NAME¶

SYNOPSIS¶

  use Fcntl;
  use POSIX::2008 qw(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¶

This module is provided "as is" unless someone volunteers to maintain it.

INCOMPATIBLE PARAMETER CHANGE¶

FILE DESCRIPTORS AND HANDLES¶

SYSTEM CALL RETURN VALUES¶

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 "open()", "read()", "write()", "readv()", "writev()", "pread()", "pwrite()", "preadv()", "pwritev()". "openat()" gets a special treatment in this module, see below.

FUNCTIONS¶

a64l

l = a64l(s);

abort

abort();

abs

ui = abs(i);

access

ret = access(path, mode);

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);

atol

l = atol(s);

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);

casinh

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

catan

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

catanh

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

catclose

ret = catclose(catd);

catgets

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

catopen

catd = catopen(name, oflag);

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);

chdir

ret = chdir(path);

chmod

ret = chmod(path, mode);

chown

ret = chown(path, uid, gid);

cimag

im = cimag(re, im);

clock

t = clock()

clock_getcpuclockid

clock_id = clock_getcpuclockid(pid);

pid defaults to $$. Returns undef on error.

clock_getres

(sec, nsec) = clock_getres(clock_id);

clock_id defaults to CLOCK_REALTIME. Returns empty list on error.

clock_gettime

(sec, nsec) = clock_gettime(clock_id);

clock_id defaults to CLOCK_REALTIME. Returns empty list on error.

clock_nanosleep

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

In scalar context returns the remaining seconds as a floating point number.

clock_settime

ret = clock_settime(clock_id, sec, nsec);

clog

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

close

ret = close(fd);

confstr

s = confstr(name);

name is one of the _CS_ integer constants.

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);

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);

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);

exp2

y = exp2(x);

expm1

y = expm1(x);

faccessat

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

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

fchdir

ret = fchdir(dirfd);

fchmod

ret = fchmod(fd, mode);

fchmodat

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

flags can be 0 or AT_SYMLINK_NOFOLLOW.

fchown

ret = fchown(fd, uid, gid);

fchownat

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

flags can be 0 or AT_SYMLINK_NOFOLLOW.

fdatasync

ret = fdatasync(fd);

fdopen

ret = fdopen(fd, mode)

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

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

fdopendir

ret = fdopendir(fd)

Returns a directory handle associated with the file descriptor fd or undef on error. Usage example:

  my $dh = do {
    sysopen my $fh, '/tmp', O_RDONLY|O_DIRECTORY|O_NOFOLLOW;
    fdopendir($fh); # or fdopendir(fileno $fh) but the former also works
                    # with handles from opendir() for which fileno does
                    # not work before Perl 5.22
  };
  my @files = readdir $dh;  # this would fail with $fh from sysopen
    

fdim

d = fdim(double x, double y);

fegetround

round = fegetround();

fesetround

ret = fesetround(round);

ffs

pos = ffs(i);

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

ret = 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

fpclassify(x);

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

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.

fsync

ret = fsync(fd);

ftruncate

ret = ftruncate(fd, length);

futimens

ret = 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();

geteuid

euid = geteuid();

getgid

gid = getgid();

gethostid

hostid = gethostid();

gethostname

hostname = gethostname();

getitimer

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

which is one of ITIMER_REAL, ITIMER_VIRTUAL, ITIMER_PROF.

getpriority

prio = getpriority(which, who);

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

who defaults to 0.

Returns undef on error.

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.

