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 This document gives a condensed list of the features available in the
26 POSIX module. Consult your operating system's manpages for general
27 information on most features. Consult perlfunc for functions which are
28 noted as being identical or almost identical to Perl's builtin
29 functions.
30 The first section describes POSIX functions from the 1003.1
32 specification. The second section describes some classes for signal
33 objects, TTY objects, and other miscellaneous objects. The remaining
34 sections list various constants and macros in an organization which
35 roughly follows IEEE Std 1003.1b-1993.
36 The notation "[C99]" indicates functions that were added in the ISO/IEC
38 9899:1999 version of the C language standard. Some may not be
39 available on your system if it adheres to an earlier standard.
40 Attempts to use any missing one will result in a fatal runtime error
41 message.
42
44 Everything is exported by default (with a handful of exceptions). This
45 is an unfortunate backwards compatibility feature and its use is
46 strongly discouraged. You should either prevent the exporting (by
47 saying "use POSIX ();", as usual) and then use fully qualified names
48 (e.g. "POSIX::SEEK_END"), or give an explicit import list. If you do
49 neither and opt for the default (as in "use POSIX;"), you will import
50 hundreds and hundreds of symbols into your namespace.
51 A few functions are not implemented because they are C specific. If
53 you attempt to call these, they will print a message telling you that
54 they aren't implemented, and suggest using the Perl equivalent, should
55 one exist. For example, trying to access the "setjmp()" call will
56 elicit the message ""setjmp() is C-specific: use eval {} instead"".
57 Furthermore, some evil vendors will claim 1003.1 compliance, but in
59 fact are not so: they will not pass the PCTS (POSIX Compliance Test
60 Suites). For example, one vendor may not define "EDEADLK", or the
61 semantics of the errno values set by open(2) might not be quite right.
62 Perl does not attempt to verify POSIX compliance. That means you can
63 currently successfully say "use POSIX", and then later in your program
64 you find that your vendor has been lax and there's no usable "ICANON"
65 macro after all. This could be construed to be a bug.
66
68 "_exit" This is identical to the C function "_exit()". It exits the
69 program immediately which means among other things buffered I/O
70 is not flushed.
71 Note that when using threads and in Linux this is not a good
73 way to exit a thread because in Linux processes and threads are
74 kind of the same thing (Note: while this is the situation in
75 early 2003 there are projects under way to have threads with
76 more POSIXly semantics in Linux). If you want not to return
77 from a thread, detach the thread.
78 "abort" This is identical to the C function "abort()". It terminates
80 the process with a "SIGABRT" signal unless caught by a signal
81 handler or if the handler does not return normally (it e.g.
82 does a "longjmp").
83 "abs" This is identical to Perl's builtin "abs()" function, returning
85 the absolute value of its numerical argument (except that
86 "POSIX::abs()" must be provided an explicit value (rather than
87 relying on an implicit $_):
88 $absolute_value = POSIX::abs(42); # good
90 $absolute_value = POSIX::abs(); # throws exception
92 "access"
94 Determines the accessibility of a file.
95 if( POSIX::access( "/", &POSIX::R_OK ) ){
97 print "have read permission\n";
98 }
99 Returns "undef" on failure. Note: do not use "access()" for
101 security purposes. Between the "access()" call and the
102 operation you are preparing for the permissions might change: a
103 classic race condition.
104 "acos" This is identical to the C function "acos()", returning the
106 arcus cosine of its numerical argument. See also Math::Trig.
107 "acosh" This is identical to the C function "acosh()", returning the
109 hyperbolic arcus cosine of its numerical argument [C99]. See
110 also Math::Trig. Added in Perl v5.22.
111 "alarm" This is identical to Perl's builtin "alarm()" function, either
113 for arming or disarming the "SIGARLM" timer, except that
114 "POSIX::alarm()" must be provided an explicit value (rather
115 than relying on an implicit $_):
116 POSIX::alarm(3) # good
118 POSIX::alarm() # throws exception
120 "asctime"
122 This is identical to the C function "asctime()". It returns a
123 string of the form
124 "Fri Jun 2 18:22:13 2000\n\0"
126 and it is called thusly
128 $asctime = asctime($sec, $min, $hour, $mday, $mon,
130 $year, $wday, $yday, $isdst);
131 The $mon is zero-based: January equals 0. The $year is
133 1900-based: 2001 equals 101. $wday and $yday default to zero
134 (and are usually ignored anyway), and $isdst defaults to -1.
135 Note the result is always in English. Use "strftime" instead
137 to get a result suitable for the current locale. That
138 function's %c format yields the locale's preferred
139 representation.
140 "asin" This is identical to the C function "asin()", returning the
142 arcus sine of its numerical argument. See also Math::Trig.
143 "asinh" This is identical to the C function "asinh()", returning the
145 hyperbolic arcus sine of its numerical argument [C99]. See
146 also Math::Trig. Added in Perl v5.22.
147 "assert"
149 Unimplemented, but you can use "die" in perlfunc and the Carp
150 module to achieve similar things.
151 "atan" This is identical to the C function "atan()", returning the
153 arcus tangent of its numerical argument. See also Math::Trig.
154 "atanh" This is identical to the C function "atanh()", returning the
156 hyperbolic arcus tangent of its numerical argument [C99]. See
157 also Math::Trig. Added in Perl v5.22.
158 "atan2" This is identical to Perl's builtin "atan2()" function,
160 returning the arcus tangent defined by its two numerical
161 arguments, the y coordinate and the x coordinate. See also
162 Math::Trig.
163 "atexit"
165 Not implemented. "atexit()" is C-specific: use "END {}"
166 instead, see perlmod.
167 "atof" Not implemented. "atof()" is C-specific. Perl converts
169 strings to numbers transparently. If you need to force a
170 scalar to a number, add a zero to it.
171 "atoi" Not implemented. "atoi()" is C-specific. Perl converts
173 strings to numbers transparently. If you need to force a
174 scalar to a number, add a zero to it. If you need to have just
175 the integer part, see "int" in perlfunc.
176 "atol" Not implemented. "atol()" is C-specific. Perl converts
178 strings to numbers transparently. If you need to force a
179 scalar to a number, add a zero to it. If you need to have just
180 the integer part, see "int" in perlfunc.
181 "bsearch"
183 "bsearch()" not supplied. For doing binary search on
184 wordlists, see Search::Dict.
185 "calloc"
187 Not implemented. "calloc()" is C-specific. Perl does memory
188 management transparently.
189 "cbrt" The cube root [C99]. Added in Perl v5.22.
191 "ceil" This is identical to the C function "ceil()", returning the
193 smallest integer value greater than or equal to the given
194 numerical argument.
195 "chdir" This is identical to Perl's builtin "chdir()" function,
197 allowing one to change the working (default) directory -- see
198 "chdir" in perlfunc -- with the exception that "POSIX::chdir()"
199 must be provided an explicit value (rather than relying on an
200 implicit $_):
201 $rv = POSIX::chdir('path/to/dir'); # good
203 $rv = POSIX::chdir(); # throws exception
205 "chmod" This is identical to Perl's builtin "chmod()" function,
207 allowing one to change file and directory permissions -- see
208 "chmod" in perlfunc -- with the exception that "POSIX::chmod()"
209 can only change one file at a time (rather than a list of
210 files):
211 $c = chmod 0664, $file1, $file2; # good
213 $c = POSIX::chmod 0664, $file1; # throws exception
215 $c = POSIX::chmod 0664, $file1, $file2; # throws exception
217 As with the built-in "chmod()", $file may be a filename or a
219 file handle.
220 "chown" This is identical to Perl's builtin "chown()" function,
222 allowing one to change file and directory owners and groups,
223 see "chown" in perlfunc.
224 "clearerr"
226 Not implemented. Use the method "IO::Handle::clearerr()"
227 instead, to reset the error state (if any) and EOF state (if
228 any) of the given stream.
229 "clock" This is identical to the C function "clock()", returning the
231 amount of spent processor time in microseconds.
232 "close" Close the file. This uses file descriptors such as those
234 obtained by calling "POSIX::open".
235 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
237 POSIX::close( $fd );
238 Returns "undef" on failure.
240 See also "close" in perlfunc.
242 "closedir"
244 This is identical to Perl's builtin "closedir()" function for
245 closing a directory handle, see "closedir" in perlfunc.
246 "cos" This is identical to Perl's builtin "cos()" function, for
248 returning the cosine of its numerical argument, see "cos" in
249 perlfunc. See also Math::Trig.
250 "cosh" This is identical to the C function "cosh()", for returning the
252 hyperbolic cosine of its numeric argument. See also
253 Math::Trig.
254 "copysign"
256 Returns "x" but with the sign of "y" [C99]. Added in Perl
257 v5.22.
258 $x_with_sign_of_y = POSIX::copysign($x, $y);
260 See also "signbit".
262 "creat" Create a new file. This returns a file descriptor like the
264 ones returned by "POSIX::open". Use "POSIX::close" to close
265 the file.
266 $fd = POSIX::creat( "foo", 0611 );
268 POSIX::close( $fd );
269 See also "sysopen" in perlfunc and its "O_CREAT" flag.
271 "ctermid"
273 Generates the path name for the controlling terminal.
274 $path = POSIX::ctermid();
276 "ctime" This is identical to the C function "ctime()" and equivalent to
278 "asctime(localtime(...))", see "asctime" and "localtime".
279 "cuserid" [POSIX.1-1988]
281 Get the login name of the owner of the current process.
282 $name = POSIX::cuserid();
284 Note: this function has not been specified by POSIX since 1990
286 and is included only for backwards compatibility. New code
287 should use "getlogin()" instead.
