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
24 I<Everything is exported by default> with the exception of any POSIX
25 functions with the same name as a built-in Perl function, such as
26 C<abs>, C<alarm>, C<rmdir>, C<write>, etc.., which will be exported
27 only if you ask for them explicitly. This is an unfortunate backwards
28 compatibility feature. You can stop the exporting by saying C<use
29 POSIX ()> and then use the fully qualified names (ie. C<POSIX::SEEK_END>).
31 This document gives a condensed list of the features available in the POSIX
32 module. Consult your operating system's manpages for general information on
33 most features. Consult L<perlfunc> for functions which are noted as being
34 identical to Perl's builtin functions.
36 The first section describes POSIX functions from the 1003.1 specification.
37 The second section describes some classes for signal objects, TTY objects,
38 and other miscellaneous objects. The remaining sections list various
39 constants and macros in an organization which roughly follows IEEE Std
44 The POSIX module is probably the most complex Perl module supplied with
45 the standard distribution. It incorporates autoloading, namespace games,
46 and dynamic loading of code that's in Perl, C, or both. It's a great
51 A few functions are not implemented because they are C specific. If you
52 attempt to call these, they will print a message telling you that they
53 aren't implemented, and suggest using the Perl equivalent should one
54 exist. For example, trying to access the setjmp() call will elicit the
55 message "setjmp() is C-specific: use eval {} instead".
57 Furthermore, some evil vendors will claim 1003.1 compliance, but in fact
58 are not so: they will not pass the PCTS (POSIX Compliance Test Suites).
59 For example, one vendor may not define EDEADLK, or the semantics of the
60 errno values set by open(2) might not be quite right. Perl does not
61 attempt to verify POSIX compliance. That means you can currently
62 successfully say "use POSIX", and then later in your program you find
63 that your vendor has been lax and there's no usable ICANON macro after
64 all. This could be construed to be a bug.
72 This is identical to the C function C<_exit()>. It exits the program
73 immediately which means among other things buffered I/O is B<not> flushed.
75 Note that when using threads and in Linux this is B<not> a good way to
76 exit a thread because in Linux processes and threads are kind of the
77 same thing (Note: while this is the situation in early 2003 there are
78 projects under way to have threads with more POSIXly semantics in Linux).
79 If you want not to return from a thread, detach the thread.
83 This is identical to the C function C<abort()>. It terminates the
84 process with a C<SIGABRT> signal unless caught by a signal handler or
85 if the handler does not return normally (it e.g. does a C<longjmp>).
89 This is identical to Perl's builtin C<abs()> function, returning
90 the absolute value of its numerical argument.
94 Determines the accessibility of a file.
96 if( POSIX::access( "/", &POSIX::R_OK ) ){
97 print "have read permission\n";
100 Returns C<undef> on failure. Note: do not use C<access()> for
101 security purposes. Between the C<access()> call and the operation
102 you are preparing for the permissions might change: a classic
107 This is identical to the C function C<acos()>, returning
108 the arcus cosine of its numerical argument. See also L<Math::Trig>.
112 This is identical to Perl's builtin C<alarm()> function,
113 either for arming or disarming the C<SIGARLM> timer.
117 This is identical to the C function C<asctime()>. It returns
120 "Fri Jun 2 18:22:13 2000\n\0"
122 and it is called thusly
124 $asctime = asctime($sec, $min, $hour, $mday, $mon, $year,
125 $wday, $yday, $isdst);
127 The C<$mon> is zero-based: January equals C<0>. The C<$year> is
128 1900-based: 2001 equals C<101>. C<$wday> and C<$yday> default to zero
129 (and are usually ignored anyway), and C<$isdst> defaults to -1.
133 This is identical to the C function C<asin()>, returning
134 the arcus sine of its numerical argument. See also L<Math::Trig>.
138 Unimplemented, but you can use L<perlfunc/die> and the L<Carp> module
139 to achieve similar things.
143 This is identical to the C function C<atan()>, returning the
144 arcus tangent of its numerical argument. See also L<Math::Trig>.
148 This is identical to Perl's builtin C<atan2()> function, returning
149 the arcus tangent defined by its two numerical arguments, the I<y>
150 coordinate and the I<x> coordinate. See also L<Math::Trig>.
154 atexit() is C-specific: use C<END {}> instead, see L<perlsub>.
158 atof() is C-specific. Perl converts strings to numbers transparently.
159 If you need to force a scalar to a number, add a zero to it.
163 atoi() is C-specific. Perl converts strings to numbers transparently.
164 If you need to force a scalar to a number, add a zero to it.
165 If you need to have just the integer part, see L<perlfunc/int>.
169 atol() is C-specific. Perl converts strings to numbers transparently.
170 If you need to force a scalar to a number, add a zero to it.
171 If you need to have just the integer part, see L<perlfunc/int>.
175 bsearch() not supplied. For doing binary search on wordlists,
180 calloc() is C-specific. Perl does memory management transparently.
184 This is identical to the C function C<ceil()>, returning the smallest
185 integer value greater than or equal to the given numerical argument.
189 This is identical to Perl's builtin C<chdir()> function, allowing
190 one to change the working (default) directory, see L<perlfunc/chdir>.
194 This is identical to Perl's builtin C<chmod()> function, allowing
195 one to change file and directory permissions, see L<perlfunc/chmod>.
199 This is identical to Perl's builtin C<chown()> function, allowing one
200 to change file and directory owners and groups, see L<perlfunc/chown>.
204 Use the method C<IO::Handle::clearerr()> instead, to reset the error
205 state (if any) and EOF state (if any) of the given stream.
209 This is identical to the C function C<clock()>, returning the
210 amount of spent processor time in microseconds.
214 Close the file. This uses file descriptors such as those obtained by calling
217 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
220 Returns C<undef> on failure.
222 See also L<perlfunc/close>.
226 This is identical to Perl's builtin C<closedir()> function for closing
227 a directory handle, see L<perlfunc/closedir>.
231 This is identical to Perl's builtin C<cos()> function, for returning
232 the cosine of its numerical argument, see L<perlfunc/cos>.
233 See also L<Math::Trig>.
237 This is identical to the C function C<cosh()>, for returning
238 the hyperbolic cosine of its numeric argument. See also L<Math::Trig>.
242 Create a new file. This returns a file descriptor like the ones returned by
243 C<POSIX::open>. Use C<POSIX::close> to close the file.
245 $fd = POSIX::creat( "foo", 0611 );
248 See also L<perlfunc/sysopen> and its C<O_CREAT> flag.
252 Generates the path name for the controlling terminal.
254 $path = POSIX::ctermid();
258 This is identical to the C function C<ctime()> and equivalent
259 to C<asctime(localtime(...))>, see L</asctime> and L</localtime>.
263 Get the login name of the owner of the current process.
265 $name = POSIX::cuserid();
269 This is identical to the C function C<difftime()>, for returning
270 the time difference (in seconds) between two times (as returned
271 by C<time()>), see L</time>.
