3 POSIX - Perl interface to IEEE Std 1003.1
9 use POSIX qw(:errno_h :fcntl_h);
11 printf "EINTR is %d\n", EINTR;
13 $sess_id = POSIX::setsid();
15 $fd = POSIX::open($path, O_CREAT|O_EXCL|O_WRONLY, 0644);
16 # note: that's a filedescriptor, *NOT* a filehandle
20 The POSIX module permits you to access all (or nearly all) the standard
21 POSIX 1003.1 identifiers. Many of these identifiers have been given Perl-ish
22 interfaces. Things which are C<#defines> in C, like EINTR or O_NDELAY, are
23 automatically exported into your namespace. All functions are only exported
24 if you ask for them explicitly. Most likely people will prefer to use the
25 fully-qualified function names.
27 This document gives a condensed list of the features available in the POSIX
28 module. Consult your operating system's manpages for general information on
29 most features. Consult L<perlfunc> for functions which are noted as being
30 identical to Perl's builtin functions.
32 The first section describes POSIX functions from the 1003.1 specification.
33 The second section describes some classes for signal objects, TTY objects,
34 and other miscellaneous objects. The remaining sections list various
35 constants and macros in an organization which roughly follows IEEE Std
40 The POSIX module is probably the most complex Perl module supplied with
41 the standard distribution. It incorporates autoloading, namespace games,
42 and dynamic loading of code that's in Perl, C, or both. It's a great
47 A few functions are not implemented because they are C specific. If you
48 attempt to call these, they will print a message telling you that they
49 aren't implemented, and suggest using the Perl equivalent should one
50 exist. For example, trying to access the setjmp() call will elicit the
51 message "setjmp() is C-specific: use eval {} instead".
53 Furthermore, some evil vendors will claim 1003.1 compliance, but in fact
54 are not so: they will not pass the PCTS (POSIX Compliance Test Suites).
55 For example, one vendor may not define EDEADLK, or the semantics of the
56 errno values set by open(2) might not be quite right. Perl does not
57 attempt to verify POSIX compliance. That means you can currently
58 successfully say "use POSIX", and then later in your program you find
59 that your vendor has been lax and there's no usable ICANON macro after
60 all. This could be construed to be a bug.
68 This is identical to the C function C<_exit()>. It exits the program
69 immediately which means among other things buffered I/O is B<not> flushed.
71 Note that when using threads and in Linux this is B<not> a good way to
72 exit a thread because in Linux processes and threads are kind of the
73 same thing (Note: while this is the situation in early 2003 there are
74 projects under way to have threads with more POSIXly semantics in Linux).
75 If you want not to return from a thread, detach the thread.
79 This is identical to the C function C<abort()>. It terminates the
80 process with a C<SIGABRT> signal unless caught by a signal handler or
81 if the handler does not return normally (it e.g. does a C<longjmp>).
85 This is identical to Perl's builtin C<abs()> function, returning
86 the absolute value of its numerical argument.
90 Determines the accessibility of a file.
92 if( POSIX::access( "/", &POSIX::R_OK ) ){
93 print "have read permission\n";
96 Returns C<undef> on failure. Note: do not use C<access()> for
97 security purposes. Between the C<access()> call and the operation
98 you are preparing for the permissions might change: a classic
103 This is identical to the C function C<acos()>, returning
104 the arcus cosine of its numerical argument. See also L<Math::Trig>.
108 This is identical to Perl's builtin C<alarm()> function,
109 either for arming or disarming the C<SIGARLM> timer.
113 This is identical to the C function C<asctime()>. It returns
116 "Fri Jun 2 18:22:13 2000\n\0"
118 and it is called thusly
120 $asctime = asctime($sec, $min, $hour, $mday, $mon, $year,
121 $wday, $yday, $isdst);
123 The C<$mon> is zero-based: January equals C<0>. The C<$year> is
124 1900-based: 2001 equals C<101>. The C<$wday>, C<$yday>, and C<$isdst>
125 default to zero (and the first two are usually ignored anyway).
129 This is identical to the C function C<asin()>, returning
130 the arcus sine of its numerical argument. See also L<Math::Trig>.
134 Unimplemented, but you can use L<perlfunc/die> and the L<Carp> module
135 to achieve similar things.
139 This is identical to the C function C<atan()>, returning the
140 arcus tangent of its numerical argument. See also L<Math::Trig>.
144 This is identical to Perl's builtin C<atan2()> function, returning
145 the arcus tangent defined by its two numerical arguments, the I<y>
146 coordinate and the I<x> coordinate. See also L<Math::Trig>.
150 atexit() is C-specific: use C<END {}> instead, see L<perlsub>.
154 atof() is C-specific. Perl converts strings to numbers transparently.
155 If you need to force a scalar to a number, add a zero to it.
159 atoi() is C-specific. Perl converts strings to numbers transparently.
160 If you need to force a scalar to a number, add a zero to it.
161 If you need to have just the integer part, see L<perlfunc/int>.
165 atol() is C-specific. Perl converts strings to numbers transparently.
166 If you need to force a scalar to a number, add a zero to it.
167 If you need to have just the integer part, see L<perlfunc/int>.
171 bsearch() not supplied. For doing binary search on wordlists,
176 calloc() is C-specific. Perl does memory management transparently.
180 This is identical to the C function C<ceil()>, returning the smallest
181 integer value greater than or equal to the given numerical argument.
185 This is identical to Perl's builtin C<chdir()> function, allowing
186 one to change the working (default) directory, see L<perlfunc/chdir>.
190 This is identical to Perl's builtin C<chmod()> function, allowing
191 one to change file and directory permissions, see L<perlfunc/chmod>.
195 This is identical to Perl's builtin C<chown()> function, allowing one
196 to change file and directory owners and groups, see L<perlfunc/chown>.
200 Use the method C<IO::Handle::clearerr()> instead, to reset the error
201 state (if any) and EOF state (if any) of the given stream.
205 This is identical to the C function C<clock()>, returning the
206 amount of spent processor time in microseconds.
210 Close the file. This uses file descriptors such as those obtained by calling
213 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
216 Returns C<undef> on failure.
218 See also L<perlfunc/close>.
222 This is identical to Perl's builtin C<closedir()> function for closing
223 a directory handle, see L<perlfunc/closedir>.
227 This is identical to Perl's builtin C<cos()> function, for returning
228 the cosine of its numerical argument, see L<perlfunc/cos>.
229 See also L<Math::Trig>.
233 This is identical to the C function C<cosh()>, for returning
234 the hyperbolic cosine of its numeric argument. See also L<Math::Trig>.
238 Create a new file. This returns a file descriptor like the ones returned by
239 C<POSIX::open>. Use C<POSIX::close> to close the file.
241 $fd = POSIX::creat( "foo", 0611 );
244 See also L<perlfunc/sysopen> and its C<O_CREAT> flag.
248 Generates the path name for the controlling terminal.
250 $path = POSIX::ctermid();
254 This is identical to the C function C<ctime()> and equivalent
255 to C<asctime(localtime(...))>, see L</asctime> and L</localtime>.
