FILE* f

@return

unsigned long

@see libc/stdio/fpending.c

fprintf

@param

struct FILE* f
char* fmt
...

@return

int

@see libc/stdio/fprintf.c

__fpurge

Discards contents of stream buffer.

@param

struct FILE* f

@return

void

@see libc/stdio/fpurge.c

fputc

Writes byte to stream.

@param

int c
struct FILE* f

@return

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

@see putc() if called within loop

@see libc/stdio/fputc.c

fputcfb

Writes byte to stream.

@param

int c
struct FILE* f

@return

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

@see libc/stdio/fputcfb.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

char* 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/fputs.c

fputwc

Writes wide character to stream.

@param

int wc
struct FILE* f

@return

unsigned int: wc if written or -1 w/ errno

@see libc/stdio/fputwc.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

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.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

@see libc/stdio/fread.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 cuase the current program to abort.

@param

rdi: is allocation address, which may be NULL

@return

@see dlfree()

@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* addrs

@return

int

@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

freeresolvconf

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

@param

struct ResolvConf** rvp

@return

void

@see libc/dns/freeresolvconf.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

char* pathname: is the file to open or NULL
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

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
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

long

@returns new offset or -1 on error

@see libc/stdio/fseek.c

__fsetlocking

Does nothing and returns FSETLOCKING_BYCALLER.

@param

struct FILE* f
int type

@return

int

@see libc/stdio/fsetlocking.c

fsetpos

@param

struct FILE* stream
unsigned long* pos

@return

int

@see libc/stdio/fsetpos.c

fstat

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

@param

int fd
struct stat* st

@return

int

@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
char* path
struct stat* st: is where result is stored
unsigned int flags: can have AT_{EMPTY_PATH,NO_AUTOMOUNT,SYMLINK_NOFOLLOW}

@return

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

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

@asyncsignalsafe

@see libc/calls/fstatat.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()

@asyncsignalsafe

@see libc/calls/fsync.c

ftell

Returns current position of stream.

@param

struct FILE* stream: is a non-null stream handle

@return

long

@returns current byte offset from beginning of file, or -1

@see libc/stdio/ftell.c

ftoa

Formats floating point number.

@param

int(*)() out
void* arg
long double value
int prec
unsigned long width
unsigned long flags

@return

int

@see xdtoa() for higher precision at the cost of bloat

@see palandprintf() which is intended caller

@see libc/fmt/palandftoa.c

ftrace

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/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.

@param

int argc
char** argv

@return

int

@see libc/runtime/_init.S for documentation

@see libc/runtime/ftrace.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

Does nothing since Cosmopolitan currently doesn't support threads.

@param

struct FILE* f

@return

int

@see libc/stdio/flockfile.c

funlockfile

Does nothing since Cosmopolitan currently doesn't support threads.

@param

struct FILE* f

@return

void

@see libc/stdio/flockfile.c

futimens

Sets atime/mtime on file descriptor.

@param

int fd
struct timespec* ts: is atime/mtime, or null for current time

@return

int

@note better than microsecond precision on most platforms

@see fstat() for reading timestamps

@see libc/time/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
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 fetch
struct FILE* f

@return

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

@see libc/stdio/fwrite.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_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_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

__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 <LIMBO>

@see libc/nexgen32e/gc.S

gclongjmp

Same as longjmp() but runs gc() / defer() destructors.

@return

void

@see libc/runtime/gc.h

gdbexec

Attachs GDB temporarilly, to do something like print a variable.

@param

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

get_current_dir_name

Returns current working directory.

If the PWD environment variable is set, that'll be returned (since it's faster than issuing a system call).

@return

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

@see libc/stdio/get_current_dir_name.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/runtime/mman.greg.c

GetAddr2linePath

@return

char*

@see libc/log/addr2linepath.c

getaddrinfo

Resolves address for internet name.

@param

char* name: is either an ip string or a utf-8 hostname
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 -1 is returned

@return

int: 0 on success or EAI_xxx value

@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

@see libc/sysv/consts.sh

@see System Five Application Binary Interface § 3.4.3

@asyncsignalsafe

@see libc/calls/getauxval.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

getchar

Reads uint8_t from standard input.

@return

: %al has result w/ rest of %rax cleared

@see libc/stdio/getchar.S

getcwd

Returns current working directory.

@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, which may be 0 if buf NULL

@return

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

@see get_current_dir_name() which is better

@error ERANGE, EINVAL

@see libc/calls/getcwd.c

getdelim

Reads string from stream.

@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: is the capacity of line (in/out)
int delim: is the stop char (and NUL is implicitly too)
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()

@note this function can't punt EINTR to caller

@see getline(), gettok_r()

@see libc/stdio/getdelim.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

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

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

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

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
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

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

char* s

@return

char*

@see libc/calls/getenv.c

getfiledescriptorsize

Determines size of open file.

@param

int fd

@return

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

@asyncsignalsafe

@see libc/calls/getfiledescriptorsize.c

GetFileSize

Returns the byte length of file by path.

@param

char* pathname

@return

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

@see getfiledescriptorsize

@see libc/calls/getfilesize.c

GetGdbPath

@return

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. On Linux, this is fast.

@return

unsigned int

@asyncsignalsafe

@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

char* name

@return

struct gr*

@see third_party/musl/grp.c

getgrnam_r

@param

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

@return

int

@see third_party/musl/grp.c

getgrouplist

@param

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

@return

int

@see third_party/musl/grp.c

gethostname

Returns name of host system, e.g.

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

@param

char* name
unsigned long len

@return

int

@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

@return

int

@see libc/calls/gethostname-nt.c

gethoststxt

Returns parsed sorted singleton hardcoded hostname→ip4 map.

@return

struct ht*

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

@see libc/dns/gethoststxt.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.

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 xgetline(), getdelim(), gettok_r()

@see libc/stdio/getline.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

__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
char* ostr

@return

int

@see optind

@see optarg

@see third_party/getopt/getopt.c

getpid

Returns process id.

@return

int

@asyncsignalsafe

@vforksafe

@see libc/calls/getpid.c

getppid

Returns parent process id.

@return

int

@asyncsignalsafe

@see libc/calls/getppid.c

getpriority

Returns 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 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

char* module
char* symbol

@return

void*

@see libc/calls/getprocaddressmodule.c

getpwent

@return

struct pw*

@see third_party/musl/pwd.c

getpwnam

@param

char* name

@return

struct pw*

@see third_party/musl/pwd.c

getpwnam_r

@param

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 random bytes appropriate for random seeding.

@param

void* buf
unsigned long size: should be the smallest value that meets your requirements
unsigned int flags: may be GRND_{RANDOM,NONBLOCK}

@return

long: number of bytes copied on success; or -1 w/ errno, which indicates only that the request couldn't be serviced by the host kernel; this wrapper will still fill the buffer with random bytes from fallback sources no matter what

@see libc/rand/getrandom.c

getresolvconf

Returns singleton with DNS server address.

@return

struct rv*

@see libc/dns/getresolvconf.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

getsid

Creates session and sets the process group id.

@param

int pid

@return

unsigned int

@see libc/calls/getsid.c

GetSymbolTable

Returns debug binary symbol table, as global singleton.

@return

struct SymbolTable*: symbol table, or NULL w/ errno on first call

@see libc/log/getsymboltable.c

GetTempPathA_flunk

Calls GetTempPathA() w/ different API.

@return

@see GetSystemDirectoryA(), GetWindowsDirectoryA()

@see libc/calls/gettemppatha-flunk.S

gettid

Returns current thread id.

@return

unsigned int

@asyncsignalsafe

@see libc/calls/gettid.c

gettimeofday

Returns system wall time in microseconds.

@param

struct it_value* tv: points to timeval that receives result if non-NULL
struct timezone* tz: receives UTC timezone if non-NULL

@return

int: always zero

@see clock_gettime() for nanosecond precision

@see strftime() for string formatting

@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/log/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. On Linux, this is fast.

@return

unsigned int

@asyncsignalsafe

@see libc/calls/getuid.c

getutf16

Decodes UTF-16 character.

@param

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

getwchar

Reads Thompson-Pike encoded varint from standard input.

@return

: %eax has result w/ rest of %rax cleared

@see libc/stdio/getwchar.S

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

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

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

long* timep

@return

struct mytm*

@see libc/time/localtime.c

gmtime_r

@param

long* timep
struct mytm* tmp

@return

struct mytm*

@see libc/time/localtime.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

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

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

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

@param

unsigned char* data
unsigned long size
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

void

@see ape/ape.lds

@see libc/runtime/hook.greg.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

iconv

@param

void* cd
char** in
unsigned long* inb
char** out
unsigned long* outb

@return

unsigned long

@see libc/unicode/iconv.c

iconv_close

@param

void* cd

@return

int

@see libc/unicode/iconv.c

iconv_open

@param

char* to
char* from

@return

void*

@see libc/unicode/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

__int128 x

@return

__int128

@see libc/fmt/imaxabs.c

index

Returns pointer to first instance of character, the BSD way.

@param

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

char* s
unsigned int i

@return

char*

@see libc/str/indexdoublenulstring.c

inet_addr

Converts dotted IPv4 address string to network order binary.

@param

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

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
void* src: is the binary-encoded address, e.g. &addr->sin_addr
char* dst: is the output string buffer
unsigned int size: is bytes in dst, which needs 16+ for IPv4

@return

char*: dst on success or NULL w/ errno

@see libc/sock/inet_ntop.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_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

_init_systemfive_jmptab

Initializes System Five system call support.

(1) Extracts parameters passed by kernel (2) Detects OS without issuing system calls (3) Unpacks magnums from libc/sysv/consts.sh (4) Replaces stack with one we control

@param

%r15: is auxv

@return

@note OpenBSD devs: let us know if you start using auxv

@see libc/sysv/systemfive.S

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

int64toarray_radix10

Converts signed 64-bit integer to string.

@param

long i
char* a: needs at least 21 bytes

@return

unsigned long: bytes written w/o nul

@see libc/fmt/itoa64radix10.greg.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
void* memory

@return

int

@vforksafe

@see libc/calls/ioctl.c

ioctl_tcgets

Returns information about terminal.

@param

int fd
struct linux* tio

@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
struct linux* tio

@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
struct winsize* ws

@return

int

@see ioctl(fd, TIOCGWINSZ, ws) dispatches here

@see libc/calls/ioctl-tiocgwinsz.c

ioctl_tiocgwinsz_nt

@param

int fd
struct winsize* ws

@return

int

@see libc/calls/ioctl-tiocgwinsz-nt.c

ioctl_tiocswinsz

Returns width and height of terminal.

@param

int fd
struct winsize* ws

@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

isabspath

Returns true if pathname could be absolute on any known platform.

The ones we know about are System V (/foo/bar), DOS (C:\foo\bar), Windows NT (\\.\C:\foo\bar), Google Cloud (gs://bucket/foo/bar), etc.

@param

char* path

@return

_Bool

@see libc/fmt/isabspath.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

isascii

Returns nonzero if c is ascii.

@param

int c

@return

int

@see libc/str/isascii.c

isatty

Returns true if file descriptor is backed by a terminal device.

@param

int fd

@return

int

@asyncsignalsafe

@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.

@param

int fd

@return

int

@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/calls/isdebuggerpresent.c

isdigit

Returns nonzero if c is decimal digit.

@param

int c

@return

int

@see libc/str/isdigit.c

isdirectory

Returns true if file exists and is a directory.

