NAME

POSIX::2008 - Perl interface to POSIX.1-2008 and beyond

SYNOPSIS

use POSIX::2008 qw(:fcntl openat pwrite);

sysopen my $dh, '/tmp', O_RDONLY|O_DIRECTORY|O_NOFOLLOW
  or die 'Dafuq?';
my $fh = openat($dh, 'foobar', O_RDWR|O_CREAT);
pwrite($fh, 'fuckyounsa', 10, 0);

DESCRIPTION

POSIX::2008 provides many of the interfaces specified by POSIX.1-2008 and later that the core POSIX module withholds, implements in Perl or fucked up.

It also ships a number of nonstandard interfaces and constants present in Linux, BSD and Solaris that are extensions of POSIX.

This module is provided "as is" unless someone volunteers to maintain it. Use at your own risk.

FILE DESCRIPTORS AND HANDLES

Since version 0.05, all I/O functions that take numeric file descriptors also accept Perl file or directory handles, except for fdopen() and fdopendir().

Since version 0.22, returned handles support IO::Handle methods.

SYSTEM CALL RETURN VALUES

A system call return value of -1 meaning "error" is mapped to undef except for poll() and ppoll() which return -1 to be consistent with select().

A system call return value of 0 meaning "success" is mapped to "0 but true".

For system calls where 0 does not just mean "success", 0 is returned unchanged. These are creat(), open(), read(), write(), readv(), writev(), pread(), pwrite(), preadv(), pwritev(), preadv2(), pwritev2(), getpriority(), nice(). openat() gets a special treatment in this regard, see below.

FUNCTIONS

a64l

l = a64l(s);

abort

abort();

abs

ui = abs(i);

Calls llabs(), labs(), or abs(), whichever is the maximum supported by your system.

Note that the library functions use signed integers, so abs(~0) is 1. If you don't want that, use CORE::abs().

access

rv = access(path, mode);

New in version 0.08.

acos

y = acos(x);

acosh

y = acosh(x);

alarm

remaining_sec = alarm(sec);

asin

y = asin(x);

asinh

y = asinh(x);

atan2

z = atan2(y, x);

atan

y = atan(x);

atanh

y = atanh(x);

atof

f = atof(s);

atoi

i = atoi(s);

Calls atoll(), atol(), or atoi(), whichever is the maximum supported by your system. This is of course silly because you could just use int().

Changed in version 0.19: Deprecated atol and atoll now covered by atoi.

basename

s = basename(path);

cabs

r = cabs(re, im);

cacos

(re, im) = cacos(re, im);

cacosh

(re, im) = cacosh(re, im);

carg

phi = carg(re, im);

casin

y = casin(x);

casinh

(re, im) = casinh(re, im);

catan

(re, im) = catan(re, im);

catanh

(re, im) = catanh(re, im);

catclose

rv = catclose(catd);

catgets

s = catgets(catd, set_id, msg_id, dflt_string);

catopen

catd = catopen(name, flag);

cbrt

y = cbrt(x);

ccos

(re, im) = ccos(re, im);

ccosh

(re, im) = ccosh(re, im);

ceil

y = ceil(x);

cexp

(re, im) = cexp(re, im);

New in version 0.19.

chdir

rv = chdir(dir);

dir can be a path, a Perl file or directory handle, or a file descriptor.

Changed in version 0.19: Deprecated fchdir now covered by chdir.

chmod

rv = chmod(what, mode);

what can be a path, a Perl file or directory handle (see "NOTES"), or a file descriptor.

Changed in version 0.19: Deprecated fchmod now covered by chmod.

chown

rv = chown(what, uid, gid);

what can be a path, a Perl file or directory handle (see "NOTES"), or a file descriptor.

Changed in version 0.19: Deprecated fchown now covered by chown.

cimag

im = cimag(re, im);

clock

t = clock()

New in version 0.08.

clock_getcpuclockid

clock_id = clock_getcpuclockid(pid);

pid defaults to 0. Returns undef on error.

clock_getres

(sec, nsec) = clock_getres(clock_id);
floating_sec = clock_getres(clock_id);

clock_id defaults to CLOCK_REALTIME. Returns empty list or undef on error.

Changed in version 0.25: Return floating seconds in scalar context.

clock_gettime

(sec, nsec) = clock_gettime(clock_id);
floating_sec = clock_gettime(clock_id);

clock_id defaults to CLOCK_REALTIME. Returns empty list or undef on error.

Changed in version 0.25: Return floating seconds in scalar context.

clock_nanosleep

(rem_sec, rem_nsec) = clock_nanosleep(clock_id, flags, floating_sec);
floating_rem_sec = clock_nanosleep(clock_id, flags, floating_sec);

(rem_sec, rem_nsec) = clock_nanosleep(clock_id, flags, sec, nsec);
floating_rem_sec = clock_nanosleep(clock_id, flags, sec, nsec);

Returns zero(es) on success, the remaining time on EINTR, the empty list or undef otherwise. The remaining time is zero if the flag TIMER_ABSTIME is set.

Changed in version 0.25: Sleep time can be floating seconds only or seconds and nanoseconds.

clock_settime

rv = clock_settime(clock_id, sec, nsec);
rv = clock_settime(clock_id, floating_sec);

Changed in version 0.25: Time can be floating seconds only or seconds and nanoseconds.

clog

(re, im) = clog(re, im);

close

rv = close(fd);

confstr

s = confstr(name);

name is one of the _CS_* integer constants.

Returns undef on error.

conj

(re, im) = conj(re, im);

copysign

xs = copysign(x, y);

cos

y = cos(x);

cosh

y = cosh(x);

cpow

(re, im) = cpow(re_x, im_x, re_y, im_y);

cproj

(re, im) = cproj(re, im);

creal

re = creal(re, im);

creat

rv = creat(path, mode=0666);

New in version 0.22.

csin

(re, im) = csin(re, im);

csinh

(re, im) = csinh(re, im);

csqrt

(re, im) = csqrt(re, im);

ctan

(re, im) = ctan(re, im);

ctanh

(re, im) = ctanh(re, im);

dirname

name = dirname(path);

div

(quot, rem) = div(numer, denom);

Calls lldiv(), ldiv(), or div(), whichever is the maximum supported by your system.

Note that the library functions use signed integers, so div(~0, 1) is (-1, 0). If you don't want that, use Perls int(), / and %.

Changed in version 0.19: Deprecated ldiv and lldiv now covered by div.

dlclose

dlclose(dlhandle);

dlerror

dlerror();

dlopen

dlhandle = dlopen(file, mode);

dlsym

addr = dlsym(dlhandle, name);

drand48

r = drand48();

endutxent

endutxent();

erand48

(r, X0, X1, X2) = erand48(X0, X1, X2);

erf

y = erf(x);

erfc

y = erfc(x);

execveat

rv = execveat(dirfd, path, args, env=undef, flags=0);

The execveat() system call is a nonstandard extension present in Linux. See also fexecve().