275 div() is C-specific, use L<perlfunc/int> on the usual C</> division and
280 This is similar to the C function C<dup()>, for duplicating a file
283 This uses file descriptors such as those obtained by calling
286 Returns C<undef> on failure.
290 This is similar to the C function C<dup2()>, for duplicating a file
291 descriptor to an another known file descriptor.
293 This uses file descriptors such as those obtained by calling
296 Returns C<undef> on failure.
300 Returns the value of errno.
302 $errno = POSIX::errno();
304 This identical to the numerical values of the C<$!>, see L<perlvar/$ERRNO>.
308 execl() is C-specific, see L<perlfunc/exec>.
312 execle() is C-specific, see L<perlfunc/exec>.
316 execlp() is C-specific, see L<perlfunc/exec>.
320 execv() is C-specific, see L<perlfunc/exec>.
324 execve() is C-specific, see L<perlfunc/exec>.
328 execvp() is C-specific, see L<perlfunc/exec>.
332 This is identical to Perl's builtin C<exit()> function for exiting the
333 program, see L<perlfunc/exit>.
337 This is identical to Perl's builtin C<exp()> function for
338 returning the exponent (I<e>-based) of the numerical argument,
343 This is identical to Perl's builtin C<abs()> function for returning
344 the absolute value of the numerical argument, see L<perlfunc/abs>.
348 Use method C<IO::Handle::close()> instead, or see L<perlfunc/close>.
352 This is identical to Perl's builtin C<fcntl()> function,
353 see L<perlfunc/fcntl>.
357 Use method C<IO::Handle::new_from_fd()> instead, or see L<perlfunc/open>.
361 Use method C<IO::Handle::eof()> instead, or see L<perlfunc/eof>.
365 Use method C<IO::Handle::error()> instead.
369 Use method C<IO::Handle::flush()> instead.
370 See also L<perlvar/$OUTPUT_AUTOFLUSH>.
374 Use method C<IO::Handle::getc()> instead, or see L<perlfunc/read>.
378 Use method C<IO::Seekable::getpos()> instead, or see L<L/seek>.
382 Use method C<IO::Handle::gets()> instead. Similar to E<lt>E<gt>, also known
383 as L<perlfunc/readline>.
387 Use method C<IO::Handle::fileno()> instead, or see L<perlfunc/fileno>.
391 This is identical to the C function C<floor()>, returning the largest
392 integer value less than or equal to the numerical argument.
396 This is identical to the C function C<fmod()>.
400 It returns the remainder C<$r = $x - $n*$y>, where C<$n = trunc($x/$y)>.
401 The C<$r> has the same sign as C<$x> and magnitude (absolute value)
402 less than the magnitude of C<$y>.
406 Use method C<IO::File::open()> instead, or see L<perlfunc/open>.
410 This is identical to Perl's builtin C<fork()> function
411 for duplicating the current process, see L<perlfunc/fork>
412 and L<perlfork> if you are in Windows.
416 Retrieves the value of a configurable limit on a file or directory. This
417 uses file descriptors such as those obtained by calling C<POSIX::open>.
419 The following will determine the maximum length of the longest allowable
420 pathname on the filesystem which holds C</var/foo>.
422 $fd = POSIX::open( "/var/foo", &POSIX::O_RDONLY );
423 $path_max = POSIX::fpathconf( $fd, &POSIX::_PC_PATH_MAX );
425 Returns C<undef> on failure.
429 fprintf() is C-specific, see L<perlfunc/printf> instead.
433 fputc() is C-specific, see L<perlfunc/print> instead.
437 fputs() is C-specific, see L<perlfunc/print> instead.
441 fread() is C-specific, see L<perlfunc/read> instead.
445 free() is C-specific. Perl does memory management transparently.
449 freopen() is C-specific, see L<perlfunc/open> instead.
453 Return the mantissa and exponent of a floating-point number.
455 ($mantissa, $exponent) = POSIX::frexp( 1.234e56 );
459 fscanf() is C-specific, use E<lt>E<gt> and regular expressions instead.
463 Use method C<IO::Seekable::seek()> instead, or see L<perlfunc/seek>.
467 Use method C<IO::Seekable::setpos()> instead, or seek L<perlfunc/seek>.
471 Get file status. This uses file descriptors such as those obtained by
472 calling C<POSIX::open>. The data returned is identical to the data from
473 Perl's builtin C<stat> function.
475 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
476 @stats = POSIX::fstat( $fd );
480 Use method C<IO::Handle::sync()> instead.
484 Use method C<IO::Seekable::tell()> instead, or see L<perlfunc/tell>.
488 fwrite() is C-specific, see L<perlfunc/print> instead.
492 This is identical to Perl's builtin C<getc()> function,
493 see L<perlfunc/getc>.
497 Returns one character from STDIN. Identical to Perl's C<getc()>,
498 see L<perlfunc/getc>.
502 Returns the name of the current working directory.
507 Returns the effective group identifier. Similar to Perl' s builtin
508 variable C<$(>, see L<perlvar/$EGID>.
512 Returns the value of the specified environment variable.
513 The same information is available through the C<%ENV> array.
517 Returns the effective user identifier. Identical to Perl's builtin C<$E<gt>>
518 variable, see L<perlvar/$EUID>.
522 Returns the user's real group identifier. Similar to Perl's builtin
523 variable C<$)>, see L<perlvar/$GID>.
527 This is identical to Perl's builtin C<getgrgid()> function for
528 returning group entries by group identifiers, see
529 L<perlfunc/getgrgid>.
533 This is identical to Perl's builtin C<getgrnam()> function for
534 returning group entries by group names, see L<perlfunc/getgrnam>.
538 Returns the ids of the user's supplementary groups. Similar to Perl's
539 builtin variable C<$)>, see L<perlvar/$GID>.
543 This is identical to Perl's builtin C<getlogin()> function for
544 returning the user name associated with the current session, see
545 L<perlfunc/getlogin>.
549 This is identical to Perl's builtin C<getpgrp()> function for
550 returning the process group identifier of the current process, see
555 Returns the process identifier. Identical to Perl's builtin
556 variable C<$$>, see L<perlvar/$PID>.
560 This is identical to Perl's builtin C<getppid()> function for
561 returning the process identifier of the parent process of the current
562 process , see L<perlfunc/getppid>.
566 This is identical to Perl's builtin C<getpwnam()> function for
567 returning user entries by user names, see L<perlfunc/getpwnam>.
571 This is identical to Perl's builtin C<getpwuid()> function for
572 returning user entries by user identifiers, see L<perlfunc/getpwuid>.
576 Returns one line from C<STDIN>, similar to E<lt>E<gt>, also known
577 as the C<readline()> function, see L<perlfunc/readline>.
579 B<NOTE>: if you have C programs that still use C<gets()>, be very
580 afraid. The C<gets()> function is a source of endless grief because
581 it has no buffer overrun checks. It should B<never> be used. The
582 C<fgets()> function should be preferred instead.
586 Returns the user's identifier. Identical to Perl's builtin C<$E<lt>> variable,
591 This is identical to Perl's builtin C<gmtime()> function for
592 converting seconds since the epoch to a date in Greenwich Mean Time,
593 see L<perlfunc/gmtime>.