@param

char* path

@return

_Bool

@see libc/calls/isdirectory.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

char* path

@return

_Bool

@see access(exe, X_OK) which is more accurate on NT

@asyncsignalsafe

@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

islower

Returns nonzero if c is lowercase alpha ascii character.

@param

int c

@return

int

@see libc/str/islower.c

isprint

Returns nonzero if c is printable ascii including space.

@param

int c

@return

int

@see libc/str/isprint.c

ispunct

Returns nonzero if c ∈ !"#$%&'()*+,-./:;<=>?@[\]^_`{|}~

@param

int c

@return

int

@see libc/str/ispunct.c

isregularfile

Returns true if file exists and is a regular file

@param

char* path

@return

_Bool

@see libc/calls/isregularfile.c

IsRunningUnderMake

Returns true if current process was spawned by GNU Make.

@return

_Bool

@see libc/log/isrunningundermake.c

issetugid

@return

int

@see libc/runtime/issetugid.c

isspace

Returns true if c is space, \t, \r, \n, \f, or \v.

@param

int c

@return

int

@see libc/str/isspace.c

IsTerminalInarticulate

Checks if we're probably running inside Emacs.

@return

_Bool

@see libc/log/isterminalinarticulate.c

isupper

Returns nonzero if c is uppercase alpha ascii character.

@param

int c

@return

int

@see libc/str/isupper.c

iswalnum

@param

unsigned int wc

@return

int

@see libc/str/iswalnum.c

iswalpha

@param

unsigned int wc

@return

int

@see libc/str/iswalpha.c

iswblank

@param

unsigned int wc

@return

int

@see libc/str/iswblank.c

iswcntrl

Returns nonzero if wc is C0 or C1 control code.

@param

unsigned int wc

@return

int

@see libc/str/iswcntrl.c

iswctype

@param

unsigned int wc
unsigned int type

@return

int

@see libc/str/iswctype.c

iswdigit

@param

unsigned int wc

@return

int

@see libc/str/iswdigit.c

iswgraph

@param

unsigned int wc

@return

int

@see libc/str/iswgraph.c

iswlower

@param

unsigned int wc

@return

int

@see libc/str/iswlower.c

iswprint

@param

unsigned int wc

@return

int

@see libc/str/iswprint.c

iswpunct

@param

unsigned int wc

@return

int

@see libc/str/iswpunct.c

iswspace

@param

unsigned int wc

@return

int

@see libc/str/iswspace.c

iswupper

@param

unsigned int wc

@return

int

@see libc/str/iswupper.c

iswxdigit

@param

unsigned int wc

@return

int

@see libc/str/iswxdigit.c

isxdigit

Returns true if c is hexadecimal digit.

@param

int c

@return

int

@see libc/str/isxdigit.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

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

Teleports code fragment inside _init().

@type

unsigned int[4][7]

@see libc/bits/initializer.internal.h

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 is for error checking

@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

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

kStartTsc

Stores CPU Timestamp Counter at startup.

It can be useful as an added source of seeding information.

@return

@note rdtsc is a 25 cycle instruction

@see libc/nexgen32e/kstarttsc.S

kTmpPath

RII constant holding /tmp/ directory.

@return

@note on win32 this is firstNonNull($TMP, $TEMP, $PWD)

@note guarantees trailing slash if non-empty

@see libc/calls/ktmppath.S

kToLower

ASCII uppercase → lowercase translation tables.

char kToLower[256]; char16_t kToLower16[256];

@return

@note kToLower16 saves 128kb; CMOVcc can't even 8-bit

@see libc/nexgen32e/ktolower.S

l64a

Converts 32-bit integer to base64.

@param

long x

@return

char*

@see libc/str/l64a.c

labs

@param

long x

@return

long

@see libc/fmt/labs.c

lchown

Changes owner and/or group of pathname, w/o dereferencing symlinks.

@param

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

𝑥: is double passed in %xmm0
𝑦: is exponent via %edi

@return

: double in %xmm0

@see libc/tinymath/ldexp.S

ldexpf

Returns 𝑥 × 2ʸ.

@param

𝑥: is float passed in %xmm0
𝑦: is exponent via %edi

@return

: float in %xmm0

@see libc/tinymath/ldexpf.S

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

lgamma

Returns natural logarithm of absolute value of gamma function.

@param

double x

@return

double

@see libc/tinymath/gamma.c

lgamma_r

@param

double x
int* signgamp

@return

double

@see libc/tinymath/gamma.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

char* existingpath
char* newpath

@return

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

@asyncsignalsafe

@see libc/calls/link.c

llabs

@param

long x

@return

long

@see libc/fmt/llabs.c

lldiv

@param

long num
long den

@return

struct lldiv_t

@see libc/fmt/lldiv.c

llog10

Fast log₁₀ when 𝑥 is an integer.

@param

rdi: is uint64 𝑥

@return

@domain 0<𝑥<2⁶⁴ ∧ 𝑥∊ℤ

@see libc/nexgen32e/llog10.S

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 kLocaleConv*

@see libc/unicode/localeconv.c

localtime

@param

long* timep

@return

struct mytm*

@see libc/time/localtime.c

localtime_r

@param

long* timep
struct mytm* tmp

@return

struct mytm*

@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()

@see libc/bits/lockcmpxchg.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/bits/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.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.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.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.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.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

_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

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

char* pathname
struct stat* st

@return

int

@asyncsignalsafe

@see libc/calls/lstat.c

lz4check

@param

void* data

@return

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

lzcnt

Finds leading bits in 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

edi: is 32-bit unsigned 𝑥 value

@return

: eax number in range [0,32) or 32 if 𝑥 is 0

@see also treasure trove of nearly identical functions

@see libc/nexgen32e/lzcnt.S

lzcntl

Finds leading bits in 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

rdi: is 64-bit unsigned 𝑥 value

@return

: rax number in range [0,64) or 64 if 𝑥 is 0

@see also treasure trove of nearly identical functions

@see libc/nexgen32e/lzcntl.S

lzcntll

Finds leading bits in 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

rdi: is 64-bit unsigned 𝑥 value

@return

: rax number in range [0,64) or 64 if 𝑥 is 0

@see also treasure trove of nearly identical functions

@see libc/nexgen32e/lzcntl.S

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

makedirs

Recursively creates directory a.k.a. folder.

@param

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

Returns (by copy) a struct containing various summary statistics:

arena: current total non-mmapped bytes allocated from system
ordblks: the number of free chunks
smblks: always zero.
hblks: current number of mmapped regions
hblkhd: total bytes held in mmapped regions
usmblks: the maximum total allocated space. This will be greater than current total if trimming has occurred.
fsmblks: always zero
uordblks: current total allocated space (normal or mmapped)
fordblks: total free space
keepcost: the maximum number of bytes that could ideally be released back to system via malloc_trim. ("ideally" means that it ignores page restrictions etc.)

Because these fields are ints, but internal bookkeeping may be kept as longs, the reported values may wrap around zero and thus be inaccurate.

@param

struct nm*

@return

struct nm

@see third_party/dlmalloc/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

@return

: new memory, or NULL w/ errno

@note malloc(0) → malloc(32)

@see dlmalloc()

@see libc/mem/malloc.S

malloc_footprint

Returns the number of bytes obtained from the system. The total number of bytes allocated by malloc, realloc etc., is less than this value. Unlike mallinfo, this function returns only a precomputed result, so can be called frequently to monitor memory consumption. Even if locks are otherwise defined, this function does not use them, so results might not be up to date.

@return

unsigned long

@see third_party/dlmalloc/malloc_footprint.c

malloc_footprint_limit

Returns the number of bytes that the heap is allowed to obtain from the system, returning the last value returned by malloc_set_footprint_limit, or the maximum size_t value if never set. The returned value reflects a permission. There is no guarantee that this number of bytes can actually be obtained from the system.

@return

unsigned long

@see third_party/dlmalloc/malloc_footprint_limit.c

malloc_inspect_all

Traverses the heap and calls the given handler for each managed region, skipping all bytes that are (or may be) used for bookkeeping purposes. Traversal does not include include chunks that have been directly memory mapped. Each reported region begins at the start address, and continues up to but not including the end address. The first used_bytes of the region contain allocated data. If used_bytes is zero, the region is unallocated. The handler is invoked with the given callback argument. If locks are defined, they are held during the entire traversal. It is a bad idea to invoke other malloc functions from within the handler.

For example, to count the number of in-use chunks with size greater than 1000, you could write:

static int count = 0;
void count_chunks(void* start, void* end, size_t used, void* arg) {
  if (used >= 1000) ++count;
}

then,

malloc_inspect_all(count_chunks, NULL);

@param

void(*)() handler
void* arg

@return

void

@see third_party/dlmalloc/malloc_inspect_all.c

malloc_max_footprint

Returns the maximum number of bytes obtained from the system. This value will be greater than current footprint if deallocated space has been reclaimed by the system. The peak number of bytes allocated by malloc, realloc etc., is less than this value. Unlike mallinfo, this function returns only a precomputed result, so can be called frequently to monitor memory consumption. Even if locks are otherwise defined, this function does not use them, so results might not be up to date.

@return

unsigned long

@see third_party/dlmalloc/malloc_max_footprint.c

malloc_set_footprint_limit

Sets the maximum number of bytes to obtain from the system, causing failure returns from malloc and related functions upon attempts to exceed this value. The argument value may be subject to page rounding to an enforceable limit; this actual value is returned. Using an argument of the maximum possible size_t effectively disables checks. If the argument is less than or equal to the current malloc_footprint, then all future allocations that require additional system memory will fail. However, invocation cannot retroactively deallocate existing used memory.

@param

unsigned long bytes

@return

unsigned long

@see third_party/dlmalloc/malloc_set_footprint_limit.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()

@see libc/mem/malloc_usable_size.S

mallopt

Sets memory allocation parameter.

The format is to provide a (parameter-number, parameter-value) pair. mallopt then sets the corresponding parameter to the argument value if it can (i.e., so long as the value is meaningful), and returns 1 if successful else 0. SVID/XPG/ANSI defines four standard param numbers for mallopt, normally defined in malloc.h. None of these are use in this malloc, so setting them has no effect. But this malloc also supports other options in mallopt:

Symbol            param #  default    allowed param values
M_TRIM_THRESHOLD     -1   2*1024*1024   any   (-1U disables trimming)
M_GRANULARITY        -2     page size   any power of 2 >= page size
M_MMAP_THRESHOLD     -3      256*1024   any   (or 0 if no MMAP support)

@param

int param_number
int value

@return

int

@see third_party/dlmalloc/mallopt.c

__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/runtime/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);

Except it offers a small saving on code size.

@param

unsigned long mapsize

@return

void*

@see libc/runtime/mapanon.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

mbrtowc

@param

int* pwc
char* src
unsigned long n
unsigned int* ps

@return

unsigned long

@see libc/fmt/mbrtowc.c

mbsrtowcs

@param

int* dest
char** src
unsigned long len
unsigned int* ps

@return

unsigned long

@see libc/fmt/mbsrtowcs.c

mbstowcs

@param

int* pwc
char* s
unsigned long wn

@return

unsigned long

@see libc/fmt/mbstowcs.c

mbtowc

@param

int* wc
char* s
unsigned long n

@return

int

@see libc/str/mbtowc.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 should be a power of two. If the argument is not a power of two, the nearest greater power is used. 8-byte alignment is guaranteed by normal malloc calls, so don't bother calling memalign with an argument of 8 or less.