288 "difftime"
290 This is identical to the C function "difftime()", for returning
291 the time difference (in seconds) between two times (as returned
292 by "time()"), see "time".
293 "div" Not implemented. "div()" is C-specific, use "int" in perlfunc
295 on the usual "/" division and the modulus "%".
296 "dup" This is similar to the C function "dup()", for duplicating a
298 file descriptor.
299 This uses file descriptors such as those obtained by calling
301 "POSIX::open".
302 Returns "undef" on failure.
304 "dup2" This is similar to the C function "dup2()", for duplicating a
306 file descriptor to an another known file descriptor.
307 This uses file descriptors such as those obtained by calling
309 "POSIX::open".
310 Returns "undef" on failure.
312 "erf" The error function [C99]. Added in Perl v5.22.
314 "erfc" The complementary error function [C99]. Added in Perl v5.22.
316 "errno" Returns the value of errno.
318 $errno = POSIX::errno();
320 This identical to the numerical values of the $!, see "$ERRNO"
322 in perlvar.
323 "execl" Not implemented. "execl()" is C-specific, see "exec" in
325 perlfunc.
326 "execle"
328 Not implemented. "execle()" is C-specific, see "exec" in
329 perlfunc.
330 "execlp"
332 Not implemented. "execlp()" is C-specific, see "exec" in
333 perlfunc.
334 "execv" Not implemented. "execv()" is C-specific, see "exec" in
336 perlfunc.
337 "execve"
339 Not implemented. "execve()" is C-specific, see "exec" in
340 perlfunc.
341 "execvp"
343 Not implemented. "execvp()" is C-specific, see "exec" in
344 perlfunc.
345 "exit" This is identical to Perl's builtin "exit()" function for
347 exiting the program, see "exit" in perlfunc.
348 "exp" This is identical to Perl's builtin "exp()" function for
350 returning the exponent (e-based) of the numerical argument, see
351 "exp" in perlfunc.
352 "expm1" Equivalent to "exp(x) - 1", but more precise for small argument
354 values [C99]. Added in Perl v5.22.
355 See also "log1p".
357 "fabs" This is identical to Perl's builtin "abs()" function for
359 returning the absolute value of the numerical argument, see
360 "abs" in perlfunc.
361 "fclose"
363 Not implemented. Use method "IO::Handle::close()" instead, or
364 see "close" in perlfunc.
365 "fcntl" This is identical to Perl's builtin "fcntl()" function, see
367 "fcntl" in perlfunc.
368 "fdopen"
370 Not implemented. Use method "IO::Handle::new_from_fd()"
371 instead, or see "open" in perlfunc.
372 "feof" Not implemented. Use method "IO::Handle::eof()" instead, or
374 see "eof" in perlfunc.
375 "ferror"
377 Not implemented. Use method "IO::Handle::error()" instead.
378 "fflush"
380 Not implemented. Use method "IO::Handle::flush()" instead.
381 See also ""$OUTPUT_AUTOFLUSH" in perlvar".
382 "fgetc" Not implemented. Use method "IO::Handle::getc()" instead, or
384 see "read" in perlfunc.
385 "fgetpos"
387 Not implemented. Use method "IO::Seekable::getpos()" instead,
388 or see "seek" in perlfunc.
389 "fgets" Not implemented. Use method "IO::Handle::gets()" instead.
391 Similar to <>, also known as "readline" in perlfunc.
392 "fileno"
394 Not implemented. Use method "IO::Handle::fileno()" instead, or
395 see "fileno" in perlfunc.
396 "floor" This is identical to the C function "floor()", returning the
398 largest integer value less than or equal to the numerical
399 argument.
400 "fdim" "Positive difference", "x - y" if "x > y", zero otherwise
402 [C99]. Added in Perl v5.22.
403 "fegetround"
405 Returns the current floating point rounding mode, one of
406 FE_TONEAREST FE_TOWARDZERO FE_UPWARD FE_DOWNWARD
408 "FE_TONEAREST" is like "round", "FE_TOWARDZERO" is like "trunc"
410 [C99]. Added in Perl v5.22.
411 "fesetround"
413 Sets the floating point rounding mode, see "fegetround" [C99].
414 Added in Perl v5.22.
415 "fma" "Fused multiply-add", "x * y + z", possibly faster (and less
417 lossy) than the explicit two operations [C99]. Added in Perl
418 v5.22.
419 my $fused = POSIX::fma($x, $y, $z);
421 "fmax" Maximum of "x" and "y", except when either is "NaN", returns
423 the other [C99]. Added in Perl v5.22.
424 my $min = POSIX::fmax($x, $y);
426 "fmin" Minimum of "x" and "y", except when either is "NaN", returns
428 the other [C99]. Added in Perl v5.22.
429 my $min = POSIX::fmin($x, $y);
431 "fmod" This is identical to the C function "fmod()".
433 $r = fmod($x, $y);
435 It returns the remainder "$r = $x - $n*$y", where
437 "$n = trunc($x/$y)". The $r has the same sign as $x and
438 magnitude (absolute value) less than the magnitude of $y.
439 "fopen" Not implemented. Use method "IO::File::open()" instead, or see
441 "open" in perlfunc.
442 "fork" This is identical to Perl's builtin "fork()" function for
444 duplicating the current process, see "fork" in perlfunc and
445 perlfork if you are in Windows.
446 "fpathconf"
448 Retrieves the value of a configurable limit on a file or
449 directory. This uses file descriptors such as those obtained
450 by calling "POSIX::open".
451 The following will determine the maximum length of the longest
453 allowable pathname on the filesystem which holds /var/foo.
454 $fd = POSIX::open( "/var/foo", &POSIX::O_RDONLY );
456 $path_max = POSIX::fpathconf($fd, &POSIX::_PC_PATH_MAX);
457 Returns "undef" on failure.
459 "fpclassify"
461 Returns one of
462 FP_NORMAL FP_ZERO FP_SUBNORMAL FP_INFINITE FP_NAN
464 telling the class of the argument [C99]. "FP_INFINITE" is
466 positive or negative infinity, "FP_NAN" is not-a-number.
467 "FP_SUBNORMAL" means subnormal numbers (also known as
468 denormals), very small numbers with low precision. "FP_ZERO" is
469 zero. "FP_NORMAL" is all the rest. Added in Perl v5.22.
470 "fprintf"
472 Not implemented. "fprintf()" is C-specific, see "printf" in
473 perlfunc instead.
474 "fputc" Not implemented. "fputc()" is C-specific, see "print" in
476 perlfunc instead.
477 "fputs" Not implemented. "fputs()" is C-specific, see "print" in
479 perlfunc instead.
480 "fread" Not implemented. "fread()" is C-specific, see "read" in
482 perlfunc instead.
483 "free" Not implemented. "free()" is C-specific. Perl does memory
485 management transparently.
486 "freopen"
488 Not implemented. "freopen()" is C-specific, see "open" in
489 perlfunc instead.
490 "frexp" Return the mantissa and exponent of a floating-point number.
492 ($mantissa, $exponent) = POSIX::frexp( 1.234e56 );
494 "fscanf"
496 Not implemented. "fscanf()" is C-specific, use <> and regular
497 expressions instead.
498 "fseek" Not implemented. Use method "IO::Seekable::seek()" instead, or
500 see "seek" in perlfunc.
501 "fsetpos"
503 Not implemented. Use method "IO::Seekable::setpos()" instead,
504 or seek "seek" in perlfunc.
505 "fstat" Get file status. This uses file descriptors such as those
507 obtained by calling "POSIX::open". The data returned is
508 identical to the data from Perl's builtin "stat" function.
509 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
511 @stats = POSIX::fstat( $fd );
512 "fsync" Not implemented. Use method "IO::Handle::sync()" instead.
514 "ftell" Not implemented. Use method "IO::Seekable::tell()" instead, or
516 see "tell" in perlfunc.
517 "fwrite"
519 Not implemented. "fwrite()" is C-specific, see "print" in
520 perlfunc instead.
521 "getc" This is identical to Perl's builtin "getc()" function, see
523 "getc" in perlfunc.
524 "getchar"
526 Returns one character from STDIN. Identical to Perl's
527 "getc()", see "getc" in perlfunc.
528 "getcwd"
530 Returns the name of the current working directory. See also
531 Cwd.
532 "getegid"
534 Returns the effective group identifier. Similar to Perl' s
535 builtin variable $(, see "$EGID" in perlvar.
536 "getenv"
538 Returns the value of the specified environment variable. The
539 same information is available through the %ENV array.
540 "geteuid"
542 Returns the effective user identifier. Identical to Perl's
543 builtin $> variable, see "$EUID" in perlvar.
544 "getgid"
546 Returns the user's real group identifier. Similar to Perl's
547 builtin variable $), see "$GID" in perlvar.
548 "getgrgid"
550 This is identical to Perl's builtin "getgrgid()" function for
551 returning group entries by group identifiers, see "getgrgid" in
552 perlfunc.
553 "getgrnam"
555 This is identical to Perl's builtin "getgrnam()" function for
556 returning group entries by group names, see "getgrnam" in
557 perlfunc.
558 "getgroups"
560 Returns the ids of the user's supplementary groups. Similar to
561 Perl's builtin variable $), see "$GID" in perlvar.
562 "getlogin"
564 This is identical to Perl's builtin "getlogin()" function for
565 returning the user name associated with the current session,
566 see "getlogin" in perlfunc.