259 Get the login name of the owner of the current process.
261 $name = POSIX::cuserid();
265 This is identical to the C function C<difftime()>, for returning
266 the time difference (in seconds) between two times (as returned
267 by C<time()>), see L</time>.
271 div() is C-specific, use L<perlfunc/int> on the usual C</> division and
276 This is similar to the C function C<dup()>, for duplicating a file
279 This uses file descriptors such as those obtained by calling
282 Returns C<undef> on failure.
286 This is similar to the C function C<dup2()>, for duplicating a file
287 descriptor to an another known file descriptor.
289 This uses file descriptors such as those obtained by calling
292 Returns C<undef> on failure.
296 Returns the value of errno.
298 $errno = POSIX::errno();
300 This identical to the numerical values of the C<$!>, see L<perlvar/$ERRNO>.
304 execl() is C-specific, see L<perlfunc/exec>.
308 execle() is C-specific, see L<perlfunc/exec>.
312 execlp() is C-specific, see L<perlfunc/exec>.
316 execv() is C-specific, see L<perlfunc/exec>.
320 execve() is C-specific, see L<perlfunc/exec>.
324 execvp() is C-specific, see L<perlfunc/exec>.
328 This is identical to Perl's builtin C<exit()> function for exiting the
329 program, see L<perlfunc/exit>.
333 This is identical to Perl's builtin C<exp()> function for
334 returning the exponent (I<e>-based) of the numerical argument,
339 This is identical to Perl's builtin C<abs()> function for returning
340 the absolute value of the numerical argument, see L<perlfunc/abs>.
344 Use method C<IO::Handle::close()> instead, or see L<perlfunc/close>.
348 This is identical to Perl's builtin C<fcntl()> function,
349 see L<perlfunc/fcntl>.
353 Use method C<IO::Handle::new_from_fd()> instead, or see L<perlfunc/open>.
357 Use method C<IO::Handle::eof()> instead, or see L<perlfunc/eof>.
361 Use method C<IO::Handle::error()> instead.
365 Use method C<IO::Handle::flush()> instead.
366 See also L<perlvar/$OUTPUT_AUTOFLUSH>.
370 Use method C<IO::Handle::getc()> instead, or see L<perlfunc/read>.
374 Use method C<IO::Seekable::getpos()> instead, or see L<L/seek>.
378 Use method C<IO::Handle::gets()> instead. Similar to E<lt>E<gt>, also known
379 as L<perlfunc/readline>.
383 Use method C<IO::Handle::fileno()> instead, or see L<perlfunc/fileno>.
387 This is identical to the C function C<floor()>, returning the largest
388 integer value less than or equal to the numerical argument.
392 This is identical to the C function C<fmod()>.
396 It returns the remainder C<$r = $x - $n*$y>, where C<$n = trunc($x/$y)>.
397 The C<$r> has the same sign as C<$x> and magnitude (absolute value)
398 less than the magnitude of C<$y>.
402 Use method C<IO::File::open()> instead, or see L<perlfunc/open>.
406 This is identical to Perl's builtin C<fork()> function
407 for duplicating the current process, see L<perlfunc/fork>
408 and L<perlfork> if you are in Windows.
412 Retrieves the value of a configurable limit on a file or directory. This
413 uses file descriptors such as those obtained by calling C<POSIX::open>.
415 The following will determine the maximum length of the longest allowable
416 pathname on the filesystem which holds C</tmp/foo>.
418 $fd = POSIX::open( "/tmp/foo", &POSIX::O_RDONLY );
419 $path_max = POSIX::fpathconf( $fd, &POSIX::_PC_PATH_MAX );
421 Returns C<undef> on failure.
425 fprintf() is C-specific, see L<perlfunc/printf> instead.
429 fputc() is C-specific, see L<perlfunc/print> instead.
433 fputs() is C-specific, see L<perlfunc/print> instead.
437 fread() is C-specific, see L<perlfunc/read> instead.
441 free() is C-specific. Perl does memory management transparently.
445 freopen() is C-specific, see L<perlfunc/open> instead.
449 Return the mantissa and exponent of a floating-point number.
451 ($mantissa, $exponent) = POSIX::frexp( 1.234e56 );
455 fscanf() is C-specific, use E<lt>E<gt> and regular expressions instead.
459 Use method C<IO::Seekable::seek()> instead, or see L<perlfunc/seek>.
463 Use method C<IO::Seekable::setpos()> instead, or seek L<perlfunc/seek>.
467 Get file status. This uses file descriptors such as those obtained by
468 calling C<POSIX::open>. The data returned is identical to the data from
469 Perl's builtin C<stat> function.
471 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
472 @stats = POSIX::fstat( $fd );
476 Use method C<IO::Handle::sync()> instead.
480 Use method C<IO::Seekable::tell()> instead, or see L<perlfunc/tell>.
484 fwrite() is C-specific, see L<perlfunc/print> instead.
488 This is identical to Perl's builtin C<getc()> function,
489 see L<perlfunc/getc>.
493 Returns one character from STDIN. Identical to Perl's C<getc()>,
494 see L<perlfunc/getc>.
498 Returns the name of the current working directory.
503 Returns the effective group identifier. Similar to Perl' s builtin
504 variable C<$(>, see L<perlvar/$EGID>.
508 Returns the value of the specified enironment variable.
509 The same information is available through the C<%ENV> array.
513 Returns the effective user identifier. Identical to Perl's builtin C<$E<gt>>
514 variable, see L<perlvar/$EUID>.
518 Returns the user's real group identifier. Similar to Perl's builtin
519 variable C<$)>, see L<perlvar/$GID>.
523 This is identical to Perl's builtin C<getgrgid()> function for
524 returning group entries by group identifiers, see
525 L<perlfunc/getgrgid>.
529 This is identical to Perl's builtin C<getgrnam()> function for
530 returning group entries by group names, see L<perlfunc/getgrnam>.
534 Returns the ids of the user's supplementary groups. Similar to Perl's
535 builtin variable C<$)>, see L<perlvar/$GID>.
539 This is identical to Perl's builtin C<getlogin()> function for
540 returning the user name associated with the current session, see
541 L<perlfunc/getlogin>.
545 This is identical to Perl's builtin C<getpgrp()> function for
546 returning the prcess group identifier of the current process, see
551 Returns the process identifier. Identical to Perl's builtin
552 variable C<$$>, see L<perlvar/$PID>.
556 This is identical to Perl's builtin C<getppid()> function for
557 returning the process identifier of the parent process of the current
558 process , see L<perlfunc/getppid>.
562 This is identical to Perl's builtin C<getpwnam()> function for
563 returning user entries by user names, see L<perlfunc/getpwnam>.
567 This is identical to Perl's builtin C<getpwuid()> function for
568 returning user entries by user identifiers, see L<perlfunc/getpwuid>.
572 Returns one line from C<STDIN>, similar to E<lt>E<gt>, also known
573 as the C<readline()> function, see L<perlfunc/readline>.