@param

rdi: is alignment in bytes
rsi: (newsize) is number of bytes needed

@return

: rax is memory address, or NULL w/ errno

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

@see dlmemalign()

@see libc/mem/memalign.S

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

memchr

Returns pointer to first instance of character.

@param

void* m: is memory to search
int c: is search byte which is masked with 255
unsigned long n: is byte length of p

@return

void*: is pointer to first instance of c or NULL if not found

@asyncsignalsafe

@see libc/str/memchr.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

memcmp

Compares memory.

@param

void* a
void* b
unsigned long n

@return

int: unsigned char subtraction at stop index

@asyncsignalsafe

@see libc/str/memcmp.c

memcpy

Copies memory.

DEST and SRC must not overlap, unless DEST≤SRC.

@param

rdi: is dest
rsi: is src
rdx: is number of bytes

@return

: original rdi copied to rax

@mode long

@asyncsignalsafe

@see libc/nexgen32e/memcpy.S

MemCpy

Copies memory w/ minimal impact ABI.

@param

rdi: is dest
rsi: is src
rdx: is number of bytes

@return

@clob flags,rcx,xmm3,xmm4

@mode long

@see libc/nexgen32e/memcpy.S

memeqmask

Creates bit mask of which bytes are the same.

@param

%rdi: points to bit mask (write-only)
%rsi: points to first buffer (read-only)
%rdx: points to second buffer (read-only)
%rcx: is byte length of both %rsi and %rdx

@return

: %rax is set to %rdi

@note buffers should be 128-byte aligned

@see libc/nexgen32e/memeqmask.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

memmem

Searches for fixed-length substring in memory region.

@param

void* haystack: is the region of memory to be searched
unsigned long haystacklen: is its character count
void* needle: contains the memory for which we're searching
unsigned long needlelen: is its character count

@return

void*: pointer to first result or NULL if not found

@see libc/str/memmem.c

memmove

Copies memory.

DEST and SRC may overlap.

@param

rdi: is dest
rsi: is src
rdx: is number of bytes

@return

: original rdi copied to rax

@clob flags,rcx

@asyncsignalsafe

@see libc/nexgen32e/memmove.S

memmove_pure

Copies memory.

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/str/memmove-pure.c

mempcpy

Copies memory.

DEST and SRC must not overlap unless DEST ≤ SRC.

@param

rdi: is dest
rsi: is src
rdx: is number of bytes

@return

: original rdi + rdx copied to rax

@see libc/nexgen32e/mempcpy.S

memrchr

Searches for last instance of byte in memory region.

@param

rdi: points to data to search
esi: is treated as unsigned char
rdx: is byte length of rdi

@return

: rax is address of last %sil in %rdi, or NULL

@note AVX2 requires Haswell (2014+) or Excavator (2015+)

@asyncsignalsafe

@see libc/nexgen32e/memrchr.S

memrchr16

Searches for last instance of uint16_t in memory region.

@param

rdi: points to data to search
esi: is treated as uint16_t
rdx: is short count in rdi

@return

: rax is address of last %si in %rdi, or NULL

@note AVX2 requires Haswell (2014+) or Excavator (2015+)

@see libc/nexgen32e/memrchr16.S

memset

Sets memory.

@param

rdi: is dest
esi: is the byte to set
edx: is the number of bytes to set

@return

: original rdi copied to rax

@mode long

@asyncsignalsafe

@see libc/nexgen32e/memset.S

MemSet

Sets memory w/ minimal-impact ABI.

@param

rdi: is dest
esi: is the byte to set
edx: is the number of bytes to set

@return

@clob flags,rcx,xmm3

@mode long

@see libc/nexgen32e/memset.S

memset16

Sets wide memory.

@param

unsigned short* dest
unsigned short c
unsigned long count

@return

unsigned short*

@asyncsignalsafe

@see libc/nexgen32e/wmemset.inc

memset_pure

Sets memory.

@param

void* p: is memory address
int c: is masked with 255 and used as repeated byte
unsigned long n: is byte length

@return

void*: p

@asyncsignalsafe

@see libc/str/memset-pure.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

char* fmt
...

@return

void

@see libc/runtime/metalprintf.greg.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

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

@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
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

mkfifo

Creates named pipe.

@param

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

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
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

@kudos Daniel Colascione for teaching how to quote

@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
char* extravar: is a VAR=val string we consider part of envp or NULL

@return

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

@error E2BIG if total number of shorts exceeded ARG_MAX (0x8000)

@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

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 mytm* tmp

@return

long

@see libc/time/localtime.c

mmap

Beseeches system for page-table entries.

char *p = mmap(NULL, 65536, PROT_READ | PROT_WRITE,
               MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
munmap(p, 65536);

@param

void* addr: optionally requests a particular virtual base address, which needs to be 64kb aligned if passed (for NT compatibility)
unsigned long size: must be >0 and needn't be a multiple of FRAMESIZE
int prot: can have PROT_READ, PROT_WRITE, PROT_EXEC, PROT_NONE, etc.
int flags: can have MAP_ANONYMOUS, MAP_SHARED, MAP_PRIVATE, etc.
int fd: is an open()'d file descriptor whose contents shall be mapped, and is ignored 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

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

mprotect

Modifies restrictions on virtual memory address range.

@param

void* addr
unsigned long len
int prot: can have PROT_{NONE,READ,WRITE,EXEC,GROWSDOWN}

@return

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

@see mmap()

@see libc/calls/mprotect.greg.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
unsigned char* b
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

@param

void* old_address
unsigned long old_size
unsigned long new_size
int flags
void* new_address

@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. In practice, what that means is just Windows NT.

@param

void* addr
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

__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.

This function may be used to punch holes in existing mappings, but your mileage may vary on Windows.

@param

void* addr: is a pointer within any memory mapped region the process has permission to control, such as address ranges returned by mmap(), the program image itself, etc.
unsigned long size: is the amount of memory to unmap, which needs to be a multiple of FRAMESIZE for anonymous mappings, because windows and for files size needs to be perfect to the byte bc openbsd

@return

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

@see libc/runtime/munmap.c

nanosleep

Sleeps for a particular amount of time.

@param

struct st_ctim* req
struct st_ctim* rem

@return

int

@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/runtime/mman.greg.c

newaddrinfo

@param

unsigned short port

@return

struct addrinfo*

@see libc/dns/newaddrinfo.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

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

nowl

Returns timestamp without needing system calls.

@return

: seconds since unix epoch in %st0

@note uses microsecond scale fallback on k8 or vm

@see libc/calls/nowl.S

nowl_art

@return

long double

@see libc/calls/now.c

nowl_sys

@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

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

ntcontext2linux

@param

struct ucontext_t* ctx
struct NtContext* cr

@return

void

@see libc/calls/ntcontext2linux.c

NtGetVersion

@return

int

@see libc/intrin/ntgetversion.c

ntoa

@param

int(*)() out
void* arg
struct __va_list* va
unsigned char signbit
unsigned long log2base
unsigned long prec
unsigned long width
unsigned char flags
char* lang

@return

int

@see libc/fmt/palandntoa.c

ntoa2

@param

int(*)() out
void* arg
unsigned __int128 value
_Bool neg
unsigned int log2base
unsigned int prec
unsigned int width
unsigned int flags
char* alphabet

@return

int

@see libc/fmt/palandntoa.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
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

char* prog: won't be PATH searched
char** argv: specifies prog arguments
char** envp
char* extravar: is added to envp to avoid setenv() in caller
struct kNtIsInheritable* opt_lpProcessAttributes
struct kNtIsInheritable* 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
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

offset2overlap

@param

long opt_offset
struct NtOverlapped* mem

@return

struct NtOverlapped*

@see libc/calls/offset2overlap.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

@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

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

@vforksafe

@see libc/calls/open.c

openanon

Creates anonymous file.

@param

char* name: is purely informative
unsigned int flags: can have O_CLOEXEC

@return

int: fd of file with no name, needing close(), or -1 w/ errno

@see memfd_create() if disk-paranoid

@see mkostempsm() for named files

@see libc/calls/openanon.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
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

@vforksafe

@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

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

openpty

Opens new pseudo teletypewriter.

@param

int* ilduce: receives controlling tty rw fd on success
int* aworker: receives subordinate tty rw fd on success
char* name
struct termios* termp: may be passed to tune a century of legacy behaviors
struct winsize* winp: may be passed to set terminal display dimensions

@return

int: file descriptor, 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

char* filename

@return

struct SymbolTable*: object freeable with CloseSymbolTable(), or NULL w/ errno

@see libc/runtime/opensymboltable.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
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
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
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
int* b
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
short* b
short* c

@return

void

@see packuswb()

@mayalias

@see libc/intrin/packsswb.c

packusdw

Casts ints to shorts w/ saturation.

@param

unsigned short* a
int* b
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
short* b
short* c

@return

void

@see packsswb()

@mayalias

@see libc/intrin/packuswb.c

paddb

Adds 8-bit integers.

@param

char* a
char* b
char* c

@return

void

@mayalias

@see libc/intrin/paddb.c

paddd

Adds 32-bit integers.

@param

int* a
int* b
int* c

@return

void

@mayalias

@see libc/intrin/paddd.c

paddq

Adds 64-bit integers.

@param

long* a
long* b
long* c

@return

void

@mayalias

@see libc/intrin/paddq.c

paddsb

Adds signed 8-bit integers w/ saturation.

@param

char* a
char* b
char* c

@return

void

@mayalias

@see libc/intrin/paddsb.c

paddsw

Adds signed 16-bit integers w/ saturation.

@param

short* a
short* b
short* c

@return

void

@mayalias

@see libc/intrin/paddsw.c

paddusb

Adds unsigned 8-bit integers w/ saturation.

@param

unsigned char* a
unsigned char* b
unsigned char* c

@return

void

@mayalias

@see libc/intrin/paddusb.c

paddusw

Adds unsigned 16-bit integers w/ saturation.

@param

unsigned short* a
unsigned short* b
unsigned short* c

@return

void

@mayalias

@see libc/intrin/paddusw.c

paddw

Adds 16-bit integers.

@param

short* a
short* b
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

palandprintf

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)
%u unsigned
%f double
%Lf long double
%p pointer (48-bit hexadecimal)

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 (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
char* format
struct __va_list* va

@return

int

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

@see printf() for wordier documentation

@asyncsignalsafe

@vforksafe

@see libc/fmt/palandprintf.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
unsigned long* b
unsigned long* c

@return

void

@mayalias

@see libc/intrin/pand.c

pandn

Nands 128-bit integers.

@param

unsigned long* a
unsigned long* b
unsigned long* c

@return

void

@mayalias

@see libc/intrin/pandn.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

parseport

@param

char* service

@return

int

@see libc/sock/parseport.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

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
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 and its callback function has been called. It's a better idea to use sigsuspend() w/ sigprocmask() to avoid race conditions

@return

int: should always be -1 w/ EINTR

@see sigsuspend()

@see libc/calls/pause.c

pavgb

Averages packed 8-bit unsigned integers w/ rounding.

@param

unsigned char* a
unsigned char* b
unsigned char* c

@return

void

@mayalias

@see libc/intrin/pavgb.c

pavgw

Averages packed 16-bit unsigned integers w/ rounding.

@param

unsigned short* a
unsigned short* b
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
unsigned char* b
unsigned char* c

@return

void

@mayalias

@see libc/intrin/pcmpeqb.c

pcmpeqd

Compares signed 32-bit integers w/ equal to predicate.