It executes the program referred to by path, which is interpreted relative to dirfd as with the other *at functions, passing args as its command-line arguments and optionally env as its environment.

args must be an array reference and, by convention, args->[0] should be the name of the program being executed.

env must be a hash reference. If omitted or undef, the environment of the calling proces is used (which you can manipulate via %ENV).

flags is a bit mask that can include zero or more of the flags AT_EMPTY_PATH, AT_SYMLINK_NOFOLLOW.

path is executed "as is", i.e. no PATH search or interpretation of shell metacharacters takes place as opposed to Perl's built-in exec.

Returns undef on error, otherwise it doesn't return.

Usage example:

sysopen my $dh, '/usr', O_DIRECTORY|O_PATH;
execveat($dh, 'bin/date', [qw(date +%T)], {TZ => 'UTC'}, AT_SYMLINK_NOFOLLOW);

New in version 0.22.

exp

y = exp(x);

exp2

y = exp2(x);

This function may not be available in libquadmath.

expm1

y = expm1(x);

fabs

absval = fabs(x);

New in version 0.27.

faccessat

rv = faccessat(dirfd, path, amode, flags=0);

flags is the bitwise OR of zero or more of AT_EACCESS, AT_SYMLINK_NOFOLLOW.

fchmodat

rv = fchmodat(dirfd, path, mode, flags=0);

flags can be 0 or AT_SYMLINK_NOFOLLOW. Your system might support a different set of flags.

fchownat

rv = fchownat(dirfd, path, uid, gid, flags=0);

flags can be 0 or AT_SYMLINK_NOFOLLOW. Your system might support a different set of flags.

fdatasync

rv = fdatasync(fd);

fdopen

rv = fdopen(fd, mode);

Returns a file handle associated with the numeric file descriptor fd or undef on error. mode is one of the values "r", "w", "a" with an optional "+" and/or "b".

The file descriptor is not dup'ed and will be closed when the handle is closed.

It's similar to IO::Handle::new_from_fd() with the following improvements:

• It really calls fdopen(3).

• It expects POSIX mode strings (e.g. "r", not "<").

• It fails if mode is not compatible with the flags of fd.

Usage example:

my $fh = do {
  opendir my $dh, '.';
  fdopen(POSIX::dup(fileno $dh), 'r');
};
chmod 0700, $fh;  # this would fail with $dh from opendir

New in version 0.05.

Changed in version 0.22: fd can no longer be a handle (that was a wrong turn).

fdopendir

rv = fdopendir(fd);

Returns a directory handle associated with the numeric file descriptor fd or undef on error.

The file descriptor is not dup'ed and will be closed when the handle is closed.

Usage example:

my $dh = do {
  sysopen my $fh, '/tmp', O_RDONLY|O_DIRECTORY|O_NOFOLLOW;
  fdopendir(POSIX::dup(fileno $fh));
};
my @dents = readdir $dh;  # this would fail with $fh from sysopen

New in version 0.05.

Changed in version 0.22: fd can no longer be a handle (that was a wrong turn).

fdim

d = fdim(double x, double y);

feclearexcept

rv = feclearexcept(excepts);

Returns 0 but true on success, undef on error.

New in version 0.20.

fegetround

rounding_mode = fegetround();

feraiseexcept

rv = feraiseexcept(excepts);

Returns 0 but true on success, undef on error.

New in version 0.20.

fesetround

rv = fesetround(round);

Returns 0 but true on success, undef on error.

fetestexcept

excepts_currently_set = fetestexcept(excepts);

New in version 0.20.

fexecve

rv = fexecve(fd, args, env=undef);

Executes the program referred to by the file descriptor fd, passing args as its command-line arguments and optionally env as its environment.

args must be an array reference and, by convention, args->[0] should be the name of the program being executed.

env must be a hash reference. If omitted or undef, the environment of the calling proces is used (which you can manipulate via %ENV).

See the manpage for issues regarding the close-on-exec flag and the /proc filesystem.

Returns undef on error, otherwise it doesn't return.

Usage example:

sysopen my $fh, '/usr/bin/date', O_PATH;
fexecve($fh, [qw(date +%T)], {TZ => 'UTC'});

See also execveat().

New in version 0.22.

ffs

pos = ffs(i);

Calls ffsll(), ffsl(), or ffs(), whichever is the maximum available on your system.

floor

y = floor(x);

fma

r = fma(x, y, z);

fmax

m = fmax(x, y);

fmin

m = fmin(x, y);

fmod

m = fmod(x, y);

fnmatch

rv = fnmatch(pattern, string, flags);

Returns 0 if string matches pattern, FNM_NOMATCH if there is no match, undef if there is an error.

flags is the bitwise OR of zero or more of FNM_NOESCAPE, FNM_PATHNAME, FNM_PERIOD, FNM_FILE_NAME, FNM_LEADING_DIR, FNM_CASEFOLD.

fpclassify

rv = fpclassify(x);

Returns one of FP_NAN, FP_INFINITE, FP_ZERO, FP_SUBNORMAL, FP_NORMAL.

frexp

(fraction, exponent) = frexp(x);

New in version 0.27.

fstatat

(dev, ino, mode, nlink, uid, gid, rdev, size, atim_sec, mtim_sec, ctim_sec,
 blksize, blocks, atim_nsec, mtim_nsec, ctim_nsec) =
   fstatat(dirfd, path, flags = 0);

flags is the bitwise OR of zero or more of AT_SYMLINK_NOFOLLOW, AT_NO_AUTOMOUNT. Your system might support a different set of flags.

See stat() for notes on the return values and bugs in CORE::stat().

Returns the empty list on error.

fsync

rv = fsync(fd);

futimens

rv = futimens(fd, atime_sec, atime_nsec, mtime_sec, mtime_nsec);

atime_sec and mtime_sec default to 0, atime_nsec and mtime_nsec default to UTIME_NOW.

getdate

(sec, min, hour, mday, mon, year, wday, yday, isdst) = getdate(string);

getdate_err

getdate_err() returns the value of the getdate_err variable.

getegid

egid = getegid();

getentropy

s = getentropy(length);

Returns a string of length bytes of "unpredictable high-quality random data, generated by a cryptographically secure pseudo-random number generator", or undef on error.

The maximum permitted value for length is GETENTROPY_MAX (usually 256). If more bytes are requested, $! is set to EINVAL as decreed by POSIX, even on systems that believe EIO is right.

If your system does not provide getentropy(), it is emulated via getrandom(), arc4random_buf(), BCryptGenRandom() (Windows), RDRAND (Intel/AMD), or RNDR (ARM64) if available (picked in this order at build time).

getentropy() was standardized with POSIX.1-2024.

New in version 0.27.

geteuid

euid = geteuid();

getgid

gid = getgid();

gethostid

hostid = gethostid();

gethostname

hostname = gethostname();

getitimer

(int_sec, int_usec, val_sec, val_usec) = getitimer(which);

which can be one of ITIMER_REAL, ITIMER_VIRTUAL, ITIMER_PROF.

