1POSIX(3pm) Perl Programmers Reference Guide POSIX(3pm)
2
6 POSIX - Perl interface to IEEE Std 1003.1
7
9 use POSIX;
10 use POSIX qw(setsid);
11 use POSIX qw(:errno_h :fcntl_h);
12 printf "EINTR is %d\n", EINTR;
14 $sess_id = POSIX::setsid();
16 $fd = POSIX::open($path, O_CREAT|O_EXCL|O_WRONLY, 0644);
18 # note: that's a filedescriptor, *NOT* a filehandle
19
21 The POSIX module permits you to access all (or nearly all) the standard
22 POSIX 1003.1 identifiers. Many of these identifiers have been given
23 Perl-ish interfaces.
24 Everything is exported by default with the exception of any POSIX
26 functions with the same name as a built-in Perl function, such as
27 "abs", "alarm", "rmdir", "write", etc.., which will be exported only if
28 you ask for them explicitly. This is an unfortunate backwards
29 compatibility feature. You can stop the exporting by saying "use POSIX
30 ()" and then use the fully qualified names (ie. "POSIX::SEEK_END").
31 This document gives a condensed list of the features available in the
33 POSIX module. Consult your operating system's manpages for general
34 information on most features. Consult perlfunc for functions which are
35 noted as being identical to Perl's builtin functions.
36 The first section describes POSIX functions from the 1003.1
38 specification. The second section describes some classes for signal
39 objects, TTY objects, and other miscellaneous objects. The remaining
40 sections list various constants and macros in an organization which
41 roughly follows IEEE Std 1003.1b-1993.
42
44 The POSIX module is probably the most complex Perl module supplied with
45 the standard distribution. It incorporates autoloading, namespace
46 games, and dynamic loading of code that's in Perl, C, or both. It's a
47 great source of wisdom.
48
50 A few functions are not implemented because they are C specific. If
51 you attempt to call these, they will print a message telling you that
52 they aren't implemented, and suggest using the Perl equivalent should
53 one exist. For example, trying to access the setjmp() call will elicit
54 the message "setjmp() is C-specific: use eval {} instead".
55 Furthermore, some evil vendors will claim 1003.1 compliance, but in
57 fact are not so: they will not pass the PCTS (POSIX Compliance Test
58 Suites). For example, one vendor may not define EDEADLK, or the
59 semantics of the errno values set by open(2) might not be quite right.
60 Perl does not attempt to verify POSIX compliance. That means you can
61 currently successfully say "use POSIX", and then later in your program
62 you find that your vendor has been lax and there's no usable ICANON
63 macro after all. This could be construed to be a bug.
64
66 _exit This is identical to the C function "_exit()". It exits the
67 program immediately which means among other things buffered I/O
68 is not flushed.
69 Note that when using threads and in Linux this is not a good
71 way to exit a thread because in Linux processes and threads are
72 kind of the same thing (Note: while this is the situation in
73 early 2003 there are projects under way to have threads with
74 more POSIXly semantics in Linux). If you want not to return
75 from a thread, detach the thread.
76 abort This is identical to the C function "abort()". It terminates
78 the process with a "SIGABRT" signal unless caught by a signal
79 handler or if the handler does not return normally (it e.g.
80 does a "longjmp").
81 abs This is identical to Perl's builtin "abs()" function, returning
83 the absolute value of its numerical argument.
84 access Determines the accessibility of a file.
86 if( POSIX::access( "/", &POSIX::R_OK ) ){
88 print "have read permission\n";
89 }
90 Returns "undef" on failure. Note: do not use "access()" for
92 security purposes. Between the "access()" call and the
93 operation you are preparing for the permissions might change: a
94 classic race condition.
95 acos This is identical to the C function "acos()", returning the
97 arcus cosine of its numerical argument. See also Math::Trig.
98 alarm This is identical to Perl's builtin "alarm()" function, either
100 for arming or disarming the "SIGARLM" timer.
101 asctime This is identical to the C function "asctime()". It returns a
103 string of the form
104 "Fri Jun 2 18:22:13 2000\n\0"
106 and it is called thusly
108 $asctime = asctime($sec, $min, $hour, $mday, $mon, $year,
110 $wday, $yday, $isdst);
111 The $mon is zero-based: January equals 0. The $year is
113 1900-based: 2001 equals 101. $wday and $yday default to zero
114 (and are usually ignored anyway), and $isdst defaults to -1.
115 asin This is identical to the C function "asin()", returning the
117 arcus sine of its numerical argument. See also Math::Trig.
118 assert Unimplemented, but you can use "die" in perlfunc and the Carp
120 module to achieve similar things.
121 atan This is identical to the C function "atan()", returning the
123 arcus tangent of its numerical argument. See also Math::Trig.
124 atan2 This is identical to Perl's builtin "atan2()" function,
126 returning the arcus tangent defined by its two numerical
127 arguments, the y coordinate and the x coordinate. See also
128 Math::Trig.
129 atexit atexit() is C-specific: use "END {}" instead, see perlsub.
131 atof atof() is C-specific. Perl converts strings to numbers
133 transparently. If you need to force a scalar to a number, add
134 a zero to it.
135 atoi atoi() is C-specific. Perl converts strings to numbers
137 transparently. If you need to force a scalar to a number, add
138 a zero to it. If you need to have just the integer part, see
139 "int" in perlfunc.
140 atol atol() is C-specific. Perl converts strings to numbers
142 transparently. If you need to force a scalar to a number, add
143 a zero to it. If you need to have just the integer part, see
144 "int" in perlfunc.
145 bsearch bsearch() not supplied. For doing binary search on wordlists,
147 see Search::Dict.
148 calloc calloc() is C-specific. Perl does memory management
150 transparently.
151 ceil This is identical to the C function "ceil()", returning the
153 smallest integer value greater than or equal to the given
154 numerical argument.
155 chdir This is identical to Perl's builtin "chdir()" function,
157 allowing one to change the working (default) directory, see
158 "chdir" in perlfunc.
159 chmod This is identical to Perl's builtin "chmod()" function,
161 allowing one to change file and directory permissions, see
162 "chmod" in perlfunc.
163 chown This is identical to Perl's builtin "chown()" function,
165 allowing one to change file and directory owners and groups,
166 see "chown" in perlfunc.
167 clearerr
169 Use the method "IO::Handle::clearerr()" instead, to reset the
170 error state (if any) and EOF state (if any) of the given
171 stream.
172 clock This is identical to the C function "clock()", returning the
174 amount of spent processor time in microseconds.
175 close Close the file. This uses file descriptors such as those
177 obtained by calling "POSIX::open".
178 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
180 POSIX::close( $fd );
181 Returns "undef" on failure.
183 See also "close" in perlfunc.
185 closedir
187 This is identical to Perl's builtin "closedir()" function for
188 closing a directory handle, see "closedir" in perlfunc.
189 cos This is identical to Perl's builtin "cos()" function, for
191 returning the cosine of its numerical argument, see "cos" in
192 perlfunc. See also Math::Trig.
193 cosh This is identical to the C function "cosh()", for returning the
195 hyperbolic cosine of its numeric argument. See also
196 Math::Trig.
197 creat Create a new file. This returns a file descriptor like the
199 ones returned by "POSIX::open". Use "POSIX::close" to close
200 the file.
201 $fd = POSIX::creat( "foo", 0611 );
203 POSIX::close( $fd );
204 See also "sysopen" in perlfunc and its "O_CREAT" flag.
206 ctermid Generates the path name for the controlling terminal.
208 $path = POSIX::ctermid();
210 ctime This is identical to the C function "ctime()" and equivalent to
212 "asctime(localtime(...))", see "asctime" and "localtime".
213 cuserid Get the login name of the owner of the current process.
215 $name = POSIX::cuserid();
217 difftime
219 This is identical to the C function "difftime()", for returning
220 the time difference (in seconds) between two times (as returned
221 by "time()"), see "time".
222 div div() is C-specific, use "int" in perlfunc on the usual "/"
224 division and the modulus "%".