575 B<NOTE>: if you have C programs that still use C<gets()>, be very
576 afraid. The C<gets()> function is a source of endless grief because
577 it has no buffer overrun checks. It should B<never> be used. The
578 C<fgets()> function should be preferred instead.
582 Returns the user's identifier. Identical to Perl's builtin C<$E<lt>> variable,
587 This is identical to Perl's builtin C<gmtime()> function for
588 converting seconds since the epoch to a date in Greenwich Mean Time,
589 see L<perlfunc/gmtime>.
593 This is identical to the C function, except that it can apply to a
594 single character or to a whole string. Note that locale settings may
595 affect what characters are considered C<isalnum>. Does not work on
596 Unicode characters code point 256 or higher. Consider using regular
597 expressions and the C</[[:alnum:]]/> construct instead, or possibly
598 the C</\w/> construct.
602 This is identical to the C function, except that it can apply to
603 a single character or to a whole string. Note that locale settings
604 may affect what characters are considered C<isalpha>. Does not work
605 on Unicode characters code point 256 or higher. Consider using regular
606 expressions and the C</[[:alpha:]]/> construct instead.
610 Returns a boolean indicating whether the specified filehandle is connected
611 to a tty. Similar to the C<-t> operator, see L<perlfunc/-X>.
615 This is identical to the C function, except that it can apply to
616 a single character or to a whole string. Note that locale settings
617 may affect what characters are considered C<iscntrl>. Does not work
618 on Unicode characters code point 256 or higher. Consider using regular
619 expressions and the C</[[:cntrl:]]/> construct instead.
623 This is identical to the C function, except that it can apply to
624 a single character or to a whole string. Note that locale settings
625 may affect what characters are considered C<isdigit> (unlikely, but
626 still possible). Does not work on Unicode characters code point 256
627 or higher. Consider using regular expressions and the C</[[:digit:]]/>
628 construct instead, or the C</\d/> construct.
632 This is identical to the C function, except that it can apply to
633 a single character or to a whole string. Note that locale settings
634 may affect what characters are considered C<isgraph>. Does not work
635 on Unicode characters code point 256 or higher. Consider using regular
636 expressions and the C</[[:graph:]]/> construct instead.
640 This is identical to the C function, except that it can apply to
641 a single character or to a whole string. Note that locale settings
642 may affect what characters are considered C<islower>. Does not work
643 on Unicode characters code point 256 or higher. Consider using regular
644 expressions and the C</[[:lower:]]/> construct instead. Do B<not> use
649 This is identical to the C function, except that it can apply to
650 a single character or to a whole string. Note that locale settings
651 may affect what characters are considered C<isprint>. Does not work
652 on Unicode characters code point 256 or higher. Consider using regular
653 expressions and the C</[[:print:]]/> construct instead.
657 This is identical to the C function, except that it can apply to
658 a single character or to a whole string. Note that locale settings
659 may affect what characters are considered C<ispunct>. Does not work
660 on Unicode characters code point 256 or higher. Consider using regular
661 expressions and the C</[[:punct:]]/> construct instead.
665 This is identical to the C function, except that it can apply to
666 a single character or to a whole string. Note that locale settings
667 may affect what characters are considered C<isspace>. Does not work
668 on Unicode characters code point 256 or higher. Consider using regular
669 expressions and the C</[[:space:]]/> construct instead, or the C</\s/>
670 construct. (Note that C</\s/> and C</[[:space:]]/> are slightly
671 different in that C</[[:space:]]/> can normally match a vertical tab,
672 while C</\s/> does not.)
676 This is identical to the C function, except that it can apply to
677 a single character or to a whole string. Note that locale settings
678 may affect what characters are considered C<isupper>. Does not work
679 on Unicode characters code point 256 or higher. Consider using regular
680 expressions and the C</[[:upper:]]/> construct instead. Do B<not> use
685 This is identical to the C function, except that it can apply to a single
686 character or to a whole string. Note that locale settings may affect what
687 characters are considered C<isxdigit> (unlikely, but still possible).
688 Does not work on Unicode characters code point 256 or higher.
689 Consider using regular expressions and the C</[[:xdigit:]]/>
690 construct instead, or simply C</[0-9a-f]/i>.
694 This is identical to Perl's builtin C<kill()> function for sending
695 signals to processes (often to terminate them), see L<perlfunc/kill>.
699 (For returning absolute values of long integers.)
700 labs() is C-specific, see L<perlfunc/abs> instead.
704 This is identical to the C function C<ldexp()>
705 for multiplying floating point numbers with powers of two.
707 $x_quadrupled = POSIX::ldexp($x, 2);
711 (For computing dividends of long integers.)
712 ldiv() is C-specific, use C</> and C<int()> instead.
716 This is identical to Perl's builtin C<link()> function
717 for creating hard links into files, see L<perlfunc/link>.
721 Get numeric formatting information. Returns a reference to a hash
722 containing the current locale formatting values.
724 Here is how to query the database for the B<de> (Deutsch or German) locale.
726 $loc = POSIX::setlocale( &POSIX::LC_ALL, "de" );
727 print "Locale = $loc\n";
728 $lconv = POSIX::localeconv();
729 print "decimal_point = ", $lconv->{decimal_point}, "\n";
730 print "thousands_sep = ", $lconv->{thousands_sep}, "\n";
731 print "grouping = ", $lconv->{grouping}, "\n";
732 print "int_curr_symbol = ", $lconv->{int_curr_symbol}, "\n";
733 print "currency_symbol = ", $lconv->{currency_symbol}, "\n";
734 print "mon_decimal_point = ", $lconv->{mon_decimal_point}, "\n";
735 print "mon_thousands_sep = ", $lconv->{mon_thousands_sep}, "\n";
736 print "mon_grouping = ", $lconv->{mon_grouping}, "\n";
737 print "positive_sign = ", $lconv->{positive_sign}, "\n";
738 print "negative_sign = ", $lconv->{negative_sign}, "\n";
739 print "int_frac_digits = ", $lconv->{int_frac_digits}, "\n";
740 print "frac_digits = ", $lconv->{frac_digits}, "\n";
741 print "p_cs_precedes = ", $lconv->{p_cs_precedes}, "\n";
742 print "p_sep_by_space = ", $lconv->{p_sep_by_space}, "\n";
743 print "n_cs_precedes = ", $lconv->{n_cs_precedes}, "\n";
744 print "n_sep_by_space = ", $lconv->{n_sep_by_space}, "\n";
745 print "p_sign_posn = ", $lconv->{p_sign_posn}, "\n";
746 print "n_sign_posn = ", $lconv->{n_sign_posn}, "\n";
750 This is identical to Perl's builtin C<localtime()> function for
751 converting seconds since the epoch to a date see L<perlfunc/localtime>.
755 This is identical to Perl's builtin C<log()> function,
756 returning the natural (I<e>-based) logarithm of the numerical argument,
761 This is identical to the C function C<log10()>,
762 returning the 10-base logarithm of the numerical argument.