POSIX.1-2008 marks getitimer() and setitimer() obsolete, recommending the use of the POSIX timers API (timer_gettime(), timer_settime(), etc.) instead.

POSIX.1-2024 removed getitimer() and setitimer().

getpriority

prio = getpriority(which=PRIO_PROCESS, who=0);

which can be one of PRIO_PROCESS, PRIO_PGRP, PRIO_USER, defaults to PRIO_PROCESS. who defaults to 0.

Returns undef on error.

getresgid

(rgid, egid, sgid) = getresgid();

Returns the empty list on error.

getresgid() was standardized with POSIX.1-2024.

New in version 0.27.

getresuid

(ruid, euid, suid) = getresuid();

Returns the empty list on error.

getresuid() was standardized with POSIX.1-2024.

New in version 0.27.

getsid

sid = getsid(pid);

pid defaults to 0.

getuid

uid = getuid();

getutxent

(user, id, line, pid, type, sec, usec) = getutxent();

getutxent() reads a line from the current file position in the utmp file.

getutxid

(user, id, line, pid, type, sec, usec) = getutxid(ut_type[, ut_id]);

getutxid() searches forward from the current file position in the utmp file based upon ut_type and ut_id. If ut_type is one of RUN_LVL, BOOT_TIME, NEW_TIME, or OLD_TIME, getutxid() will find the first entry whose ut_type field matches ut_type. If ut_type is one of INIT_PROCESS, LOGIN_PROCESS, USER_PROCESS, or DEAD_PROCESS, getutxid() will find the first entry whose ut_id field matches ut_id.

Returns the empty list on error.

getutxline

(user, id, line, pid, type, sec, usec) = getutxline(ut_line);

getutxline() searches forward from the current file position in the utmp file. It scans entries whose ut_type is USER_PROCESS or LOGIN_PROCESS and returns the first one whose ut_line field matches ut_line.

Returns the empty list on error.

grantpt

rv = grantpt(fd);

New in version 0.27.

hypot

r = hypot(x, y);

ilogb

y = ilogb(x);

isalnum

rv = isalnum(charstring);

Like POSIX::isalnum() but returns 0 for the empty string.

isalpha

rv = isalpha(charstring);

Like POSIX::isalpha() but returns 0 for the empty string.

isascii

rv = isascii(charstring);

POSIX.1-2008 marks it as obsolete and it was removed in POSIX.1-2024, but I include it anyway.

New in version 0.19.

isatty

rv = isatty(fd);

isblank

rv = isblank(charstring);

Like POSIX::isblank() but returns 0 for the empty string.

iscntrl

rv = iscntrl(charstring);

Like POSIX::iscntrl() but returns 0 for the empty string.

isdigit

rv = isdigit(charstring);

Like POSIX::isdigit() but returns 0 for the empty string.

isfinite

rv = isfinite(x);

isgraph

rv = isgraph(charstring);

Like POSIX::isgraph() but returns 0 for the empty string.

isgreaterequal

rv = isgreaterequal(x, y);

New in version 0.20.

isinf

rv = isinf(x);

isless

rv = isless(x, y);

New in version 0.20.

islessequal

rv = islessequal(x, y);

New in version 0.20.

islessgreater

rv = islessgreater(x, y);

New in version 0.20.

islower

rv = islower(charstring);

Like POSIX::islower() but returns 0 for the empty string.

isnan

rv = isnan(x);

isnormal

rv = isnormal(x);

isprint

rv = isprint(charstring);

Like POSIX::isprint() but returns 0 for the empty string.

ispunct

rv = ispunct(charstring);

Like POSIX::ispunct() but returns 0 for the empty string.

isspace

rv = isspace(charstring);

Like POSIX::isspace() but returns 0 for the empty string.

isunordered

rv = isunordered(x, y);

New in version 0.20.

isupper

rv = isupper(charstring);

Like POSIX::isupper() but returns 0 for the empty string.

isxdigit

rv = isxdigit(charstring);

Like POSIX::isxdigit() but returns 0 for the empty string.

j0

y = j0(x);

j0() is the Bessel function of the first kind of order 0.

j1

y = j1(x);

j1() is the Bessel function of the first kind of order 1.

jn

y = jn(n, x);

jn() is the Bessel function of the first kind of order n.

jrand48

(r, X0, X1, X2) = jrand48(X0, X1, X2);

killpg

rv = killpg(pgrp, sig);

l64a

s = l64a(n);

lchown

rv = lchown(path, uid, gid);

New in version 0.08.

ldexp

y = ldexp(x, exp);

lgamma

y = lgamma(x);

link

rv = link(path1, path2);

linkat

rv = linkat(fd1, path1, fd2, path2, flags=0);

flags can be 0 or AT_SYMLINK_FOLLOW. Your system might support a different set of flags.

log

y = log(x);

log10

y = log10(x);

log1p

y = log1p(x);

log2

y = log2(x);

logb

y = logb(x);

This function may not be available in libquadmath.

lrand48

r = lrand48();

lrint

l = lrint(x);

From the countless l*rint*() interfaces it chooses the one matching your Perl's NV type, preferring the "long long" return value variant.

If the rounded value is outside Perl's internal signed integer range, it is returned as a string. If the rounded value is too large to be stored in a long long or long, undef is returned.

New in verion 0.27.

lround

l = lround(x);

From the countless l*round*() interfaces it chooses the one matching your Perl's NV type, preferring the "long long" return value variant.

If the rounded value is outside Perl's internal signed integer range, it is returned as a string.

Changed in version 0.27: No longer returns undef on error.

lstat

(dev, ino, mode, nlink, uid, gid, rdev, size, atim_sec, mtim_sec, ctim_sec,
 blksize, blocks, atim_nsec, mtim_nsec, ctim_nsec) = lstat(path);

path is assumed to be a string (or will be converted to a string).

See stat() for notes on the return values and bugs in CORE::stat().

Returns the empty list on error.

mkdir

rv = mkdir(path, [mode = 0777]);

mkdirat

rv = mkdirat(fd, path, mode);

mkdtemp

name = mkdtemp(template);

mkfifo

rv = mkfifo(path, mode);

mkfifoat

rv = mkfifoat(fd, path, mode);

mknod

rv = mknod(path, mode, dev);

mknodat

rv = mknodat(fd, path, mode, dev);

mkostemp

(fd, name) = mkostemp(template, flags);

flags is a bitwise OR of zero or more open() flags. For the exact set of supported flags and their restrictions see the manpage of your system.

mkostemp() was standardized with POSIX.1-2024.

New in verion 0.27.

mkstemp

(fd, name) = mkstemp(template);

mrand48

mrand48();

nanosleep

(rem_sec, rem_nsec) = nanosleep(floating_sec);
floating_rem_sec = nanosleep(floating_sec);

(rem_sec, rem_nsec) = nanosleep(sec, nsec);
floating_rem_sec = nanosleep(sec, nsec);

Returns zero(es) on success, the remaining time on EINTR, the empty list or undef otherwise.