225 dup This is similar to the C function "dup()", for duplicating a
227 file descriptor.
228 This uses file descriptors such as those obtained by calling
230 "POSIX::open".
231 Returns "undef" on failure.
233 dup2 This is similar to the C function "dup2()", for duplicating a
235 file descriptor to an another known file descriptor.
236 This uses file descriptors such as those obtained by calling
238 "POSIX::open".
239 Returns "undef" on failure.
241 errno Returns the value of errno.
243 $errno = POSIX::errno();
245 This identical to the numerical values of the $!, see "$ERRNO"
247 in perlvar.
248 execl execl() is C-specific, see "exec" in perlfunc.
250 execle execle() is C-specific, see "exec" in perlfunc.
252 execlp execlp() is C-specific, see "exec" in perlfunc.
254 execv execv() is C-specific, see "exec" in perlfunc.
256 execve execve() is C-specific, see "exec" in perlfunc.
258 execvp execvp() is C-specific, see "exec" in perlfunc.
260 exit This is identical to Perl's builtin "exit()" function for
262 exiting the program, see "exit" in perlfunc.
263 exp This is identical to Perl's builtin "exp()" function for
265 returning the exponent (e-based) of the numerical argument, see
266 "exp" in perlfunc.
267 fabs This is identical to Perl's builtin "abs()" function for
269 returning the absolute value of the numerical argument, see
270 "abs" in perlfunc.
271 fclose Use method "IO::Handle::close()" instead, or see "close" in
273 perlfunc.
274 fcntl This is identical to Perl's builtin "fcntl()" function, see
276 "fcntl" in perlfunc.
277 fdopen Use method "IO::Handle::new_from_fd()" instead, or see "open"
279 in perlfunc.
280 feof Use method "IO::Handle::eof()" instead, or see "eof" in
282 perlfunc.
283 ferror Use method "IO::Handle::error()" instead.
285 fflush Use method "IO::Handle::flush()" instead. See also
287 "$OUTPUT_AUTOFLUSH" in perlvar.
288 fgetc Use method "IO::Handle::getc()" instead, or see "read" in
290 perlfunc.
291 fgetpos Use method "IO::Seekable::getpos()" instead, or see "seek" in
293 L.
294 fgets Use method "IO::Handle::gets()" instead. Similar to <>, also
296 known as "readline" in perlfunc.
297 fileno Use method "IO::Handle::fileno()" instead, or see "fileno" in
299 perlfunc.
300 floor This is identical to the C function "floor()", returning the
302 largest integer value less than or equal to the numerical
303 argument.
304 fmod This is identical to the C function "fmod()".
306 $r = fmod($x, $y);
308 It returns the remainder "$r = $x - $n*$y", where "$n =
310 trunc($x/$y)". The $r has the same sign as $x and magnitude
311 (absolute value) less than the magnitude of $y.
312 fopen Use method "IO::File::open()" instead, or see "open" in
314 perlfunc.
315 fork This is identical to Perl's builtin "fork()" function for
317 duplicating the current process, see "fork" in perlfunc and
318 perlfork if you are in Windows.
319 fpathconf
321 Retrieves the value of a configurable limit on a file or
322 directory. This uses file descriptors such as those obtained
323 by calling "POSIX::open".
324 The following will determine the maximum length of the longest
326 allowable pathname on the filesystem which holds "/var/foo".
327 $fd = POSIX::open( "/var/foo", &POSIX::O_RDONLY );
329 $path_max = POSIX::fpathconf( $fd, &POSIX::_PC_PATH_MAX );
330 Returns "undef" on failure.
332 fprintf fprintf() is C-specific, see "printf" in perlfunc instead.
334 fputc fputc() is C-specific, see "print" in perlfunc instead.
336 fputs fputs() is C-specific, see "print" in perlfunc instead.
338 fread fread() is C-specific, see "read" in perlfunc instead.
340 free free() is C-specific. Perl does memory management
342 transparently.
343 freopen freopen() is C-specific, see "open" in perlfunc instead.
345 frexp Return the mantissa and exponent of a floating-point number.
347 ($mantissa, $exponent) = POSIX::frexp( 1.234e56 );
349 fscanf fscanf() is C-specific, use <> and regular expressions instead.
351 fseek Use method "IO::Seekable::seek()" instead, or see "seek" in
353 perlfunc.
354 fsetpos Use method "IO::Seekable::setpos()" instead, or seek "seek" in
356 perlfunc.
357 fstat Get file status. This uses file descriptors such as those
359 obtained by calling "POSIX::open". The data returned is
360 identical to the data from Perl's builtin "stat" function.
361 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
363 @stats = POSIX::fstat( $fd );
364 fsync Use method "IO::Handle::sync()" instead.
366 ftell Use method "IO::Seekable::tell()" instead, or see "tell" in
368 perlfunc.
369 fwrite fwrite() is C-specific, see "print" in perlfunc instead.
371 getc This is identical to Perl's builtin "getc()" function, see
373 "getc" in perlfunc.
374 getchar Returns one character from STDIN. Identical to Perl's
376 "getc()", see "getc" in perlfunc.
377 getcwd Returns the name of the current working directory. See also
379 Cwd.
380 getegid Returns the effective group identifier. Similar to Perl' s
382 builtin variable $(, see "$EGID" in perlvar.
383 getenv Returns the value of the specified environment variable. The
385 same information is available through the %ENV array.
386 geteuid Returns the effective user identifier. Identical to Perl's
388 builtin $> variable, see "$EUID" in perlvar.
389 getgid Returns the user's real group identifier. Similar to Perl's
391 builtin variable $), see "$GID" in perlvar.
392 getgrgid
394 This is identical to Perl's builtin "getgrgid()" function for
395 returning group entries by group identifiers, see "getgrgid" in
396 perlfunc.
397 getgrnam
399 This is identical to Perl's builtin "getgrnam()" function for
400 returning group entries by group names, see "getgrnam" in
401 perlfunc.
402 getgroups
404 Returns the ids of the user's supplementary groups. Similar to
405 Perl's builtin variable $), see "$GID" in perlvar.
406 getlogin
408 This is identical to Perl's builtin "getlogin()" function for
409 returning the user name associated with the current session,
410 see "getlogin" in perlfunc.
411 getpgrp This is identical to Perl's builtin "getpgrp()" function for
413 returning the process group identifier of the current process,
414 see "getpgrp" in perlfunc.
415 getpid Returns the process identifier. Identical to Perl's builtin
417 variable $$, see "$PID" in perlvar.
418 getppid This is identical to Perl's builtin "getppid()" function for
420 returning the process identifier of the parent process of the
421 current process , see "getppid" in perlfunc.
422 getpwnam
424 This is identical to Perl's builtin "getpwnam()" function for
425 returning user entries by user names, see "getpwnam" in
426 perlfunc.
427 getpwuid
429 This is identical to Perl's builtin "getpwuid()" function for
430 returning user entries by user identifiers, see "getpwuid" in
431 perlfunc.
432 gets Returns one line from "STDIN", similar to <>, also known as the
434 "readline()" function, see "readline" in perlfunc.
435 NOTE: if you have C programs that still use "gets()", be very
437 afraid. The "gets()" function is a source of endless grief
438 because it has no buffer overrun checks. It should never be
439 used. The "fgets()" function should be preferred instead.
440 getuid Returns the user's identifier. Identical to Perl's builtin $<
442 variable, see "$UID" in perlvar.
443 gmtime This is identical to Perl's builtin "gmtime()" function for
445 converting seconds since the epoch to a date in Greenwich Mean
446 Time, see "gmtime" in perlfunc.
447 isalnum This is identical to the C function, except that it can apply
449 to a single character or to a whole string. Note that locale
450 settings may affect what characters are considered "isalnum".
451 Does not work on Unicode characters code point 256 or higher.
452 Consider using regular expressions and the "/[[:alnum:]]/"
453 construct instead, or possibly the "/\w/" construct.