765 sub log10 { log($_[0]) / log(10) }
769 sub log10 { log($_[0]) / 2.30258509299405 }
773 sub log10 { log($_[0]) * 0.434294481903252 }
777 longjmp() is C-specific: use L<perlfunc/die> instead.
781 Move the file's read/write position. This uses file descriptors such as
782 those obtained by calling C<POSIX::open>.
784 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
785 $off_t = POSIX::lseek( $fd, 0, &POSIX::SEEK_SET );
787 Returns C<undef> on failure.
791 malloc() is C-specific. Perl does memory management transparently.
795 This is identical to the C function C<mblen()>.
796 Perl does not have any support for the wide and multibyte
797 characters of the C standards, so this might be a rather
802 This is identical to the C function C<mbstowcs()>.
803 Perl does not have any support for the wide and multibyte
804 characters of the C standards, so this might be a rather
809 This is identical to the C function C<mbtowc()>.
810 Perl does not have any support for the wide and multibyte
811 characters of the C standards, so this might be a rather
816 memchr() is C-specific, see L<perlfunc/index> instead.
820 memcmp() is C-specific, use C<eq> instead, see L<perlop>.
824 memcpy() is C-specific, use C<=>, see L<perlop>, or see L<perlfunc/substr>.
828 memmove() is C-specific, use C<=>, see L<perlop>, or see L<perlfunc/substr>.
832 memset() is C-specific, use C<x> instead, see L<perlop>.
836 This is identical to Perl's builtin C<mkdir()> function
837 for creating directories, see L<perlfunc/mkdir>.
841 This is similar to the C function C<mkfifo()> for creating
844 if (mkfifo($path, $mode)) { ....
846 Returns C<undef> on failure. The C<$mode> is similar to the
847 mode of C<mkdir()>, see L<perlfunc/mkdir>.
851 Convert date/time info to a calendar time.
855 mktime(sec, min, hour, mday, mon, year, wday = 0, yday = 0, isdst = 0)
857 The month (C<mon>), weekday (C<wday>), and yearday (C<yday>) begin at zero.
858 I.e. January is 0, not 1; Sunday is 0, not 1; January 1st is 0, not 1. The
859 year (C<year>) is given in years since 1900. I.e. The year 1995 is 95; the
860 year 2001 is 101. Consult your system's C<mktime()> manpage for details
861 about these and the other arguments.
863 Calendar time for December 12, 1995, at 10:30 am.
865 $time_t = POSIX::mktime( 0, 30, 10, 12, 11, 95 );
866 print "Date = ", POSIX::ctime($time_t);
868 Returns C<undef> on failure.
872 Return the integral and fractional parts of a floating-point number.
874 ($fractional, $integral) = POSIX::modf( 3.14 );
878 This is similar to the C function C<nice()>, for changing
879 the scheduling preference of the current process. Positive
880 arguments mean more polite process, negative values more
881 needy process. Normal user processes can only be more polite.
883 Returns C<undef> on failure.
887 offsetof() is C-specific, you probably want to see L<perlfunc/pack> instead.
891 Open a file for reading for writing. This returns file descriptors, not
892 Perl filehandles. Use C<POSIX::close> to close the file.
894 Open a file read-only with mode 0666.
896 $fd = POSIX::open( "foo" );
898 Open a file for read and write.
900 $fd = POSIX::open( "foo", &POSIX::O_RDWR );
902 Open a file for write, with truncation.
904 $fd = POSIX::open( "foo", &POSIX::O_WRONLY | &POSIX::O_TRUNC );
906 Create a new file with mode 0640. Set up the file for writing.
908 $fd = POSIX::open( "foo", &POSIX::O_CREAT | &POSIX::O_WRONLY, 0640 );
910 Returns C<undef> on failure.
912 See also L<perlfunc/sysopen>.
916 Open a directory for reading.
918 $dir = POSIX::opendir( "/tmp" );
919 @files = POSIX::readdir( $dir );
920 POSIX::closedir( $dir );
922 Returns C<undef> on failure.
926 Retrieves the value of a configurable limit on a file or directory.
928 The following will determine the maximum length of the longest allowable
929 pathname on the filesystem which holds C</tmp>.
931 $path_max = POSIX::pathconf( "/tmp", &POSIX::_PC_PATH_MAX );
933 Returns C<undef> on failure.
937 This is similar to the C function C<pause()>, which suspends
938 the execution of the current process until a signal is received.
940 Returns C<undef> on failure.
944 This is identical to the C function C<perror()>, which outputs to the
945 standard error stream the specified message followed by ": " and the
946 current error string. Use the C<warn()> function and the C<$!>
947 variable instead, see L<perlfunc/warn> and L<perlvar/$ERRNO>.
951 Create an interprocess channel. This returns file descriptors like those
952 returned by C<POSIX::open>.
954 ($fd0, $fd1) = POSIX::pipe();
955 POSIX::write( $fd0, "hello", 5 );
956 POSIX::read( $fd1, $buf, 5 );
958 See also L<perlfunc/pipe>.
962 Computes C<$x> raised to the power C<$exponent>.
964 $ret = POSIX::pow( $x, $exponent );
966 You can also use the C<**> operator, see L<perlop>.
970 Formats and prints the specified arguments to STDOUT.
971 See also L<perlfunc/printf>.
975 putc() is C-specific, see L<perlfunc/print> instead.
979 putchar() is C-specific, see L<perlfunc/print> instead.
983 puts() is C-specific, see L<perlfunc/print> instead.
987 qsort() is C-specific, see L<perlfunc/sort> instead.
991 Sends the specified signal to the current process.
992 See also L<perlfunc/kill> and the C<$$> in L<perlvar/$PID>.
996 C<rand()> is non-portable, see L<perlfunc/rand> instead.
1000 Read from a file. This uses file descriptors such as those obtained by
1001 calling C<POSIX::open>. If the buffer C<$buf> is not large enough for the
1002 read then Perl will extend it to make room for the request.
1004 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
1005 $bytes = POSIX::read( $fd, $buf, 3 );
1007 Returns C<undef> on failure.
1009 See also L<perlfunc/sysread>.
1013 This is identical to Perl's builtin C<readdir()> function
1014 for reading directory entries, see L<perlfunc/readdir>.
1018 realloc() is C-specific. Perl does memory management transparently.
1022 This is identical to Perl's builtin C<unlink()> function
1023 for removing files, see L<perlfunc/unlink>.
1027 This is identical to Perl's builtin C<rename()> function
1028 for renaming files, see L<perlfunc/rename>.
1032 Seeks to the beginning of the file.
1036 This is identical to Perl's builtin C<rewinddir()> function for
1037 rewinding directory entry streams, see L<perlfunc/rewinddir>.
1041 This is identical to Perl's builtin C<rmdir()> function
1042 for removing (empty) directories, see L<perlfunc/rmdir>.