597 This is identical to the C function, except that it can apply to a
598 single character or to a whole string. Note that locale settings may
599 affect what characters are considered C<isalnum>. Does not work on
600 Unicode characters code point 256 or higher. Consider using regular
601 expressions and the C</[[:alnum:]]/> construct instead, or possibly
602 the C</\w/> construct.
606 This is identical to the C function, except that it can apply to
607 a single character or to a whole string. Note that locale settings
608 may affect what characters are considered C<isalpha>. Does not work
609 on Unicode characters code point 256 or higher. Consider using regular
610 expressions and the C</[[:alpha:]]/> construct instead.
614 Returns a boolean indicating whether the specified filehandle is connected
615 to a tty. Similar to the C<-t> operator, see L<perlfunc/-X>.
619 This is identical to the C function, except that it can apply to
620 a single character or to a whole string. Note that locale settings
621 may affect what characters are considered C<iscntrl>. Does not work
622 on Unicode characters code point 256 or higher. Consider using regular
623 expressions and the C</[[:cntrl:]]/> construct instead.
627 This is identical to the C function, except that it can apply to
628 a single character or to a whole string. Note that locale settings
629 may affect what characters are considered C<isdigit> (unlikely, but
630 still possible). Does not work on Unicode characters code point 256
631 or higher. Consider using regular expressions and the C</[[:digit:]]/>
632 construct instead, or the C</\d/> construct.
636 This is identical to the C function, except that it can apply to
637 a single character or to a whole string. Note that locale settings
638 may affect what characters are considered C<isgraph>. Does not work
639 on Unicode characters code point 256 or higher. Consider using regular
640 expressions and the C</[[:graph:]]/> construct instead.
644 This is identical to the C function, except that it can apply to
645 a single character or to a whole string. Note that locale settings
646 may affect what characters are considered C<islower>. Does not work
647 on Unicode characters code point 256 or higher. Consider using regular
648 expressions and the C</[[:lower:]]/> construct instead. Do B<not> use
653 This is identical to the C function, except that it can apply to
654 a single character or to a whole string. Note that locale settings
655 may affect what characters are considered C<isprint>. Does not work
656 on Unicode characters code point 256 or higher. Consider using regular
657 expressions and the C</[[:print:]]/> construct instead.
661 This is identical to the C function, except that it can apply to
662 a single character or to a whole string. Note that locale settings
663 may affect what characters are considered C<ispunct>. Does not work
664 on Unicode characters code point 256 or higher. Consider using regular
665 expressions and the C</[[:punct:]]/> construct instead.
669 This is identical to the C function, except that it can apply to
670 a single character or to a whole string. Note that locale settings
671 may affect what characters are considered C<isspace>. Does not work
672 on Unicode characters code point 256 or higher. Consider using regular
673 expressions and the C</[[:space:]]/> construct instead, or the C</\s/>
674 construct. (Note that C</\s/> and C</[[:space:]]/> are slightly
675 different in that C</[[:space:]]/> can normally match a vertical tab,
676 while C</\s/> does not.)
680 This is identical to the C function, except that it can apply to
681 a single character or to a whole string. Note that locale settings
682 may affect what characters are considered C<isupper>. Does not work
683 on Unicode characters code point 256 or higher. Consider using regular
684 expressions and the C</[[:upper:]]/> construct instead. Do B<not> use
689 This is identical to the C function, except that it can apply to a single
690 character or to a whole string. Note that locale settings may affect what
691 characters are considered C<isxdigit> (unlikely, but still possible).
692 Does not work on Unicode characters code point 256 or higher.
693 Consider using regular expressions and the C</[[:xdigit:]]/>
694 construct instead, or simply C</[0-9a-f]/i>.
698 This is identical to Perl's builtin C<kill()> function for sending
699 signals to processes (often to terminate them), see L<perlfunc/kill>.
703 (For returning absolute values of long integers.)
704 labs() is C-specific, see L<perlfunc/abs> instead.
708 This is identical to the C function C<ldexp()>
709 for multiplying floating point numbers with powers of two.
711 $x_quadrupled = POSIX::ldexp($x, 2);
715 (For computing dividends of long integers.)
716 ldiv() is C-specific, use C</> and C<int()> instead.
720 This is identical to Perl's builtin C<link()> function
721 for creating hard links into files, see L<perlfunc/link>.
725 Get numeric formatting information. Returns a reference to a hash
726 containing the current locale formatting values.
728 Here is how to query the database for the B<de> (Deutsch or German) locale.
730 $loc = POSIX::setlocale( &POSIX::LC_ALL, "de" );
731 print "Locale = $loc\n";
732 $lconv = POSIX::localeconv();
733 print "decimal_point = ", $lconv->{decimal_point}, "\n";
734 print "thousands_sep = ", $lconv->{thousands_sep}, "\n";
735 print "grouping = ", $lconv->{grouping}, "\n";
736 print "int_curr_symbol = ", $lconv->{int_curr_symbol}, "\n";
737 print "currency_symbol = ", $lconv->{currency_symbol}, "\n";
738 print "mon_decimal_point = ", $lconv->{mon_decimal_point}, "\n";
739 print "mon_thousands_sep = ", $lconv->{mon_thousands_sep}, "\n";
740 print "mon_grouping = ", $lconv->{mon_grouping}, "\n";
741 print "positive_sign = ", $lconv->{positive_sign}, "\n";
742 print "negative_sign = ", $lconv->{negative_sign}, "\n";
743 print "int_frac_digits = ", $lconv->{int_frac_digits}, "\n";
744 print "frac_digits = ", $lconv->{frac_digits}, "\n";
745 print "p_cs_precedes = ", $lconv->{p_cs_precedes}, "\n";
746 print "p_sep_by_space = ", $lconv->{p_sep_by_space}, "\n";
747 print "n_cs_precedes = ", $lconv->{n_cs_precedes}, "\n";
748 print "n_sep_by_space = ", $lconv->{n_sep_by_space}, "\n";
749 print "p_sign_posn = ", $lconv->{p_sign_posn}, "\n";
750 print "n_sign_posn = ", $lconv->{n_sign_posn}, "\n";
754 This is identical to Perl's builtin C<localtime()> function for
755 converting seconds since the epoch to a date see L<perlfunc/localtime>.
759 This is identical to Perl's builtin C<log()> function,
760 returning the natural (I<e>-based) logarithm of the numerical argument,
765 This is identical to the C function C<log10()>,
766 returning the 10-base logarithm of the numerical argument.
769 sub log10 { log($_[0]) / log(10) }
773 sub log10 { log($_[0]) / 2.30258509299405 }
777 sub log10 { log($_[0]) * 0.434294481903252 }
781 longjmp() is C-specific: use L<perlfunc/die> instead.
785 Move the file's read/write position. This uses file descriptors such as
786 those obtained by calling C<POSIX::open>.