454 isalpha This is identical to the C function, except that it can apply
456 to a single character or to a whole string. Note that locale
457 settings may affect what characters are considered "isalpha".
458 Does not work on Unicode characters code point 256 or higher.
459 Consider using regular expressions and the "/[[:alpha:]]/"
460 construct instead.
461 isatty Returns a boolean indicating whether the specified filehandle
463 is connected to a tty. Similar to the "-t" operator, see "-X"
464 in perlfunc.
465 iscntrl This is identical to the C function, except that it can apply
467 to a single character or to a whole string. Note that locale
468 settings may affect what characters are considered "iscntrl".
469 Does not work on Unicode characters code point 256 or higher.
470 Consider using regular expressions and the "/[[:cntrl:]]/"
471 construct instead.
472 isdigit This is identical to the C function, except that it can apply
474 to a single character or to a whole string. Note that locale
475 settings may affect what characters are considered "isdigit"
476 (unlikely, but still possible). Does not work on Unicode
477 characters code point 256 or higher. Consider using regular
478 expressions and the "/[[:digit:]]/" construct instead, or the
479 "/\d/" construct.
480 isgraph This is identical to the C function, except that it can apply
482 to a single character or to a whole string. Note that locale
483 settings may affect what characters are considered "isgraph".
484 Does not work on Unicode characters code point 256 or higher.
485 Consider using regular expressions and the "/[[:graph:]]/"
486 construct instead.
487 islower This is identical to the C function, except that it can apply
489 to a single character or to a whole string. Note that locale
490 settings may affect what characters are considered "islower".
491 Does not work on Unicode characters code point 256 or higher.
492 Consider using regular expressions and the "/[[:lower:]]/"
493 construct instead. Do not use "/[a-z]/".
494 isprint This is identical to the C function, except that it can apply
496 to a single character or to a whole string. Note that locale
497 settings may affect what characters are considered "isprint".
498 Does not work on Unicode characters code point 256 or higher.
499 Consider using regular expressions and the "/[[:print:]]/"
500 construct instead.
501 ispunct This is identical to the C function, except that it can apply
503 to a single character or to a whole string. Note that locale
504 settings may affect what characters are considered "ispunct".
505 Does not work on Unicode characters code point 256 or higher.
506 Consider using regular expressions and the "/[[:punct:]]/"
507 construct instead.
508 isspace This is identical to the C function, except that it can apply
510 to a single character or to a whole string. Note that locale
511 settings may affect what characters are considered "isspace".
512 Does not work on Unicode characters code point 256 or higher.
513 Consider using regular expressions and the "/[[:space:]]/"
514 construct instead, or the "/\s/" construct. (Note that "/\s/"
515 and "/[[:space:]]/" are slightly different in that
516 "/[[:space:]]/" can normally match a vertical tab, while "/\s/"
517 does not.)
518 isupper This is identical to the C function, except that it can apply
520 to a single character or to a whole string. Note that locale
521 settings may affect what characters are considered "isupper".
522 Does not work on Unicode characters code point 256 or higher.
523 Consider using regular expressions and the "/[[:upper:]]/"
524 construct instead. Do not use "/[A-Z]/".
525 isxdigit
527 This is identical to the C function, except that it can apply
528 to a single character or to a whole string. Note that locale
529 settings may affect what characters are considered "isxdigit"
530 (unlikely, but still possible). Does not work on Unicode
531 characters code point 256 or higher. Consider using regular
532 expressions and the "/[[:xdigit:]]/" construct instead, or
533 simply "/[0-9a-f]/i".
534 kill This is identical to Perl's builtin "kill()" function for
536 sending signals to processes (often to terminate them), see
537 "kill" in perlfunc.
538 labs (For returning absolute values of long integers.) labs() is
540 C-specific, see "abs" in perlfunc instead.
541 lchown This is identical to the C function, except the order of
543 arguments is consistent with Perl's builtin "chown()" with the
544 added restriction of only one path, not an list of paths. Does
545 the same thing as the "chown()" function but changes the owner
546 of a symbolic link instead of the file the symbolic link points
547 to.
548 ldexp This is identical to the C function "ldexp()" for multiplying
550 floating point numbers with powers of two.
551 $x_quadrupled = POSIX::ldexp($x, 2);
553 ldiv (For computing dividends of long integers.) ldiv() is
555 C-specific, use "/" and "int()" instead.
556 link This is identical to Perl's builtin "link()" function for
558 creating hard links into files, see "link" in perlfunc.
559 localeconv
561 Get numeric formatting information. Returns a reference to a
562 hash containing the current locale formatting values.
563 Here is how to query the database for the de (Deutsch or
565 German) locale.
566 $loc = POSIX::setlocale( &POSIX::LC_ALL, "de" );
568 print "Locale = $loc\n";
569 $lconv = POSIX::localeconv();
570 print "decimal_point = ", $lconv->{decimal_point}, "\n";
571 print "thousands_sep = ", $lconv->{thousands_sep}, "\n";
572 print "grouping = ", $lconv->{grouping}, "\n";
573 print "int_curr_symbol = ", $lconv->{int_curr_symbol}, "\n";
574 print "currency_symbol = ", $lconv->{currency_symbol}, "\n";
575 print "mon_decimal_point = ", $lconv->{mon_decimal_point}, "\n";
576 print "mon_thousands_sep = ", $lconv->{mon_thousands_sep}, "\n";
577 print "mon_grouping = ", $lconv->{mon_grouping}, "\n";
578 print "positive_sign = ", $lconv->{positive_sign}, "\n";
579 print "negative_sign = ", $lconv->{negative_sign}, "\n";
580 print "int_frac_digits = ", $lconv->{int_frac_digits}, "\n";
581 print "frac_digits = ", $lconv->{frac_digits}, "\n";
582 print "p_cs_precedes = ", $lconv->{p_cs_precedes}, "\n";
583 print "p_sep_by_space = ", $lconv->{p_sep_by_space}, "\n";
584 print "n_cs_precedes = ", $lconv->{n_cs_precedes}, "\n";
585 print "n_sep_by_space = ", $lconv->{n_sep_by_space}, "\n";
586 print "p_sign_posn = ", $lconv->{p_sign_posn}, "\n";
587 print "n_sign_posn = ", $lconv->{n_sign_posn}, "\n";
588 localtime
590 This is identical to Perl's builtin "localtime()" function for
591 converting seconds since the epoch to a date see "localtime" in
592 perlfunc.
593 log This is identical to Perl's builtin "log()" function, returning
595 the natural (e-based) logarithm of the numerical argument, see
596 "log" in perlfunc.
597 log10 This is identical to the C function "log10()", returning the
599 10-base logarithm of the numerical argument. You can also use
600 sub log10 { log($_[0]) / log(10) }
602 or
604 sub log10 { log($_[0]) / 2.30258509299405 }
606 or
608 sub log10 { log($_[0]) * 0.434294481903252 }
610 longjmp longjmp() is C-specific: use "die" in perlfunc instead.
612 lseek Move the file's read/write position. This uses file
614 descriptors such as those obtained by calling "POSIX::open".
615 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
617 $off_t = POSIX::lseek( $fd, 0, &POSIX::SEEK_SET );
618 Returns "undef" on failure.
620 malloc malloc() is C-specific. Perl does memory management
622 transparently.
623 mblen This is identical to the C function "mblen()". Perl does not
625 have any support for the wide and multibyte characters of the C
626 standards, so this might be a rather useless function.
627 mbstowcs
629 This is identical to the C function "mbstowcs()". Perl does
630 not have any support for the wide and multibyte characters of
631 the C standards, so this might be a rather useless function.
632 mbtowc This is identical to the C function "mbtowc()". Perl does not
634 have any support for the wide and multibyte characters of the C
635 standards, so this might be a rather useless function.
636 memchr memchr() is C-specific, see "index" in perlfunc instead.
638 memcmp memcmp() is C-specific, use "eq" instead, see perlop.
640 memcpy memcpy() is C-specific, use "=", see perlop, or see "substr" in
642 perlfunc.