@param

int* a
int* b
int* c

@return

void

@mayalias

@see libc/intrin/pcmpeqd.c

pcmpeqw

Compares signed 16-bit integers w/ equal to predicate.

@param

short* a
short* b
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
char* b
char* c

@return

void

@mayalias

@see libc/intrin/pcmpgtb.c

pcmpgtd

Compares signed 32-bit integers w/ greater than predicate.

@param

int* a
int* b
int* c

@return

void

@mayalias

@see libc/intrin/pcmpgtd.c

pcmpgtw

Compares signed 16-bit integers w/ greater than predicate.

@param

short* a
short* b
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

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

int* a
int* b
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
short* b
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
short* b
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

int* a
int* b
int* c

@return

void

@note goes fast w/ ssse3

@mayalias

@see libc/intrin/phsubd.c

phsubsw

Subtracts adjacent shorts w/ saturation.

@param

short* a
short* b
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
short* b
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

@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, O_NONBLOCK, O_DIRECT

@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
unsigned char* b
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
short* b
short* c

@return

void

@mayalias

@see libc/intrin/pmaddwd.c

pmaxsw

Gets maximum of signed 16-bit integers.

@param

short* a
short* b
short* c

@return

void

@mayalias

@see libc/intrin/pmaxsw.c

pmaxub

Returns minimum of 8-bit unsigned integers.

@param

unsigned char* a
unsigned char* b
unsigned char* c

@return

void

@mayalias

@see libc/intrin/pmaxub.c

pminsw

Gets minimum of signed 16-bit integers.

@param

short* a
short* b
short* c

@return

void

@mayalias

@see libc/intrin/pminsw.c

pminub

Returns minimum of 8-bit unsigned integers.

@param

unsigned char* a
unsigned char* b
unsigned char* c

@return

void

@mayalias

@see libc/intrin/pminub.c

pmovmskb

Turns result of byte comparison into bitmask.

@param

unsigned char* p

@return

unsigned int

@see pcmpeqb(), bsf(), etc.

@see libc/intrin/pmovmskb.c

pmulhrsw

Multiplies Q15 numbers.

@param

short* a
short* b
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
unsigned short* b
unsigned short* c

@return

void

@mayalias

@see libc/intrin/pmulhuw.c

pmulhw

Multiplies 16-bit signed integers and stores high word.

@param

short* a
short* b
short* c

@return

void

@mayalias

@see libc/intrin/pmulhw.c

pmulld

Multiplies 32-bit signed integers.

@param

int* a
int* b
int* c

@return

void

@see pmuludq()

@mayalias

@see libc/intrin/pmulld.c

pmullw

Multiplies 16-bit signed integers.

@param

short* a
short* b
short* c

@return

void

@mayalias

@see libc/intrin/pmullw.c

pmuludq

Multiplies 32-bit unsigned integers w/ promotion.

@param

unsigned long* a
unsigned int* b
unsigned int* c

@return

void

@see pmulld()

@mayalias

@see libc/intrin/pmuludq.c

pochisq

@param

double ax
int df

@return

double

@see libc/rand/poz.c

popcnt

Returns number of bits set in integer.

@param

unsigned long x

@return

unsigned long

@see libc/bits/popcnt.c

popen

Spawns subprocess and returns pipe stream.

@param

char* cmdline
char* mode

@return

struct FILE*

@see pclose()

@see libc/stdio/popen.c

por

Ors 128-bit integers.

@param

unsigned long* a
unsigned long* b
unsigned long* c

@return

void

@mayalias

@see libc/intrin/por.c

posix2time

@param

long t

@return

long

@see libc/time/localtime.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 (1) assigns the allocated memory to *pp rather than returning it, (2) fails and returns EINVAL if the alignment is not a power of two (3) fails and returns ENOMEM if memory cannot be allocated.

@param

rdi: is void **pp
rsi: is size_t align
rdx: is size_t size

@return

: eax

@see libc/mem/posix_memalign.S

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

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.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

__pow_finite

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.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.S

__powf_finite

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.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

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 data from multiple buffers from file descriptor at offset.

@param

int fd
struct iovec* iovec
int count: is recommended to be 16 or fewer; if it exceeds IOV_MAX then the extra buffers are simply ignored
long off

@return

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

@asyncsignalsafe

@vforksafe

@see libc/calls/preadv.c

__print

Prints string, by any means necessary.

This function offers a subset of write(STDERR_FILENO) functionality. It's designed to work even when the runtime hasn't initialized, e.g. before _init() gets called.

@param

void* data
unsigned long len: can be computed w/ tinystrlen()

@return

void

@clob nothing except flags

@see libc/runtime/print.greg.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 string to stdout.

Cosmopolitan supports most of the standard formatting behaviors described by man 3 printf, in addition to the following:

%jd, %jx, etc. are {,u}intmax_t which in Cosmopolitan is 128-bit.
%'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.
%n inserts "\n" on non-Windows and "\r\n" on Windows. This is the same behavior as Java. It's incompatible with glibc's behavior, since that's problematic according to Android's security team.
%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

char* fmt
...

@return

int

@see palandprintf() for intuitive reference documentation

@see {,v}{,s{,n},{,{,x}as},f,d}printf

@see libc/stdio/printf.c

PrintMemoryIntervals

@param

int fd
struct _mmi* mm

@return

void

@see libc/runtime/printmemoryintervals.c

__prot2nt

Converts System Five memory protection flags to Windows NT, Part 1.

@param

int prot
int flags

@return

unsigned int

@see libc/sysv/consts.sh

@see libc/calls/prot2nt.greg.c

psadbw

Computes sum of absolute differences.

@param

unsigned long* a
unsigned char* b
unsigned char* c

@return

void

@mayalias

@see libc/intrin/psadbw.c

pshufb

Shuffles and/or clears 8-bit integers.

@param

unsigned char* a
unsigned char* b
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
int* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/pshufd.c

pshufhw

Shuffles lower half of word vector.

@param

short* b
short* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/pshufhw.c

pshuflw

Shuffles lower half of word vector.

@param

short* b
short* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/pshuflw.c

pshufw

Shuffles mmx vector.

@param

short* b
short* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/pshufw.c

psignb

Conditionally negates or zeroes signed bytes.

@param

char* a
char* b
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
int* b
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
short* b
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
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 right by n bytes w/ zero-fill.

@param

unsigned char* b: receives output
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
unsigned int* b
unsigned long* c

@return

void

@mayalias

@see libc/intrin/pslldv.c

psllq

Multiplies longs by two power.

@param

unsigned long* a
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
unsigned long* b
unsigned long* c

@return

void

@mayalias

@see libc/intrin/psllqv.c

psllw

Multiplies shorts by two power.

@param

unsigned short* a
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
unsigned short* b
unsigned long* c

@return

void

@mayalias

@see libc/intrin/psllwv.c

psrad

Divides ints by two power.

@param

int* a
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
int* b
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
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
short* b
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
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
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
unsigned int* b
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
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
unsigned long* b
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
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
unsigned short* b
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
unsigned char* b
unsigned char* c

@return

void

@mayalias

@see libc/intrin/psubb.c

psubd

Subtracts 32-bit integers.

@param

int* a
int* b
int* c

@return

void

@mayalias

@see libc/intrin/psubd.c

psubq

Subtracts 64-bit integers.

@param

long* a
long* b
long* c

@return

void

@mayalias

@see libc/intrin/psubq.c

psubsb

Subtracts signed 8-bit integers w/ saturation.

@param

char* a
char* b
char* c

@return

void

@mayalias

@see libc/intrin/psubsb.c

psubsw

Subtracts signed 16-bit integers w/ saturation.

@param

short* a
short* b
short* c

@return

void

@mayalias

@see libc/intrin/psubsw.c

psubusb

Subtracts unsigned 8-bit integers w/ saturation.

@param

unsigned char* a
unsigned char* b
unsigned char* c

@return

void

@mayalias

@see libc/intrin/psubusb.c

psubusw

Subtracts unsigned 16-bit integers w/ saturation.

@param

unsigned short* a
unsigned short* b
unsigned short* c

@return

void

@mayalias

@see libc/intrin/psubusw.c

psubw

Subtracts 16-bit integers.

@param

short* a
short* b
short* c

@return

void

@mayalias

@see libc/intrin/psubw.c

pthread_cancel

@param

void* thread

@return

int

@see libc/runtime/pthread.c

pthread_mutex_lock

@param

int* mutex

@return

int

@see libc/runtime/pthread.c

pthread_mutex_trylock

@param

int* mutex

@return

int

@see libc/runtime/pthread.c

pthread_mutex_unlock

@param

int* mutex

@return

int

@see libc/runtime/pthread.c

pthread_once

@param

_Bool* once
void(*)() init

@return

int

@see libc/runtime/pthread.c

ptrace

Traces process.

@param

int request: can be PTRACE_xxx
int pid
void* addr
void* data

@return

long

@note de facto linux only atm

@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

punpckhbw

Interleaves high bytes.

@param

unsigned char* a
unsigned char* b
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
unsigned int* b
unsigned int* c

@return

void

@mayalias

@see libc/intrin/punpckhdq.c

punpckhqdq

Interleaves high quadwords.

@param

unsigned long* a
unsigned long* b
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
unsigned short* b
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
unsigned char* b
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
unsigned int* b
unsigned int* c

@return

void

@mayalias

@see libc/intrin/punpckldq.c

punpcklqdq

Interleaves low quadwords.

@param

unsigned long* a
unsigned long* b
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
unsigned short* b
unsigned short* c

@return

void

@mayalias

@see libc/intrin/punpcklwd.c

putchar

Writes byte to stdout.

@param

int c

@return

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

@see libc/stdio/putchar.c

putenv

Emplaces environment key=value.

@param

char* string

@return

int

@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

char* s

@return

int

@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

%edi: is the wide character
%rsi: is the FILE stream pointer

@return

: %eax is set to %edi param or -1 on error

@see libc/stdio/putwc.S

putwchar

Writes wide character to stdout.

@param

int wc

@return

unsigned int: wc if written or -1 w/ errno

@see libc/stdio/putwchar.c

pvalloc

Equivalent to valloc(minimum-page-that-holds(n)), that is, round up n to nearest pagesize.

@param

rdi: is number of bytes needed

@return

: rax is memory address, or NULL w/ errno

@see dlpvalloc()

@see libc/mem/pvalloc.S

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

@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* iovec
int count: is recommended to be 16 or fewer; if it exceeds IOV_MAX then the extra buffers are simply ignored
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
unsigned long* b
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 qsort_r()

@see libc/alg/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/alg/qsort.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 random number using a linear congruential generator.

Please note that, unlike rand32(), the rand() function uses the same seed at startup by default, unless srand() is called. This makes it useful in cases where deterministic behavior is needed.

@return

int

@see libc/rand/rand.c

rand32

This function is an independent 32-bit clone of rand64().

@return

unsigned int

@see libc/rand/rand32.c

rand64

Returns nondeterministic random number.

This function uses a good random source if it's available, which takes ~400 cycles (~99ns). Otherwise it's seeded at program start with the system provided random value and may perform a few microseconds worth of system calls to get a good value.

@return

unsigned long

@see rngset()

@see libc/rand/rand64.c

randf

@return

float

@see libc/rand/randf.c

rawmemchr

Returns pointer to first instance of character.