1046 scanf() is C-specific, use E<lt>E<gt> and regular expressions instead,
1051 Sets the real group identifier and the effective group identifier for
1052 this process. Similar to assigning a value to the Perl's builtin
1053 C<$)> variable, see L<perlvar/$GID>, except that the latter
1054 will change only the real user identifier, and that the setgid()
1055 uses only a single numeric argument, as opposed to a space-separated
1060 C<setjmp()> is C-specific: use C<eval {}> instead,
1061 see L<perlfunc/eval>.
1065 Modifies and queries program's locale. The following examples assume
1067 use POSIX qw(setlocale LC_ALL LC_CTYPE);
1071 The following will set the traditional UNIX system locale behavior
1072 (the second argument C<"C">).
1074 $loc = setlocale( LC_ALL, "C" );
1076 The following will query the current LC_CTYPE category. (No second
1077 argument means 'query'.)
1079 $loc = setlocale( LC_CTYPE );
1081 The following will set the LC_CTYPE behaviour according to the locale
1082 environment variables (the second argument C<"">).
1083 Please see your systems C<setlocale(3)> documentation for the locale
1084 environment variables' meaning or consult L<perllocale>.
1086 $loc = setlocale( LC_CTYPE, "" );
1088 The following will set the LC_COLLATE behaviour to Argentinian
1089 Spanish. B<NOTE>: The naming and availability of locales depends on
1090 your operating system. Please consult L<perllocale> for how to find
1091 out which locales are available in your system.
1093 $loc = setlocale( LC_ALL, "es_AR.ISO8859-1" );
1097 This is similar to the C function C<setpgid()> for
1098 setting the process group identifier of the current process.
1100 Returns C<undef> on failure.
1104 This is identical to the C function C<setsid()> for
1105 setting the session identifier of the current process.
1109 Sets the real user identifier and the effective user identifier for
1110 this process. Similar to assigning a value to the Perl's builtin
1111 C<$E<lt>> variable, see L<perlvar/$UID>, except that the latter
1112 will change only the real user identifier.
1116 Detailed signal management. This uses C<POSIX::SigAction> objects for the
1117 C<action> and C<oldaction> arguments. Consult your system's C<sigaction>
1118 manpage for details.
1122 sigaction(sig, action, oldaction = 0)
1124 Returns C<undef> on failure.
1128 siglongjmp() is C-specific: use L<perlfunc/die> instead.
1132 Examine signals that are blocked and pending. This uses C<POSIX::SigSet>
1133 objects for the C<sigset> argument. Consult your system's C<sigpending>
1134 manpage for details.
1140 Returns C<undef> on failure.
1144 Change and/or examine calling process's signal mask. This uses
1145 C<POSIX::SigSet> objects for the C<sigset> and C<oldsigset> arguments.
1146 Consult your system's C<sigprocmask> manpage for details.
1150 sigprocmask(how, sigset, oldsigset = 0)
1152 Returns C<undef> on failure.
1156 C<sigsetjmp()> is C-specific: use C<eval {}> instead,
1157 see L<perlfunc/eval>.
1161 Install a signal mask and suspend process until signal arrives. This uses
1162 C<POSIX::SigSet> objects for the C<signal_mask> argument. Consult your
1163 system's C<sigsuspend> manpage for details.
1167 sigsuspend(signal_mask)
1169 Returns C<undef> on failure.
1173 This is identical to Perl's builtin C<sin()> function
1174 for returning the sine of the numerical argument,
1175 see L<perlfunc/sin>. See also L<Math::Trig>.
1179 This is identical to the C function C<sinh()>
1180 for returning the hyperbolic sine of the numerical argument.
1181 See also L<Math::Trig>.
1185 This is functionally identical to Perl's builtin C<sleep()> function
1186 for suspending the execution of the current for process for certain
1187 number of seconds, see L<perlfunc/sleep>. There is one signifanct
1188 difference, however: C<POSIX::sleep()> returns the number of
1189 B<unslept> seconds, while the C<CORE::sleep()> returns the
1190 number of slept seconds.
1194 This is similar to Perl's builtin C<sprintf()> function
1195 for returning a string that has the arguments formatted as requested,
1196 see L<perlfunc/sprintf>.
1200 This is identical to Perl's builtin C<sqrt()> function.
1201 for returning the square root of the numerical argument,
1202 see L<perlfunc/sqrt>.
1206 Give a seed the pseudorandom number generator, see L<perlfunc/srand>.
1210 sscanf() is C-specific, use regular expressions instead,
1215 This is identical to Perl's builtin C<stat()> function
1216 for retutning information about files and directories.
1220 strcat() is C-specific, use C<.=> instead, see L<perlop>.
1224 strchr() is C-specific, see L<perlfunc/index> instead.
1228 strcmp() is C-specific, use C<eq> or C<cmp> instead, see L<perlop>.
1232 This is identical to the C function C<strcoll()>
1233 for collating (comparing) strings transformed using
1234 the C<strxfrm()> function. Not really needed since
1235 Perl can do this transparently, see L<perllocale>.
1239 strcpy() is C-specific, use C<=> instead, see L<perlop>.
1243 strcspn() is C-specific, use regular expressions instead,
1248 Returns the error string for the specified errno.
1249 Identical to the string form of the C<$!>, see L<perlvar/$ERRNO>.
1253 Convert date and time information to string. Returns the string.
1257 strftime(fmt, sec, min, hour, mday, mon, year, wday = -1, yday = -1, isdst = -1)
1259 The month (C<mon>), weekday (C<wday>), and yearday (C<yday>) begin at zero.
1260 I.e. January is 0, not 1; Sunday is 0, not 1; January 1st is 0, not 1. The
1261 year (C<year>) is given in years since 1900. I.e., the year 1995 is 95; the
1262 year 2001 is 101. Consult your system's C<strftime()> manpage for details
1263 about these and the other arguments.
1265 If you want your code to be portable, your format (C<fmt>) argument
1266 should use only the conversion specifiers defined by the ANSI C
1267 standard (C89, to play safe). These are C<aAbBcdHIjmMpSUwWxXyYZ%>.
1268 But even then, the B<results> of some of the conversion specifiers are
1269 non-portable. For example, the specifiers C<aAbBcpZ> change according
1270 to the locale settings of the user, and both how to set locales (the
1271 locale names) and what output to expect are non-standard.
1272 The specifier C<c> changes according to the timezone settings of the
1273 user and the timezone computation rules of the operating system.
1274 The C<Z> specifier is notoriously unportable since the names of
1275 timezones are non-standard. Sticking to the numeric specifiers is the
1278 The given arguments are made consistent as though by calling
1279 C<mktime()> before calling your system's C<strftime()> function,
1280 except that the C<isdst> value is not affected.
1282 The string for Tuesday, December 12, 1995.
1284 $str = POSIX::strftime( "%A, %B %d, %Y", 0, 0, 0, 12, 11, 95, 2 );
1289 strlen() is C-specific, use C<length()> instead, see L<perlfunc/length>.
1293 strncat() is C-specific, use C<.=> instead, see L<perlop>.