643 memmove memmove() is C-specific, use "=", see perlop, or see "substr"
645 in perlfunc.
646 memset memset() is C-specific, use "x" instead, see perlop.
648 mkdir This is identical to Perl's builtin "mkdir()" function for
650 creating directories, see "mkdir" in perlfunc.
651 mkfifo This is similar to the C function "mkfifo()" for creating FIFO
653 special files.
654 if (mkfifo($path, $mode)) { ....
656 Returns "undef" on failure. The $mode is similar to the mode
658 of "mkdir()", see "mkdir" in perlfunc, though for "mkfifo" you
659 must specify the $mode.
660 mktime Convert date/time info to a calendar time.
662 Synopsis:
664 mktime(sec, min, hour, mday, mon, year, wday = 0, yday = 0, isdst = -1)
666 The month ("mon"), weekday ("wday"), and yearday ("yday") begin
668 at zero. I.e. January is 0, not 1; Sunday is 0, not 1; January
669 1st is 0, not 1. The year ("year") is given in years since
670 1900. I.e. The year 1995 is 95; the year 2001 is 101. Consult
671 your system's "mktime()" manpage for details about these and
672 the other arguments.
673 Calendar time for December 12, 1995, at 10:30 am.
675 $time_t = POSIX::mktime( 0, 30, 10, 12, 11, 95 );
677 print "Date = ", POSIX::ctime($time_t);
678 Returns "undef" on failure.
680 modf Return the integral and fractional parts of a floating-point
682 number.
683 ($fractional, $integral) = POSIX::modf( 3.14 );
685 nice This is similar to the C function "nice()", for changing the
687 scheduling preference of the current process. Positive
688 arguments mean more polite process, negative values more needy
689 process. Normal user processes can only be more polite.
690 Returns "undef" on failure.
692 offsetof
694 offsetof() is C-specific, you probably want to see "pack" in
695 perlfunc instead.
696 open Open a file for reading for writing. This returns file
698 descriptors, not Perl filehandles. Use "POSIX::close" to close
699 the file.
700 Open a file read-only with mode 0666.
702 $fd = POSIX::open( "foo" );
704 Open a file for read and write.
706 $fd = POSIX::open( "foo", &POSIX::O_RDWR );
708 Open a file for write, with truncation.
710 $fd = POSIX::open( "foo", &POSIX::O_WRONLY | &POSIX::O_TRUNC );
712 Create a new file with mode 0640. Set up the file for writing.
714 $fd = POSIX::open( "foo", &POSIX::O_CREAT | &POSIX::O_WRONLY, 0640 );
716 Returns "undef" on failure.
718 See also "sysopen" in perlfunc.
720 opendir Open a directory for reading.
722 $dir = POSIX::opendir( "/var" );
724 @files = POSIX::readdir( $dir );
725 POSIX::closedir( $dir );
726 Returns "undef" on failure.
728 pathconf
730 Retrieves the value of a configurable limit on a file or
731 directory.
732 The following will determine the maximum length of the longest
734 allowable pathname on the filesystem which holds "/var".
735 $path_max = POSIX::pathconf( "/var", &POSIX::_PC_PATH_MAX );
737 Returns "undef" on failure.
739 pause This is similar to the C function "pause()", which suspends the
741 execution of the current process until a signal is received.
742 Returns "undef" on failure.
744 perror This is identical to the C function "perror()", which outputs
746 to the standard error stream the specified message followed by
747 ": " and the current error string. Use the "warn()" function
748 and the $! variable instead, see "warn" in perlfunc and
749 "$ERRNO" in perlvar.
750 pipe Create an interprocess channel. This returns file descriptors
752 like those returned by "POSIX::open".
753 my ($read, $write) = POSIX::pipe();
755 POSIX::write( $write, "hello", 5 );
756 POSIX::read( $read, $buf, 5 );
757 See also "pipe" in perlfunc.
759 pow Computes $x raised to the power $exponent.
761 $ret = POSIX::pow( $x, $exponent );
763 You can also use the "**" operator, see perlop.
765 printf Formats and prints the specified arguments to STDOUT. See also
767 "printf" in perlfunc.
768 putc putc() is C-specific, see "print" in perlfunc instead.
770 putchar putchar() is C-specific, see "print" in perlfunc instead.
772 puts puts() is C-specific, see "print" in perlfunc instead.
774 qsort qsort() is C-specific, see "sort" in perlfunc instead.
776 raise Sends the specified signal to the current process. See also
778 "kill" in perlfunc and the $$ in "$PID" in perlvar.
779 rand "rand()" is non-portable, see "rand" in perlfunc instead.
781 read Read from a file. This uses file descriptors such as those
783 obtained by calling "POSIX::open". If the buffer $buf is not
784 large enough for the read then Perl will extend it to make room
785 for the request.
786 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
788 $bytes = POSIX::read( $fd, $buf, 3 );
789 Returns "undef" on failure.
791 See also "sysread" in perlfunc.
793 readdir This is identical to Perl's builtin "readdir()" function for
795 reading directory entries, see "readdir" in perlfunc.
796 realloc realloc() is C-specific. Perl does memory management
798 transparently.
799 remove This is identical to Perl's builtin "unlink()" function for
801 removing files, see "unlink" in perlfunc.
802 rename This is identical to Perl's builtin "rename()" function for
804 renaming files, see "rename" in perlfunc.
805 rewind Seeks to the beginning of the file.
807 rewinddir
809 This is identical to Perl's builtin "rewinddir()" function for
810 rewinding directory entry streams, see "rewinddir" in perlfunc.
811 rmdir This is identical to Perl's builtin "rmdir()" function for
813 removing (empty) directories, see "rmdir" in perlfunc.
814 scanf scanf() is C-specific, use <> and regular expressions instead,
816 see perlre.
817 setgid Sets the real group identifier and the effective group
819 identifier for this process. Similar to assigning a value to
820 the Perl's builtin $) variable, see "$EGID" in perlvar, except
821 that the latter will change only the real user identifier, and
822 that the setgid() uses only a single numeric argument, as
823 opposed to a space-separated list of numbers.
824 setjmp "setjmp()" is C-specific: use "eval {}" instead, see "eval" in
826 perlfunc.
827 setlocale
829 Modifies and queries program's locale. The following examples
830 assume
831 use POSIX qw(setlocale LC_ALL LC_CTYPE);
833 has been issued.
835 The following will set the traditional UNIX system locale
837 behavior (the second argument "C").
838 $loc = setlocale( LC_ALL, "C" );
840 The following will query the current LC_CTYPE category. (No
842 second argument means 'query'.)
843 $loc = setlocale( LC_CTYPE );
845 The following will set the LC_CTYPE behaviour according to the
847 locale environment variables (the second argument ""). Please
848 see your systems setlocale(3) documentation for the locale
849 environment variables' meaning or consult perllocale.
850 $loc = setlocale( LC_CTYPE, "" );
852 The following will set the LC_COLLATE behaviour to Argentinian
854 Spanish. NOTE: The naming and availability of locales depends
855 on your operating system. Please consult perllocale for how to
856 find out which locales are available in your system.
857 $loc = setlocale( LC_COLLATE, "es_AR.ISO8859-1" );
859 setpgid This is similar to the C function "setpgid()" for setting the
861 process group identifier of the current process.
862 Returns "undef" on failure.
864 setsid This is identical to the C function "setsid()" for setting the
866 session identifier of the current process.
867 setuid Sets the real user identifier and the effective user identifier
869 for this process. Similar to assigning a value to the Perl's
870 builtin $< variable, see "$UID" in perlvar, except that the
871 latter will change only the real user identifier.
872 sigaction
874 Detailed signal management. This uses "POSIX::SigAction"
875 objects for the "action" and "oldaction" arguments (the
876 oldaction can also be just a hash reference). Consult your
877 system's "sigaction" manpage for details, see also
878 "POSIX::SigRt".