@param

void* m: is memory to search
int c: is search byte which is masked with 255

@return

void*: is pointer to first instance of c

@see libc/str/rawmemchr.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

Intel Secure Key Digital Random Number Generator Introduced w/ Ivy Bridge c. 2013 and Excavator c. 2015

@return

unsigned long

@see rdseed(), rand32(), rand64(), and randcpy()

@see libc/rand/rdrand.c

rdseed

Intel Securer Key Digital Random Number Generator Introduced w/ Ivy Bridge c. 2013 and Excavator c. 2015

@return

unsigned long

@see rdrand(), rand32(), rand64(), and randcpy()

@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

@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
"\033[A"          CURSOR UP
"\033[38;5;202m"  ORANGERED
"\eOP"            PF1

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.

String control sequences, e.g. "\e_hello\e\\" currently are not tokenized as a single read. Lastly note, this function has limited support for UNICODE representations of C0/C1 control codes, e.g.

"\000"            NUL
"\300\200"        NUL
"\302\233A"       CURSOR UP

@param

int fd
char* buf: is guaranteed to receive a NUL terminator if size>0
unsigned long size

@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

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()

@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()

@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

@see libc/mem/reallocarray.c

realpath

@param

char* path
char* resolved_path

@return

char*

@see libc/calls/realpath.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

@see libc/sock/recv.c

regcomp

Compiles regular expression, e.g.

regex_t rx;
EXPECT_EQ(REG_OK, regcomp(&rx, "^[A-Za-z]{2}$", REG_EXTENDED));
EXPECT_EQ(REG_OK, regexec(&rx, "→A", 0, NULL, 0));
regfree(&rx);

@param

struct regex_t* preg: points to state, and needs regfree() afterwards
char* regex: is utf-8 regular expression 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()
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().

@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/runtime/memtrack.c

ReleaseMemoryNt

@param

struct _mmi* mm
int l
int r

@return

void

@see libc/runtime/memtracknt.c

rem1000000000int64

Returns 𝑥 % 1,000,000,000.

@param

rdi: int64 𝑥

@return

: rax has remainder

@see libc/nexgen32e/rem1000000000int64.S

rem1000000int64

Returns 𝑥 % 1,000,000.

@param

rdi: int64 𝑥

@return

: rax has remainder

@see libc/nexgen32e/rem1000000int64.S

rem10000int64

Returns 𝑥 % 10,000.

@param

rdi: int64 𝑥

@return

: rax has remainder

@see libc/nexgen32e/rem10000int64.S

rem1000int64

Returns 𝑥 % 1,000.

@param

rdi: int64 𝑥

@return

: rax has remainder

@see libc/nexgen32e/rem1000int64.S

rem100int64

Returns 𝑥 % 100.

@param

rdi: int64 𝑥

@return

: rax has remainder

@see libc/nexgen32e/rem100int64.S

rem10int64

Returns 𝑥 % 10.

@param

rdi: int64 𝑥

@return

: rax has remainder

@see libc/nexgen32e/rem10int64.S

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

char* name

@return

int: 0 on success or -1 w/ errno

@see unlink() and rmdir() which this abstracts

@see libc/calls/remove.c

rename

Moves file the Unix way.

@param

char* oldpathname
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
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
char* newpath

@return

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

@see libc/calls/renameat.c

replacestr

Replaces all instances of NEEDLE in S with REPLACEMENT.

@param

char* s
char* needle: can't be empty
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

char* path: is NULL propagating

@return

char*: must be free()'d

@see libc/x/replaceuser.c

__reservefd

Finds open file descriptor slot.

@return

int

@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
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

@return

int: number of matches found, or -1 w/ errno

@error EAFNOSUPPORT. ENETDOWN, ENAMETOOLONG, EBADMSG

@see libc/dns/resolvedns.c

resolvehoststxt

Finds address associated with name in HOSTS.TXT table.

This function performs binary search, so sorthoststxt() must be called on the table beforehand.

@param

struct HostsTxt* ht: can be gethoststxt()
int af: can be AF_INET, AF_UNSPEC
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
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

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* stream

@return

void

@see libc/stdio/rewind.c

rijndaelinit

Computes key schedule for rijndael().

@param

struct Rijndael* ctx: receives round keys
unsigned int n: is 14 for AES-256, 12 for AES-192, and 10 for AES-128
unsigned int k1
unsigned int k2

@return

void

@see libc/crypto/rijndaelinit.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

Seventeen 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

rmdir

Deletes empty directory.

@param

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

char* path

@return

int

@see libc/x/rmrf.c

rngset

Fills memory with random bytes, e.g.

char buf[1024]; rngset(buf, sizeof(buf), rand64, -1);

@param

void* buf
unsigned long size
unsigned long(*)() seed: can be rand64() and is always called at least once
unsigned long reseed: is bytes between seed() calls and -1 disables it

@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

RoundDecimalPlaces

@param

double f
double digs
double(*)() rounder

@return

double

@see libc/fmt/rounddecimalplaces.c

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

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

𝑥: is double passed in %xmm0
𝑦: is exponent via %edi

@return

: double in %xmm0

@see libc/tinymath/ldexp.S

scalblnf

Returns 𝑥 × 2ʸ.

@param

𝑥: is float passed in %xmm0
𝑦: is exponent via %edi

@return

: float in %xmm0

@see libc/tinymath/ldexpf.S

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

𝑥: is double passed in %xmm0
𝑦: is exponent via %edi

@return

: double in %xmm0

@see libc/tinymath/ldexp.S

scalbnf

Returns 𝑥 × 2ʸ.

@param

𝑥: is float passed in %xmm0
𝑦: is exponent via %edi

@return

: float in %xmm0

@see libc/tinymath/ldexpf.S

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

char* fmt
...

@return

int

@see libc/fmt/vcscanf.h

@see libc/stdio/scanf.c

sched_setaffinity

Asks kernel to only schedule process on particular CPUs.

@param

int pid: 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

@see libc/calls/sched_setaffinity.c

sched_yield

Asks kernel to deschedule thread momentarily.

@return

int

@see libc/calls/sched_yield.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

@see libc/sock/send.c

serializednsheader

Serializes DNS message header to wire.

@param

unsigned char* buf
unsigned long size
struct header header

@return

int: 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 dq 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
unsigned long size

@return

void

@see libc/stdio/setbuffer.c

setegid

Sets effective group ID.

@param

%edi: is group id

@return

@see setgid(), getauxval(AT_SECURE)

@see libc/calls/setegid.S

setenv

Copies variable to environment.

@param

char* name
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

%edi: is user id

@return

@see setuid(), getauxval(AT_SECURE)

@see libc/calls/seteuid.S

setgrent

@return

void

@see third_party/musl/grp.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.

@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* out_opt_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

setlocale

Sets program locale.

Cosmopolitan only supports the C or POSIX locale.

@param

int category
char* locale

@return

char*

@see libc/unicode/setlocale.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: nonzero on success or -1 w/ errno

@see getpriority(), nice()

@see libc/calls/setpriority.c

setpwent

@return

void

@see third_party/musl/pwd.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 setregid(), getauxval(AT_SECURE)

@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 setreuid(), getauxval(AT_SECURE)

@see libc/calls/setresuid.c

setrlimit

Sets resource limit for current process.

@param

int resource: can be RLIMIT_{CPU,FSIZE,DATA,STACK,CORE,RSS,etc.}
struct rlimit* rlim: specifies new resource limit

@return

int: 0 on success or -1 w/ errno

@see libc/sysv/consts.sh

@see libc/calls/setrlimit.c

setsid

Creates session and sets the process group id.

@return

int

@see libc/calls/setsid.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

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 stream will own, but won't free
int mode: may be _IOFBF, _IOLBF, or _IONBF
unsigned long size: must be a two power if buf is provided

@return

int: 0 on success or -1 on error

@see libc/stdio/setvbuf.c

ShowBacktrace

@param

int fd
struct StackFrame* bp

@return

void

@see libc/log/backtrace2.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
double* b
double* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/shufpd.c

shufps

Shuffles float vector.

@param

float* c
float* b
float* a
unsigned char m

@return

void

@mayalias

@see libc/intrin/shufps.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));

@param

int sig
struct copy* act
struct copy* oldact

@return

int

@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: true, false, or -1 w/ errno

@asyncsignalsafe

@see libc/calls/sigaddset.c

sigdelset

Removes signal from set.

@param

struct sigset_t* set
int sig

@return

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

@asyncsignalsafe

@see libc/calls/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/calls/sigemptyset.c

sigfillset

Adds all signals to set.

@param

struct sigset_t* set

@return

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

@asyncsignalsafe

@see libc/calls/sigfillset.c

sigignore

Configures process to ignore signal.

@param

int sig

@return

int

@see libc/calls/sigignore.c

sigismember

Returns true if signal is member of set.

@param

struct sigset_t* set
int sig

@return

int: true, false, or -1 w/ errno

@asyncsignalsafe

@see libc/calls/sigismember.c

signal

Installs kernel interrupt handler.

@param

int sig
void(*)() func

@return

void(*)()

@see sigaction() which has more features

@see libc/calls/signal.c

sigprocmask

Changes program signal blocking state, e.g.:

sigset_t oldmask;
sigprocmask(SIG_BLOCK, &kSigsetFull, &oldmask);
sigprocmask(SIG_SETMASK, &oldmask, NULL);

@param

int how: can be SIG_BLOCK (U), SIG_UNBLOCK (/), SIG_SETMASK (=)
struct kSigsetEmpty* opt_set
struct kSigsetEmpty* opt_out_oldset

@return

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

@asyncsignalsafe

@vforksafe

@see libc/calls/sigprocmask.c

sigsuspend

Blocks until SIG ∉ MASK is delivered to process.

@param

struct kSigsetEmpty* ignore: is a bitset of signals to block temporarily

@return

int: -1 w/ EINTR

@asyncsignalsafe

@see libc/calls/sigsuspend.c

sin

Returns sine of 𝑥.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

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

@see libc/tinymath/sin.S

sincos

Returns sine and cosine of 𝑥.

@param

𝑥: is double scalar in low half of %xmm0
%rdi: is double *out_sin
%rsi: is double *out_cos

@return

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

@see libc/tinymath/sincos.S

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

sinf

Returns sine 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/sinf.S

sinh

Returns hyperbolic sine of 𝑥.

@param

double x

@return

double

@see libc/tinymath/sinh.c

sinhf

Returns hyperbolic sine of 𝑥.

@param

float x

@return

float

@see libc/tinymath/sinhf.c

sinhl

Returns hyperbolic sine of 𝑥.

@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

sleb128

Encodes sleb-128 signed integer.

@param

void* buf
unsigned long size
__int128 x

@return

int

@see libc/fmt/sleb128.c

sleep

Sleeps for a particular amount of time.

@param

unsigned int seconds

@return

int

@asyncsignalsafe

@see libc/calls/sleep.c

slowcall

Applies no-clobber guarantee to System Five function call.

Reentrant
Realigns stack
Doesn't assume red zone
Clobbers nothing (except %rax and flags)

This function may be called using an stdcall convention. It's useful for files named FOO.hookabi.c and BAR.ncabi.c to make calls into other parts of the system, that don't conform to the same restricted ABI.

@param

six: args and fn addr pushed on stack in reverse order

@return

: %rax has function return value, and stack is cleaned up

@see libc/shadowargs.hook.c for intended use case

@see libc/nexgen32e/slowcall.S

snprintf

Formats string to buffer.

@param

char* buf
unsigned long count
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 palandprintf() and printf() for detailed documentation

@asyncsignalsafe

@vforksafe

@see libc/fmt/snprintf.c

socketconnect

Opens socket client connection.