788 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
789 $off_t = POSIX::lseek( $fd, 0, &POSIX::SEEK_SET );
791 Returns C<undef> on failure.
795 malloc() is C-specific. Perl does memory management transparently.
799 This is identical to the C function C<mblen()>.
800 Perl does not have any support for the wide and multibyte
801 characters of the C standards, so this might be a rather
806 This is identical to the C function C<mbstowcs()>.
807 Perl does not have any support for the wide and multibyte
808 characters of the C standards, so this might be a rather
813 This is identical to the C function C<mbtowc()>.
814 Perl does not have any support for the wide and multibyte
815 characters of the C standards, so this might be a rather
820 memchr() is C-specific, see L<perlfunc/index> instead.
824 memcmp() is C-specific, use C<eq> instead, see L<perlop>.
828 memcpy() is C-specific, use C<=>, see L<perlop>, or see L<perlfunc/substr>.
832 memmove() is C-specific, use C<=>, see L<perlop>, or see L<perlfunc/substr>.
836 memset() is C-specific, use C<x> instead, see L<perlop>.
840 This is identical to Perl's builtin C<mkdir()> function
841 for creating directories, see L<perlfunc/mkdir>.
845 This is similar to the C function C<mkfifo()> for creating
848 if (mkfifo($path, $mode)) { ....
850 Returns C<undef> on failure. The C<$mode> is similar to the
851 mode of C<mkdir()>, see L<perlfunc/mkdir>, though for C<mkfifo>
852 you B<must> specify the C<$mode>.
856 Convert date/time info to a calendar time.
860 mktime(sec, min, hour, mday, mon, year, wday = 0, yday = 0, isdst = -1)
862 The month (C<mon>), weekday (C<wday>), and yearday (C<yday>) begin at zero.
863 I.e. January is 0, not 1; Sunday is 0, not 1; January 1st is 0, not 1. The
864 year (C<year>) is given in years since 1900. I.e. The year 1995 is 95; the
865 year 2001 is 101. Consult your system's C<mktime()> manpage for details
866 about these and the other arguments.
868 Calendar time for December 12, 1995, at 10:30 am.
870 $time_t = POSIX::mktime( 0, 30, 10, 12, 11, 95 );
871 print "Date = ", POSIX::ctime($time_t);
873 Returns C<undef> on failure.
877 Return the integral and fractional parts of a floating-point number.
879 ($fractional, $integral) = POSIX::modf( 3.14 );
883 This is similar to the C function C<nice()>, for changing
884 the scheduling preference of the current process. Positive
885 arguments mean more polite process, negative values more
886 needy process. Normal user processes can only be more polite.
888 Returns C<undef> on failure.
892 offsetof() is C-specific, you probably want to see L<perlfunc/pack> instead.
896 Open a file for reading for writing. This returns file descriptors, not
897 Perl filehandles. Use C<POSIX::close> to close the file.
899 Open a file read-only with mode 0666.
901 $fd = POSIX::open( "foo" );
903 Open a file for read and write.
905 $fd = POSIX::open( "foo", &POSIX::O_RDWR );
907 Open a file for write, with truncation.
909 $fd = POSIX::open( "foo", &POSIX::O_WRONLY | &POSIX::O_TRUNC );
911 Create a new file with mode 0640. Set up the file for writing.
913 $fd = POSIX::open( "foo", &POSIX::O_CREAT | &POSIX::O_WRONLY, 0640 );
915 Returns C<undef> on failure.
917 See also L<perlfunc/sysopen>.
921 Open a directory for reading.
923 $dir = POSIX::opendir( "/var" );
924 @files = POSIX::readdir( $dir );
925 POSIX::closedir( $dir );
927 Returns C<undef> on failure.
931 Retrieves the value of a configurable limit on a file or directory.
933 The following will determine the maximum length of the longest allowable
934 pathname on the filesystem which holds C</var>.
936 $path_max = POSIX::pathconf( "/var", &POSIX::_PC_PATH_MAX );
938 Returns C<undef> on failure.
942 This is similar to the C function C<pause()>, which suspends
943 the execution of the current process until a signal is received.
945 Returns C<undef> on failure.
949 This is identical to the C function C<perror()>, which outputs to the
950 standard error stream the specified message followed by ": " and the
951 current error string. Use the C<warn()> function and the C<$!>
952 variable instead, see L<perlfunc/warn> and L<perlvar/$ERRNO>.
956 Create an interprocess channel. This returns file descriptors like those
957 returned by C<POSIX::open>.
959 my ($read, $write) = POSIX::pipe();
960 POSIX::write( $write, "hello", 5 );
961 POSIX::read( $read, $buf, 5 );
963 See also L<perlfunc/pipe>.
967 Computes C<$x> raised to the power C<$exponent>.
969 $ret = POSIX::pow( $x, $exponent );
971 You can also use the C<**> operator, see L<perlop>.
975 Formats and prints the specified arguments to STDOUT.
976 See also L<perlfunc/printf>.
980 putc() is C-specific, see L<perlfunc/print> instead.
984 putchar() is C-specific, see L<perlfunc/print> instead.
988 puts() is C-specific, see L<perlfunc/print> instead.
992 qsort() is C-specific, see L<perlfunc/sort> instead.
996 Sends the specified signal to the current process.
997 See also L<perlfunc/kill> and the C<$$> in L<perlvar/$PID>.
1001 C<rand()> is non-portable, see L<perlfunc/rand> instead.
1005 Read from a file. This uses file descriptors such as those obtained by
1006 calling C<POSIX::open>. If the buffer C<$buf> is not large enough for the
1007 read then Perl will extend it to make room for the request.
1009 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
1010 $bytes = POSIX::read( $fd, $buf, 3 );
1012 Returns C<undef> on failure.
1014 See also L<perlfunc/sysread>.
1018 This is identical to Perl's builtin C<readdir()> function
1019 for reading directory entries, see L<perlfunc/readdir>.
1023 realloc() is C-specific. Perl does memory management transparently.
1027 This is identical to Perl's builtin C<unlink()> function
1028 for removing files, see L<perlfunc/unlink>.
1032 This is identical to Perl's builtin C<rename()> function
1033 for renaming files, see L<perlfunc/rename>.
1037 Seeks to the beginning of the file.
1041 This is identical to Perl's builtin C<rewinddir()> function for
1042 rewinding directory entry streams, see L<perlfunc/rewinddir>.
1046 This is identical to Perl's builtin C<rmdir()> function
1047 for removing (empty) directories, see L<perlfunc/rmdir>.
1051 scanf() is C-specific, use E<lt>E<gt> and regular expressions instead,
1056 Sets the real group identifier and the effective group identifier for
1057 this process. Similar to assigning a value to the Perl's builtin
1058 C<$)> variable, see L<perlvar/$EGID>, except that the latter
1059 will change only the real user identifier, and that the setgid()
1060 uses only a single numeric argument, as opposed to a space-separated
1065 C<setjmp()> is C-specific: use C<eval {}> instead,
1066 see L<perlfunc/eval>.
1070 Modifies and queries program's locale. The following examples assume
1072 use POSIX qw(setlocale LC_ALL LC_CTYPE);
1076 The following will set the traditional UNIX system locale behavior
1077 (the second argument C<"C">).