879 Synopsis:
881 sigaction(signal, action, oldaction = 0)
883 Returns "undef" on failure. The "signal" must be a number
885 (like SIGHUP), not a string (like "SIGHUP"), though Perl does
886 try hard to understand you.
887 If you use the SA_SIGINFO flag, the signal handler will in
889 addition to the first argument, the signal name, also receive a
890 second argument, a hash reference, inside which are the
891 following keys with the following semantics, as defined by
892 POSIX/SUSv3:
893 signo the signal number
895 errno the error number
896 code if this is zero or less, the signal was sent by
897 a user process and the uid and pid make sense,
898 otherwise the signal was sent by the kernel
899 The following are also defined by POSIX/SUSv3, but
901 unfortunately not very widely implemented:
902 pid the process id generating the signal
904 uid the uid of the process id generating the signal
905 status exit value or signal for SIGCHLD
906 band band event for SIGPOLL
907 A third argument is also passed to the handler, which contains
909 a copy of the raw binary contents of the siginfo structure: if
910 a system has some non-POSIX fields, this third argument is
911 where to unpack() them from.
912 Note that not all siginfo values make sense simultaneously
914 (some are valid only for certain signals, for example), and not
915 all values make sense from Perl perspective, you should to
916 consult your system's "sigaction" and possibly also "siginfo"
917 documentation.
918 siglongjmp
920 siglongjmp() is C-specific: use "die" in perlfunc instead.
921 sigpending
923 Examine signals that are blocked and pending. This uses
924 "POSIX::SigSet" objects for the "sigset" argument. Consult
925 your system's "sigpending" manpage for details.
926 Synopsis:
928 sigpending(sigset)
930 Returns "undef" on failure.
932 sigprocmask
934 Change and/or examine calling process's signal mask. This uses
935 "POSIX::SigSet" objects for the "sigset" and "oldsigset"
936 arguments. Consult your system's "sigprocmask" manpage for
937 details.
938 Synopsis:
940 sigprocmask(how, sigset, oldsigset = 0)
942 Returns "undef" on failure.
944 sigsetjmp
946 "sigsetjmp()" is C-specific: use "eval {}" instead, see "eval"
947 in perlfunc.
948 sigsuspend
950 Install a signal mask and suspend process until signal arrives.
951 This uses "POSIX::SigSet" objects for the "signal_mask"
952 argument. Consult your system's "sigsuspend" manpage for
953 details.
954 Synopsis:
956 sigsuspend(signal_mask)
958 Returns "undef" on failure.
960 sin This is identical to Perl's builtin "sin()" function for
962 returning the sine of the numerical argument, see "sin" in
963 perlfunc. See also Math::Trig.
964 sinh This is identical to the C function "sinh()" for returning the
966 hyperbolic sine of the numerical argument. See also
967 Math::Trig.
968 sleep This is functionally identical to Perl's builtin "sleep()"
970 function for suspending the execution of the current for
971 process for certain number of seconds, see "sleep" in perlfunc.
972 There is one significant difference, however: "POSIX::sleep()"
973 returns the number of unslept seconds, while the
974 "CORE::sleep()" returns the number of slept seconds.
975 sprintf This is similar to Perl's builtin "sprintf()" function for
977 returning a string that has the arguments formatted as
978 requested, see "sprintf" in perlfunc.
979 sqrt This is identical to Perl's builtin "sqrt()" function. for
981 returning the square root of the numerical argument, see "sqrt"
982 in perlfunc.
983 srand Give a seed the pseudorandom number generator, see "srand" in
985 perlfunc.
986 sscanf sscanf() is C-specific, use regular expressions instead, see
988 perlre.
989 stat This is identical to Perl's builtin "stat()" function for
991 returning information about files and directories.
992 strcat strcat() is C-specific, use ".=" instead, see perlop.
994 strchr strchr() is C-specific, see "index" in perlfunc instead.
996 strcmp strcmp() is C-specific, use "eq" or "cmp" instead, see perlop.
998 strcoll This is identical to the C function "strcoll()" for collating
1000 (comparing) strings transformed using the "strxfrm()" function.
1001 Not really needed since Perl can do this transparently, see
1002 perllocale.
1003 strcpy strcpy() is C-specific, use "=" instead, see perlop.
1005 strcspn strcspn() is C-specific, use regular expressions instead, see
1007 perlre.
1008 strerror
1010 Returns the error string for the specified errno. Identical to
1011 the string form of the $!, see "$ERRNO" in perlvar.
1012 strftime
1014 Convert date and time information to string. Returns the
1015 string.
1016 Synopsis:
1018 strftime(fmt, sec, min, hour, mday, mon, year, wday = -1, yday = -1, isdst = -1)
1020 The month ("mon"), weekday ("wday"), and yearday ("yday") begin
1022 at zero. I.e. January is 0, not 1; Sunday is 0, not 1; January
1023 1st is 0, not 1. The year ("year") is given in years since
1024 1900. I.e., the year 1995 is 95; the year 2001 is 101.
1025 Consult your system's "strftime()" manpage for details about
1026 these and the other arguments.
1027 If you want your code to be portable, your format ("fmt")
1029 argument should use only the conversion specifiers defined by
1030 the ANSI C standard (C89, to play safe). These are
1031 "aAbBcdHIjmMpSUwWxXyYZ%". But even then, the results of some
1032 of the conversion specifiers are non-portable. For example,
1033 the specifiers "aAbBcpZ" change according to the locale
1034 settings of the user, and both how to set locales (the locale
1035 names) and what output to expect are non-standard. The
1036 specifier "c" changes according to the timezone settings of the
1037 user and the timezone computation rules of the operating
1038 system. The "Z" specifier is notoriously unportable since the
1039 names of timezones are non-standard. Sticking to the numeric
1040 specifiers is the safest route.
1041 The given arguments are made consistent as though by calling
1043 "mktime()" before calling your system's "strftime()" function,
1044 except that the "isdst" value is not affected.
1045 The string for Tuesday, December 12, 1995.
1047 $str = POSIX::strftime( "%A, %B %d, %Y", 0, 0, 0, 12, 11, 95, 2 );
1049 print "$str\n";
1050 strlen strlen() is C-specific, use "length()" instead, see "length" in
1052 perlfunc.
1053 strncat strncat() is C-specific, use ".=" instead, see perlop.
1055 strncmp strncmp() is C-specific, use "eq" instead, see perlop.
1057 strncpy strncpy() is C-specific, use "=" instead, see perlop.
1059 strpbrk strpbrk() is C-specific, use regular expressions instead, see
1061 perlre.
1062 strrchr strrchr() is C-specific, see "rindex" in perlfunc instead.
1064 strspn strspn() is C-specific, use regular expressions instead, see
1066 perlre.
1067 strstr This is identical to Perl's builtin "index()" function, see
1069 "index" in perlfunc.
1070 strtod String to double translation. Returns the parsed number and the
1072 number of characters in the unparsed portion of the string.
1073 Truly POSIX-compliant systems set $! ($ERRNO) to indicate a
1074 translation error, so clear $! before calling strtod. However,
1075 non-POSIX systems may not check for overflow, and therefore
1076 will never set $!.
1077 strtod should respect any POSIX setlocale() settings.
1079 To parse a string $str as a floating point number use
1081 $! = 0;
1083 ($num, $n_unparsed) = POSIX::strtod($str);
1084 The second returned item and $! can be used to check for valid
1086 input:
1087 if (($str eq '') || ($n_unparsed != 0) || $!) {
1089 die "Non-numeric input $str" . ($! ? ": $!\n" : "\n");
1090 }
1091 When called in a scalar context strtod returns the parsed
1093 number.
1094 strtok strtok() is C-specific, use regular expressions instead, see
1096 perlre, or "split" in perlfunc.
1097 strtol String to (long) integer translation. Returns the parsed
1099 number and the number of characters in the unparsed portion of
1100 the string. Truly POSIX-compliant systems set $! ($ERRNO) to
1101 indicate a translation error, so clear $! before calling
1102 strtol. However, non-POSIX systems may not check for overflow,
1103 and therefore will never set $!.