1297 strncmp() is C-specific, use C<eq> instead, see L<perlop>.
1301 strncpy() is C-specific, use C<=> instead, see L<perlop>.
1305 strpbrk() is C-specific, use regular expressions instead,
1310 strrchr() is C-specific, see L<perlfunc/rindex> instead.
1314 strspn() is C-specific, use regular expressions instead,
1319 This is identical to Perl's builtin C<index()> function,
1320 see L<perlfunc/index>.
1324 String to double translation. Returns the parsed number and the number
1325 of characters in the unparsed portion of the string. Truly
1326 POSIX-compliant systems set $! ($ERRNO) to indicate a translation
1327 error, so clear $! before calling strtod. However, non-POSIX systems
1328 may not check for overflow, and therefore will never set $!.
1330 strtod should respect any POSIX I<setlocale()> settings.
1332 To parse a string $str as a floating point number use
1335 ($num, $n_unparsed) = POSIX::strtod($str);
1337 The second returned item and $! can be used to check for valid input:
1339 if (($str eq '') || ($n_unparsed != 0) || !$!) {
1340 die "Non-numeric input $str" . $! ? ": $!\n" : "\n";
1343 When called in a scalar context strtod returns the parsed number.
1347 strtok() is C-specific, use regular expressions instead, see
1348 L<perlre>, or L<perlfunc/split>.
1352 String to (long) integer translation. Returns the parsed number and
1353 the number of characters in the unparsed portion of the string. Truly
1354 POSIX-compliant systems set $! ($ERRNO) to indicate a translation
1355 error, so clear $! before calling strtol. However, non-POSIX systems
1356 may not check for overflow, and therefore will never set $!.
1358 strtol should respect any POSIX I<setlocale()> settings.
1360 To parse a string $str as a number in some base $base use
1363 ($num, $n_unparsed) = POSIX::strtol($str, $base);
1365 The base should be zero or between 2 and 36, inclusive. When the base
1366 is zero or omitted strtol will use the string itself to determine the
1367 base: a leading "0x" or "0X" means hexadecimal; a leading "0" means
1368 octal; any other leading characters mean decimal. Thus, "1234" is
1369 parsed as a decimal number, "01234" as an octal number, and "0x1234"
1370 as a hexadecimal number.
1372 The second returned item and $! can be used to check for valid input:
1374 if (($str eq '') || ($n_unparsed != 0) || !$!) {
1375 die "Non-numeric input $str" . $! ? ": $!\n" : "\n";
1378 When called in a scalar context strtol returns the parsed number.
1382 String to unsigned (long) integer translation. strtoul() is identical
1383 to strtol() except that strtoul() only parses unsigned integers. See
1384 L</strtol> for details.
1386 Note: Some vendors supply strtod() and strtol() but not strtoul().
1387 Other vendors that do supply strtoul() parse "-1" as a valid value.
1391 String transformation. Returns the transformed string.
1393 $dst = POSIX::strxfrm( $src );
1395 Used in conjunction with the C<strcoll()> function, see L</strcoll>.
1397 Not really needed since Perl can do this transparently, see
1402 Retrieves values of system configurable variables.
1404 The following will get the machine's clock speed.
1406 $clock_ticks = POSIX::sysconf( &POSIX::_SC_CLK_TCK );
1408 Returns C<undef> on failure.
1412 This is identical to Perl's builtin C<system()> function, see
1417 This is identical to the C function C<tan()>, returning the
1418 tangent of the numerical argument. See also L<Math::Trig>.
1422 This is identical to the C function C<tanh()>, returning the
1423 hyperbolic tangent of the numerical argument. See also L<Math::Trig>.
1427 This is similar to the C function C<tcdrain()> for draining
1428 the output queue of its argument stream.
1430 Returns C<undef> on failure.
1434 This is similar to the C function C<tcflow()> for controlling
1435 the flow of its argument stream.
1437 Returns C<undef> on failure.
1441 This is similar to the C function C<tcflush()> for flushing
1442 the I/O buffers of its argument stream.
1444 Returns C<undef> on failure.
1448 This is identical to the C function C<tcgetpgrp()> for returning the
1449 process group identifier of the foreground process group of the controlling
1454 This is similar to the C function C<tcsendbreak()> for sending
1455 a break on its argument stream.
1457 Returns C<undef> on failure.
1461 This is similar to the C function C<tcsetpgrp()> for setting the
1462 process group identifier of the foreground process group of the controlling
1465 Returns C<undef> on failure.
1469 This is identical to Perl's builtin C<time()> function
1470 for returning the number of seconds since the epoch
1471 (whatever it is for the system), see L<perlfunc/time>.
1475 The times() function returns elapsed realtime since some point in the past
1476 (such as system startup), user and system times for this process, and user
1477 and system times used by child processes. All times are returned in clock
1480 ($realtime, $user, $system, $cuser, $csystem) = POSIX::times();
1482 Note: Perl's builtin C<times()> function returns four values, measured in
1487 Use method C<IO::File::new_tmpfile()> instead, or see L<File::Temp>.
1491 Returns a name for a temporary file.
1493 $tmpfile = POSIX::tmpnam();
1495 For security reasons, which are probably detailed in your system's
1496 documentation for the C library tmpnam() function, this interface
1497 should not be used; instead see L<File::Temp>.
1501 This is identical to the C function, except that it can apply to a single
1502 character or to a whole string. Consider using the C<lc()> function,
1503 see L<perlfunc/lc>, or the equivalent C<\L> operator inside doublequotish
1508 This is identical to the C function, except that it can apply to a single
1509 character or to a whole string. Consider using the C<uc()> function,
1510 see L<perlfunc/uc>, or the equivalent C<\U> operator inside doublequotish
1515 This is identical to the C function C<ttyname()> for returning the
1516 name of the current terminal.
1520 Retrieves the time conversion information from the C<tzname> variable.
1523 ($std, $dst) = POSIX::tzname();
1527 This is identical to the C function C<tzset()> for setting
1528 the current timezone based on the environment variable C<TZ>,
1529 to be used by C<ctime()>, C<localtime()>, C<mktime()>, and C<strftime()>
1534 This is identical to Perl's builtin C<umask()> function
1535 for setting (and querying) the file creation permission mask,
1536 see L<perlfunc/umask>.
1540 Get name of current operating system.
1542 ($sysname, $nodename, $release, $version, $machine) = POSIX::uname();
1544 Note that the actual meanings of the various fields are not
1545 that well standardized, do not expect any great portability.
1546 The C<$sysname> might be the name of the operating system,
1547 the C<$nodename> might be the name of the host, the C<$release>
1548 might be the (major) release number of the operating system,
1549 the C<$version> might be the (minor) release number of the
1550 operating system, and the C<$machine> might be a hardware identifier.
1555 Use method C<IO::Handle::ungetc()> instead.
1559 This is identical to Perl's builtin C<unlink()> function
1560 for removing files, see L<perlfunc/unlink>.