1079 $loc = setlocale( LC_ALL, "C" );
1081 The following will query the current LC_CTYPE category. (No second
1082 argument means 'query'.)
1084 $loc = setlocale( LC_CTYPE );
1086 The following will set the LC_CTYPE behaviour according to the locale
1087 environment variables (the second argument C<"">).
1088 Please see your systems C<setlocale(3)> documentation for the locale
1089 environment variables' meaning or consult L<perllocale>.
1091 $loc = setlocale( LC_CTYPE, "" );
1093 The following will set the LC_COLLATE behaviour to Argentinian
1094 Spanish. B<NOTE>: The naming and availability of locales depends on
1095 your operating system. Please consult L<perllocale> for how to find
1096 out which locales are available in your system.
1098 $loc = setlocale( LC_ALL, "es_AR.ISO8859-1" );
1102 This is similar to the C function C<setpgid()> for
1103 setting the process group identifier of the current process.
1105 Returns C<undef> on failure.
1109 This is identical to the C function C<setsid()> for
1110 setting the session identifier of the current process.
1114 Sets the real user identifier and the effective user identifier for
1115 this process. Similar to assigning a value to the Perl's builtin
1116 C<$E<lt>> variable, see L<perlvar/$UID>, except that the latter
1117 will change only the real user identifier.
1121 Detailed signal management. This uses C<POSIX::SigAction> objects for
1122 the C<action> and C<oldaction> arguments (the oldaction can also be
1123 just a hash reference). Consult your system's C<sigaction> manpage
1124 for details, see also C<POSIX::SigRt>.
1128 sigaction(signal, action, oldaction = 0)
1130 Returns C<undef> on failure. The C<signal> must be a number (like
1131 SIGHUP), not a string (like "SIGHUP"), though Perl does try hard
1134 If you use the SA_SIGINFO flag, the signal handler will in addition to
1135 the first argument, the signal name, also receive a second argument, a
1136 hash reference, inside which are the following keys with the following
1137 semantics, as defined by POSIX/SUSv3:
1139 signo the signal number
1140 errno the error number
1141 code if this is zero or less, the signal was sent by
1142 a user process and the uid and pid make sense,
1143 otherwise the signal was sent by the kernel
1145 The following are also defined by POSIX/SUSv3, but unfortunately
1146 not very widely implemented:
1148 pid the process id generating the signal
1149 uid the uid of the process id generating the signal
1150 status exit value or signal for SIGCHLD
1151 band band event for SIGPOLL
1153 A third argument is also passed to the handler, which contains a copy
1154 of the raw binary contents of the siginfo structure: if a system has
1155 some non-POSIX fields, this third argument is where to unpack() them
1158 Note that not all siginfo values make sense simultaneously (some are
1159 valid only for certain signals, for example), and not all values make
1160 sense from Perl perspective, you should to consult your system's
1161 C<sigaction> and possibly also C<siginfo> documentation.
1165 siglongjmp() is C-specific: use L<perlfunc/die> instead.
1169 Examine signals that are blocked and pending. This uses C<POSIX::SigSet>
1170 objects for the C<sigset> argument. Consult your system's C<sigpending>
1171 manpage for details.
1177 Returns C<undef> on failure.
1181 Change and/or examine calling process's signal mask. This uses
1182 C<POSIX::SigSet> objects for the C<sigset> and C<oldsigset> arguments.
1183 Consult your system's C<sigprocmask> manpage for details.
1187 sigprocmask(how, sigset, oldsigset = 0)
1189 Returns C<undef> on failure.
1193 C<sigsetjmp()> is C-specific: use C<eval {}> instead,
1194 see L<perlfunc/eval>.
1198 Install a signal mask and suspend process until signal arrives. This uses
1199 C<POSIX::SigSet> objects for the C<signal_mask> argument. Consult your
1200 system's C<sigsuspend> manpage for details.
1204 sigsuspend(signal_mask)
1206 Returns C<undef> on failure.
1210 This is identical to Perl's builtin C<sin()> function
1211 for returning the sine of the numerical argument,
1212 see L<perlfunc/sin>. See also L<Math::Trig>.
1216 This is identical to the C function C<sinh()>
1217 for returning the hyperbolic sine of the numerical argument.
1218 See also L<Math::Trig>.
1222 This is functionally identical to Perl's builtin C<sleep()> function
1223 for suspending the execution of the current for process for certain
1224 number of seconds, see L<perlfunc/sleep>. There is one significant
1225 difference, however: C<POSIX::sleep()> returns the number of
1226 B<unslept> seconds, while the C<CORE::sleep()> returns the
1227 number of slept seconds.
1231 This is similar to Perl's builtin C<sprintf()> function
1232 for returning a string that has the arguments formatted as requested,
1233 see L<perlfunc/sprintf>.
1237 This is identical to Perl's builtin C<sqrt()> function.
1238 for returning the square root of the numerical argument,
1239 see L<perlfunc/sqrt>.
1243 Give a seed the pseudorandom number generator, see L<perlfunc/srand>.
1247 sscanf() is C-specific, use regular expressions instead,
1252 This is identical to Perl's builtin C<stat()> function
1253 for returning information about files and directories.
1257 strcat() is C-specific, use C<.=> instead, see L<perlop>.
1261 strchr() is C-specific, see L<perlfunc/index> instead.
1265 strcmp() is C-specific, use C<eq> or C<cmp> instead, see L<perlop>.
1269 This is identical to the C function C<strcoll()>
1270 for collating (comparing) strings transformed using
1271 the C<strxfrm()> function. Not really needed since
1272 Perl can do this transparently, see L<perllocale>.
1276 strcpy() is C-specific, use C<=> instead, see L<perlop>.
1280 strcspn() is C-specific, use regular expressions instead,
1285 Returns the error string for the specified errno.
1286 Identical to the string form of the C<$!>, see L<perlvar/$ERRNO>.
1290 Convert date and time information to string. Returns the string.
1294 strftime(fmt, sec, min, hour, mday, mon, year, wday = -1, yday = -1, isdst = -1)
1296 The month (C<mon>), weekday (C<wday>), and yearday (C<yday>) begin at zero.
1297 I.e. January is 0, not 1; Sunday is 0, not 1; January 1st is 0, not 1. The
1298 year (C<year>) is given in years since 1900. I.e., the year 1995 is 95; the
1299 year 2001 is 101. Consult your system's C<strftime()> manpage for details
1300 about these and the other arguments.
1302 If you want your code to be portable, your format (C<fmt>) argument
1303 should use only the conversion specifiers defined by the ANSI C
1304 standard (C89, to play safe). These are C<aAbBcdHIjmMpSUwWxXyYZ%>.
1305 But even then, the B<results> of some of the conversion specifiers are
1306 non-portable. For example, the specifiers C<aAbBcpZ> change according
1307 to the locale settings of the user, and both how to set locales (the
1308 locale names) and what output to expect are non-standard.