567 "getpayload"
569 use POSIX ':nan_payload';
570 getpayload($var)
571 Returns the "NaN" payload. Added in Perl v5.24.
573 Note the API instability warning in "setpayload".
575 See "nan" for more discussion about "NaN".
577 "getpgrp"
579 This is identical to Perl's builtin "getpgrp()" function for
580 returning the process group identifier of the current process,
581 see "getpgrp" in perlfunc.
582 "getpid"
584 Returns the process identifier. Identical to Perl's builtin
585 variable $$, see "$PID" in perlvar.
586 "getppid"
588 This is identical to Perl's builtin "getppid()" function for
589 returning the process identifier of the parent process of the
590 current process , see "getppid" in perlfunc.
591 "getpwnam"
593 This is identical to Perl's builtin "getpwnam()" function for
594 returning user entries by user names, see "getpwnam" in
595 perlfunc.
596 "getpwuid"
598 This is identical to Perl's builtin "getpwuid()" function for
599 returning user entries by user identifiers, see "getpwuid" in
600 perlfunc.
601 "gets" Returns one line from "STDIN", similar to <>, also known as the
603 "readline()" function, see "readline" in perlfunc.
604 NOTE: if you have C programs that still use "gets()", be very
606 afraid. The "gets()" function is a source of endless grief
607 because it has no buffer overrun checks. It should never be
608 used. The "fgets()" function should be preferred instead.
609 "getuid"
611 Returns the user's identifier. Identical to Perl's builtin $<
612 variable, see "$UID" in perlvar.
613 "gmtime"
615 This is identical to Perl's builtin "gmtime()" function for
616 converting seconds since the epoch to a date in Greenwich Mean
617 Time, see "gmtime" in perlfunc.
618 "hypot" Equivalent to "sqrt(x * x + y * y)" except more stable on very
620 large or very small arguments [C99]. Added in Perl v5.22.
621 "ilogb" Integer binary logarithm [C99]. Added in Perl v5.22.
623 For example "ilogb(20)" is 4, as an integer.
625 See also "logb".
627 "Inf" The infinity as a constant:
629 use POSIX qw(Inf);
631 my $pos_inf = +Inf; # Or just Inf.
632 my $neg_inf = -Inf;
633 See also "isinf", and "fpclassify".
635 "isalnum"
637 This function has been removed as of Perl v5.24. It was very
638 similar to matching against "qr/ ^ [[:alnum:]]+ $ /x", which
639 you should convert to use instead. See "POSIX Character
640 Classes" in perlrecharclass.
641 "isalpha"
643 This function has been removed as of Perl v5.24. It was very
644 similar to matching against "qr/ ^ [[:alpha:]]+ $ /x", which
645 you should convert to use instead. See "POSIX Character
646 Classes" in perlrecharclass.
647 "isatty"
649 Returns a boolean indicating whether the specified filehandle
650 is connected to a tty. Similar to the "-t" operator, see "-X"
651 in perlfunc.
652 "iscntrl"
654 This function has been removed as of Perl v5.24. It was very
655 similar to matching against "qr/ ^ [[:cntrl:]]+ $ /x", which
656 you should convert to use instead. See "POSIX Character
657 Classes" in perlrecharclass.
658 "isdigit"
660 This function has been removed as of Perl v5.24. It was very
661 similar to matching against "qr/ ^ [[:digit:]]+ $ /x", which
662 you should convert to use instead. See "POSIX Character
663 Classes" in perlrecharclass.
664 "isfinite"
666 Returns true if the argument is a finite number (that is, not
667 an infinity, or the not-a-number) [C99]. Added in Perl v5.22.
668 See also "isinf", "isnan", and "fpclassify".
670 "isgraph"
672 This function has been removed as of Perl v5.24. It was very
673 similar to matching against "qr/ ^ [[:graph:]]+ $ /x", which
674 you should convert to use instead. See "POSIX Character
675 Classes" in perlrecharclass.
676 "isgreater"
678 (Also "isgreaterequal", "isless", "islessequal",
679 "islessgreater", "isunordered")
680 Floating point comparisons which handle the "NaN" [C99]. Added
682 in Perl v5.22.
683 "isinf" Returns true if the argument is an infinity (positive or
685 negative) [C99]. Added in Perl v5.22.
686 See also "Inf", "isnan", "isfinite", and "fpclassify".
688 "islower"
690 This function has been removed as of Perl v5.24. It was very
691 similar to matching against "qr/ ^ [[:lower:]]+ $ /x", which
692 you should convert to use instead. See "POSIX Character
693 Classes" in perlrecharclass.
694 "isnan" Returns true if the argument is "NaN" (not-a-number) [C99].
696 Added in Perl v5.22.
697 Note that you can also test for ""NaN"-ness" with equality
699 operators ("==" or "!="), as in
700 print "x is not a NaN\n" if $x == $x;
702 since the "NaN" is not equal to anything, including itself.
704 See also "nan", "NaN", "isinf", and "fpclassify".
706 "isnormal"
708 Returns true if the argument is normal (that is, not a
709 subnormal/denormal, and not an infinity, or a not-a-number)
710 [C99]. Added in Perl v5.22.
711 See also "isfinite", and "fpclassify".
713 "isprint"
715 This function has been removed as of Perl v5.24. It was very
716 similar to matching against "qr/ ^ [[:print:]]+ $ /x", which
717 you should convert to use instead. See "POSIX Character
718 Classes" in perlrecharclass.
719 "ispunct"
721 This function has been removed as of Perl v5.24. It was very
722 similar to matching against "qr/ ^ [[:punct:]]+ $ /x", which
723 you should convert to use instead. See "POSIX Character
724 Classes" in perlrecharclass.
725 "issignaling"
727 use POSIX ':nan_payload';
728 issignaling($var, $payload)
729 Return true if the argument is a signaling NaN. Added in Perl
731 v5.24.
732 Note the API instability warning in "setpayload".
734 See "nan" for more discussion about "NaN".
736 "isspace"
738 This function has been removed as of Perl v5.24. It was very
739 similar to matching against "qr/ ^ [[:space:]]+ $ /x", which
740 you should convert to use instead. See "POSIX Character
741 Classes" in perlrecharclass.
742 "isupper"
744 This function has been removed as of Perl v5.24. It was very
745 similar to matching against "qr/ ^ [[:upper:]]+ $ /x", which
746 you should convert to use instead. See "POSIX Character
747 Classes" in perlrecharclass.
748 "isxdigit"
750 This function has been removed as of Perl v5.24. It was very
751 similar to matching against "qr/ ^ [[:xdigit:]]+ $ /x", which
752 you should convert to use instead. See "POSIX Character
753 Classes" in perlrecharclass.
754 "j0"
756 "j1"
757 "jn"
758 "y0"
759 "y1"
760 "yn" The Bessel function of the first kind of the order zero.
761 "kill" This is identical to Perl's builtin "kill()" function for
763 sending signals to processes (often to terminate them), see
764 "kill" in perlfunc.
765 "labs" Not implemented. (For returning absolute values of long
767 integers.) "labs()" is C-specific, see "abs" in perlfunc
768 instead.
769 "lchown"
771 This is identical to the C function, except the order of
772 arguments is consistent with Perl's builtin "chown()" with the
773 added restriction of only one path, not a list of paths. Does
774 the same thing as the "chown()" function but changes the owner
775 of a symbolic link instead of the file the symbolic link points
776 to.
777 POSIX::lchown($uid, $gid, $file_path);
779 "ldexp" This is identical to the C function "ldexp()" for multiplying
781 floating point numbers with powers of two.
782 $x_quadrupled = POSIX::ldexp($x, 2);
784 "ldiv" Not implemented. (For computing dividends of long integers.)
786 "ldiv()" is C-specific, use "/" and "int()" instead.
787 "lgamma"
789 The logarithm of the Gamma function [C99]. Added in Perl
790 v5.22.
791 See also "tgamma".
793 "log1p" Equivalent to "log(1 + x)", but more stable results for small
795 argument values [C99]. Added in Perl v5.22.
796 "log2" Logarithm base two [C99]. Added in Perl v5.22.
798 See also "expm1".
800 "logb" Integer binary logarithm [C99]. Added in Perl v5.22.
802 For example "logb(20)" is 4, as a floating point number.
804 See also "ilogb".
806 "link" This is identical to Perl's builtin "link()" function for
808 creating hard links into files, see "link" in perlfunc.
809 "localeconv"
811 Get numeric formatting information. Returns a reference to a
812 hash containing the formatting values of the locale that
813 currently underlies the program, regardless of whether or not
814 it is called from within the scope of a "use locale". Users of
815 this function should also read perllocale, which provides a
816 comprehensive discussion of Perl locale handling, including a
817 section devoted to this function. Prior to Perl 5.28, or when
818 operating in a non thread-safe environment, it should not be
819 used in a threaded application unless it's certain that the
820 underlying locale is C or POSIX. This is because it otherwise
821 changes the locale, which globally affects all threads
822 simultaneously. Windows platforms starting with Visual Studio
823 2005 are mostly thread-safe, but use of this function in those
824 prior to Visual Studio 2015 can have a race with a thread that
825 has called "switch_to_global_locale" in perlapi.