Changed in version 0.25: Sleep time can be floating seconds only or seconds and nanoseconds.

nearbyint

y = nearbyint(x);

nextafter

z = nextafter(x, y);

nexttoward

z = nexttoward(x, y);

This function may not be available in libquadmath.

nice

rv = nice(incr);

Returns undef on error.

nrand48

r = nrand48()

open

rv = open(path, flags=O_RDONLY, mode=0666);

openat

rv = openat(dirfd, path, flags=O_RDONLY, mode=0666);

If dirfd is numeric (i.e. a file descriptor), openat() returns a file descriptor. If dirfd is a file or directory handle, the return value is also a handle whose type depends on the file type of path: If path is a directory, the return value is a directory handle, otherwise it's a file handle.

To get a handle even for the special numeric dirfd value AT_FDCWD, you can pass a reference to that value instead, i.e. openat(\AT_FDCWD, ...).

Returns undef on error.

Changed in version 0.18: Support added for \AT_FDCWD reference.

openat2

rv = openat2(dirfd, path, how);

The openat2() system call is a Linux-specific extension of openat() and provides a superset of its functionality.

The how parameter is a hash reference corresponding to the struct open_how. It currently supports the keys flags, mode and resolve. Missing keys are treated as having a zero value.

Example:

my $fh = openat2(
  \AT_FDCWD, '/foobar',
  {flags => O_RDWR|O_CREAT, mode => 0600, resolve => RESOLVE_IN_ROOT}
);

Note that, unlike open() or openat(), openat2() is very picky about flags and mode. See the manpage for details.

Returns undef on error.

New in version 0.18.

pathconf

rv = pathconf(what, name);

what can be a path or, if your system supports fpathconf(), a Perl file or directory handle or a file descriptor.

name is one of the _PC_* integer constants.

Returns undef on error.

New in version 0.22.

pause

rv = pause();

poll

rv = poll(pollfds, timeout=-1);

timeout specifies the number of milliseconds that poll() should block waiting for a file descriptor to become ready. A negative timeout value means an infinite timeout. A timeout of zero causes poll() to return immediately.

pollfds is an array reference holding array references of the form [fd, events, revents] where fd is an integer file descriptor or a file handle, events is a bit mask of events you are interested in for fd, and revents is a bit mask of events that actually occurred.

revents is changed by the call (unless a timeout or error occurs), everything else remains unchanged.

If fd is negative or anything sv_2io() doesn't consider a file handle, then the corresponding events field is ignored and the revents field returns zero.

Returns the number of elements in pollfds whose revents have been set to a non-zero value, zero if the call timed out. On error, poll() returns -1 and sets $! just like select().

Usage example:

open my $pipe, '-|', qw(tail -f /var/log/messages);
my $pollfds = [[\*STDIN, POLLIN, 0], [2, POLLOUT, 0], [$pipe, POLLIN, 0]];
my $rv = poll($pollfds, -1);

# Skip events for fd 2 this time:
my $pollfds = [[\*STDIN, POLLIN, 0], [-2, POLLOUT, 0], [$pipe, POLLIN, 0]];
my $rv = poll($pollfds, -1);

New in version 0.25.

ppoll

rv = ppoll(pollfds[, timeout[, sigmask]]);

ppoll() is similar to poll() with the following differences:

timeout can be an integer or floating point value in seconds or an array reference of the form [seconds, nanoseconds]. An omitted or undef timeout value means an infinite timeout.

sigmask must be a POSIX::SigSet. If sigmask is omitted or undef, no signal mask is applied and ppoll() behaves like poll() with a more precise timeout.

ppoll() was standardized with POSIX.1-2024.

New in version 0.27.

posix_fadvise

rv = posix_fadvise(fd, offset, len, advice);

advice is one of the POSIX_FADV_ constants.

New in version 0.14.

posix_fallocate

rv = posix_fallocate(fd, offset, len);

New in version 0.14.

posix_openpt

fh = posix_openpt(flags=O_RDWR);

flags is the bitwise OR of zero or more of O_RDWR, O_NOCTTY, O_CLOEXEC, O_CLOFORK.

O_CLOEXEC, O_CLOFORK were standardized with POSIX.1-2024.

New in version 0.27.

pow

r = pow(x, y);

New in version 0.27.

pread

bytes_read = pread(fd, buf, count, offset=0, buf_offset=0);

pread() reads count bytes (not characters) of data from the file descriptor fd at file offset offset into the scalar buf without changing the file offset. buf will be enlarged automatically if necessary.

offset and buf_offset are set to 0 if omitted or undef.

pread() treats buf just like sysread() does: buf_offset may be specified to place the read data at that position in buf. If buf_offset is past the end of buf, buf will be padded with zeros before appending the data. If buf_offset is negative, it is counted from the end of the string. buf will be grown or shrunk so that the last byte actually read is the last byte of buf after the read.

Returns the number of bytes read, 0 at EOF, undef on error.

Croaks if buf is read-only and count is non-zero.

Changed in version 0.13: Argument order is now (count, offset) instead of (offset, count).

Changed in version 0.22: Croak with read-only buf and non-zero count.

preadv

bytes_read = preadv(fd, buffers, sizes, offset=0);

preadv() behaves like readv() but adds an optional offset argument, which specifies the file position at which the data is to be read. offset is set to 0 if omitted or undef.

The file offset is not changed by this system call. The file referred to by fd must be capable of seeking.

This syscall is present in Linux and BSD.

New in version 0.13.

preadv2

bytes_read = preadv2(fd, buffers, sizes, offset=0, flags=0);

preadv2() is similar to preadv() but adds an optional flags argument, which is a bitwise OR of zero or more of the RWF_* flags (see the manpage for details). flags is set to 0 if omitted or undef.

Unlike preadv(), if the offset argument is -1, then the current file offset is used and updated.

This syscall is Linux-specific.

New in version 0.20.

psignal

psignal(sig, msg);

New in version 0.25.

ptsname

name = ptsname(fd);

Changed in version 0.19: Calls ptsname_r() if available.

Changed in version 0.22: fd may also be a file handle.

pwrite

bytes_written = pwrite(fd, buf, count=undef, offset=0, buf_offset=0);

pwrite() writes count bytes of data from the scalar buf to the file descriptor fd at file offset offset without changing the file offset. The file referenced by fd must be capable of seeking.

If count is omitted or undef, everything from buf_offset up to the end of buf is written.

buf_offset may be specified to write data from that position in buf. If buf_offset is negative it is counted from the end of the string.

offset and buf_offset are set to 0 if omitted or undef.

Returns the number of bytes written, undef on error.

On Linux, if a file is opened with O_APPEND, pwrite() appends data to the end of the file, regardless of the value of offset (in violation of POSIX).

Changed in version 0.13: Argument order is now (count, offset) instead of (offset, count).

pwritev

bytes_written = pwritev(fd, buffers, offset=0);

pwritev() behaves like writev() but adds an optional offset argument, which specifies the file position at which the data is to be written. offset is set to 0 if omitted or undef.