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.

hypot

r = hypot(x, y);

ilogb

y = ilogb(x);

isalpha

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

isatty

ret = isatty(fd)

isblank

ret = isblank(charstring)

Returns 1 if charstring consists only of blank characters (i.e. spaces and/or tabs). Returns 0 otherwise (also for the empty string).

iscntrl

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

isdigit

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

isfinite

isfinite(x);

isgraph

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

isinf

isinf(x);

islower

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

isnan

isnan(x);

isnormal

isnormal(x);

isprint

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

ispunct

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

isspace

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

isupper

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

isxdigit

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

ret = killpg(pgrp, sig);

l64a

s = l64a(n);

lchown

ret = lchown(path, uid, gid)

ldexp

y = ldexp(x, exp);

ldiv

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

lgamma

y = lgamma(x);

link

ret = link(path1, path2);

linkat

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

flags can be 0 or AT_SYMLINK_FOLLOW.

log1p

y = log1p(x);

log2

y = log2(x);

logb

y = logb(x);

lrand48

r = lrand48();

lround

l = lround(x)

lstat

ret = lstat(path);

mkdir

ret = mkdir(path, mode);

mkdirat

ret = mkdirat(fd, path, mode);

mkdtemp

name = mkdtemp(template);

mkfifo

ret = mkfifo(path, mode);

mkfifoat

ret = mkfifoat(fd, path, mode);

mknod

ret = mknod(path, mode, dev);

mknodat

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

mkstemp

(fd, name) = mkstemp(template);

mrand48

mrand48();

nanosleep

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

In scalar context returns the remaining seconds as a floating point number.

nearbyint

y = nearbyint(x);

nextafter

z = nextafter(x, y);

nrand48

r = nrand48()

open

ret = open(path, oflag[, mode]);

oflag defaults to O_RDONLY, mode defaults to 0600.

openat

ret = openat(fd, path, oflag[, mode]);

oflag defaults to O_RDONLY, mode defaults to 0600.

If fd is numeric (i.e. a file descriptor), "openat()" returns a file descriptor. If fd 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.

Returns undef on error.

posix_fadvise

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

advice is one of the "POSIX_FADV_" constants.

Returns undef on error

posix_fallocate

ret = posix_fallocate(fd, offset, len);

pread

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

"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.

preadv

bytes_read = preadv(fd, buffers, sizes, [offset])

"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.

ptsname

name = ptsname(fd);

pwrite

bytes_written = pwrite(fd, buf, [count, offset, buf_offset]);

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).

pwritev

bytes_written = pwritev(fd, buffers, [offset])

"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.

random

r = random();

read

bytes_read = read(fd, buf, count);

Like POSIX::read() but returns 0 at EOF instead of "0 but true".

readv

bytes_read = readv(fd, buffers, sizes);

Example:

  sysopen my $fh, '/tmp/foobar', O_RDWR|O_CREAT|O_TRUNC;
  pwrite($fh, 'foobar', 6, 0);
  readv($fh, my @buf, [4, 0, 4, 4]);
  # -> @buf is ('foob', '', 'ar')
    

"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 or an array reference. sizes must be an array reference.

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.

If the total byte count of sizes exceeds the number of bytes actually read from fd, there may be one partly filled buffer and the rest of sizes is skipped, so you may end up with less strings in buffers than there are elements in sizes.

"readv()" returns the number of bytes read (which may be less than the total bytes in sizes) or undef on error.

readlink

name = readlink(path);

Returns undef on error.

readlinkat

name = readlinkat(dirfd, path);

Returns undef on error.

remainder

r = remainder(x, y);

remove

ret = remove(path);

Calls the actual C library function "remove()".

Note that 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.

rename

ret = rename(old, new);

renameat

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

round

r = round(x);

scalbn

y = scalbn(x, n);

seed48

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

setegid

ret = setegid(gid);

seteuid

ret = seteuid(uid);

setgid

ret = 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.

setpriority

ret = setpriority(value, which, who);

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

Returns true on success, undef on error.

who defaults to 0.

setregid

ret = setregid(rgid, egid);

setreuid

ret = setreuid(ruid, euid);

setuid

ret = setuid(uid);

setutxent

setutxent();

sighold

ret = sighold(sig);

sigignore

ret = sigignore(sig);

signbit

b = signbit(x);

sigpause

sigpause(sig);

sigrelse

ret = sigrelse(sig);

sinh

y = sinh(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(path);

strptime

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

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 and will be returned as initialized if they are not affected by the format string. Unprocessed uninitialized or undef fields are returned as undef.