826 Here is how to query the database for the de (Deutsch or
828 German) locale.
829 my $loc = POSIX::setlocale( &POSIX::LC_ALL, "de" );
831 print "Locale: \"$loc\"\n";
832 my $lconv = POSIX::localeconv();
833 foreach my $property (qw(
834 decimal_point
835 thousands_sep
836 grouping
837 int_curr_symbol
838 currency_symbol
839 mon_decimal_point
840 mon_thousands_sep
841 mon_grouping
842 positive_sign
843 negative_sign
844 int_frac_digits
845 frac_digits
846 p_cs_precedes
847 p_sep_by_space
848 n_cs_precedes
849 n_sep_by_space
850 p_sign_posn
851 n_sign_posn
852 int_p_cs_precedes
853 int_p_sep_by_space
854 int_n_cs_precedes
855 int_n_sep_by_space
856 int_p_sign_posn
857 int_n_sign_posn
858 ))
859 {
860 printf qq(%s: "%s",\n),
861 $property, $lconv->{$property};
862 }
863 The members whose names begin with "int_p_" and "int_n_" were
865 added by POSIX.1-2008 and are only available on systems that
866 support them.
867 "localtime"
869 This is identical to Perl's builtin "localtime()" function for
870 converting seconds since the epoch to a date see "localtime" in
871 perlfunc except that "POSIX::localtime()" must be provided an
872 explicit value (rather than relying on an implicit $_):
873 @localtime = POSIX::localtime(time); # good
875 @localtime = localtime(); # good
877 @localtime = POSIX::localtime(); # throws exception
879 "log" This is identical to Perl's builtin "log()" function, returning
881 the natural (e-based) logarithm of the numerical argument, see
882 "log" in perlfunc.
883 "log10" This is identical to the C function "log10()", returning the
885 10-base logarithm of the numerical argument. You can also use
886 sub log10 { log($_[0]) / log(10) }
888 or
890 sub log10 { log($_[0]) / 2.30258509299405 }
892 or
894 sub log10 { log($_[0]) * 0.434294481903252 }
896 "longjmp"
898 Not implemented. "longjmp()" is C-specific: use "die" in
899 perlfunc instead.
900 "lseek" Move the file's read/write position. This uses file
902 descriptors such as those obtained by calling "POSIX::open".
903 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
905 $off_t = POSIX::lseek( $fd, 0, &POSIX::SEEK_SET );
906 Returns "undef" on failure.
908 "lrint" Depending on the current floating point rounding mode, rounds
910 the argument either toward nearest (like "round"), toward zero
911 (like "trunc"), downward (toward negative infinity), or upward
912 (toward positive infinity) [C99]. Added in Perl v5.22.
913 For the rounding mode, see "fegetround".
915 "lround"
917 Like "round", but as integer, as opposed to floating point
918 [C99]. Added in Perl v5.22.
919 See also "ceil", "floor", "trunc".
921 Owing to an oversight, this is not currently exported by
923 default, or as part of the ":math_h_c99" export tag; importing
924 it must therefore be done by explicit name.
925 "malloc"
927 Not implemented. "malloc()" is C-specific. Perl does memory
928 management transparently.
929 "mblen" This is the same as the C function "mblen()" on unthreaded
931 perls. On threaded perls, it transparently (almost)
932 substitutes the more thread-safe "mbrlen"(3), if available,
933 instead of "mblen".
934 Core Perl does not have any support for wide and multibyte
936 locales, except Unicode UTF-8 locales. This function, in
937 conjunction with "mbtowc" and "wctomb" may be used to roll your
938 own decoding/encoding of other types of multi-byte locales.
939 Use "undef" as the first parameter to this function to get the
941 effect of passing NULL as the first parameter to "mblen". This
942 resets any shift state to its initial value. The return value
943 is undefined if "mbrlen" was substituted, so you should never
944 rely on it.
945 When the first parameter is a scalar containing a value that
947 either is a PV string or can be forced into one, the return
948 value is the number of bytes occupied by the first character of
949 that string; or 0 if that first character is the wide NUL
950 character; or negative if there is an error. This is based on
951 the locale that currently underlies the program, regardless of
952 whether or not the function is called from Perl code that is
953 within the scope of "use locale". Perl makes no attempt at
954 hiding from your code any differences in the "errno" setting
955 between "mblen" and "mbrlen". It does set "errno" to 0 before
956 calling them.
957 The optional second parameter is ignored if it is larger than
959 the actual length of the first parameter string.
960 "mbtowc"
962 This is the same as the C function "mbtowc()" on unthreaded
963 perls. On threaded perls, it transparently (almost)
964 substitutes the more thread-safe "mbrtowc"(3), if available,
965 instead of "mbtowc".
966 Core Perl does not have any support for wide and multibyte
968 locales, except Unicode UTF-8 locales. This function, in
969 conjunction with "mblen" and "wctomb" may be used to roll your
970 own decoding/encoding of other types of multi-byte locales.
971 The first parameter is a scalar into which, upon success, the
973 wide character represented by the multi-byte string contained
974 in the second parameter is stored. The optional third
975 parameter is ignored if it is larger than the actual length of
976 the second parameter string.
977 Use "undef" as the second parameter to this function to get the
979 effect of passing NULL as the second parameter to "mbtowc".
980 This resets any shift state to its initial value. The return
981 value is undefined if "mbrtowc" was substituted, so you should
982 never rely on it.
983 When the second parameter is a scalar containing a value that
985 either is a PV string or can be forced into one, the return
986 value is the number of bytes occupied by the first character of
987 that string; or 0 if that first character is the wide NUL
988 character; or negative if there is an error. This is based on
989 the locale that currently underlies the program, regardless of
990 whether or not the function is called from Perl code that is
991 within the scope of "use locale". Perl makes no attempt at
992 hiding from your code any differences in the "errno" setting
993 between "mbtowc" and "mbrtowc". It does set "errno" to 0
994 before calling them.
995 "memchr"
997 Not implemented. "memchr()" is C-specific, see "index" in
998 perlfunc instead.
999 "memcmp"
1001 Not implemented. "memcmp()" is C-specific, use "eq" instead,
1002 see perlop.
1003 "memcpy"
1005 Not implemented. "memcpy()" is C-specific, use "=", see
1006 perlop, or see "substr" in perlfunc.
1007 "memmove"
1009 Not implemented. "memmove()" is C-specific, use "=", see
1010 perlop, or see "substr" in perlfunc.
1011 "memset"
1013 Not implemented. "memset()" is C-specific, use "x" instead,
1014 see perlop.
1015 "mkdir" This is identical to Perl's builtin "mkdir()" function for
1017 creating directories, see "mkdir" in perlfunc.
1018 "mkfifo"
1020 This is similar to the C function "mkfifo()" for creating FIFO
1021 special files.
1022 if (mkfifo($path, $mode)) { ....
1024 Returns "undef" on failure. The $mode is similar to the mode
1026 of "mkdir()", see "mkdir" in perlfunc, though for "mkfifo" you
1027 must specify the $mode.
1028 "mktime"
1030 Convert date/time info to a calendar time.
1031 Synopsis:
1033 mktime(sec, min, hour, mday, mon, year, wday = 0,
1035 yday = 0, isdst = -1)
1036 The month ("mon"), weekday ("wday"), and yearday ("yday") begin
1038 at zero, i.e., January is 0, not 1; Sunday is 0, not 1; January
1039 1st is 0, not 1. The year ("year") is given in years since
1040 1900; i.e., the year 1995 is 95; the year 2001 is 101. Consult
1041 your system's "mktime()" manpage for details about these and
1042 the other arguments.
1043 Calendar time for December 12, 1995, at 10:30 am.
1045 $time_t = POSIX::mktime( 0, 30, 10, 12, 11, 95 );
1047 print "Date = ", POSIX::ctime($time_t);
1048 Returns "undef" on failure.
1050 "modf" Return the integral and fractional parts of a floating-point
1052 number.
1053 ($fractional, $integral) = POSIX::modf( 3.14 );
1055 See also "round".
1057 "NaN" The not-a-number as a constant:
1059 use POSIX qw(NaN);
1061 my $nan = NaN;
1062 See also "nan", "/isnan", and "fpclassify".
1064 "nan"
1066 my $nan = nan();
1067 Returns "NaN", not-a-number [C99]. Added in Perl v5.22.
1069 The returned NaN is always a quiet NaN, as opposed to
1071 signaling.
1072 With an argument, can be used to generate a NaN with payload.
1074 The argument is first interpreted as a floating point number,
1075 but then any fractional parts are truncated (towards zero), and
1076 the value is interpreted as an unsigned integer. The bits of
1077 this integer are stored in the unused bits of the NaN.
1078 The result has a dual nature: it is a NaN, but it also carries
1080 the integer inside it. The integer can be retrieved with
1081 "getpayload". Note, though, that the payload is not
1082 propagated, not even on copies, and definitely not in
1083 arithmetic operations.
1084 How many bits fit in the NaN depends on what kind of floating
1086 points are being used, but on the most common platforms (64-bit
1087 IEEE 754, or the x86 80-bit long doubles) there are 51 and 61
1088 bits available, respectively. (There would be 52 and 62, but
1089 the quiet/signaling bit of NaNs takes away one.) However,
1090 because of the floating-point-to- integer-and-back conversions,
1091 please test carefully whether you get back what you put in. If
1092 your integers are only 32 bits wide, you probably should not
1093 rely on more than 32 bits of payload.
1094 Whether a "signaling" NaN is in any way different from a
1096 "quiet" NaN, depends on the platform. Also note that the
1097 payload of the default NaN (no argument to nan()) is not
1098 necessarily zero, use "setpayload" to explicitly set the
1099 payload. On some platforms like the 32-bit x86, (unless using
1100 the 80-bit long doubles) the signaling bit is not supported at
1101 all.
1102 See also "isnan", "NaN", "setpayload" and "issignaling".
1104 "nearbyint"
1106 Returns the nearest integer to the argument, according to the
1107 current rounding mode (see "fegetround") [C99]. Added in Perl
1108 v5.22.