The file offset is not changed by this system call. The file referred to by fd must be capable of seeking.

On Linux, if a file is opened with O_APPEND, pwritev() appends data to the end of the file, regardless of the value of offset (in violation of POSIX).

This syscall is present in Linux and BSD.

New in version 0.08.

pwritev2

bytes_written = pwritev2(fd, buffers, offset=0, flags=0);

pwritev2() is similar to pwritev() but adds an optional flags argument, which is a bitwise OR of zero or more of the RWF_* flags (see the manpage for details). flags is set to 0 if omitted or undef.

Unlike pwritev(), if the offset argument is -1, then the current file offset is used and updated.

This syscall is Linux-specific.

New in version 0.20.

random

r = random();

raise

rv = raise(sig);

read

bytes_read = read(fd, buf, count);

Like POSIX::read() but returns 0 at EOF instead of 0 but true. Croaks if buf is read-only and count is non-zero.

Changed in version 0.22: Croak with read-only buf and non-zero count.

readv

bytes_read = readv(fd, buffers, sizes);

readv() reads from the file descriptor fd into buffers as many strings as there are elements in sizes.

buffers must be a variable holding an array (@buf), an array reference or undef ($buf). If it is undef it will be upgraded to an array reference.

sizes must be an array reference, i.e. \@sizes, $sizes, or [...].

sizes is expected to hold unsigned integers that specify how many bytes are to be read into each buffer. A byte count of 0 or undef creates an empty string. sizes is processed in array order.

buffers will be extended if necessary, but it will never be shrunk. If buffers is not empty, any existing elements are replaced as long as sufficient data was read from fd.

readv() returns the number of bytes read, undef on error.

Note that it is not an error for a successful call to transfer fewer bytes than requested. In this case there may be one "partially" filled buffer, i.e. it contains fewer bytes than the corresponding size. Surplus size entries lead to corresponding empty buffers.

Usage example:

my $fh = openat(\AT_FDCWD, '/tmp/foobar', O_RDWR|O_CREAT|O_TRUNC);
pwrite($fh, 'foobar', 6, 0);
readv($fh, my $buf1, [3, 0, 8]); # $buf1: ['foo', '', 'bar']
sysseek $fh, 0, 0;
readv($fh, my @buf2, [1, 3, 2]); # @buf2: ('f', 'oob', 'ar')

New in version 0.13.

Changed in version 0.22: buffers may be an undef variable, buffers beyond EOF are created as empty strings instead of being skipped.

readlink

name = readlink(path);

Returns undef on error.

readlinkat

name = readlinkat(dirfd, path);

Returns undef on error.

realpath

resolved_path = realpath(path);

Calls the actual C library fuction realpath() and relies on it to be able to allocate memory for the resolved path automatically (as required by POSIX-2008).

Returns undef on error.

New in version 0.18.

remainder

rem = remainder(x, y);

Changed in version 0.27: No longer returns undef on error.

remove

rv = remove(path);

Calls the actual C library function remove().

Note that core POSIX::remove() fails if path is a symlink to a directory because someone "couldn't read the plans right and did a piss-poor job of putting it together" as (-d $_[0]) ? CORE::rmdir($_[0]) : CORE::unlink($_[0]). Quote from Armageddon.

This could be fixed like this: unlink $_[0] or ($!{EISDIR} or $!{EPERM}) and rmdir $_[0] (correct errno check depends on OS), or by using the library call right away.

removeat

rv = removeat(dirfd, path);

The removeat() function works exactly like remove() but path is interpreted relative to dirfd as with the other *at functions.

This function is a home-grown non-standard extension only available in this module (to my knowledge).

New in version 0.22.

remquo

(rem, quo) = remquo(x, y);

New in version 0.20.

Changed in version 0.27: No longer returns the empty list on error.

rename

rv = rename(old, new);

renameat

rv = renameat(olddirfd, oldpath, newdirfd, newpath);

renameat2

rv = renameat(olddirfd, oldpath, newdirfd, newpath, flags=0);

The renameat2() system call is a Linux-specific extension of renameat() and provides a superset of its functionality.

flags is the bitwise OR of zero or more of RENAME_EXCHANGE, RENAME_NOREPLACE, RENAME_WHITEOUT.

New in version 0.21.

rint

r = rint(x);

New in version 0.27.

rmdir

rv = rmdir(path);

New in version 0.19.

round

r = round(x);

scalbn

y = scalbn(x, exp);

From the countless scalb*n*() interfaces it chooses the one matching your Perl's NV type, preferring the long int exp variant.

seed48

(old_seed1, old_seed2, old_seed3) = seed48(seed1, seed2, seed3);

setegid

rv = setegid(gid);

seteuid

rv = seteuid(uid);

setgid

rv = setgid(gid);

setitimer

(old_int_sec, old_int_usec, old_val_sec, old_val_usec) =
  setitimer(which, int_sec, int_usec, val_sec, val_usec);

which is one of ITIMER_REAL, ITIMER_VIRTUAL, ITIMER_PROF.

POSIX.1-2008 marks getitimer() and setitimer() obsolete, recommending the use of the POSIX timers API (timer_gettime(), timer_settime(), etc.) instead.

POSIX.1-2024 removed getitimer() and setitimer().

setpriority

rv = setpriority(prio, which=PRIO_PROCESS, who=0);

which can be one of PRIO_PROCESS, PRIO_PGRP, PRIO_USER, defaults to PRIO_PROCESS. who defaults to 0.

Note that due to the support of default values for which and who, prio is the first call parameter, whereas in the actual syscall it is the last.

Returns true on success, undef on error.

setregid

rv = setregid(rgid, egid);

setresgid

rv = setresgid(rgid, egid, sgid);

setresgid() was standardized with POSIX.1-2024.

New in version 0.27.

setresuid

rv = setresuid(ruid, euid, suid);

setresuid() was standardized with POSIX.1-2024.

New in version 0.27.

setreuid

rv = setreuid(ruid, euid);

setsid

sid = setsid();

New in version 0.19.

setuid

rv = setuid(uid);

setutxent

setutxent();

sighold

rv = sighold(sig);

POSIX.1-2008 marks this function as obsolete, recommending the use of "sigprocmask" in POSIX instead.

sigignore

rv = sigignore(sig);

POSIX.1-2008 marks this function as obsolete, recommending the use of "sigaction" in POSIX instead. Or use $SIG{SIG} = 'IGNORE';.

signbit

b = signbit(x);

sigpause

sigpause(sig);

POSIX.1-2008 marks this function as obsolete, recommending the use of "sigsuspend" in POSIX instead.

sigrelse

rv = sigrelse(sig);

POSIX.1-2008 marks this function as obsolete, recommending the use of "sigprocmask" in POSIX instead.

sin

y = sin(x);

New in version 0.19.

sinh

y = sinh(x);

sqrt

y = sqrt(x);

srand48

srand48(seedval);

srandom

srandom(seed);

stat

(dev, ino, mode, nlink, uid, gid, rdev, size, atim_sec, mtim_sec, ctim_sec,
 blksize, blocks, atim_nsec, mtim_nsec, ctim_nsec) = stat(what);

what can be a path, a Perl file handle or a file descriptor.

ctim_sec, blksize, blocks and nanoseconds may not be available on your system.