1104 strtol should respect any POSIX setlocale() settings.
1106 To parse a string $str as a number in some base $base use
1108 $! = 0;
1110 ($num, $n_unparsed) = POSIX::strtol($str, $base);
1111 The base should be zero or between 2 and 36, inclusive. When
1113 the base is zero or omitted strtol will use the string itself
1114 to determine the base: a leading "0x" or "0X" means
1115 hexadecimal; a leading "0" means octal; any other leading
1116 characters mean decimal. Thus, "1234" is parsed as a decimal
1117 number, "01234" as an octal number, and "0x1234" as a
1118 hexadecimal number.
1119 The second returned item and $! can be used to check for valid
1121 input:
1122 if (($str eq '') || ($n_unparsed != 0) || !$!) {
1124 die "Non-numeric input $str" . $! ? ": $!\n" : "\n";
1125 }
1126 When called in a scalar context strtol returns the parsed
1128 number.
1129 strtoul String to unsigned (long) integer translation. strtoul() is
1131 identical to strtol() except that strtoul() only parses
1132 unsigned integers. See "strtol" for details.
1133 Note: Some vendors supply strtod() and strtol() but not
1135 strtoul(). Other vendors that do supply strtoul() parse "-1"
1136 as a valid value.
1137 strxfrm String transformation. Returns the transformed string.
1139 $dst = POSIX::strxfrm( $src );
1141 Used in conjunction with the "strcoll()" function, see
1143 "strcoll".
1144 Not really needed since Perl can do this transparently, see
1146 perllocale.
1147 sysconf Retrieves values of system configurable variables.
1149 The following will get the machine's clock speed.
1151 $clock_ticks = POSIX::sysconf( &POSIX::_SC_CLK_TCK );
1153 Returns "undef" on failure.
1155 system This is identical to Perl's builtin "system()" function, see
1157 "system" in perlfunc.
1158 tan This is identical to the C function "tan()", returning the
1160 tangent of the numerical argument. See also Math::Trig.
1161 tanh This is identical to the C function "tanh()", returning the
1163 hyperbolic tangent of the numerical argument. See also
1164 Math::Trig.
1165 tcdrain This is similar to the C function "tcdrain()" for draining the
1167 output queue of its argument stream.
1168 Returns "undef" on failure.
1170 tcflow This is similar to the C function "tcflow()" for controlling
1172 the flow of its argument stream.
1173 Returns "undef" on failure.
1175 tcflush This is similar to the C function "tcflush()" for flushing the
1177 I/O buffers of its argument stream.
1178 Returns "undef" on failure.
1180 tcgetpgrp
1182 This is identical to the C function "tcgetpgrp()" for returning
1183 the process group identifier of the foreground process group of
1184 the controlling terminal.
1185 tcsendbreak
1187 This is similar to the C function "tcsendbreak()" for sending a
1188 break on its argument stream.
1189 Returns "undef" on failure.
1191 tcsetpgrp
1193 This is similar to the C function "tcsetpgrp()" for setting the
1194 process group identifier of the foreground process group of the
1195 controlling terminal.
1196 Returns "undef" on failure.
1198 time This is identical to Perl's builtin "time()" function for
1200 returning the number of seconds since the epoch (whatever it is
1201 for the system), see "time" in perlfunc.
1202 times The times() function returns elapsed realtime since some point
1204 in the past (such as system startup), user and system times for
1205 this process, and user and system times used by child
1206 processes. All times are returned in clock ticks.
1207 ($realtime, $user, $system, $cuser, $csystem) = POSIX::times();
1209 Note: Perl's builtin "times()" function returns four values,
1211 measured in seconds.
1212 tmpfile Use method "IO::File::new_tmpfile()" instead, or see
1214 File::Temp.
1215 tmpnam Returns a name for a temporary file.
1217 $tmpfile = POSIX::tmpnam();
1219 For security reasons, which are probably detailed in your
1221 system's documentation for the C library tmpnam() function,
1222 this interface should not be used; instead see File::Temp.
1223 tolower This is identical to the C function, except that it can apply
1225 to a single character or to a whole string. Consider using the
1226 "lc()" function, see "lc" in perlfunc, or the equivalent "\L"
1227 operator inside doublequotish strings.
1228 toupper This is identical to the C function, except that it can apply
1230 to a single character or to a whole string. Consider using the
1231 "uc()" function, see "uc" in perlfunc, or the equivalent "\U"
1232 operator inside doublequotish strings.
1233 ttyname This is identical to the C function "ttyname()" for returning
1235 the name of the current terminal.
1236 tzname Retrieves the time conversion information from the "tzname"
1238 variable.
1239 POSIX::tzset();
1241 ($std, $dst) = POSIX::tzname();
1242 tzset This is identical to the C function "tzset()" for setting the
1244 current timezone based on the environment variable "TZ", to be
1245 used by "ctime()", "localtime()", "mktime()", and "strftime()"
1246 functions.
1247 umask This is identical to Perl's builtin "umask()" function for
1249 setting (and querying) the file creation permission mask, see
1250 "umask" in perlfunc.
1251 uname Get name of current operating system.
1253 ($sysname, $nodename, $release, $version, $machine) = POSIX::uname();
1255 Note that the actual meanings of the various fields are not
1257 that well standardized, do not expect any great portability.
1258 The $sysname might be the name of the operating system, the
1259 $nodename might be the name of the host, the $release might be
1260 the (major) release number of the operating system, the
1261 $version might be the (minor) release number of the operating
1262 system, and the $machine might be a hardware identifier.
1263 Maybe.
1264 ungetc Use method "IO::Handle::ungetc()" instead.
1266 unlink This is identical to Perl's builtin "unlink()" function for
1268 removing files, see "unlink" in perlfunc.
1269 utime This is identical to Perl's builtin "utime()" function for
1271 changing the time stamps of files and directories, see "utime"
1272 in perlfunc.
1273 vfprintf
1275 vfprintf() is C-specific, see "printf" in perlfunc instead.
1276 vprintf vprintf() is C-specific, see "printf" in perlfunc instead.
1278 vsprintf
1280 vsprintf() is C-specific, see "sprintf" in perlfunc instead.
1281 wait This is identical to Perl's builtin "wait()" function, see
1283 "wait" in perlfunc.
1284 waitpid Wait for a child process to change state. This is identical to
1286 Perl's builtin "waitpid()" function, see "waitpid" in perlfunc.
1287 $pid = POSIX::waitpid( -1, POSIX::WNOHANG );
1289 print "status = ", ($? / 256), "\n";
1290 wcstombs
1292 This is identical to the C function "wcstombs()". Perl does
1293 not have any support for the wide and multibyte characters of
1294 the C standards, so this might be a rather useless function.
1295 wctomb This is identical to the C function "wctomb()". Perl does not
1297 have any support for the wide and multibyte characters of the C
1298 standards, so this might be a rather useless function.
1299 write Write to a file. This uses file descriptors such as those
1301 obtained by calling "POSIX::open".
1302 $fd = POSIX::open( "foo", &POSIX::O_WRONLY );
1304 $buf = "hello";
1305 $bytes = POSIX::write( $fd, $buf, 5 );
1306 Returns "undef" on failure.
1308 See also "syswrite" in perlfunc.
1310
1312 POSIX::SigAction
1313 new Creates a new "POSIX::SigAction" object which corresponds to
1314 the C "struct sigaction". This object will be destroyed
1315 automatically when it is no longer needed. The first parameter
1316 is the handler, a sub reference. The second parameter is a
1317 "POSIX::SigSet" object, it defaults to the empty set. The
1318 third parameter contains the "sa_flags", it defaults to 0.
1319 $sigset = POSIX::SigSet->new(SIGINT, SIGQUIT);
1321 $sigaction = POSIX::SigAction->new( \&handler, $sigset, &POSIX::SA_NOCLDSTOP );
1322 This "POSIX::SigAction" object is intended for use with the
1324 "POSIX::sigaction()" function.