1309 The specifier C<c> changes according to the timezone settings of the
1310 user and the timezone computation rules of the operating system.
1311 The C<Z> specifier is notoriously unportable since the names of
1312 timezones are non-standard. Sticking to the numeric specifiers is the
1315 The given arguments are made consistent as though by calling
1316 C<mktime()> before calling your system's C<strftime()> function,
1317 except that the C<isdst> value is not affected.
1319 The string for Tuesday, December 12, 1995.
1321 $str = POSIX::strftime( "%A, %B %d, %Y", 0, 0, 0, 12, 11, 95, 2 );
1326 strlen() is C-specific, use C<length()> instead, see L<perlfunc/length>.
1330 strncat() is C-specific, use C<.=> instead, see L<perlop>.
1334 strncmp() is C-specific, use C<eq> instead, see L<perlop>.
1338 strncpy() is C-specific, use C<=> instead, see L<perlop>.
1342 strpbrk() is C-specific, use regular expressions instead,
1347 strrchr() is C-specific, see L<perlfunc/rindex> instead.
1351 strspn() is C-specific, use regular expressions instead,
1356 This is identical to Perl's builtin C<index()> function,
1357 see L<perlfunc/index>.
1361 String to double translation. Returns the parsed number and the number
1362 of characters in the unparsed portion of the string. Truly
1363 POSIX-compliant systems set $! ($ERRNO) to indicate a translation
1364 error, so clear $! before calling strtod. However, non-POSIX systems
1365 may not check for overflow, and therefore will never set $!.
1367 strtod should respect any POSIX I<setlocale()> settings.
1369 To parse a string $str as a floating point number use
1372 ($num, $n_unparsed) = POSIX::strtod($str);
1374 The second returned item and $! can be used to check for valid input:
1376 if (($str eq '') || ($n_unparsed != 0) || $!) {
1377 die "Non-numeric input $str" . ($! ? ": $!\n" : "\n");
1380 When called in a scalar context strtod returns the parsed number.
1384 strtok() is C-specific, use regular expressions instead, see
1385 L<perlre>, or L<perlfunc/split>.
1389 String to (long) integer translation. Returns the parsed number and
1390 the number of characters in the unparsed portion of the string. Truly
1391 POSIX-compliant systems set $! ($ERRNO) to indicate a translation
1392 error, so clear $! before calling strtol. However, non-POSIX systems
1393 may not check for overflow, and therefore will never set $!.
1395 strtol should respect any POSIX I<setlocale()> settings.
1397 To parse a string $str as a number in some base $base use
1400 ($num, $n_unparsed) = POSIX::strtol($str, $base);
1402 The base should be zero or between 2 and 36, inclusive. When the base
1403 is zero or omitted strtol will use the string itself to determine the
1404 base: a leading "0x" or "0X" means hexadecimal; a leading "0" means
1405 octal; any other leading characters mean decimal. Thus, "1234" is
1406 parsed as a decimal number, "01234" as an octal number, and "0x1234"
1407 as a hexadecimal number.
1409 The second returned item and $! can be used to check for valid input:
1411 if (($str eq '') || ($n_unparsed != 0) || !$!) {
1412 die "Non-numeric input $str" . $! ? ": $!\n" : "\n";
1415 When called in a scalar context strtol returns the parsed number.
1419 String to unsigned (long) integer translation. strtoul() is identical
1420 to strtol() except that strtoul() only parses unsigned integers. See
1421 L</strtol> for details.
1423 Note: Some vendors supply strtod() and strtol() but not strtoul().
1424 Other vendors that do supply strtoul() parse "-1" as a valid value.
1428 String transformation. Returns the transformed string.
1430 $dst = POSIX::strxfrm( $src );
1432 Used in conjunction with the C<strcoll()> function, see L</strcoll>.
1434 Not really needed since Perl can do this transparently, see
1439 Retrieves values of system configurable variables.
1441 The following will get the machine's clock speed.
1443 $clock_ticks = POSIX::sysconf( &POSIX::_SC_CLK_TCK );
1445 Returns C<undef> on failure.
1449 This is identical to Perl's builtin C<system()> function, see
1454 This is identical to the C function C<tan()>, returning the
1455 tangent of the numerical argument. See also L<Math::Trig>.
1459 This is identical to the C function C<tanh()>, returning the
1460 hyperbolic tangent of the numerical argument. See also L<Math::Trig>.
1464 This is similar to the C function C<tcdrain()> for draining
1465 the output queue of its argument stream.
1467 Returns C<undef> on failure.
1471 This is similar to the C function C<tcflow()> for controlling
1472 the flow of its argument stream.
1474 Returns C<undef> on failure.
1478 This is similar to the C function C<tcflush()> for flushing
1479 the I/O buffers of its argument stream.
1481 Returns C<undef> on failure.
1485 This is identical to the C function C<tcgetpgrp()> for returning the
1486 process group identifier of the foreground process group of the controlling
1491 This is similar to the C function C<tcsendbreak()> for sending
1492 a break on its argument stream.
1494 Returns C<undef> on failure.
1498 This is similar to the C function C<tcsetpgrp()> for setting the
1499 process group identifier of the foreground process group of the controlling
1502 Returns C<undef> on failure.
1506 This is identical to Perl's builtin C<time()> function
1507 for returning the number of seconds since the epoch
1508 (whatever it is for the system), see L<perlfunc/time>.
1512 The times() function returns elapsed realtime since some point in the past
1513 (such as system startup), user and system times for this process, and user
1514 and system times used by child processes. All times are returned in clock
1517 ($realtime, $user, $system, $cuser, $csystem) = POSIX::times();
1519 Note: Perl's builtin C<times()> function returns four values, measured in
1524 Use method C<IO::File::new_tmpfile()> instead, or see L<File::Temp>.
1528 Returns a name for a temporary file.
1530 $tmpfile = POSIX::tmpnam();
1532 For security reasons, which are probably detailed in your system's
1533 documentation for the C library tmpnam() function, this interface
1534 should not be used; instead see L<File::Temp>.
1538 This is identical to the C function, except that it can apply to a single
1539 character or to a whole string. Consider using the C<lc()> function,
1540 see L<perlfunc/lc>, or the equivalent C<\L> operator inside doublequotish
1545 This is identical to the C function, except that it can apply to a single
1546 character or to a whole string. Consider using the C<uc()> function,
1547 see L<perlfunc/uc>, or the equivalent C<\U> operator inside doublequotish
1552 This is identical to the C function C<ttyname()> for returning the
1553 name of the current terminal.
1557 Retrieves the time conversion information from the C<tzname> variable.
1560 ($std, $dst) = POSIX::tzname();
1564 This is identical to the C function C<tzset()> for setting
1565 the current timezone based on the environment variable C<TZ>,
1566 to be used by C<ctime()>, C<localtime()>, C<mktime()>, and C<strftime()>
1571 This is identical to Perl's builtin C<umask()> function
1572 for setting (and querying) the file creation permission mask,
1573 see L<perlfunc/umask>.