@param

struct addrinfo* ai: can be obtained via getaddrinfo()
int flags

@return

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

@see libc/sock/socketconnect.c

sorthoststxt

Sorts entries in HOSTS.TXT table.

This function enables resolvehoststxt() to be called so hard-coded hostname lookups take logarithmic time; you can blackhole all the spam you want, in your /etc/hosts file.

The sorted order, defined by dnsnamecmp(), also makes it possible to efficiently search for subdomains, once the initial sort is done.

@param

struct HostsTxt* ht

@return

void

@see libc/dns/sorthoststxt.c

spacepad

@param

int(*)() out
void* arg
unsigned long n

@return

int

@see libc/fmt/spacepad.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
char* fmt
...

@return

int

@see palandprintf() 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

sscanf

String decoder.

@param

char* str
char* fmt
...

@return

int

@see libc/fmt/vcscanf.h (for docs and implementation)

@see libc/fmt/sscanf.c

__stack_chk_fail

Aborts program under enemy fire to avoid being taken alive.

@return

void

@see libc/runtime/stackchkfail.c

__start_fatal

Prints initial part of fatal message.

@param

char* file
int line

@return

void

@note this is support code for __check_fail(), __assert_fail(), etc.

@see __start_fatal_ndebug()

@see libc/log/startfatal.c

__start_fatal_ndebug

Prints initial part of fatal message.

@return

void

@note this is support code for __check_fail(), __assert_fail(), etc.

@see __start_fatal()

@see libc/log/startfatal_ndebug.c

startswith

Returns true if s has prefix.

@param

char* s: is a NUL-terminated string
char* prefix: is also NUL-terminated

@return

_Bool

@see libc/str/startswith.c

startswith16

Returns true if s has prefix.

@param

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

@return

_Bool

@see libc/str/startswith16.c

stat

Returns information about thing.

@param

char* path
struct stat* st: is where result is stored

@return

int

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

@asyncsignalsafe

@see libc/calls/stat.c

__stat2linux

Transcodes “The Dismal Data Structure” from BSD→Linux ABI.

@param

void* ms

@return

void

@asyncsignalsafe

@see libc/calls/stat2linux.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
char* s

@return

char*: pointer to nul byte

@note 𝑑 and 𝑠 can't overlap

@asyncsignalsafe

@see libc/str/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
char* src
unsigned long stride

@return

char*: dest + stride

@see stncpy(), memccpy()

@asyncsignalsafe

@see libc/str/stpncpy.c

strcasecmp

Compares NUL-terminated strings case-insensitively.

@param

char* a: is first non-null NUL-terminated string pointer
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/strcasecmp.c

strcasecmp16

Compares NUL-terminated UCS-2 strings case-insensitively.

@param

unsigned short* l
unsigned short* r

@return

int: is <0, 0, or >0 based on uint16_t comparison

@asyncsignalsafe

@see libc/str/strcasecmp16.c

strcasecmp16to8

@param

unsigned short* s1
char* s2

@return

int

@see libc/str/strcasecmp8to16.c

strcasecmp8to16

Compares UTF-8 and UTF-16 strings, ignoring case.

@param

char* s1
unsigned short* s2

@return

int

@see libc/str/strcasecmp8to16.c

strcat

Appends 𝑠 to 𝑑.

@param

char* d
char* s

@return

char*: 𝑑

@asyncsignalsafe

@see libc/str/strcat.c

strcat16

Appends 𝑠 to 𝑑.

@param

unsigned short* d
unsigned short* s

@return

unsigned short*: 𝑑

@asyncsignalsafe

@see libc/str/strcat16.c

strchr

Returns pointer to first instance of character.

@param

char* s: is a NUL-terminated string
int c: is masked with 255 as byte to search for

@return

char*: pointer to first instance of c or NULL if not found noting that if c is NUL we return pointer to terminator

@asyncsignalsafe

@see libc/str/strchr.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

strchrnul

Returns pointer to first instance of character.

@param

char* s: is a NUL-terminated string
int c: is masked with 255 as byte to search for

@return

char*: pointer to first instance of c, or pointer to NUL terminator if c is not found

@see libc/str/strchrnul.c

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

char* s

@return

unsigned long

@see libc/str/strclen.c

strclen16

Returns number of characters in UTF-16 or UCS-2 string.

@param

unsigned short* s

@return

unsigned long

@see libc/str/strclen16.c

strcmp

Compares NUL-terminated strings.

@param

char* a: is first non-null NUL-terminated string pointer
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

unsigned short* l
unsigned short* r

@return

int: is <0, 0, or >0 based on uint16_t comparison

@asyncsignalsafe

@see libc/str/strcmp16.c

strcmp16to8

@param

unsigned short* s1
char* s2

@return

int

@see libc/str/strcmp8to16.c

strcmp8to16

Compares UTF-8 and UTF-16 strings.

@param

char* s1
unsigned short* s2

@return

int

@see libc/str/strcmp8to16.c

strcoll

Compares strings in the C locale.

@param

char* p
char* q

@return

int

@see libc/str/strcoll.c

strcpy

Copies bytes from 𝑠 to 𝑑 until a NUL is encountered.

@param

char* d
char* s

@return

char*: original dest

@note 𝑑 and 𝑠 can't overlap

@asyncsignalsafe

@see libc/str/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
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.

@param

rdi: is string
rsi: is reject nul-terminated character set

@return

: rax is index of first byte in charset

@see strspn(), strtok_r()

@asyncsignalsafe

@see libc/nexgen32e/strcspn.S

strcspn16

Returns prefix length, consisting of chars not in reject. a.k.a. Return index of first byte that's in charset.

@param

unsigned short* s
unsigned short* reject: is nul-terminated character set

@return

unsigned long

@see strspn(), strtok_r()

@asyncsignalsafe

@see libc/str/strcspn16.c

strcspn_pure

Returns prefix length, consisting of chars not in reject. a.k.a. Return index of first byte that's in charset.

@param

char* s
char* reject: is nul-terminated character set

@return

unsigned long

@see strspn(), strtok_r()

@asyncsignalsafe

@see libc/str/strcspn-pure.c

strdup

Allocates new copy of string.

@param

char* s: is a NUL-terminated byte string

@return

char*: new string or NULL w/ errno

@error ENOMEM

@see libc/mem/strdup.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
char* buf
unsigned long size

@return

int: 0 on success, or error code

@see libc/fmt/strerror_r.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 size
char* f
struct tmp* t

@return

unsigned long: bytes copied excluding nul, or 0 on error

@see libc/time/strftime.c

strlcat

Appends string SRC to DEST, the BSD way.

@param

char* dest: is a buffer holding a NUL-terminated string
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
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

rdi: is non-null NUL-terminated string pointer

@return

: rax is number of bytes (excluding NUL)

@clob ax,dx,cx,xmm3,xmm4

@note h/t agner fog

@asyncsignalsafe

@see libc/nexgen32e/strlen.S

strlen16

Returns length of NUL-terminated char16_t string.

@param

rdi: is non-null NUL-terminated char16_t string pointer

@return

: rax is the number of shorts, excluding the NUL

@asyncsignalsafe

@see libc/nexgen32e/strsak16.S

strlen_pure

Returns length of NUL-terminated string.

@param

char* s

@return

unsigned long

@see libc/str/strlen-pure.c

strncasecmp

Compares NUL-terminated strings case-insensitively w/ limit.

@param

char* a: is first non-null NUL-terminated string pointer
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

unsigned short* a: is first non-null NUL-terminated char16 string pointer
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

unsigned short* s1
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

char* s1
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
char* s
unsigned long n

@return

char*: 𝑑

@note 𝑑 and 𝑠 can't overlap

@asyncsignaslenafe

@see libc/str/strncat.c

strnclen

@param

char* s
unsigned long n

@return

unsigned long

@see libc/str/strclen.c

strnclen16

@param

unsigned short* p
unsigned long n

@return

unsigned long

@see libc/str/strclen16.c

strncmp

Compares NUL-terminated strings w/ limit.

@param

char* a: is first non-null NUL-terminated string pointer
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

unsigned short* a: is first non-null NUL-terminated char16 string pointer
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

unsigned short* s1
char* s2
unsigned long n

@return

int

@see libc/str/strncmp8to16.c

strncmp8to16

Compares UTF-8 and UTF-16 strings, with limit.

@param

char* s1
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.

@param

char* dest
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

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/mem/strndup.c

strnlen

Returns length of NUL-terminated string w/ limit.

@param

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 memory, with limit.

@param

rdi: is non-null memory
rsi: is the maximum number of shorts to consider

@return

: rax is the number of shorts, excluding the NUL

@asyncsignalsafe

@see libc/nexgen32e/strsak16.S

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 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 bytes.

@param

rdi: is a nullable NUL-terminated string pointer
rsi: is the maximum number of bytes to consider

@return

: rax is the number of bytes, excluding the NUL

@see libc/nexgen32e/strsak.S

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

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

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

char* s
char* accept

@return

char*

@asyncsignalsafe

@see libc/str/strpbrk.c

strpbrk16

Returns pointer to first byte matching any in accept, or NULL.

@param

unsigned short* s
unsigned short* accept

@return

unsigned short*

@asyncsignalsafe

@see libc/str/strpbrk16.c

strptime

@param

char* s
char* f
struct tm* tm

@return

char*

@see libc/time/strptime.c

strrchr

Searches for last instance of character in string.

@param

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

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

strsak

Swiss army knife of string character scanning. Used to be fourteen fast functions in one.

@param

rdi: is non-null string memory
rsi: is max number of bytes to consider
dl: is search character #1
dh: 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 bytes exhausted (for length v. NULL)

@return

: rax end pointer after r8/r9/r10 modifications

@see libc/nexgen32e/strsak.S

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
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 name associated with signal code.

@param

int sig

@return

char*

@see sigaction()

@see libc/str/strsignal.c

strspn

Returns prefix length, consisting of chars in accept.

@param

char* s
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

unsigned short* s
unsigned short* accept: is nul-terminated character set

@return

unsigned long

@see strcspn(), strtok_r()

@asyncsignalsafe

@see libc/str/strspn16.c

strstr

Searches for substring.

@param

char* haystack: is the search area, as a NUL-terminated string
char* needle: is the desired substring, also NUL-terminated

@return

char*: pointer to first substring within haystack, or NULL

@asyncsignalsafe

@see memmem()

@see libc/str/strstr.c

strstr16

Searches for substring.

@param

unsigned short* haystack: is the search area, as a NUL-terminated string
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

char* s00
char** se

@return

double

@see third_party/gdtoa/strtod.c

strtodg

@param

char* s00
char** se
struct FPI* fpi
int* exp
unsigned int* bits

@return

int

@see third_party/gdtoa/strtodg.c

strtodI

@param

char* s
char** sp
double* dd

@return

int

@see third_party/gdtoa/strtodI.c

strtof

@param

char* s
char** sp

@return

float

@see third_party/gdtoa/strtof.c

strtoId

@param

char* s
char** sp
double* f0
double* f1

@return

int

@see third_party/gdtoa/strtoId.c

strtoIdd

@param

char* s
char** sp
double* f0
double* f1

@return

int

@see third_party/gdtoa/strtoIdd.c

strtoIf

@param

char* s
char** sp
float* f0
float* f1

@return

int

@see third_party/gdtoa/strtoIf.c

strtoimax

Decodes 128-bit signed integer from ASCII string.