1325 handler
1327 mask
1328 flags accessor functions to get/set the values of a SigAction object.
1329 $sigset = $sigaction->mask;
1331 $sigaction->flags(&POSIX::SA_RESTART);
1332 safe accessor function for the "safe signals" flag of a SigAction
1334 object; see perlipc for general information on safe (a.k.a.
1335 "deferred") signals. If you wish to handle a signal safely,
1336 use this accessor to set the "safe" flag in the
1337 "POSIX::SigAction" object:
1338 $sigaction->safe(1);
1340 You may also examine the "safe" flag on the output action
1342 object which is filled in when given as the third parameter to
1343 "POSIX::sigaction()":
1344 sigaction(SIGINT, $new_action, $old_action);
1346 if ($old_action->safe) {
1347 # previous SIGINT handler used safe signals
1348 }
1349 POSIX::SigRt
1351 %SIGRT A hash of the POSIX realtime signal handlers. It is an
1352 extension of the standard %SIG, the $POSIX::SIGRT{SIGRTMIN} is
1353 roughly equivalent to $SIG{SIGRTMIN}, but the right POSIX moves
1354 (see below) are made with the POSIX::SigSet and
1355 POSIX::sigaction instead of accessing the %SIG.
1356 You can set the %POSIX::SIGRT elements to set the POSIX
1358 realtime signal handlers, use "delete" and "exists" on the
1359 elements, and use "scalar" on the %POSIX::SIGRT to find out how
1360 many POSIX realtime signals there are available (SIGRTMAX -
1361 SIGRTMIN + 1, the SIGRTMAX is a valid POSIX realtime signal).
1362 Setting the %SIGRT elements is equivalent to calling this:
1364 sub new {
1366 my ($rtsig, $handler, $flags) = @_;
1367 my $sigset = POSIX::SigSet($rtsig);
1368 my $sigact = POSIX::SigAction->new($handler, $sigset, $flags);
1369 sigaction($rtsig, $sigact);
1370 }
1371 The flags default to zero, if you want something different you
1373 can either use "local" on $POSIX::SigRt::SIGACTION_FLAGS, or
1374 you can derive from POSIX::SigRt and define your own "new()"
1375 (the tied hash STORE method of the %SIGRT calls "new($rtsig,
1376 $handler, $SIGACTION_FLAGS)", where the $rtsig ranges from zero
1377 to SIGRTMAX - SIGRTMIN + 1).
1378 Just as with any signal, you can use sigaction($rtsig, undef,
1380 $oa) to retrieve the installed signal handler (or, rather, the
1381 signal action).
1382 NOTE: whether POSIX realtime signals really work in your
1384 system, or whether Perl has been compiled so that it works with
1385 them, is outside of this discussion.
1386 SIGRTMIN
1388 Return the minimum POSIX realtime signal number available, or
1389 "undef" if no POSIX realtime signals are available.
1390 SIGRTMAX
1392 Return the maximum POSIX realtime signal number available, or
1393 "undef" if no POSIX realtime signals are available.
1394 POSIX::SigSet
1396 new Create a new SigSet object. This object will be destroyed
1397 automatically when it is no longer needed. Arguments may be
1398 supplied to initialize the set.
1399 Create an empty set.
1401 $sigset = POSIX::SigSet->new;
1403 Create a set with SIGUSR1.
1405 $sigset = POSIX::SigSet->new( &POSIX::SIGUSR1 );
1407 addset Add a signal to a SigSet object.
1409 $sigset->addset( &POSIX::SIGUSR2 );
1411 Returns "undef" on failure.
1413 delset Remove a signal from the SigSet object.
1415 $sigset->delset( &POSIX::SIGUSR2 );
1417 Returns "undef" on failure.
1419 emptyset
1421 Initialize the SigSet object to be empty.
1422 $sigset->emptyset();
1424 Returns "undef" on failure.
1426 fillset Initialize the SigSet object to include all signals.
1428 $sigset->fillset();
1430 Returns "undef" on failure.
1432 ismember
1434 Tests the SigSet object to see if it contains a specific
1435 signal.
1436 if( $sigset->ismember( &POSIX::SIGUSR1 ) ){
1438 print "contains SIGUSR1\n";
1439 }
1440 POSIX::Termios
1442 new Create a new Termios object. This object will be destroyed
1443 automatically when it is no longer needed. A Termios object
1444 corresponds to the termios C struct. new() mallocs a new one,
1445 getattr() fills it from a file descriptor, and setattr() sets a
1446 file descriptor's parameters to match Termios' contents.
1447 $termios = POSIX::Termios->new;
1449 getattr Get terminal control attributes.
1451 Obtain the attributes for stdin.
1453 $termios->getattr( 0 ) # Recommended for clarity.
1455 $termios->getattr()
1456 Obtain the attributes for stdout.
1458 $termios->getattr( 1 )
1460 Returns "undef" on failure.
1462 getcc Retrieve a value from the c_cc field of a termios object. The
1464 c_cc field is an array so an index must be specified.
1465 $c_cc[1] = $termios->getcc(1);
1467 getcflag
1469 Retrieve the c_cflag field of a termios object.
1470 $c_cflag = $termios->getcflag;
1472 getiflag
1474 Retrieve the c_iflag field of a termios object.
1475 $c_iflag = $termios->getiflag;
1477 getispeed
1479 Retrieve the input baud rate.
1480 $ispeed = $termios->getispeed;
1482 getlflag
1484 Retrieve the c_lflag field of a termios object.
1485 $c_lflag = $termios->getlflag;
1487 getoflag
1489 Retrieve the c_oflag field of a termios object.
1490 $c_oflag = $termios->getoflag;
1492 getospeed
1494 Retrieve the output baud rate.
1495 $ospeed = $termios->getospeed;
1497 setattr Set terminal control attributes.
1499 Set attributes immediately for stdout.
1501 $termios->setattr( 1, &POSIX::TCSANOW );
1503 Returns "undef" on failure.
1505 setcc Set a value in the c_cc field of a termios object. The c_cc
1507 field is an array so an index must be specified.
1508 $termios->setcc( &POSIX::VEOF, 1 );
1510 setcflag
1512 Set the c_cflag field of a termios object.
1513 $termios->setcflag( $c_cflag | &POSIX::CLOCAL );
1515 setiflag
1517 Set the c_iflag field of a termios object.
1518 $termios->setiflag( $c_iflag | &POSIX::BRKINT );
1520 setispeed
1522 Set the input baud rate.
1523 $termios->setispeed( &POSIX::B9600 );
1525 Returns "undef" on failure.
1527 setlflag
1529 Set the c_lflag field of a termios object.
1530 $termios->setlflag( $c_lflag | &POSIX::ECHO );
1532 setoflag
1534 Set the c_oflag field of a termios object.
1535 $termios->setoflag( $c_oflag | &POSIX::OPOST );
1537 setospeed
1539 Set the output baud rate.
1540 $termios->setospeed( &POSIX::B9600 );