1564 This is identical to Perl's builtin C<utime()> function
1565 for changing the time stamps of files and directories,
1566 see L<perlfunc/utime>.
1570 vfprintf() is C-specific, see L<perlfunc/printf> instead.
1574 vprintf() is C-specific, see L<perlfunc/printf> instead.
1578 vsprintf() is C-specific, see L<perlfunc/sprintf> instead.
1582 This is identical to Perl's builtin C<wait()> function,
1583 see L<perlfunc/wait>.
1587 Wait for a child process to change state. This is identical to Perl's
1588 builtin C<waitpid()> function, see L<perlfunc/waitpid>.
1590 $pid = POSIX::waitpid( -1, POSIX::WNOHANG );
1591 print "status = ", ($? / 256), "\n";
1595 This is identical to the C function C<wcstombs()>.
1596 Perl does not have any support for the wide and multibyte
1597 characters of the C standards, so this might be a rather
1602 This is identical to the C function C<wctomb()>.
1603 Perl does not have any support for the wide and multibyte
1604 characters of the C standards, so this might be a rather
1609 Write to a file. This uses file descriptors such as those obtained by
1610 calling C<POSIX::open>.
1612 $fd = POSIX::open( "foo", &POSIX::O_WRONLY );
1614 $bytes = POSIX::write( $b, $buf, 5 );
1616 Returns C<undef> on failure.
1618 See also L<perlfunc/syswrite>.
1624 =head2 POSIX::SigAction
1630 Creates a new C<POSIX::SigAction> object which corresponds to the C
1631 C<struct sigaction>. This object will be destroyed automatically when it is
1632 no longer needed. The first parameter is the fully-qualified name of a sub
1633 which is a signal-handler. The second parameter is a C<POSIX::SigSet>
1634 object, it defaults to the empty set. The third parameter contains the
1635 C<sa_flags>, it defaults to 0.
1637 $sigset = POSIX::SigSet->new(SIGINT, SIGQUIT);
1638 $sigaction = POSIX::SigAction->new( 'main::handler', $sigset, &POSIX::SA_NOCLDSTOP );
1640 This C<POSIX::SigAction> object should be used with the C<POSIX::sigaction()>
1653 accessor functions to get/set the values of a SigAction object.
1655 $sigset = $sigaction->mask;
1656 $sigaction->flags(&POSIX::SA_RESTART);
1660 =head2 POSIX::SigSet
1666 Create a new SigSet object. This object will be destroyed automatically
1667 when it is no longer needed. Arguments may be supplied to initialize the
1670 Create an empty set.
1672 $sigset = POSIX::SigSet->new;
1674 Create a set with SIGUSR1.
1676 $sigset = POSIX::SigSet->new( &POSIX::SIGUSR1 );
1680 Add a signal to a SigSet object.
1682 $sigset->addset( &POSIX::SIGUSR2 );
1684 Returns C<undef> on failure.
1688 Remove a signal from the SigSet object.
1690 $sigset->delset( &POSIX::SIGUSR2 );
1692 Returns C<undef> on failure.
1696 Initialize the SigSet object to be empty.
1698 $sigset->emptyset();
1700 Returns C<undef> on failure.
1704 Initialize the SigSet object to include all signals.
1708 Returns C<undef> on failure.
1712 Tests the SigSet object to see if it contains a specific signal.
1714 if( $sigset->ismember( &POSIX::SIGUSR1 ) ){
1715 print "contains SIGUSR1\n";
1720 =head2 POSIX::Termios
1726 Create a new Termios object. This object will be destroyed automatically
1727 when it is no longer needed. A Termios object corresponds to the termios
1728 C struct. new() mallocs a new one, getattr() fills it from a file descriptor,
1729 and setattr() sets a file descriptor's parameters to match Termios' contents.
1731 $termios = POSIX::Termios->new;
1735 Get terminal control attributes.
1737 Obtain the attributes for stdin.
1741 Obtain the attributes for stdout.
1743 $termios->getattr( 1 )
1745 Returns C<undef> on failure.
1749 Retrieve a value from the c_cc field of a termios object. The c_cc field is
1750 an array so an index must be specified.
1752 $c_cc[1] = $termios->getcc(1);
1756 Retrieve the c_cflag field of a termios object.
1758 $c_cflag = $termios->getcflag;
1762 Retrieve the c_iflag field of a termios object.
1764 $c_iflag = $termios->getiflag;
1768 Retrieve the input baud rate.
1770 $ispeed = $termios->getispeed;
1774 Retrieve the c_lflag field of a termios object.
1776 $c_lflag = $termios->getlflag;
1780 Retrieve the c_oflag field of a termios object.
1782 $c_oflag = $termios->getoflag;
1786 Retrieve the output baud rate.
1788 $ospeed = $termios->getospeed;
1792 Set terminal control attributes.
1794 Set attributes immediately for stdout.
1796 $termios->setattr( 1, &POSIX::TCSANOW );
1798 Returns C<undef> on failure.
1802 Set a value in the c_cc field of a termios object. The c_cc field is an
1803 array so an index must be specified.
1805 $termios->setcc( &POSIX::VEOF, 1 );
1809 Set the c_cflag field of a termios object.
1811 $termios->setcflag( $c_cflag | &POSIX::CLOCAL );
1815 Set the c_iflag field of a termios object.
1817 $termios->setiflag( $c_iflag | &POSIX::BRKINT );
1821 Set the input baud rate.
1823 $termios->setispeed( &POSIX::B9600 );
1825 Returns C<undef> on failure.
1829 Set the c_lflag field of a termios object.
1831 $termios->setlflag( $c_lflag | &POSIX::ECHO );
1835 Set the c_oflag field of a termios object.
1837 $termios->setoflag( $c_oflag | &POSIX::OPOST );
1841 Set the output baud rate.
1843 $termios->setospeed( &POSIX::B9600 );