Returns an empty list on error.

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.

symlink

symlink(old, new);

symlinkat

ret = symlinkat(old, dirfd, new);

sync

sync();

tan

y = tan(x);

tanh

y = tanh(x);

tgamma

y = tgamma(x);

timer_create

timerid = timer_create(clockid, signal);

Returns undef on error.

timer_delete

timer_delete(timerid);

Returns '0 but true' on success, undef on error.

timer_getoverrun

count = timer_getoverrun(timerid);

Returns undef on error.

timer_gettime

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

Returns an empty list on error.

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.

truncate

ret = truncate(path, length);

trunc

y = trunc(x);

unlinkat

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

flags can be 0 or AT_REMOVEDIR.

unlink

ret = unlink(path);

utimensat

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

flags can be 0 or AT_SYMLINK_NOFOLLOW, defaults to 0.

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

write

bytes_written = write(fd, buf[, count]);

Like POSIX::write() but returns 0 instead of "0 but true" if 0 bytes were written, and it does not write more bytes than buf contains.

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

writev

bytes_written = writev(fd, buffers);

writev() writes multiple buffers from buffers to the file associated with the file descriptor fd. buffers must be an array reference. The buffers are processed in array order. Undefined or empty elements are skipped.

Returns the number of bytes written or undef on error.

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¶

 :at     All *at() functions like openat() etc. plus all AT_ 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(), pwrite(), pwritev()
 :clock  All clock* functions and all CLOCK* constants
 :fcntl  All F_, FD_, O_, POSIX_FADV_ and SEEK_ constants (for AT_ use :at)
 :fnm    C<fnmatch()> and all FNM_ constants
 :time_h All CLOCK_ and TIMER_ constants
 :timer  All timer_ functions and TIMER_ constants

CONSTANTS¶

"BOOT_TIME" "NEW_TIME" "OLD_TIME" "DEAD_PROCESS" "INIT_PROCESS" "LOGIN_PROCESS" "USER_PROCESS" "RUN_LVL"

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

"_CS_GNU_LIBC_VERSION" "_CS_GNU_LIBPTHREAD_VERSION" "_CS_PATH"

"F_DUPFD" "F_DUPFD_CLOEXEC" "F_GETFD" "F_SETFD" "F_GETFL" "F_SETFL" "F_GETLK" "F_SETLK" "F_SETLKW" "F_GETOWN" "F_SETOWN" "F_RDLCK" "F_UNLCK" "F_WRLCK"

"FD_CLOEXEC"

"FNM_CASEFOLD" "FNM_FILE_NAME" "FNM_LEADING_DIR" "FNM_NOESCAPE" "FNM_NOMATCH" "FNM_PATHNAME" "FNM_PERIOD"

"FP_INFINITE" "FP_NAN" "FP_NORMAL" "FP_SUBNORMAL" "FP_ZERO"

"TIMER_ABSTIME" "ITIMER_PROF" "ITIMER_REAL" "ITIMER_VIRTUAL"

"O_ACCMODE" "O_APPEND" "O_CLOEXEC" "O_CREAT" "O_DIRECTORY" "O_DSYNC" "O_EXEC" "O_NOCTTY" "O_NOFOLLOW" "O_NONBLOCK" "O_RDONLY" "O_RDWR" "O_RSYNC" "O_SEARCH" "O_SYNC" "O_TMPFILE" "O_TRUNC" "O_TTY_INIT" "O_WRONLY"

"POSIX_FADV_NORMAL" "POSIX_FADV_SEQUENTIAL" "POSIX_FADV_RANDOM" "POSIX_FADV_NOREUSE" "POSIX_FADV_WILLNEED" "POSIX_FADV_DONTNEED"

"RTLD_GLOBAL" "RTLD_LAZY" "RTLD_LOCAL" "RTLD_NOW"

"SEEK_SET" "SEEK_CUR" "SEEK_END"

"UTIME_NOW" "UTIME_OMIT"

NOTES¶

AUTHOR¶

LICENSE¶