1542 Returns "undef" on failure.
1544 Baud rate values
1546 B38400 B75 B200 B134 B300 B1800 B150 B0 B19200 B1200 B9600 B600
1547 B4800 B50 B2400 B110
1548 Terminal interface values
1550 TCSADRAIN TCSANOW TCOON TCIOFLUSH TCOFLUSH TCION TCIFLUSH
1551 TCSAFLUSH TCIOFF TCOOFF
1552 c_cc field values
1554 VEOF VEOL VERASE VINTR VKILL VQUIT VSUSP VSTART VSTOP VMIN
1555 VTIME NCCS
1556 c_cflag field values
1558 CLOCAL CREAD CSIZE CS5 CS6 CS7 CS8 CSTOPB HUPCL PARENB PARODD
1559 c_iflag field values
1561 BRKINT ICRNL IGNBRK IGNCR IGNPAR INLCR INPCK ISTRIP IXOFF IXON
1562 PARMRK
1563 c_lflag field values
1565 ECHO ECHOE ECHOK ECHONL ICANON IEXTEN ISIG NOFLSH TOSTOP
1566 c_oflag field values
1568 OPOST
1569
1571 Constants
1572 _PC_CHOWN_RESTRICTED _PC_LINK_MAX _PC_MAX_CANON _PC_MAX_INPUT
1573 _PC_NAME_MAX _PC_NO_TRUNC _PC_PATH_MAX _PC_PIPE_BUF
1574 _PC_VDISABLE
1575
1577 Constants
1578 _POSIX_ARG_MAX _POSIX_CHILD_MAX _POSIX_CHOWN_RESTRICTED
1579 _POSIX_JOB_CONTROL _POSIX_LINK_MAX _POSIX_MAX_CANON
1580 _POSIX_MAX_INPUT _POSIX_NAME_MAX _POSIX_NGROUPS_MAX
1581 _POSIX_NO_TRUNC _POSIX_OPEN_MAX _POSIX_PATH_MAX _POSIX_PIPE_BUF
1582 _POSIX_SAVED_IDS _POSIX_SSIZE_MAX _POSIX_STREAM_MAX
1583 _POSIX_TZNAME_MAX _POSIX_VDISABLE _POSIX_VERSION
1584
1586 Constants
1587 _SC_ARG_MAX _SC_CHILD_MAX _SC_CLK_TCK _SC_JOB_CONTROL
1588 _SC_NGROUPS_MAX _SC_OPEN_MAX _SC_PAGESIZE _SC_SAVED_IDS
1589 _SC_STREAM_MAX _SC_TZNAME_MAX _SC_VERSION
1590
1592 Constants
1593 E2BIG EACCES EADDRINUSE EADDRNOTAVAIL EAFNOSUPPORT EAGAIN
1594 EALREADY EBADF EBUSY ECHILD ECONNABORTED ECONNREFUSED
1595 ECONNRESET EDEADLK EDESTADDRREQ EDOM EDQUOT EEXIST EFAULT EFBIG
1596 EHOSTDOWN EHOSTUNREACH EINPROGRESS EINTR EINVAL EIO EISCONN
1597 EISDIR ELOOP EMFILE EMLINK EMSGSIZE ENAMETOOLONG ENETDOWN
1598 ENETRESET ENETUNREACH ENFILE ENOBUFS ENODEV ENOENT ENOEXEC
1599 ENOLCK ENOMEM ENOPROTOOPT ENOSPC ENOSYS ENOTBLK ENOTCONN
1600 ENOTDIR ENOTEMPTY ENOTSOCK ENOTTY ENXIO EOPNOTSUPP EPERM
1601 EPFNOSUPPORT EPIPE EPROCLIM EPROTONOSUPPORT EPROTOTYPE ERANGE
1602 EREMOTE ERESTART EROFS ESHUTDOWN ESOCKTNOSUPPORT ESPIPE ESRCH
1603 ESTALE ETIMEDOUT ETOOMANYREFS ETXTBSY EUSERS EWOULDBLOCK EXDEV
1604
1606 Constants
1607 FD_CLOEXEC F_DUPFD F_GETFD F_GETFL F_GETLK F_OK F_RDLCK F_SETFD
1608 F_SETFL F_SETLK F_SETLKW F_UNLCK F_WRLCK O_ACCMODE O_APPEND
1609 O_CREAT O_EXCL O_NOCTTY O_NONBLOCK O_RDONLY O_RDWR O_TRUNC
1610 O_WRONLY
1611
1613 Constants
1614 DBL_DIG DBL_EPSILON DBL_MANT_DIG DBL_MAX DBL_MAX_10_EXP
1615 DBL_MAX_EXP DBL_MIN DBL_MIN_10_EXP DBL_MIN_EXP FLT_DIG
1616 FLT_EPSILON FLT_MANT_DIG FLT_MAX FLT_MAX_10_EXP FLT_MAX_EXP
1617 FLT_MIN FLT_MIN_10_EXP FLT_MIN_EXP FLT_RADIX FLT_ROUNDS
1618 LDBL_DIG LDBL_EPSILON LDBL_MANT_DIG LDBL_MAX LDBL_MAX_10_EXP
1619 LDBL_MAX_EXP LDBL_MIN LDBL_MIN_10_EXP LDBL_MIN_EXP
1620
1622 Constants
1623 ARG_MAX CHAR_BIT CHAR_MAX CHAR_MIN CHILD_MAX INT_MAX INT_MIN
1624 LINK_MAX LONG_MAX LONG_MIN MAX_CANON MAX_INPUT MB_LEN_MAX
1625 NAME_MAX NGROUPS_MAX OPEN_MAX PATH_MAX PIPE_BUF SCHAR_MAX
1626 SCHAR_MIN SHRT_MAX SHRT_MIN SSIZE_MAX STREAM_MAX TZNAME_MAX
1627 UCHAR_MAX UINT_MAX ULONG_MAX USHRT_MAX
1628
1630 Constants
1631 LC_ALL LC_COLLATE LC_CTYPE LC_MONETARY LC_NUMERIC LC_TIME
1632
1634 Constants
1635 HUGE_VAL
1636
1638 Constants
1639 SA_NOCLDSTOP SA_NOCLDWAIT SA_NODEFER SA_ONSTACK SA_RESETHAND
1640 SA_RESTART SA_SIGINFO SIGABRT SIGALRM SIGCHLD SIGCONT SIGFPE
1641 SIGHUP SIGILL SIGINT SIGKILL SIGPIPE SIGQUIT SIGSEGV SIGSTOP
1642 SIGTERM SIGTSTP SIGTTIN SIGTTOU SIGUSR1 SIGUSR2 SIG_BLOCK
1643 SIG_DFL SIG_ERR SIG_IGN SIG_SETMASK SIG_UNBLOCK
1644
1646 Constants
1647 S_IRGRP S_IROTH S_IRUSR S_IRWXG S_IRWXO S_IRWXU S_ISGID S_ISUID
1648 S_IWGRP S_IWOTH S_IWUSR S_IXGRP S_IXOTH S_IXUSR
1649 Macros S_ISBLK S_ISCHR S_ISDIR S_ISFIFO S_ISREG
1651
1653 Constants
1654 EXIT_FAILURE EXIT_SUCCESS MB_CUR_MAX RAND_MAX
1655
1657 Constants
1658 BUFSIZ EOF FILENAME_MAX L_ctermid L_cuserid L_tmpname TMP_MAX
1659
1661 Constants
1662 CLK_TCK CLOCKS_PER_SEC
1663
1665 Constants
1666 R_OK SEEK_CUR SEEK_END SEEK_SET STDIN_FILENO STDOUT_FILENO
1667 STDERR_FILENO W_OK X_OK
1668
1670 Constants
1671 WNOHANG WUNTRACED
1672 WNOHANG Do not suspend the calling process until a
1674 child process changes state but instead return
1675 immediately.
1676 WUNTRACED Catch stopped child processes.
1678 Macros WIFEXITED WEXITSTATUS WIFSIGNALED WTERMSIG WIFSTOPPED WSTOPSIG
1680 WIFEXITED WIFEXITED($?) returns true if the child process
1682 exited normally ("exit()" or by falling off the
1683 end of "main()")
1684 WEXITSTATUS WEXITSTATUS($?) returns the normal exit status
1686 of the child process (only meaningful if
1687 WIFEXITED($?) is true)
1688 WIFSIGNALED WIFSIGNALED($?) returns true if the child
1690 process terminated because of a signal
1691 WTERMSIG WTERMSIG($?) returns the signal the child
1693 process terminated for (only meaningful if
1694 WIFSIGNALED($?) is true)
1695 WIFSTOPPED WIFSTOPPED($?) returns true if the child
1697 process is currently stopped (can happen only
1698 if you specified the WUNTRACED flag to
1699 waitpid())
1700 WSTOPSIG WSTOPSIG($?) returns the signal the child
1702 process was stopped for (only meaningful if
1703 WIFSTOPPED($?) is true)
1704perl v5.12.4 2011-06-20 POSIX(3pm)