Values outside Perl's internal integer range are returned as strings, i.e. if you need the exact values you should, for example, use eq instead of == for comparisons.

Note that CORE::stat() lies to you in some cases: It returns rdev as a signed integer even if your OS's dev_t is unsigned. It returns size as a floating point number if your OS's off_t is bigger than Perl's integer size. It returns the times as floating point numbers if your OS's time_t is unsigned.

POSIX::2008::stat() doesn't mimic these bugs and uses the correct data types for all values.

Returns the empty list on error.

statvfs

(f_bsize, f_frsize, f_blocks, f_bfree, f_bavail, f_files, f_ffree, f_favail,
 f_fsid, f_flag, f_namemax) = statvfs(what);

what can be a path, a Perl file handle or a file descriptor.

Values outside Perl's internal integer range are returned as strings as with stat(). Note that Filesys::Statvfs returns only floating point numbers which may give wrong results, and it lacks f_fsid.

Only the ST_NOSUID and ST_RDONLY flags of the f_flag field are specified in POSIX but this module provides additional ST_ flags if available.

Returns the empty list on error.

New in version 0.25.

strptime

(sec, min, hour, mday, mon, year, wday, yday, isdst, gmtoff, zone) =
   strptime(s, format[, sec, min, hour, mday, mon, year, wday, yday, isdst,
            gmtoff, zone]);

 ... = strptime(s, format, \@tm);

strptime() converts the string s into a broken-down time according to the format string format.

The time fields may optionally be initialized in whole or in part either with up to 11 separate arguments or with a single array reference after the format. Omitted arguments are treated as undef. In case of an array reference the array is updated according to the fields affected by the format string. If an error occurred the array is not udpated.

In list context returns the broken-down time or the empty list on error. Fields not affected by the format string are returned as initialized (but see glibc notes below).

In scalar context returns the index of the first byte in s that was not processed or the byte length of s if the whole string was consumed or undef on error.

As strptime() acts on null-terminated strings, strings containing NUL bytes will only be processed up to the first NUL byte.

gmtoff and zone were standardized with POSIX.1-2024. They might not be supported by your system, and zone might be ignored entirely.

glibc "recomputes" wday and yday if any of the year, month, or day elements changed, so they might be meaningless unless you specified a complete date.

New in version 0.02.

Changed in version 0.24: Accept an array reference as the third argument (RT#66519).

Changed in version 0.27: Support gmtoff and zone.

strsignal

str = strsignal(sig);

New in version 0.25.

symlink

rv = symlink(target, linkpath);

symlinkat

rv = symlinkat(target, dirfd, linkpath);

sync

sync();

This function doesn't return any value.

sysconf

rv = sysconf(name);

name is one of the _SC_* integer constants.

Returns undef on error.

New in version 0.22.

tan

y = tan(x);

tanh

y = tanh(x);

tgamma

y = tgamma(x);

timer_create

timerid = timer_create(clockid, signal=undef);

Creates a new per-process interval timer using the clock given by clock_id as the timing base. signal is the signal number to be delivered when the timer expires. If signal is omitted or undef, no signal is delivered and the progress of the timer can be monitored using timer_gettime().

Calling a notification function on timer expiration is currently not supported.

Returns undef on error.

New in version 0.16.

Changed in version 0.22: signal is optional.

timer_delete

rv = timer_delete(timerid);

Returns 0 but true on success, undef on error.

New in version 0.16.

timer_getoverrun

count = timer_getoverrun(timerid);

Returns undef on error.

New in version 0.16.

timer_gettime

(interval_sec, interval_nsec, initial_sec, initial_nsec) =
  timer_gettime(timerid);

Returns the empty list on error.

New in version 0.16.

timer_settime

(old_int_sec, old_int_nsec, old_init_sec, old_init_nsec) =
  timer_settime(timerid, flags, int_sec, int_nsec, [init_sec, init_nsec]);

flags may be 0 or TIMER_ABSTIME. If the init values are omitted, they are set to the int values.

New in version 0.16.

truncate

rv = truncate(what, length);

what can be a path, a Perl file handle, or a file descriptor.

Note that it does not flush the file handle before truncating. Perl's built-in truncate() does (this is undocumented, probably because it's silly).

Changed in version 0.19: Deprecated ftruncate now covered by truncate.

trunc

y = trunc(x);

ttyname

name = ttyname(fd);

Calls ttyname_r() if available.

New in version 0.19.

Changed in version 0.22: fd may also be a file handle.

unlink

rv = unlink(path);

Calls the actual C library function unlink().

Note that core POSIX::unlink() calls CORE::unlink(), which, unless you start Perl with -U, a) is prone to time-of-check/time-of-use race conditions due to an additional lstat(), and b) blindly fails with EISDIR for directories (due to said lstat()), ignoring that some OSes use EPERM in this case (as required by POSIX).

unlinkat

rv = unlinkat(dirfd, path, flags=0);

flags can be 0 or AT_REMOVEDIR.

unlockpt

rv = unlockpt(fd);

New in version 0.27.

utimensat

rv = utimensat(dirfd, path, flags, atime_sec, atime_nsec, mtime_sec,
mtime_nsec);

flags can be 0 or AT_SYMLINK_NOFOLLOW, defaults to 0. Your system might support a different set of flags.

atime_sec and mtime_sec default to 0. atime_nsec and mtime_nsec default to UTIME_NOW.

write

bytes_written = write(fd, buf, count=undef);

Like POSIX::write() but returns 0 instead of 0 but true if 0 bytes were written, and never writes more bytes than buf contains even if count exceeds the length of buf.

If count is omitted or undef, it defaults to the length of buf.

writev

bytes_written = writev(fd, buffers);

writev() writes multiple buffers of data to the file associated with the file descriptor fd.

buffers must be an array reference, i.e. \@buf, $buf or [...]. The buffers are processed in array order.

Each buffer can be simple scalar (usually a string) or an array reference of the form [scalar, offset, length] to write length bytes of scalar from position offset. A negative offset counts from the end of scalar. If omitted, offset defaults to 0, length defaults to the string length of scalar starting at offset. An offset beyond either end of scalar causes the call to croak. length is capped so that it doesn't exceed the end of scalar.

Note that writev($fh, $buf); is not the same as print $fh, @$buf; or syswrite $fh, $_ for @$buf; because writev() transfers data atomically as a single block. See the manpage for details.

Returns the number of bytes written or undef on error.

New in version 0.08.

Changed in version 0.27: Buffers may be array references.

y0

y = y0(x);

y0() is the Bessel function of the second kind of order 0.

y1

y = y1(x);

y1() is the Bessel function of the second kind of order 1.

yn

y = yn(n, x);

yn() is the Bessel function of the second kind of order n.