1577 Get name of current operating system.
1579 ($sysname, $nodename, $release, $version, $machine) = POSIX::uname();
1581 Note that the actual meanings of the various fields are not
1582 that well standardized, do not expect any great portability.
1583 The C<$sysname> might be the name of the operating system,
1584 the C<$nodename> might be the name of the host, the C<$release>
1585 might be the (major) release number of the operating system,
1586 the C<$version> might be the (minor) release number of the
1587 operating system, and the C<$machine> might be a hardware identifier.
1592 Use method C<IO::Handle::ungetc()> instead.
1596 This is identical to Perl's builtin C<unlink()> function
1597 for removing files, see L<perlfunc/unlink>.
1601 This is identical to Perl's builtin C<utime()> function
1602 for changing the time stamps of files and directories,
1603 see L<perlfunc/utime>.
1607 vfprintf() is C-specific, see L<perlfunc/printf> instead.
1611 vprintf() is C-specific, see L<perlfunc/printf> instead.
1615 vsprintf() is C-specific, see L<perlfunc/sprintf> instead.
1619 This is identical to Perl's builtin C<wait()> function,
1620 see L<perlfunc/wait>.
1624 Wait for a child process to change state. This is identical to Perl's
1625 builtin C<waitpid()> function, see L<perlfunc/waitpid>.
1627 $pid = POSIX::waitpid( -1, POSIX::WNOHANG );
1628 print "status = ", ($? / 256), "\n";
1632 This is identical to the C function C<wcstombs()>.
1633 Perl does not have any support for the wide and multibyte
1634 characters of the C standards, so this might be a rather
1639 This is identical to the C function C<wctomb()>.
1640 Perl does not have any support for the wide and multibyte
1641 characters of the C standards, so this might be a rather
1646 Write to a file. This uses file descriptors such as those obtained by
1647 calling C<POSIX::open>.
1649 $fd = POSIX::open( "foo", &POSIX::O_WRONLY );
1651 $bytes = POSIX::write( $fd, $buf, 5 );
1653 Returns C<undef> on failure.
1655 See also L<perlfunc/syswrite>.
1661 =head2 POSIX::SigAction
1667 Creates a new C<POSIX::SigAction> object which corresponds to the C
1668 C<struct sigaction>. This object will be destroyed automatically when
1669 it is no longer needed. The first parameter is the handler, a sub
1670 reference. The second parameter is a C<POSIX::SigSet> object, it
1671 defaults to the empty set. The third parameter contains the
1672 C<sa_flags>, it defaults to 0.
1674 $sigset = POSIX::SigSet->new(SIGINT, SIGQUIT);
1675 $sigaction = POSIX::SigAction->new( \&handler, $sigset, &POSIX::SA_NOCLDSTOP );
1677 This C<POSIX::SigAction> object is intended for use with the C<POSIX::sigaction()>
1690 accessor functions to get/set the values of a SigAction object.
1692 $sigset = $sigaction->mask;
1693 $sigaction->flags(&POSIX::SA_RESTART);
1697 accessor function for the "safe signals" flag of a SigAction object; see
1698 L<perlipc> for general information on safe (a.k.a. "deferred") signals. If
1699 you wish to handle a signal safely, use this accessor to set the "safe" flag
1700 in the C<POSIX::SigAction> object:
1702 $sigaction->safe(1);
1704 You may also examine the "safe" flag on the output action object which is
1705 filled in when given as the third parameter to C<POSIX::sigaction()>:
1707 sigaction(SIGINT, $new_action, $old_action);
1708 if ($old_action->safe) {
1709 # previous SIGINT handler used safe signals
1720 A hash of the POSIX realtime signal handlers. It is an extension of
1721 the standard %SIG, the $POSIX::SIGRT{SIGRTMIN} is roughly equivalent
1722 to $SIG{SIGRTMIN}, but the right POSIX moves (see below) are made with
1723 the POSIX::SigSet and POSIX::sigaction instead of accessing the %SIG.
1725 You can set the %POSIX::SIGRT elements to set the POSIX realtime
1726 signal handlers, use C<delete> and C<exists> on the elements, and use
1727 C<scalar> on the C<%POSIX::SIGRT> to find out how many POSIX realtime
1728 signals there are available (SIGRTMAX - SIGRTMIN + 1, the SIGRTMAX is
1729 a valid POSIX realtime signal).
1731 Setting the %SIGRT elements is equivalent to calling this:
1734 my ($rtsig, $handler, $flags) = @_;
1735 my $sigset = POSIX:SigSet($rtsig);
1736 my $sigact = POSIX::SigAction->new($handler, $sigset, $flags);
1737 sigaction($rtsig, $sigact);
1740 The flags default to zero, if you want something different you can
1741 either use C<local> on $POSIX::RtSig::SIGACTION_FLAGS, or you can
1742 derive from POSIX::SigRt and define your own C<new()> (the tied hash
1743 STORE method of the %SIGRT calls C<new($rtsig, $handler, $SIGACTION_FLAGS)>,
1744 where the $rtsig ranges from zero to SIGRTMAX - SIGRTMIN + 1).
1746 Just as with any signal, you can use sigaction($rtsig, undef, $oa) to
1747 retrieve the installed signal handler (or, rather, the signal action).
1749 B<NOTE:> whether POSIX realtime signals really work in your system, or
1750 whether Perl has been compiled so that it works with them, is outside
1755 Return the minimum POSIX realtime signal number available, or C<undef>
1756 if no POSIX realtime signals are available.
1760 Return the maximum POSIX realtime signal number available, or C<undef>
1761 if no POSIX realtime signals are available.
1765 =head2 POSIX::SigSet
1771 Create a new SigSet object. This object will be destroyed automatically
1772 when it is no longer needed. Arguments may be supplied to initialize the
1775 Create an empty set.
1777 $sigset = POSIX::SigSet->new;
1779 Create a set with SIGUSR1.
1781 $sigset = POSIX::SigSet->new( &POSIX::SIGUSR1 );
1785 Add a signal to a SigSet object.
1787 $sigset->addset( &POSIX::SIGUSR2 );
1789 Returns C<undef> on failure.
1793 Remove a signal from the SigSet object.
1795 $sigset->delset( &POSIX::SIGUSR2 );
1797 Returns C<undef> on failure.
1801 Initialize the SigSet object to be empty.
1803 $sigset->emptyset();
1805 Returns C<undef> on failure.
1809 Initialize the SigSet object to include all signals.
1813 Returns C<undef> on failure.
1817 Tests the SigSet object to see if it contains a specific signal.
1819 if( $sigset->ismember( &POSIX::SIGUSR1 ) ){
1820 print "contains SIGUSR1\n";
1825 =head2 POSIX::Termios
1831 Create a new Termios object. This object will be destroyed automatically
1832 when it is no longer needed. A Termios object corresponds to the termios
1833 C struct. new() mallocs a new one, getattr() fills it from a file descriptor,
1834 and setattr() sets a file descriptor's parameters to match Termios' contents.
1836 $termios = POSIX::Termios->new;
1840 Get terminal control attributes.
1842 Obtain the attributes for stdin.
1844 $termios->getattr( 0 ) # Recommended for clarity.