1109 "nextafter"
1111 Returns the next representable floating point number after "x"
1112 in the direction of "y" [C99]. Added in Perl v5.22.
1113 my $nextafter = POSIX::nextafter($x, $y);
1115 Like "nexttoward", but potentially less accurate.
1117 "nexttoward"
1119 Returns the next representable floating point number after "x"
1120 in the direction of "y" [C99]. Added in Perl v5.22.
1121 my $nexttoward = POSIX::nexttoward($x, $y);
1123 Like "nextafter", but potentially more accurate.
1125 "nice" This is similar to the C function "nice()", for changing the
1127 scheduling preference of the current process. Positive
1128 arguments mean a more polite process, negative values a more
1129 needy process. Normal (non-root) user processes can only
1130 change towards being more polite.
1131 Returns "undef" on failure.
1133 "offsetof"
1135 Not implemented. "offsetof()" is C-specific, you probably want
1136 to see "pack" in perlfunc instead.
1137 "open" Open a file for reading for writing. This returns file
1139 descriptors, not Perl filehandles. Use "POSIX::close" to close
1140 the file.
1141 Open a file read-only with mode 0666.
1143 $fd = POSIX::open( "foo" );
1145 Open a file for read and write.
1147 $fd = POSIX::open( "foo", &POSIX::O_RDWR );
1149 Open a file for write, with truncation.
1151 $fd = POSIX::open(
1153 "foo", &POSIX::O_WRONLY | &POSIX::O_TRUNC
1154 );
1155 Create a new file with mode 0640. Set up the file for writing.
1157 $fd = POSIX::open(
1159 "foo", &POSIX::O_CREAT | &POSIX::O_WRONLY, 0640
1160 );
1161 Returns "undef" on failure.
1163 See also "sysopen" in perlfunc.
1165 "opendir"
1167 Open a directory for reading.
1168 $dir = POSIX::opendir( "/var" );
1170 @files = POSIX::readdir( $dir );
1171 POSIX::closedir( $dir );
1172 Returns "undef" on failure.
1174 "pathconf"
1176 Retrieves the value of a configurable limit on a file or
1177 directory.
1178 The following will determine the maximum length of the longest
1180 allowable pathname on the filesystem which holds "/var".
1181 $path_max = POSIX::pathconf( "/var",
1183 &POSIX::_PC_PATH_MAX );
1184 Returns "undef" on failure.
1186 "pause" This is similar to the C function "pause()", which suspends the
1188 execution of the current process until a signal is received.
1189 Returns "undef" on failure.
1191 "perror"
1193 This is identical to the C function "perror()", which outputs
1194 to the standard error stream the specified message followed by
1195 ": " and the current error string. Use the "warn()" function
1196 and the $! variable instead, see "warn" in perlfunc and
1197 "$ERRNO" in perlvar.
1198 "pipe" Create an interprocess channel. This returns file descriptors
1200 like those returned by "POSIX::open".
1201 my ($read, $write) = POSIX::pipe();
1203 POSIX::write( $write, "hello", 5 );
1204 POSIX::read( $read, $buf, 5 );
1205 See also "pipe" in perlfunc.
1207 "pow" Computes $x raised to the power $exponent.
1209 $ret = POSIX::pow( $x, $exponent );
1211 You can also use the "**" operator, see perlop.
1213 "printf"
1215 Formats and prints the specified arguments to "STDOUT". See
1216 also "printf" in perlfunc.
1217 "putc" Not implemented. "putc()" is C-specific, see "print" in
1219 perlfunc instead.
1220 "putchar"
1222 Not implemented. "putchar()" is C-specific, see "print" in
1223 perlfunc instead.
1224 "puts" Not implemented. "puts()" is C-specific, see "print" in
1226 perlfunc instead.
1227 "qsort" Not implemented. "qsort()" is C-specific, see "sort" in
1229 perlfunc instead.
1230 "raise" Sends the specified signal to the current process. See also
1232 "kill" in perlfunc and the $$ in "$PID" in perlvar.
1233 "rand" Not implemented. "rand()" is non-portable, see "rand" in
1235 perlfunc instead.
1236 "read" Read from a file. This uses file descriptors such as those
1238 obtained by calling "POSIX::open". If the buffer $buf is not
1239 large enough for the read then Perl will extend it to make room
1240 for the request.
1241 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
1243 $bytes = POSIX::read( $fd, $buf, 3 );
1244 Returns "undef" on failure.
1246 See also "sysread" in perlfunc.
1248 "readdir"
1250 This is identical to Perl's builtin "readdir()" function for
1251 reading directory entries, see "readdir" in perlfunc.
1252 "realloc"
1254 Not implemented. "realloc()" is C-specific. Perl does memory
1255 management transparently.
1256 "remainder"
1258 Given "x" and "y", returns the value "x - n*y", where "n" is
1259 the integer closest to "x"/"y" [C99]. Added in Perl v5.22.
1260 my $remainder = POSIX::remainder($x, $y)
1262 See also "remquo".
1264 "remove"
1266 Deletes a name from the filesystem. Calls "unlink" in perlfunc
1267 for files and "rmdir" in perlfunc for directories.
1268 "remquo"
1270 Like "remainder" but also returns the low-order bits of the
1271 quotient (n) [C99]. Added in Perl v5.22.
1272 (This is quite esoteric interface, mainly used to implement
1274 numerical algorithms.)
1275 "rename"
1277 This is identical to Perl's builtin "rename()" function for
1278 renaming files, see "rename" in perlfunc.
1279 "rewind"
1281 Seeks to the beginning of the file.
1282 "rewinddir"
1284 This is identical to Perl's builtin "rewinddir()" function for
1285 rewinding directory entry streams, see "rewinddir" in perlfunc.
1286 "rint" Identical to "lrint".
1288 "rmdir" This is identical to Perl's builtin "rmdir()" function for
1290 removing (empty) directories, see "rmdir" in perlfunc.
1291 "round" Returns the integer (but still as floating point) nearest to
1293 the argument [C99]. Added in Perl v5.22.
1294 See also "ceil", "floor", "lround", "modf", and "trunc".
1296 "scalbn"
1298 Returns "x * 2**y" [C99]. Added in Perl v5.22.
1299 See also "frexp" and "ldexp".
1301 "scanf" Not implemented. "scanf()" is C-specific, use <> and regular
1303 expressions instead, see perlre.
1304 "setgid"
1306 Sets the real group identifier and the effective group
1307 identifier for this process. Similar to assigning a value to
1308 the Perl's builtin $) variable, see "$EGID" in perlvar, except
1309 that the latter will change only the real user identifier, and
1310 that the setgid() uses only a single numeric argument, as
1311 opposed to a space-separated list of numbers.
1312 "setjmp"
1314 Not implemented. "setjmp()" is C-specific: use "eval {}"
1315 instead, see "eval" in perlfunc.
1316 "setlocale"
1318 WARNING! Prior to Perl 5.28 or on a system that does not
1319 support thread-safe locale operations, do NOT use this function
1320 in a thread. The locale will change in all other threads at
1321 the same time, and should your thread get paused by the
1322 operating system, and another started, that thread will not
1323 have the locale it is expecting. On some platforms, there can
1324 be a race leading to segfaults if two threads call this
1325 function nearly simultaneously. This warning does not apply on
1326 unthreaded builds, or on perls where "${^SAFE_LOCALES}" exists
1327 and is non-zero; namely Perl 5.28 and later compiled to be
1328 locale-thread-safe.
1329 This function modifies and queries the program's underlying
1331 locale. Users of this function should read perllocale, whch
1332 provides a comprehensive discussion of Perl locale handling,
1333 knowledge of which is necessary to properly use this function.
1334 It contains a section devoted to this function. The discussion
1335 here is merely a summary reference for "setlocale()". Note
1336 that Perl itself is almost entirely unaffected by the locale
1337 except within the scope of "use locale". (Exceptions are
1338 listed in "Not within the scope of "use locale"" in perllocale,
1339 and locale-dependent functions within the POSIX module ARE
1340 always affected by the current locale.)
1341 The following examples assume
1343 use POSIX qw(setlocale LC_ALL LC_CTYPE);
1345 has been issued.
1347 The following will set the traditional UNIX system locale
1349 behavior (the second argument "C").
1350 $loc = setlocale( LC_ALL, "C" );
1352 The following will query the current "LC_CTYPE" category. (No
1354 second argument means 'query'.)
1355 $loc = setlocale( LC_CTYPE );
1357 The following will set the "LC_CTYPE" behaviour according to
1359 the locale environment variables (the second argument "").
1360 Please see your system's setlocale(3) documentation for the
1361 locale environment variables' meaning or consult perllocale.
1362 $loc = setlocale( LC_CTYPE, "" );
1364 The following will set the "LC_COLLATE" behaviour to
1366 Argentinian Spanish. NOTE: The naming and availability of
1367 locales depends on your operating system. Please consult
1368 perllocale for how to find out which locales are available in
1369 your system.
1370 $loc = setlocale( LC_COLLATE, "es_AR.ISO8859-1" );
1372 "setpayload"
1374 use POSIX ':nan_payload';
1375 setpayload($var, $payload);
1376 Sets the "NaN" payload of var. Added in Perl v5.24.
1378 NOTE: the NaN payload APIs are based on the latest (as of June
1380 2015) proposed ISO C interfaces, but they are not yet a
1381 standard. Things may change.
1382 See "nan" for more discussion about "NaN".
1384 See also "setpayloadsig", "isnan", "getpayload", and
1386 "issignaling".