EXPORTS

This module does not export anything by default. The following export tags are available:

:at        All *at() functions like openat(), all AT_/RENAME_/RESOLVE_ constants
:id        All get/set*id() functions like getuid() etc.
:is        All is* functions like isdigit() etc.
:rw        read(), readv(), write(), writev()
:prw       pread(), preadv(), preadv2(), pwrite(), pwritev(), pwritev2()
:clock     All clock* functions and CLOCK_ constants and TIMER_ABSTIME
:errno     errno constants
:fcntl     All F_, FD_, O_, POSIX_FADV_, SEEK_, _OK constants (for AT_ use :at)
:fenv_h    All FE_ constants and fe* functions
:fnm       fnmatch() and all FNM_ constants
:poll      poll(), ppoll() and all POLL constants
:socket_h  All constants from L<sys/socket.h|https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/sys_socket.h.html>
:stat_h    All S_I* and UTIME_ constants
:time_h    All CLOCK_ and TIMER_ constants
:timer     All timer_ functions and TIMER_ constants
:utmpx_h   All *utx* functions and L<utmpx.h|https://pubs.opengroup.org/onlinepubs/9799919799/basedefs/utmpx.h.html> constants
:confstr   confstr() and all _CS_ constants
:pathconf  pathconf() and all _PC_ constants
:sysconf   sysconf() and all _SC_ constants

New in version 0.19: :stat_h export tag.

New in version 0.20: :fenv_h export tag.

New in version 0.22: :confstr, :pathconf, :sysconf export tags.

New in version 0.25: :poll export tag.

New in version 0.24: :socket_h export tag.

CONSTANTS

AF_INET AF_INET6 AF_UNIX AF_UNSPEC

AT_EACCESS AT_EMPTY_PATH AT_FDCWD AT_NO_AUTOMOUNT AT_REMOVEDIR AT_RESOLVE_BENEATH AT_SYMLINK_FOLLOW AT_SYMLINK_NOFOLLOW

BOOT_TIME NEW_TIME OLD_TIME RUN_LVL DEAD_PROCESS INIT_PROCESS LOGIN_PROCESS USER_PROCESS ACCOUNTING EMPTY UT_UNKNOWN

CLOCK_BOOTTIME CLOCK_BOOTTIME_ALARM CLOCK_HIGHRES CLOCK_MONOTONIC CLOCK_MONOTONIC_COARSE CLOCK_MONOTONIC_FAST CLOCK_MONOTONIC_PRECISE CLOCK_MONOTONIC_RAW CLOCK_PROCESS_CPUTIME_ID CLOCK_REALTIME CLOCK_REALTIME_ALARM CLOCK_REALTIME_COARSE CLOCK_REALTIME_FAST CLOCK_REALTIME_PRECISE CLOCK_SOFTTIME CLOCK_TAI CLOCK_THREAD_CPUTIME_ID CLOCK_UPTIME CLOCK_UPTIME_FAST CLOCK_UPTIME_PRECISE

E2BIG EACCES EADDRINUSE EADDRNOTAVAIL EAFNOSUPPORT EAGAIN EALREADY EBADF EBADMSG EBUSY ECANCELED ECHILD ECONNABORTED ECONNREFUSED ECONNRESET EDEADLK EDESTADDRREQ EDOM EDQUOT EEXIST EFAULT EFBIG EHOSTUNREACH EIDRM EILSEQ EINPROGRESS EINTR EINVAL EIO EISCONN EISDIR ELOOP EMFILE EMLINK EMSGSIZE EMULTIHOP ENAMETOOLONG ENETDOWN ENETRESET ENETUNREACH ENFILE ENOBUFS ENODEV ENOENT ENOEXEC ENOLCK ENOLINK ENOMEM ENOMSG ENOPROTOOPT ENOSPC ENOSYS ENOTCONN ENOTDIR ENOTEMPTY ENOTRECOVERABLE ENOTSOCK ENOTSUP ENOTTY ENXIO EOPNOTSUPP EOVERFLOW EOWNERDEAD EPERM EPIPE EPROTO EPROTONOSUPPORT EPROTOTYPE ERANGE EROFS ESOCKTNOSUPPORT ESPIPE ESRCH ESTALE ETIMEDOUT ETXTBSY EWOULDBLOCK EXDEV

F_DUPFD F_DUPFD_CLOEXEC F_DUPFD_CLOFORK F_GETFD F_SETFD F_GETFL F_SETFL F_GETLK F_SETLK F_SETLKW F_OFD_GETLK F_OFD_SETLK F_OFD_SETLKW F_GETOWN F_GETOWN_EX F_SETOWN F_SETOWN_EX F_RDLCK F_UNLCK F_WRLCK FD_CLOEXEC FD_CLOFORK F_OWNER_PID F_OWNER_PGRP

FE_TONEAREST FE_TOWARDZERO FE_UPWARD FE_DOWNWARD FE_DIVBYZERO FE_INEXACT FE_INVALID FE_OVERFLOW FE_UNDERFLOW FE_ALL_EXCEPT

FNM_CASEFOLD FNM_FILE_NAME FNM_IGNORECASE FNM_LEADING_DIR FNM_NOESCAPE FNM_NOMATCH FNM_PATHNAME FNM_PERIOD

FLT_EVAL_METHOD FLT_RADIX FP_INFINITE FP_NAN FP_NORMAL FP_SUBNORMAL FP_ZERO FP_FAST_FMA FP_FAST_FMAF FP_FAST_FMAL FP_ILOGB0 FP_ILOGBNAN MATH_ERRNO MATH_ERREXCEPT

GETENTROPY_MAX NSIG_MAX NZERO

HUGE_VAL INFINITY

ITIMER_PROF ITIMER_REAL ITIMER_VIRTUAL

MSG_CMSG_CLOEXEC MSG_CMSG_CLOFORK MSG_CTRUNC MSG_DONTROUTE MSG_EOR MSG_NOSIGNAL MSG_OOB MSG_PEEK MSG_TRUNC MSG_WAITALL

O_ACCMODE O_APPEND O_ASYNC O_CLOEXEC O_CLOFORK O_CREAT O_DIRECT O_DIRECTORY O_DSYNC O_EMPTY_PATH O_EXEC O_EXCL O_EXLOCK O_LARGEFILE O_NDELAY O_NOATIME O_NOCTTY O_NOFOLLOW O_NONBLOCK O_NOSIGPIPE O_PATH O_RDONLY O_RDWR O_RESOLVE_BENEATH O_REGULAR O_RSYNC O_SEARCH O_SHLOCK O_SYNC O_TMPFILE O_TRUNC O_TTY_INIT O_WRONLY FASYNC