@param

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: the decoded saturated number

@see strtoumax

@see libc/fmt/strtoimax.c

strtoIx

@param

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
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
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

Converts string to number.

@param

char* s
char** opt_out_end
int optional_base: is recommended as 0 for flexidecimal

@return

long

@see libc/fmt/strtol.c

strtold

Converts string to long double.

@param

char* s
char** endptr

@return

long double

@see third_party/gdtoa/strtold.c

strtoll

@param

char* s
char** endptr
int optional_base

@return

long

@see libc/fmt/strtoll.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

char* nptr
long minval
long maxval
char** errstr

@return

long

@see libc/fmt/strtonum.c

strtopd

@param

char* s
char** sp
double* d

@return

int

@see third_party/gdtoa/strtopd.c

strtopdd

@param

char* s
char** sp
double* dd

@return

int

@see third_party/gdtoa/strtopdd.c

strtopf

@param

char* s
char** sp
float* f

@return

int

@see third_party/gdtoa/strtopf.c

strtopx

@param

char* s
char** sp
void* V

@return

int

@see third_party/gdtoa/strtopx.c

strtord

@param

char* s
char** sp
int rounding
double* d

@return

int

@see third_party/gdtoa/strtord.c

strtordd

@param

char* s
char** sp
int rounding
double* dd

@return

int

@see third_party/gdtoa/strtordd.c

strtorf

@param

char* s
char** sp
int rounding
float* f

@return

int

@see third_party/gdtoa/strtorf.c

strtorx

@param

char* s
char** sp
int rounding
void* L

@return

int

@see third_party/gdtoa/strtorx.c

strtoul

@param

char* s
char** endptr
int optional_base

@return

unsigned long

@see libc/fmt/strtoul.c

strtoull

@param

char* s
char** endptr
int optional_base

@return

unsigned long

@see libc/fmt/strtoull.c

strtoumax

Decodes 128-bit unsigned integer from ASCII string.

This is a more restricted form of strtoimax() that's useful for folks needing to decode numbers in the range [1^127, 1^128).

@param

char* s
char** endptr
int base

@return

unsigned __int128

@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

char* l0
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

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

unsigned short* s
unsigned long o

@return

int

@see libc/unicode/strwidth16.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

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

char* target: can be relative and needn't exist
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

char* target: can be relative and needn't exist
int newdirfd
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/symlinkat.c

sync

Flushes file system changes to disk by any means necessary.

@return

void

@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_abort_nt

@noreturn

@see libc/runtime/abort-nt.c

sys_chdir_nt

@param

char* path

@return

int

@see libc/calls/chdir-nt.c

sys_close_nt

@param

struct kEmptyFd* fd

@return

int

@see libc/calls/close-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(), and dup3() for Windows NT.

@param

int oldfd
int newfd
int flags

@return

int

@see libc/calls/dup-nt.c

sys_execve

@param

char* prog
char** argv
char** envp

@return

int

@see libc/calls/execve-sysv.c

sys_execve_nt

@param

char* program
char** argv
char** envp

@return

int

@see libc/calls/execve-nt.c

sys_faccessat_nt

@param

int dirfd
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_fcntl_nt

@param

int fd
int cmd
unsigned int 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 stat* st

@return

int

@asyncsignalsafe

@see libc/calls/fstat-sysv.c

sys_fstat_metal

@param

int fd
struct stat* 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
char* pathname
struct stat* st
int flags

@return

int

@asyncsignalsafe

@see libc/calls/fstatat-sysv.c

sys_fstatat_nt

@param

int dirfd
char* path
struct stat* st
unsigned int flags

@return

int

@see libc/calls/fstatat-nt.c

sys_ftruncate_nt

@param

int fd
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.c

sys_getcwd_xnu

@param

char* res
unsigned long size

@return

char*

@see libc/calls/getcwd-xnu.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_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_gettimeofday_nt

@param

struct it_value* tv
struct timezone* tz

@return

int

@see libc/calls/gettimeofday-nt.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_link_nt

@param

char* existingpath
char* newpath

@return

int

@see libc/calls/link-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
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 DirectMap

@see libc/runtime/directmap.c

sys_mmap_metal

@param

void* paddr
unsigned long size
int prot
int flags
int fd
long off

@return

struct res

@see libc/runtime/directmap-metal.c

sys_mmap_nt

@param

void* addr
unsigned long size
int prot
int flags
long handle
long off

@return

struct dm

@see libc/runtime/directmap-nt.c

sys_msync_nt

@param

void* addr
unsigned long size
int flags

@return

int

@see libc/runtime/msync-nt.c

sys_munmap_metal

@param

void* addr
unsigned long size

@return

int

@see libc/runtime/munmap-metal.c

sys_nanosleep_nt

@param

struct st_ctim* req
struct st_ctim* rem

@return

int

@see libc/calls/nanosleep-nt.c

sys_open_nt

@param

int dirfd
char* file
unsigned int flags
int mode

@return

long

@see libc/calls/open-nt.c

sys_openat_metal

@param

int dirfd
char* file
int flags
unsigned int mode

@return

int

@see libc/calls/openat-metal.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_read_nt

@param

struct kEmptyFd* fd
struct iovec* iov
unsigned long iovlen
long opt_offset

@return

long

@see libc/calls/read-nt.c

sys_readv_metal

@param

struct kEmptyFd* fd
struct iovec* iov
int iovlen

@return

long

@see libc/calls/readv-metal.c

sys_readv_serial

@param

struct kEmptyFd* fd
struct iovec* iov
int iovlen

@return

long

@see libc/calls/readv-serial.c

sys_renameat_nt

@param

int olddirfd
char* oldpath
int newdirfd
char* newpath

@return

int

@see libc/calls/renameat-nt.c

sys_sched_yield_nt

@return

int

@see libc/calls/sched_yield-nt.c

sys_setitimer_nt

@param

int which
struct itv* newvalue
struct itv* 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_symlinkat_nt

@param

char* target
int newdirfd
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

char* path
unsigned long length

@return

int

@see libc/calls/truncate-nt.c

sys_unlinkat_nt

@param

int dirfd
char* path
int flags

@return

int

@see libc/calls/unlinkat-nt.c

sys_utimensat

@param

int dirfd
char* path
struct st_ctim* ts
int flags

@return

int

@see libc/calls/utimensat-sysv.c

sys_utimensat_nt

@param

int dirfd
char* path
ANONYMOUS-STRUCT* ts
int flags

@return

int

@see libc/calls/utimensat-nt.c

sys_utimensat_xnu

@param

int dirfd
char* path
struct st_ctim* ts
int flags

@return

int

@see libc/calls/utimensat-xnu.c

sys_utimes_nt

@param

char* path
struct it_value* tv

@return

int

@see libc/calls/sys_utimes_nt.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

struct kEmptyFd* fd
struct iovec* iov
unsigned long iovlen
long opt_offset

@return

long

@see libc/calls/write-nt.c

sys_writev_metal

@param

struct kEmptyFd* fd
struct iovec* iov
int iovlen

@return

long

@see libc/calls/writev-metal.c

sys_writev_serial

@param

struct kEmptyFd* 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

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.

@param

int thing: can be _SC_XXX

@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

system

Launches program with system command interpreter.

@param

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

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

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

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

@see libc/tinymath/tan.S

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.

@param

double x

@return

double

@see libc/tinymath/tanh.c

tanhf

Returns hyperbolic tangent of 𝑥.

@param

float x

@return

float

@see libc/tinymath/tanhf.c

tanhl

Returns hyperbolic tangent of 𝑥.

@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
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

tcgetattr

Obtains the termios struct.

@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

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

telldir

Returns offset into directory data.

@param

struct dirstream* dir

@return

long

@see libc/stdio/dirstream.c

tempnam

Creates name for temporary file.

@param

char* dir
char* pfx

@return

char*

@see third_party/musl/tempnam.c

__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

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

time2posix

@param

long t

@return

long

@see libc/time/localtime.c

timegm

@param

struct mytm* tmp

@return

long

@see libc/time/localtime.c

timelocal

@param

struct mytm* tmp

@return

long

@see libc/time/localtime.c

timeoff

@param

struct mytm* tmp
long offset

@return

long

@see libc/time/localtime.c

times

Returns accounting data for process on time-sharing system.

@param

struct tms* out_times

@return

long

@see libc/time/times.c

TimeSpecToFileTime

Converts UNIX nanosecond timestamp to Windows COBOL timestamp.

@param

struct ts ts

@return

ANONYMOUS-STRUCT

@see libc/fmt/timespectofiletime.c

TimeToFileTime

@param

long t

@return

ANONYMOUS-STRUCT

@see libc/fmt/timetofiletime.c

TimeValToFileTime

@param

struct it_value* tv

@return

ANONYMOUS-STRUCT

@see libc/fmt/timevaltofiletime.c

timingsafe_memcmp

Lexicographically compares the first len bytes in b1 and b2.

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 afterw finding the first differing byte.

@param

void* b1
void* b2
unsigned long len

@return

int

@note each byte is interpreted as unsigned char

@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

tinystrlen

8-bit strlen that's tiny and near optimal if data's tiny.

@param

RDI: is char *s
EAX: is unsigned length

@return

@see libc/nexgen32e/strsak.S

@see libc/nexgen32e/tinystrlen.greg.S

tinystrlen16

16-bit strlen that's tiny and near optimal if data's tiny.

@param

RDI: is char16_t *s
EAX: is unsigned length

@return

@see libc/nexgen32e/strsak16.S

@see libc/nexgen32e/tinystrlen16.greg.S

tinystrncmp

Compares strings w/ limit & no-clobber greg abi.

@param

%rdi: is first string
%rsi: is second string
%rdx: is max length

@return

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

@clob flags only

@asyncsignalsafe

@see libc/nexgen32e/tinystrncmp.ncabi.S

tinystrnlen

8-bit strnlen that's tiny and near optimal if data's tiny.

@param

RDI: is char *s
RSI: is size_t n
EAX: is unsigned length

@return

@see libc/nexgen32e/strsak.S

@see libc/nexgen32e/tinystrnlen.greg.S

tinystrnlen16

16-bit strnlen that's tiny and near optimal if data's tiny.

@param

RDI: is char16_t *s
RSI: is size_t n
EAX: is unsigned length

@return

@see libc/nexgen32e/strsak16.S

@see libc/nexgen32e/tinystrnlen16.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

tmpfile

Creates a temporary file.

@return

struct FILE*

@see mkostempsm(), kTmpPath

@see libc/stdio/tmpfile.c

tolower

Converts character to lower case.

@param

int c

@return

int

@see libc/str/tolower.c

touch

Creates new file or changes modified time on existing one.

@param

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

towlower

Converts wide character to lower case.

@param

unsigned int wc

@return

unsigned int

@see libc/str/towlower.c

towupper

Converts wide character to upper case.

@param

unsigned int wc

@return

unsigned int

@see libc/str/towupper.c

tpdecode

Thompson-Pike Varint Decoder.

@param

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/str/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.

@param

char* dst: is output buffer
unsigned long dstsize: is bytes in dst
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.

@param

unsigned short* dst: is output buffer
unsigned long dstsize: is shorts in dst
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

TrackMemoryInterval

@param

struct _mmi* mm
int x
int y
long h
int prot
int flags

@return

int

@see libc/runtime/memtrack.c

triplf

Hoses interrupt descriptor table and triple-faults the system.