1387 "setpayloadsig"
1389 use POSIX ':nan_payload';
1390 setpayloadsig($var, $payload);
1391 Like "setpayload" but also makes the NaN signaling. Added in
1393 Perl v5.24.
1394 Depending on the platform the NaN may or may not behave
1396 differently.
1397 Note the API instability warning in "setpayload".
1399 Note that because how the floating point formats work out, on
1401 the most common platforms signaling payload of zero is best
1402 avoided, since it might end up being identical to "+Inf".
1403 See also "nan", "isnan", "getpayload", and "issignaling".
1405 "setpgid"
1407 This is similar to the C function "setpgid()" for setting the
1408 process group identifier of the current process.
1409 Returns "undef" on failure.
1411 "setsid"
1413 This is identical to the C function "setsid()" for setting the
1414 session identifier of the current process.
1415 "setuid"
1417 Sets the real user identifier and the effective user identifier
1418 for this process. Similar to assigning a value to the Perl's
1419 builtin $< variable, see "$UID" in perlvar, except that the
1420 latter will change only the real user identifier.
1421 "sigaction"
1423 Detailed signal management. This uses "POSIX::SigAction"
1424 objects for the "action" and "oldaction" arguments (the
1425 oldaction can also be just a hash reference). Consult your
1426 system's "sigaction" manpage for details, see also
1427 "POSIX::SigRt".
1428 Synopsis:
1430 sigaction(signal, action, oldaction = 0)
1432 Returns "undef" on failure. The "signal" must be a number
1434 (like "SIGHUP"), not a string (like "SIGHUP"), though Perl does
1435 try hard to understand you.
1436 If you use the "SA_SIGINFO" flag, the signal handler will in
1438 addition to the first argument, the signal name, also receive a
1439 second argument, a hash reference, inside which are the
1440 following keys with the following semantics, as defined by
1441 POSIX/SUSv3:
1442 signo the signal number
1444 errno the error number
1445 code if this is zero or less, the signal was sent by
1446 a user process and the uid and pid make sense,
1447 otherwise the signal was sent by the kernel
1448 The constants for specific "code" values can be imported
1450 individually or using the ":signal_h_si_code" tag, since Perl
1451 v5.24.
1452 The following are also defined by POSIX/SUSv3, but
1454 unfortunately not very widely implemented:
1455 pid the process id generating the signal
1457 uid the uid of the process id generating the signal
1458 status exit value or signal for SIGCHLD
1459 band band event for SIGPOLL
1460 addr address of faulting instruction or memory
1461 reference for SIGILL, SIGFPE, SIGSEGV or SIGBUS
1462 A third argument is also passed to the handler, which contains
1464 a copy of the raw binary contents of the "siginfo" structure:
1465 if a system has some non-POSIX fields, this third argument is
1466 where to "unpack()" them from.
1467 Note that not all "siginfo" values make sense simultaneously
1469 (some are valid only for certain signals, for example), and not
1470 all values make sense from Perl perspective, you should to
1471 consult your system's "sigaction" and possibly also "siginfo"
1472 documentation.
1473 "siglongjmp"
1475 Not implemented. "siglongjmp()" is C-specific: use "die" in
1476 perlfunc instead.
1477 "signbit"
1479 Returns zero for positive arguments, non-zero for negative
1480 arguments [C99]. Added in Perl v5.22.
1481 "sigpending"
1483 Examine signals that are blocked and pending. This uses
1484 "POSIX::SigSet" objects for the "sigset" argument. Consult
1485 your system's "sigpending" manpage for details.
1486 Synopsis:
1488 sigpending(sigset)
1490 Returns "undef" on failure.
1492 "sigprocmask"
1494 Change and/or examine calling process's signal mask. This uses
1495 "POSIX::SigSet" objects for the "sigset" and "oldsigset"
1496 arguments. Consult your system's "sigprocmask" manpage for
1497 details.
1498 Synopsis:
1500 sigprocmask(how, sigset, oldsigset = 0)
1502 Returns "undef" on failure.
1504 Note that you can't reliably block or unblock a signal from its
1506 own signal handler if you're using safe signals. Other signals
1507 can be blocked or unblocked reliably.
1508 "sigsetjmp"
1510 Not implemented. "sigsetjmp()" is C-specific: use "eval {}"
1511 instead, see "eval" in perlfunc.
1512 "sigsuspend"
1514 Install a signal mask and suspend process until signal arrives.
1515 This uses "POSIX::SigSet" objects for the "signal_mask"
1516 argument. Consult your system's "sigsuspend" manpage for
1517 details.
1518 Synopsis:
1520 sigsuspend(signal_mask)
1522 Returns "undef" on failure.
1524 "sin" This is identical to Perl's builtin "sin()" function for
1526 returning the sine of the numerical argument, see "sin" in
1527 perlfunc. See also Math::Trig.
1528 "sinh" This is identical to the C function "sinh()" for returning the
1530 hyperbolic sine of the numerical argument. See also
1531 Math::Trig.
1532 "sleep" This is functionally identical to Perl's builtin "sleep()"
1534 function for suspending the execution of the current for
1535 process for certain number of seconds, see "sleep" in perlfunc.
1536 There is one significant difference, however: "POSIX::sleep()"
1537 returns the number of unslept seconds, while the
1538 "CORE::sleep()" returns the number of slept seconds.
1539 "sprintf"
1541 This is similar to Perl's builtin "sprintf()" function for
1542 returning a string that has the arguments formatted as
1543 requested, see "sprintf" in perlfunc.
1544 "sqrt" This is identical to Perl's builtin "sqrt()" function. for
1546 returning the square root of the numerical argument, see "sqrt"
1547 in perlfunc.
1548 "srand" Give a seed the pseudorandom number generator, see "srand" in
1550 perlfunc.
1551 "sscanf"
1553 Not implemented. "sscanf()" is C-specific, use regular
1554 expressions instead, see perlre.
1555 "stat" This is identical to Perl's builtin "stat()" function for
1557 returning information about files and directories.
1558 "strcat"
1560 Not implemented. "strcat()" is C-specific, use ".=" instead,
1561 see perlop.
1562 "strchr"
1564 Not implemented. "strchr()" is C-specific, see "index" in
1565 perlfunc instead.
1566 "strcmp"
1568 Not implemented. "strcmp()" is C-specific, use "eq" or "cmp"
1569 instead, see perlop.
1570 "strcoll"
1572 This is identical to the C function "strcoll()" for collating
1573 (comparing) strings transformed using the "strxfrm()" function.
1574 Not really needed since Perl can do this transparently, see
1575 perllocale.
1576 Beware that in a UTF-8 locale, anything you pass to this
1578 function must be in UTF-8; and when not in a UTF-8 locale,
1579 anything passed must not be UTF-8 encoded.
1580 Note also that it doesn't make sense for a string to be encoded
1582 in one locale (say, ISO-8859-6, Arabic) and to collate it based
1583 on another (like ISO-8859-7, Greek). The results will be
1584 essentially meaningless.
1585 "strcpy"
1587 Not implemented. "strcpy()" is C-specific, use "=" instead,
1588 see perlop.
1589 "strcspn"
1591 Not implemented. "strcspn()" is C-specific, use regular
1592 expressions instead, see perlre.
1593 "strerror"
1595 Returns the error string for the specified errno. Identical to
1596 the string form of $!, see "$ERRNO" in perlvar.
1597 "strftime"
1599 Convert date and time information to string. Returns the
1600 string.
1601 Synopsis:
1603 strftime(fmt, sec, min, hour, mday, mon, year,
1605 wday = -1, yday = -1, isdst = -1)
1606 The month ("mon"), weekday ("wday"), and yearday ("yday") begin
1608 at zero, i.e., January is 0, not 1; Sunday is 0, not 1; January
1609 1st is 0, not 1. The year ("year") is given in years since
1610 1900, i.e., the year 1995 is 95; the year 2001 is 101. Consult
1611 your system's "strftime()" manpage for details about these and
1612 the other arguments.
1613 If you want your code to be portable, your format ("fmt")
1615 argument should use only the conversion specifiers defined by
1616 the ANSI C standard (C89, to play safe). These are
1617 "aAbBcdHIjmMpSUwWxXyYZ%". But even then, the results of some
1618 of the conversion specifiers are non-portable. For example,
1619 the specifiers "aAbBcpZ" change according to the locale
1620 settings of the user, and both how to set locales (the locale
1621 names) and what output to expect are non-standard. The
1622 specifier "c" changes according to the timezone settings of the
1623 user and the timezone computation rules of the operating
1624 system. The "Z" specifier is notoriously unportable since the
1625 names of timezones are non-standard. Sticking to the numeric
1626 specifiers is the safest route.
1627 The given arguments are made consistent as though by calling
1629 "mktime()" before calling your system's "strftime()" function,
1630 except that the "isdst" value is not affected.
1631 The string for Tuesday, December 12, 1995.
1633 $str = POSIX::strftime( "%A, %B %d, %Y",
1635 0, 0, 0, 12, 11, 95, 2 );
1636 print "$str\n";
1637 "strlen"
1639 Not implemented. "strlen()" is C-specific, use "length()"
1640 instead, see "length" in perlfunc.
1641 "strncat"
1643 Not implemented. "strncat()" is C-specific, use ".=" instead,
1644 see perlop.
1645 "strncmp"
1647 Not implemented. "strncmp()" is C-specific, use "eq" instead,
1648 see perlop.
1649 "strncpy"
1651 Not implemented. "strncpy()" is C-specific, use "=" instead,
1652 see perlop.
1653 "strpbrk"
1655 Not implemented. "strpbrk()" is C-specific, use regular
1656 expressions instead, see perlre.