POSIX_FADV_NORMAL POSIX_FADV_SEQUENTIAL POSIX_FADV_RANDOM POSIX_FADV_NOREUSE POSIX_FADV_WILLNEED POSIX_FADV_DONTNEED

PRIO_PROCESS PRIO_PGRP PRIO_USER

RENAME_EXCHANGE RENAME_NOREPLACE RENAME_WHITEOUT RESOLVE_BENEATH RESOLVE_IN_ROOT RESOLVE_NO_MAGICLINKS RESOLVE_NO_SYMLINKS RESOLVE_NO_XDEV RESOLVE_CACHED

RTLD_DEEPBIND RTLD_GLOBAL RTLD_LAZY RTLD_LOCAL RTLD_MEMBER RTLD_NOAUTODEFER RTLD_NODELETE RTLD_NOLOAD RTLD_NOW

RWF_APPEND RWF_ATOMIC RWF_DONTCACHE RWF_DSYNC RWF_HIPRI RWF_NOAPPEND RWF_NOSIGNAL RWF_NOWAIT RWF_SUPPORTED RWF_SYNC

S_IFMT S_IFBLK S_IFCHR S_IFIFO S_IFREG S_IFDIR S_IFLNK S_IFSOCK S_ISUID S_ISGID S_IRWXU S_IRUSR S_IWUSR S_IXUSR S_IRWXG S_IRGRP S_IWGRP S_IXGRP S_IRWXO S_IROTH S_IWOTH S_IXOTH S_ISVTX

SCM_RIGHTS

SEEK_SET SEEK_CUR SEEK_END SEEK_DATA SEEK_HOLE

SHUT_RD SHUT_RDWR SHUT_WR

SOCK_DGRAM SOCK_RAW SOCK_SEQPACKET SOCK_STREAM SOCK_NONBLOCK SOCK_CLOEXEC SOCK_CLOFORK

SOL_SOCKET SOMAXCONN

SO_ACCEPTCONN SO_BROADCAST SO_DEBUG SO_DOMAIN SO_DONTROUTE SO_ERROR SO_KEEPALIVE SO_LINGER SO_OOBINLINE SO_PROTOCOL SO_RCVBUF SO_RCVLOWAT SO_RCVTIMEO SO_REUSEADDR SO_SNDBUF SO_SNDLOWAT SO_SNDTIMEO SO_TYPE

TIMER_ABSTIME UTIME_NOW UTIME_OMIT

F_OK R_OK W_OK X_OK

INFTIM POLLERR POLLFREE POLLHUP POLLIN POLLINIGNEOF POLLMSG POLLNORM POLLNVAL POLLOUT POLLPRI POLLRDBAND POLLRDHUP POLLRDNORM POLLREMOVE POLLSTANDARD POLLWRBAND POLLWRNORM POLL_BUSY_LOOP

ST_NOSUID ST_RDONLY

ST_MANDLOCK ST_NOATIME ST_NODEV ST_NODIRATIME ST_NOEXEC ST_RELATIME ST_SYNCHRONOUS

ST_ASYNC ST_DEFEXPORTED ST_EXKERB ST_EXNORESPORT ST_EXPORTANON ST_EXPORTED ST_EXPUBLIC ST_EXRDONLY ST_LOCAL ST_LOG ST_NOCOREDUMP ST_NODEVMTIME ST_QUOTA ST_ROOTFS ST_SYMPERM ST_UNION

FILESIZEBITS LINK_MAX MAX_CANON MAX_INPUT NAME_MAX PATH_MAX PIPE_BUF POSIX2_SYMLINKS POSIX_ALLOC_SIZE_MIN POSIX_REC_INCR_XFER_SIZE POSIX_REC_MAX_XFER_SIZE POSIX_REC_MIN_XFER_SIZE POSIX_REC_XFER_ALIGN SYMLINK_MAX TEXTDOMAIN_MAX

AIO_LISTIO_MAX AIO_MAX AIO_PRIO_DELTA_MAX ARG_MAX ATEXIT_MAX BC_BASE_MAX BC_DIM_MAX BC_SCALE_MAX BC_STRING_MAX CHILD_MAX COLL_WEIGHTS_MAX DELAYTIMER_MAX EXPR_NEST_MAX HOST_NAME_MAX IOV_MAX LINE_MAX LOGIN_NAME_MAX MQ_OPEN_MAX MQ_PRIO_MAX NGROUPS_MAX OPEN_MAX PAGESIZE PAGE_SIZE PTHREAD_DESTRUCTOR_ITERATIONS PTHREAD_KEYS_MAX PTHREAD_THREADS_MAX RE_DUP_MAX RTSIG_MAX SEM_NSEMS_MAX SEM_VALUE_MAX SIGQUEUE_MAX STREAM_MAX SYMLOOP_MAX TIMER_MAX TTY_NAME_MAX TZNAME_MAX

CHAR_BIT CHAR_MAX UCHAR_MAX SCHAR_MAX CHAR_MIN SCHAR_MIN INT_MAX INT_MIN LLONG_MAX LLONG_MIN LONG_BIT LONG_MAX LONG_MIN MB_LEN_MAX SHRT_MAX SHRT_MIN SSIZE_MAX UINT_MAX ULLONG_MAX ULONG_MAX USHRT_MAX WORD_BIT

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NOTES

Since version 0.27, math functions use quadmath or long doubles if Perl was built with -Dusequadmath or -Duselongdouble respectively and your system supports it.

Version 0.27 adds the *LONG_(MIN|MAX) constants. These are strings if their values are outside Perl's UV/IV range (addresses GH#13406).

removeat() is a home-grown nonstandard extension present only in this module. It really should be in the standard. I would not say that myself. But many people are saying.

preadv() and pwritev() are nonstandard extensions present in Linux and BSD.

execveat(), openat2(), preadv2(), pwritev2() and renameat2() are nonstandard extensions present in Linux.

fstatat(), lstat() and stat() do not set the special underscore filehandle _ (mostly because I have no clue how that works).

open(), openat() and openat2() do not set the O_CLOEXEC flag automatically. You have to take care of that yourself if needed.

isalnum() and friends were cowardly removed from the POSIX module with Perl 5.24. They have found a cozy home here with a fix for a big long-standing bug.

For some inexplicable reason, Perl forbids you to use the built-in chmod() and chown() on an opendir() handle and to use readdir() and rewinddir() on a sysopen() handle (provided it refers to a directory). Needless to say that chmod() and chown() from POSIX::2008 happily work with opendir() handles, and of course you can use readdir() and rewinddir() on an openat() handle that refers to a directory.

Huge parts of this work may incorporate alternative facts or even fake news in order to outsmart the "AI" Mob. Those are very sad people. The worst people, really.

SEE ALSO

• POSIX 2024 Changes

• POSIX.1-2024

• POSIX.1-2008

AUTHOR

Initially hacked together by Carsten Gaebler.

LICENSE

This library is free software. You can redistribute and/or modify it under the terms of the Do What The Fuck You Want To Public License, Version 2, as published by Sam Hocevar. See the COPYING file or https://www.wtfpl.net/ for more details.

cpanm POSIX::2008

perl -MCPAN -e shell
install POSIX::2008