@return

@see youtu.be/GIKfEAF2Yhw?t=67

@mode long,legacy,real

@see libc/nexgen32e/triplf.S

trunc

Rounds to integer, toward zero.

@param

𝑥: is double scalar in low half of %xmm0

@return

: double scalar in low half of %xmm0

@define trunc(𝑥+copysign(.5,𝑥))

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

@see roundsd $_MM_FROUND_TO_ZERO|_MM_FROUND_NO_EXC,%xmm0,%xmm0

@see libc/tinymath/trunc.S

truncate

Reduces or extends underlying physical medium of file.

If file was originally larger, content >length is lost.

@param

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

@param

int fd

@return

char*

@see libc/calls/ttyname.c

ttyname_r

@param

int fd
char* buf
unsigned long size

@return

int

@see libc/calls/ttyname_r.c

tzcnt

Finds lowest set bit in 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

edi: is 32-bit unsigned 𝑥 value

@return

: eax number in range [0,32) or 32 if 𝑥 is 0

@see also treasure trove of nearly identical functions

@see libc/nexgen32e/tzcnt.S

tzcntl

Finds lowest set bit in 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

rdi: is 64-bit unsigned 𝑥 value

@return

: rax number in range [0,64) or 64 if 𝑥 is 0

@see also treasure trove of nearly identical functions

@see libc/nexgen32e/tzcntl.S

tzcntll

Finds lowest set bit in 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

rdi: is 64-bit unsigned 𝑥 value

@return

: rax number in range [0,64) or 64 if 𝑥 is 0

@see also treasure trove of nearly identical functions

@see libc/nexgen32e/tzcntl.S

tzname

@type

char*[2]

@see libc/time/localtime.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_radix10

Converts unsigned 64-bit integer to string.

@param

unsigned long i
char* a: needs at least 21 bytes

@return

unsigned long: bytes written w/o nul

@see libc/fmt/itoa64radix10.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

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
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

unsigned short* s

@return

void*

@note no NUL terminator is added to end of buf

@see tunbing(), unbingbuf(), unbing()

@see libc/x/unbingstr.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

ungetc

@param

int c
struct FILE* f

@return

int

@see libc/stdio/ungetc.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
char* hexdigs

@return

void*

@see libc/fmt/unhexbuf.c

unhexstr

@param

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

Deletes file.

Please note the deletion process has different interesting properties on each platform. For example, on System V, if open descriptors exist then only the name of the file is removed and it's actually deleted later on when appropriate.

@param

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

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.

@param

int dirfd: is normally AT_FDCWD but if it's an open directory and path is relative, then path becomes relative to dirfd
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

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

unrijndaelinit

Computes key schedule for unrijndael().

@param

struct Rijndael* ctx
unsigned int n: is 14 for AES-256, 12 for AES-192, and 10 for AES-128
unsigned int k1
unsigned int k2

@return

void

@see libc/crypto/unrijndaelinit.c

unsetenv

Removes environment variable.

@param

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

usleep

Sleeps for particular amount of microseconds.

@param

unsigned int microseconds

@return

int

@see libc/time/usleep.c

utime

Changes last accessed/modified times on file.

@param

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.

@param

int dirfd
char* path
struct st_ctim* ts: is atime/mtime, or null for current time
int flags: can have AT_SYMLINK_NOFOLLOW

@return

int

@note no xnu/rhel5 support if dirfd≠AT_FDCWD∨flags≠0

@asyncsignalsafe

@see libc/calls/utimensat.c

utimes

Changes last accessed/modified times on file.

@param

char* path
struct it_value* tv

@return

int: 0 on success or -1 w/ errno

@asyncsignalsafe

@see stat()

@see libc/calls/utimes.c

valloc

Equivalent to memalign(4096, n).

@param

rdi: is number of bytes needed

@return

: rax is memory address, or NULL w/ errno

@see dlvalloc()

@see libc/mem/valloc.S

vasprintf

Formats string w/ dynamic memory allocation.

@param

char** strp
char* fmt
struct __va_list* va

@return

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

@see xasprintf() for a better API

@see libc/mem/vasprintf.c

vcls

Clears display page.

@param

es:di: arbitrary address within video page

@return

: es:ax starting address

@mode long,legacy,real

@see libc/nexgen32e/vcls.S

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
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
char* fmt
struct __va_list* va

@return

int

@asyncsignalsafe

@vforksafe

@see libc/calls/vdprintf.c

verr

@param

int eval
char* fmt
struct __va_list* va

@noreturn

@see libc/log/verr.c

verrx

@param

int eval
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:

LOGF("connecting to foo");
connect(...)
LOGF("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
char* file
int line
struct FILE* f
char* fmt
struct __va_list* va

@return

void

@see libc/log/vflogf.c

vflogf_onfail

Takes corrective action if logging is on the fritz.

@param

struct FILE* f

@return

void

@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

@param

struct FILE* f
char* fmt
struct __va_list* va

@return

int

@see libc/stdio/vfprintf.c

vfscanf

Stream decoder.

@param

struct FILE* stream
char* fmt
struct __va_list* ap

@return

int

@see libc/fmt/vcscanf.h

@see libc/stdio/vfscanf.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

@param

char* fmt
struct __va_list* va

@return

int

@see libc/stdio/vprintf.c

vscanf

String decoder.

@param

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
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 palandprintf() 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
char* fmt
struct __va_list* va

@return

int

@see palandprintf() and printf() for detailed documentation

@see vsnprintf() for modern alternative w/ buf size param

@see libc/fmt/vsprintf.c

vsscanf

Decodes string.

@param

char* str
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

vwarn

@param

char* fmt
struct __va_list* va

@return

void

@see libc/log/vwarn.c

vwarnx

@param

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

@vforksafe

@see libc/calls/wait.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

@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

@see libc/calls/wait4.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

@see libc/calls/waitpid.c

warn

@param

char* fmt
...

@return

void

@see libc/log/warn.c

warnx

@param

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

wcscasecmp

Compares NUL-terminated wide strings case-insensitively.

@param

int* a: is first non-null NUL-terminated string pointer
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
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

int* a: is first non-null NUL-terminated string pointer
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

wcscpy

Copies NUL-terminated wide character string.

𝑑 and 𝑠 must not overlap unless 𝑑 ≤ 𝑠.

@param

int* d
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

int* s
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

int* s

@return

int*

@see libc/mem/wcsdup.c

wcsendswith

Returns true if s has suffix.

@param

int* s: is a NUL-terminated string
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

int* a: is first non-null NUL-terminated string pointer
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

wcsncmp

Compares NUL-terminated wide strings w/ limit.

@param

int* a: is first non-null NUL-terminated string pointer
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
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

wcsnwidth

Returns monospace display width of wide character string.

@param

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

int* s
int* accept

@return

int*

@asyncsignalsafe

@see libc/str/wcspbrk.c

wcsrchr

Searches for last instance of wchar_t in string.

@param

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

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

int* s
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

int* s: is a NUL-terminated string
int* prefix: is also NUL-terminated

@return

_Bool

@see libc/str/wcsstartswith.c

wcsstr

Searches for substring.

@param

int* haystack: is the search area, as a NUL-terminated string
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

wcstoimax

@param

int* s
int** endptr
int base

@return

__int128

@see libc/fmt/wcstoimax.c

wcstol

@param

int* s
int** end
int opt_base

@return

long

@see libc/fmt/wcstol.c

wcswidth

Returns monospace display width of wide character string.

@param

int* pwcs
unsigned long o

@return

int

@see libc/unicode/wcswidth.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

wctype

@param

char* name

@return

unsigned int

@see libc/str/iswctype.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.

@return

@see free_s() which can ignore static/stack and clear refs

@see libc/runtime/weakfree.S

__winerr

Return path for failed Win32 API calls.

@return

long: -1 w/ few exceptions

@note this is a code-size saving device

@see libc/calls/winerr.greg.c

WinMainForked

@return

void

@see libc/runtime/fork-nt.c

winrandish

Returns somewhat randomish number on Windows.

@return

long

@see libc/rand/winrandish.c

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

wmemcpy

@param

int* dest
int* src
unsigned long count

@return

int*

@see libc/str/wmemcpy.c

wmemmove

@param

int* dest
int* src
unsigned long count

@return

int*

@see libc/str/wmemmove.c

wmempcpy

@param

int* dest
int* src
unsigned long count

@return

int*

@see libc/str/wmempcpy.c

wmemrchr

Searches for last instance of wchar_t in memory region.

@param

rdi: points to data to search
esi: is treated as int32_t (officially wchar_t)
rdx: is short count in rdi

@return

: rax is address of last %esi in %rdi, or NULL

@note AVX2 requires Haswell (2014+) or Excavator (2015+)

@see libc/nexgen32e/memrchr32.S

wmemset

Sets wide memory.

@param

int* dest
int c
unsigned long count

@return

int*

@asyncsignalsafe

@see libc/nexgen32e/wmemset.inc

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

@see libc/calls/write.c

xasprintf

Returns dynamically formatted string.

@param

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

char* path
void* data
unsigned long size: can be -1 to strlen(data)

@return

int: if failed, -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

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

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 getline() for a more difficult api

@see libc/x/xgetline.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 it_value* 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

char* path
char* other

@return

char*: newly allocated string of resulting path

@see libc/x/xjoinpaths.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

xrealloc

Relocates, extends, and/or shrinks memory──or die.

This API is fabulous since it categorically eliminates an extremely common type of memory bug, by simply redefining it as a crash.

@param

void* p1
unsigned long newsize

@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

@see libc/x/xsigaction.c

xslurp

Reads entire file into memory.

@param

char* path
unsigned long* opt_out_size

@return

char*: NUL-terminated malloc'd contents, or NULL w/ errno

@note this is uninterruptible

@see libc/x/xslurp.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

char* s
...

@return

char*

@see gc()

@see libc/x/xstrcat.c

xstrdup

Allocates new copy of string, or dies.

@param

char* s

@return

char*

@see libc/x/xstrdup.c

xstrmul

Multiplies string.

@param

char* s
unsigned long n

@return

char*

@see libc/x/xstrmul.c

xstrndup

Allocates new copy of string, with byte limit.

@param

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

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
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

char* fmt
struct __va_list* va

@return

char*: fully formatted string, which must be free()'d

@see xasprintf()

@see libc/x/xvasprintf.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

char*[10]

@see third_party/zlib/zutil.c

zcalloc

@param

void* opaque
unsigned int items
unsigned int 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

char*

@see third_party/zlib/zutil.c

zipfindcentraldir

Locates End Of Central Directory record in ZIP file.

We search backwards for the End Of Central Directory Record magnum. The ZIP spec says this can be anywhere in the last 64kb. We go all the way since .com.dbg binaries will have lots of DWARF stuff after the embedded .com binary. As such, we sanity check the other fields too to make sure the record seems legit and it's not just a random occurrence of the magnum.

@param

unsigned char* p: points to file memory
unsigned long n: is byte size of file

@return

unsigned char*

@see libc/str/zipfindcentraldir.c

__zipos_close

Closes compressed object.

@param

int fd: is vetted by close()

@return

int

@see libc/zipos/close.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*

@see libc/zipos/get.c

__zipos_open

Loads compressed file from αcτµαlly pδrταblε εxεcµταblε object store.

@param

struct ZiposUri* name
unsigned int flags
int mode

@return

int

@note don't call open() from signal handlers

@see libc/zipos/open.c

__zipos_parseuri

Extracts information about ZIP URI if it is one.

@param

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

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

char*

@see third_party/zlib/zlib.h