1657 "strrchr"
1659 Not implemented. "strrchr()" is C-specific, see "rindex" in
1660 perlfunc instead.
1661 "strspn"
1663 Not implemented. "strspn()" is C-specific, use regular
1664 expressions instead, see perlre.
1665 "strstr"
1667 This is identical to Perl's builtin "index()" function, see
1668 "index" in perlfunc.
1669 "strtod"
1671 String to double translation. Returns the parsed number and the
1672 number of characters in the unparsed portion of the string.
1673 Truly POSIX-compliant systems set $! ($ERRNO) to indicate a
1674 translation error, so clear $! before calling "strtod".
1675 However, non-POSIX systems may not check for overflow, and
1676 therefore will never set $!.
1677 "strtod" respects any POSIX "setlocale()" "LC_NUMERIC"
1679 settings, regardless of whether or not it is called from Perl
1680 code that is within the scope of "use locale". Prior to Perl
1681 5.28, or when operating in a non thread-safe environment, it
1682 should not be used in a threaded application unless it's
1683 certain that the underlying locale is C or POSIX. This is
1684 because it otherwise changes the locale, which globally affects
1685 all threads simultaneously.
1686 To parse a string $str as a floating point number use
1688 $! = 0;
1690 ($num, $n_unparsed) = POSIX::strtod($str);
1691 The second returned item and $! can be used to check for valid
1693 input:
1694 if (($str eq '') || ($n_unparsed != 0) || $!) {
1696 die "Non-numeric input $str" . ($! ? ": $!\n" : "\n");
1697 }
1698 When called in a scalar context "strtod" returns the parsed
1700 number.
1701 "strtok"
1703 Not implemented. "strtok()" is C-specific, use regular
1704 expressions instead, see perlre, or "split" in perlfunc.
1705 "strtol"
1707 String to (long) integer translation. Returns the parsed
1708 number and the number of characters in the unparsed portion of
1709 the string. Truly POSIX-compliant systems set $! ($ERRNO) to
1710 indicate a translation error, so clear $! before calling
1711 "strtol". However, non-POSIX systems may not check for
1712 overflow, and therefore will never set $!.
1713 "strtol" should respect any POSIX setlocale() settings.
1715 To parse a string $str as a number in some base $base use
1717 $! = 0;
1719 ($num, $n_unparsed) = POSIX::strtol($str, $base);
1720 The base should be zero or between 2 and 36, inclusive. When
1722 the base is zero or omitted "strtol" will use the string itself
1723 to determine the base: a leading "0x" or "0X" means
1724 hexadecimal; a leading "0" means octal; any other leading
1725 characters mean decimal. Thus, "1234" is parsed as a decimal
1726 number, "01234" as an octal number, and "0x1234" as a
1727 hexadecimal number.
1728 The second returned item and $! can be used to check for valid
1730 input:
1731 if (($str eq '') || ($n_unparsed != 0) || !$!) {
1733 die "Non-numeric input $str" . $! ? ": $!\n" : "\n";
1734 }
1735 When called in a scalar context "strtol" returns the parsed
1737 number.
1738 "strtold"
1740 Like "strtod" but for long doubles. Defined only if the system
1741 supports long doubles.
1742 "strtoul"
1744 String to unsigned (long) integer translation. "strtoul()" is
1745 identical to "strtol()" except that "strtoul()" only parses
1746 unsigned integers. See "strtol" for details.
1747 Note: Some vendors supply "strtod()" and "strtol()" but not
1749 "strtoul()". Other vendors that do supply "strtoul()" parse
1750 "-1" as a valid value.
1751 "strxfrm"
1753 String transformation. Returns the transformed string.
1754 $dst = POSIX::strxfrm( $src );
1756 Used with "eq" or "cmp" as an alternative to "strcoll".
1758 Not really needed since Perl can do this transparently, see
1760 perllocale.
1761 Beware that in a UTF-8 locale, anything you pass to this
1763 function must be in UTF-8; and when not in a UTF-8 locale,
1764 anything passed must not be UTF-8 encoded.
1765 "sysconf"
1767 Retrieves values of system configurable variables.
1768 The following will get the machine's clock speed.
1770 $clock_ticks = POSIX::sysconf( &POSIX::_SC_CLK_TCK );
1772 Returns "undef" on failure.
1774 "system"
1776 This is identical to Perl's builtin "system()" function, see
1777 "system" in perlfunc.
1778 "tan" This is identical to the C function "tan()", returning the
1780 tangent of the numerical argument. See also Math::Trig.
1781 "tanh" This is identical to the C function "tanh()", returning the
1783 hyperbolic tangent of the numerical argument. See also
1784 Math::Trig.
1785 "tcdrain"
1787 This is similar to the C function "tcdrain()" for draining the
1788 output queue of its argument stream.
1789 Returns "undef" on failure.
1791 "tcflow"
1793 This is similar to the C function "tcflow()" for controlling
1794 the flow of its argument stream.
1795 Returns "undef" on failure.
1797 "tcflush"
1799 This is similar to the C function "tcflush()" for flushing the
1800 I/O buffers of its argument stream.
1801 Returns "undef" on failure.
1803 "tcgetpgrp"
1805 This is identical to the C function "tcgetpgrp()" for returning
1806 the process group identifier of the foreground process group of
1807 the controlling terminal.
1808 "tcsendbreak"
1810 This is similar to the C function "tcsendbreak()" for sending a
1811 break on its argument stream.
1812 Returns "undef" on failure.
1814 "tcsetpgrp"
1816 This is similar to the C function "tcsetpgrp()" for setting the
1817 process group identifier of the foreground process group of the
1818 controlling terminal.
1819 Returns "undef" on failure.
1821 "tgamma"
1823 The Gamma function [C99]. Added in Perl v5.22.
1824 See also "lgamma".
1826 "time" This is identical to Perl's builtin "time()" function for
1828 returning the number of seconds since the epoch (whatever it is
1829 for the system), see "time" in perlfunc.
1830 "times" The "times()" function returns elapsed realtime since some
1832 point in the past (such as system startup), user and system
1833 times for this process, and user and system times used by child
1834 processes. All times are returned in clock ticks.
1835 ($realtime, $user, $system, $cuser, $csystem)
1837 = POSIX::times();
1838 Note: Perl's builtin "times()" function returns four values,
1840 measured in seconds.
1841 "tmpfile"
1843 Not implemented. Use method "IO::File::new_tmpfile()" instead,
1844 or see File::Temp.
1845 "tmpnam"
1847 For security reasons, which are probably detailed in your
1848 system's documentation for the C library "tmpnam()" function,
1849 this interface is no longer available since Perl v5.26; instead
1850 use File::Temp.
1851 "tolower"
1853 This function has been removed as of Perl v5.26. This is
1854 identical to the C function, except that it can apply to a
1855 single character or to a whole string, and currently operates
1856 as if the locale always is "C". Consider using the "lc()"
1857 function, see "lc" in perlfunc, see "lc" in perlfunc, or the
1858 equivalent "\L" operator inside doublequotish strings.
1859 "toupper"
1861 This function has been removed as of Perl v5.26. This is
1862 similar to the C function, except that it can apply to a single
1863 character or to a whole string, and currently operates as if
1864 the locale always is "C". Consider using the "uc()" function,
1865 see "uc" in perlfunc, or the equivalent "\U" operator inside
1866 doublequotish strings.
1867 "trunc" Returns the integer toward zero from the argument [C99]. Added
1869 in Perl v5.22.
1870 See also "ceil", "floor", and "round".
1872 "ttyname"
1874 This is identical to the C function "ttyname()" for returning
1875 the name of the current terminal.
1876 "tzname"
1878 Retrieves the time conversion information from the "tzname"
1879 variable.
1880 POSIX::tzset();
1882 ($std, $dst) = POSIX::tzname();
1883 "tzset" This is identical to the C function "tzset()" for setting the
1885 current timezone based on the environment variable "TZ", to be
1886 used by "ctime()", "localtime()", "mktime()", and "strftime()"
1887 functions.
1888 "umask" This is identical to Perl's builtin "umask()" function for
1890 setting (and querying) the file creation permission mask, see
1891 "umask" in perlfunc.
1892 "uname" Get name of current operating system.
1894 ($sysname, $nodename, $release, $version, $machine)
1896 = POSIX::uname();
1897 Note that the actual meanings of the various fields are not
1899 that well standardized, do not expect any great portability.
1900 The $sysname might be the name of the operating system, the
1901 $nodename might be the name of the host, the $release might be
1902 the (major) release number of the operating system, the
1903 $version might be the (minor) release number of the operating
1904 system, and the $machine might be a hardware identifier.
1905 Maybe.
1906 "ungetc"
1908 Not implemented. Use method "IO::Handle::ungetc()" instead.
1909 "unlink"
1911 This is identical to Perl's builtin "unlink()" function for
1912 removing files, see "unlink" in perlfunc.
1913 "utime" This is identical to Perl's builtin "utime()" function for
1915 changing the time stamps of files and directories, see "utime"
1916 in perlfunc.
1917 "vfprintf"
1919 Not implemented. "vfprintf()" is C-specific, see "printf" in
1920 perlfunc instead.
1921 "vprintf"
1923 Not implemented. "vprintf()" is C-specific, see "printf" in
1924 perlfunc instead.
1925 "vsprintf"
1927 Not implemented. "vsprintf()" is C-specific, see "sprintf" in
1928 perlfunc instead.
1929 "wait" This is identical to Perl's builtin "wait()" function, see
1931 "wait" in perlfunc.