1845 Returns C<undef> on failure.
1847 =item Baud rate values
1849 B38400 B75 B200 B134 B300 B1800 B150 B0 B19200 B1200 B9600 B600 B4800 B50 B2400 B110
1851 =item Terminal interface values
1853 TCSADRAIN TCSANOW TCOON TCIOFLUSH TCOFLUSH TCION TCIFLUSH TCSAFLUSH TCIOFF TCOOFF
1855 =item c_cc field values
1857 VEOF VEOL VERASE VINTR VKILL VQUIT VSUSP VSTART VSTOP VMIN VTIME NCCS
1859 =item c_cflag field values
1861 CLOCAL CREAD CSIZE CS5 CS6 CS7 CS8 CSTOPB HUPCL PARENB PARODD
1863 =item c_iflag field values
1865 BRKINT ICRNL IGNBRK IGNCR IGNPAR INLCR INPCK ISTRIP IXOFF IXON PARMRK
1867 =item c_lflag field values
1869 ECHO ECHOE ECHOK ECHONL ICANON IEXTEN ISIG NOFLSH TOSTOP
1871 =item c_oflag field values
1877 =head1 PATHNAME CONSTANTS
1883 _PC_CHOWN_RESTRICTED _PC_LINK_MAX _PC_MAX_CANON _PC_MAX_INPUT _PC_NAME_MAX _PC_NO_TRUNC _PC_PATH_MAX _PC_PIPE_BUF _PC_VDISABLE
1887 =head1 POSIX CONSTANTS
1893 _POSIX_ARG_MAX _POSIX_CHILD_MAX _POSIX_CHOWN_RESTRICTED _POSIX_JOB_CONTROL _POSIX_LINK_MAX _POSIX_MAX_CANON _POSIX_MAX_INPUT _POSIX_NAME_MAX _POSIX_NGROUPS_MAX _POSIX_NO_TRUNC _POSIX_OPEN_MAX _POSIX_PATH_MAX _POSIX_PIPE_BUF _POSIX_SAVED_IDS _POSIX_SSIZE_MAX _POSIX_STREAM_MAX _POSIX_TZNAME_MAX _POSIX_VDISABLE _POSIX_VERSION
1897 =head1 SYSTEM CONFIGURATION
1903 _SC_ARG_MAX _SC_CHILD_MAX _SC_CLK_TCK _SC_JOB_CONTROL _SC_NGROUPS_MAX _SC_OPEN_MAX _SC_PAGESIZE _SC_SAVED_IDS _SC_STREAM_MAX _SC_TZNAME_MAX _SC_VERSION
1913 E2BIG EACCES EADDRINUSE EADDRNOTAVAIL EAFNOSUPPORT EAGAIN EALREADY EBADF
1914 EBUSY ECHILD ECONNABORTED ECONNREFUSED ECONNRESET EDEADLK EDESTADDRREQ
1915 EDOM EDQUOT EEXIST EFAULT EFBIG EHOSTDOWN EHOSTUNREACH EINPROGRESS EINTR
1916 EINVAL EIO EISCONN EISDIR ELOOP EMFILE EMLINK EMSGSIZE ENAMETOOLONG
1917 ENETDOWN ENETRESET ENETUNREACH ENFILE ENOBUFS ENODEV ENOENT ENOEXEC
1918 ENOLCK ENOMEM ENOPROTOOPT ENOSPC ENOSYS ENOTBLK ENOTCONN ENOTDIR
1919 ENOTEMPTY ENOTSOCK ENOTTY ENXIO EOPNOTSUPP EPERM EPFNOSUPPORT EPIPE
1920 EPROCLIM EPROTONOSUPPORT EPROTOTYPE ERANGE EREMOTE ERESTART EROFS
1921 ESHUTDOWN ESOCKTNOSUPPORT ESPIPE ESRCH ESTALE ETIMEDOUT ETOOMANYREFS
1922 ETXTBSY EUSERS EWOULDBLOCK EXDEV
1932 FD_CLOEXEC F_DUPFD F_GETFD F_GETFL F_GETLK F_OK F_RDLCK F_SETFD F_SETFL F_SETLK F_SETLKW F_UNLCK F_WRLCK O_ACCMODE O_APPEND O_CREAT O_EXCL O_NOCTTY O_NONBLOCK O_RDONLY O_RDWR O_TRUNC O_WRONLY
1942 DBL_DIG DBL_EPSILON DBL_MANT_DIG DBL_MAX DBL_MAX_10_EXP DBL_MAX_EXP DBL_MIN DBL_MIN_10_EXP DBL_MIN_EXP FLT_DIG FLT_EPSILON FLT_MANT_DIG FLT_MAX FLT_MAX_10_EXP FLT_MAX_EXP FLT_MIN FLT_MIN_10_EXP FLT_MIN_EXP FLT_RADIX FLT_ROUNDS LDBL_DIG LDBL_EPSILON LDBL_MANT_DIG LDBL_MAX LDBL_MAX_10_EXP LDBL_MAX_EXP LDBL_MIN LDBL_MIN_10_EXP LDBL_MIN_EXP
1952 ARG_MAX CHAR_BIT CHAR_MAX CHAR_MIN CHILD_MAX INT_MAX INT_MIN LINK_MAX LONG_MAX LONG_MIN MAX_CANON MAX_INPUT MB_LEN_MAX NAME_MAX NGROUPS_MAX OPEN_MAX PATH_MAX PIPE_BUF SCHAR_MAX SCHAR_MIN SHRT_MAX SHRT_MIN SSIZE_MAX STREAM_MAX TZNAME_MAX UCHAR_MAX UINT_MAX ULONG_MAX USHRT_MAX
1962 LC_ALL LC_COLLATE LC_CTYPE LC_MONETARY LC_NUMERIC LC_TIME
1982 SA_NOCLDSTOP SA_NOCLDWAIT SA_NODEFER SA_ONSTACK SA_RESETHAND SA_RESTART
1983 SA_SIGINFO SIGABRT SIGALRM SIGCHLD SIGCONT SIGFPE SIGHUP SIGILL SIGINT
1984 SIGKILL SIGPIPE SIGQUIT SIGSEGV SIGSTOP SIGTERM SIGTSTP SIGTTIN SIGTTOU
1985 SIGUSR1 SIGUSR2 SIG_BLOCK SIG_DFL SIG_ERR SIG_IGN SIG_SETMASK
1996 S_IRGRP S_IROTH S_IRUSR S_IRWXG S_IRWXO S_IRWXU S_ISGID S_ISUID S_IWGRP S_IWOTH S_IWUSR S_IXGRP S_IXOTH S_IXUSR
2000 S_ISBLK S_ISCHR S_ISDIR S_ISFIFO S_ISREG
2010 EXIT_FAILURE EXIT_SUCCESS MB_CUR_MAX RAND_MAX
2020 BUFSIZ EOF FILENAME_MAX L_ctermid L_cuserid L_tmpname TMP_MAX
2030 CLK_TCK CLOCKS_PER_SEC
2040 R_OK SEEK_CUR SEEK_END SEEK_SET STDIN_FILENO STDOUT_FILENO STDERR_FILENO W_OK X_OK
2056 Do not suspend the calling process until a child process
2057 changes state but instead return immediately.
2061 Catch stopped child processes.
2067 WIFEXITED WEXITSTATUS WIFSIGNALED WTERMSIG WIFSTOPPED WSTOPSIG
2073 WIFEXITED($?) returns true if the child process exited normally
2074 (C<exit()> or by falling off the end of C<main()>)
2078 WEXITSTATUS($?) returns the normal exit status of the child process
2079 (only meaningful if WIFEXITED($?) is true)
2083 WIFSIGNALED($?) returns true if the child process terminated because
2088 WTERMSIG($?) returns the signal the child process terminated for
2089 (only meaningful if WIFSIGNALED($?) is true)
2093 WIFSTOPPED($?) returns true if the child process is currently stopped
2094 (can happen only if you specified the WUNTRACED flag to waitpid())
2098 WSTOPSIG($?) returns the signal the child process was stopped for
2099 (only meaningful if WIFSTOPPED($?) is true)