1847 Obtain the attributes for stdout.
1849 $termios->getattr( 1 )
1851 Returns C<undef> on failure.
1855 Retrieve a value from the c_cc field of a termios object. The c_cc field is
1856 an array so an index must be specified.
1858 $c_cc[1] = $termios->getcc(1);
1862 Retrieve the c_cflag field of a termios object.
1864 $c_cflag = $termios->getcflag;
1868 Retrieve the c_iflag field of a termios object.
1870 $c_iflag = $termios->getiflag;
1874 Retrieve the input baud rate.
1876 $ispeed = $termios->getispeed;
1880 Retrieve the c_lflag field of a termios object.
1882 $c_lflag = $termios->getlflag;
1886 Retrieve the c_oflag field of a termios object.
1888 $c_oflag = $termios->getoflag;
1892 Retrieve the output baud rate.
1894 $ospeed = $termios->getospeed;
1898 Set terminal control attributes.
1900 Set attributes immediately for stdout.
1902 $termios->setattr( 1, &POSIX::TCSANOW );
1904 Returns C<undef> on failure.
1908 Set a value in the c_cc field of a termios object. The c_cc field is an
1909 array so an index must be specified.
1911 $termios->setcc( &POSIX::VEOF, 1 );
1915 Set the c_cflag field of a termios object.
1917 $termios->setcflag( $c_cflag | &POSIX::CLOCAL );
1921 Set the c_iflag field of a termios object.
1923 $termios->setiflag( $c_iflag | &POSIX::BRKINT );
1927 Set the input baud rate.
1929 $termios->setispeed( &POSIX::B9600 );
1931 Returns C<undef> on failure.
1935 Set the c_lflag field of a termios object.
1937 $termios->setlflag( $c_lflag | &POSIX::ECHO );
1941 Set the c_oflag field of a termios object.
1943 $termios->setoflag( $c_oflag | &POSIX::OPOST );
1947 Set the output baud rate.
1949 $termios->setospeed( &POSIX::B9600 );
1951 Returns C<undef> on failure.
1953 =item Baud rate values
1955 B38400 B75 B200 B134 B300 B1800 B150 B0 B19200 B1200 B9600 B600 B4800 B50 B2400 B110
1957 =item Terminal interface values
1959 TCSADRAIN TCSANOW TCOON TCIOFLUSH TCOFLUSH TCION TCIFLUSH TCSAFLUSH TCIOFF TCOOFF
1961 =item c_cc field values
1963 VEOF VEOL VERASE VINTR VKILL VQUIT VSUSP VSTART VSTOP VMIN VTIME NCCS
1965 =item c_cflag field values
1967 CLOCAL CREAD CSIZE CS5 CS6 CS7 CS8 CSTOPB HUPCL PARENB PARODD
1969 =item c_iflag field values
1971 BRKINT ICRNL IGNBRK IGNCR IGNPAR INLCR INPCK ISTRIP IXOFF IXON PARMRK
1973 =item c_lflag field values
1975 ECHO ECHOE ECHOK ECHONL ICANON IEXTEN ISIG NOFLSH TOSTOP
1977 =item c_oflag field values
1983 =head1 PATHNAME CONSTANTS
1989 _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
1993 =head1 POSIX CONSTANTS
1999 _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
2003 =head1 SYSTEM CONFIGURATION
2009 _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
2019 E2BIG EACCES EADDRINUSE EADDRNOTAVAIL EAFNOSUPPORT EAGAIN EALREADY EBADF
2020 EBUSY ECHILD ECONNABORTED ECONNREFUSED ECONNRESET EDEADLK EDESTADDRREQ
2021 EDOM EDQUOT EEXIST EFAULT EFBIG EHOSTDOWN EHOSTUNREACH EINPROGRESS EINTR
2022 EINVAL EIO EISCONN EISDIR ELOOP EMFILE EMLINK EMSGSIZE ENAMETOOLONG
2023 ENETDOWN ENETRESET ENETUNREACH ENFILE ENOBUFS ENODEV ENOENT ENOEXEC
2024 ENOLCK ENOMEM ENOPROTOOPT ENOSPC ENOSYS ENOTBLK ENOTCONN ENOTDIR
2025 ENOTEMPTY ENOTSOCK ENOTTY ENXIO EOPNOTSUPP EPERM EPFNOSUPPORT EPIPE
2026 EPROCLIM EPROTONOSUPPORT EPROTOTYPE ERANGE EREMOTE ERESTART EROFS
2027 ESHUTDOWN ESOCKTNOSUPPORT ESPIPE ESRCH ESTALE ETIMEDOUT ETOOMANYREFS
2028 ETXTBSY EUSERS EWOULDBLOCK EXDEV
2038 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
2048 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
2058 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
2068 LC_ALL LC_COLLATE LC_CTYPE LC_MONETARY LC_NUMERIC LC_TIME
2088 SA_NOCLDSTOP SA_NOCLDWAIT SA_NODEFER SA_ONSTACK SA_RESETHAND SA_RESTART
2089 SA_SIGINFO SIGABRT SIGALRM SIGCHLD SIGCONT SIGFPE SIGHUP SIGILL SIGINT
2090 SIGKILL SIGPIPE SIGQUIT SIGSEGV SIGSTOP SIGTERM SIGTSTP SIGTTIN SIGTTOU
2091 SIGUSR1 SIGUSR2 SIG_BLOCK SIG_DFL SIG_ERR SIG_IGN SIG_SETMASK
2102 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
2106 S_ISBLK S_ISCHR S_ISDIR S_ISFIFO S_ISREG
2116 EXIT_FAILURE EXIT_SUCCESS MB_CUR_MAX RAND_MAX
2126 BUFSIZ EOF FILENAME_MAX L_ctermid L_cuserid L_tmpname TMP_MAX
2136 CLK_TCK CLOCKS_PER_SEC
2146 R_OK SEEK_CUR SEEK_END SEEK_SET STDIN_FILENO STDOUT_FILENO STDERR_FILENO W_OK X_OK
2162 Do not suspend the calling process until a child process
2163 changes state but instead return immediately.
2167 Catch stopped child processes.
2173 WIFEXITED WEXITSTATUS WIFSIGNALED WTERMSIG WIFSTOPPED WSTOPSIG
2179 WIFEXITED($?) returns true if the child process exited normally
2180 (C<exit()> or by falling off the end of C<main()>)
2184 WEXITSTATUS($?) returns the normal exit status of the child process
2185 (only meaningful if WIFEXITED($?) is true)
2189 WIFSIGNALED($?) returns true if the child process terminated because
2194 WTERMSIG($?) returns the signal the child process terminated for
2195 (only meaningful if WIFSIGNALED($?) is true)
2199 WIFSTOPPED($?) returns true if the child process is currently stopped
2200 (can happen only if you specified the WUNTRACED flag to waitpid())
2204 WSTOPSIG($?) returns the signal the child process was stopped for
2205 (only meaningful if WIFSTOPPED($?) is true)