1932 "waitpid"
1934 Wait for a child process to change state. This is identical to
1935 Perl's builtin "waitpid()" function, see "waitpid" in perlfunc.
1936 $pid = POSIX::waitpid( -1, POSIX::WNOHANG );
1938 print "status = ", ($? / 256), "\n";
1939 See "mblen".
1941 "wctomb"
1943 This is the same as the C function "wctomb()" on unthreaded
1944 perls. On threaded perls, it transparently (almost)
1945 substitutes the more thread-safe "wcrtomb"(3), if available,
1946 instead of "wctomb".
1947 Core Perl does not have any support for wide and multibyte
1949 locales, except Unicode UTF-8 locales. This function, in
1950 conjunction with "mblen" and "mbtowc" may be used to roll your
1951 own decoding/encoding of other types of multi-byte locales.
1952 Use "undef" as the first parameter to this function to get the
1954 effect of passing NULL as the first parameter to "wctomb".
1955 This resets any shift state to its initial value. The return
1956 value is undefined if "wcrtomb" was substituted, so you should
1957 never rely on it.
1958 When the first parameter is a scalar, the code point contained
1960 in the scalar second parameter is converted into a multi-byte
1961 string and stored into the first parameter scalar. This is
1962 based on the locale that currently underlies the program,
1963 regardless of whether or not the function is called from Perl
1964 code that is within the scope of "use locale". The return
1965 value is the number of bytes stored; or negative if the code
1966 point isn't representable in the current locale. Perl makes no
1967 attempt at hiding from your code any differences in the "errno"
1968 setting between "wctomb" and "wcrtomb". It does set "errno" to
1969 0 before calling them.
1970 "write" Write to a file. This uses file descriptors such as those
1972 obtained by calling "POSIX::open".
1973 $fd = POSIX::open( "foo", &POSIX::O_WRONLY );
1975 $buf = "hello";
1976 $bytes = POSIX::write( $fd, $buf, 5 );
1977 Returns "undef" on failure.
1979 See also "syswrite" in perlfunc.
1981
1983 "POSIX::SigAction"
1984 "new" Creates a new "POSIX::SigAction" object which corresponds to
1985 the C "struct sigaction". This object will be destroyed
1986 automatically when it is no longer needed. The first parameter
1987 is the handler, a sub reference. The second parameter is a
1988 "POSIX::SigSet" object, it defaults to the empty set. The
1989 third parameter contains the "sa_flags", it defaults to 0.
1990 $sigset = POSIX::SigSet->new(SIGINT, SIGQUIT);
1992 $sigaction = POSIX::SigAction->new(
1993 \&handler, $sigset, &POSIX::SA_NOCLDSTOP
1994 );
1995 This "POSIX::SigAction" object is intended for use with the
1997 "POSIX::sigaction()" function.
1998 "handler"
2000 "mask"
2001 "flags" accessor functions to get/set the values of a SigAction object.
2002 $sigset = $sigaction->mask;
2004 $sigaction->flags(&POSIX::SA_RESTART);
2005 "safe" accessor function for the "safe signals" flag of a SigAction
2007 object; see perlipc for general information on safe (a.k.a.
2008 "deferred") signals. If you wish to handle a signal safely,
2009 use this accessor to set the "safe" flag in the
2010 "POSIX::SigAction" object:
2011 $sigaction->safe(1);
2013 You may also examine the "safe" flag on the output action
2015 object which is filled in when given as the third parameter to
2016 "POSIX::sigaction()":
2017 sigaction(SIGINT, $new_action, $old_action);
2019 if ($old_action->safe) {
2020 # previous SIGINT handler used safe signals
2021 }
2022 "POSIX::SigRt"
2024 %SIGRT A hash of the POSIX realtime signal handlers. It is an
2025 extension of the standard %SIG, the $POSIX::SIGRT{SIGRTMIN} is
2026 roughly equivalent to $SIG{SIGRTMIN}, but the right POSIX moves
2027 (see below) are made with the "POSIX::SigSet" and
2028 "POSIX::sigaction" instead of accessing the %SIG.
2029 You can set the %POSIX::SIGRT elements to set the POSIX
2031 realtime signal handlers, use "delete" and "exists" on the
2032 elements, and use "scalar" on the %POSIX::SIGRT to find out how
2033 many POSIX realtime signals there are available
2034 "(SIGRTMAX - SIGRTMIN + 1", the "SIGRTMAX" is a valid POSIX
2035 realtime signal).
2036 Setting the %SIGRT elements is equivalent to calling this:
2038 sub new {
2040 my ($rtsig, $handler, $flags) = @_;
2041 my $sigset = POSIX::SigSet($rtsig);
2042 my $sigact = POSIX::SigAction->new($handler,$sigset,$flags);
2043 sigaction($rtsig, $sigact);
2044 }
2045 The flags default to zero, if you want something different you
2047 can either use "local" on $POSIX::SigRt::SIGACTION_FLAGS, or
2048 you can derive from POSIX::SigRt and define your own "new()"
2049 (the tied hash STORE method of the %SIGRT calls "new($rtsig,
2050 $handler, $SIGACTION_FLAGS)", where the $rtsig ranges from zero
2051 to "SIGRTMAX - SIGRTMIN + 1)".
2052 Just as with any signal, you can use "sigaction($rtsig, undef,
2054 $oa)" to retrieve the installed signal handler (or, rather, the
2055 signal action).
2056 NOTE: whether POSIX realtime signals really work in your
2058 system, or whether Perl has been compiled so that it works with
2059 them, is outside of this discussion.
2060 "SIGRTMIN"
2062 Return the minimum POSIX realtime signal number available, or
2063 "undef" if no POSIX realtime signals are available.
2064 "SIGRTMAX"
2066 Return the maximum POSIX realtime signal number available, or
2067 "undef" if no POSIX realtime signals are available.
2068 "POSIX::SigSet"
2070 "new" Create a new SigSet object. This object will be destroyed
2071 automatically when it is no longer needed. Arguments may be
2072 supplied to initialize the set.
2073 Create an empty set.
2075 $sigset = POSIX::SigSet->new;
2077 Create a set with "SIGUSR1".
2079 $sigset = POSIX::SigSet->new( &POSIX::SIGUSR1 );
2081 Throws an error if any of the signals supplied cannot be added
2083 to the set.
2084 "addset"
2086 Add a signal to a SigSet object.
2087 $sigset->addset( &POSIX::SIGUSR2 );
2089 Returns "undef" on failure.
2091 "delset"
2093 Remove a signal from the SigSet object.
2094 $sigset->delset( &POSIX::SIGUSR2 );
2096 Returns "undef" on failure.
2098 "emptyset"
2100 Initialize the SigSet object to be empty.
2101 $sigset->emptyset();
2103 Returns "undef" on failure.
2105 "fillset"
2107 Initialize the SigSet object to include all signals.
2108 $sigset->fillset();
2110 Returns "undef" on failure.
2112 "ismember"
2114 Tests the SigSet object to see if it contains a specific
2115 signal.
2116 if( $sigset->ismember( &POSIX::SIGUSR1 ) ){
2118 print "contains SIGUSR1\n";
2119 }
2120 "POSIX::Termios"
2122 "new" Create a new Termios object. This object will be destroyed
2123 automatically when it is no longer needed. A Termios object
2124 corresponds to the "termios" C struct. "new()" mallocs a new
2125 one, "getattr()" fills it from a file descriptor, and
2126 "setattr()" sets a file descriptor's parameters to match
2127 Termios' contents.
2128 $termios = POSIX::Termios->new;
2130 "getattr"
2132 Get terminal control attributes.
2133 Obtain the attributes for "stdin".
2135 $termios->getattr( 0 ) # Recommended for clarity.
2137 $termios->getattr()
2138 Obtain the attributes for stdout.
2140 $termios->getattr( 1 )
2142 Returns "undef" on failure.
2144 "getcc" Retrieve a value from the "c_cc" field of a "termios" object.
2146 The "c_cc" field is an array so an index must be specified.
2147 $c_cc[1] = $termios->getcc(1);
2149 "getcflag"
2151 Retrieve the "c_cflag" field of a "termios" object.
2152 $c_cflag = $termios->getcflag;
2154 "getiflag"
2156 Retrieve the "c_iflag" field of a "termios" object.
2157 $c_iflag = $termios->getiflag;
2159 "getispeed"
2161 Retrieve the input baud rate.
2162 $ispeed = $termios->getispeed;
2164 "getlflag"
2166 Retrieve the "c_lflag" field of a "termios" object.
2167 $c_lflag = $termios->getlflag;
2169 "getoflag"
2171 Retrieve the "c_oflag" field of a "termios" object.
2172 $c_oflag = $termios->getoflag;
2174 "getospeed"
2176 Retrieve the output baud rate.
2177 $ospeed = $termios->getospeed;
2179 "setattr"
2181 Set terminal control attributes.
2182 Set attributes immediately for stdout.
2184 $termios->setattr( 1, &POSIX::TCSANOW );
2186 Returns "undef" on failure.
2188 "setcc" Set a value in the "c_cc" field of a "termios" object. The
2190 "c_cc" field is an array so an index must be specified.
2191 $termios->setcc( &POSIX::VEOF, 1 );
2193 "setcflag"
2195 Set the "c_cflag" field of a "termios" object.
2196 $termios->setcflag( $c_cflag | &POSIX::CLOCAL );
2198 "setiflag"
2200 Set the "c_iflag" field of a "termios" object.
2201 $termios->setiflag( $c_iflag | &POSIX::BRKINT );
2203 "setispeed"
2205 Set the input baud rate.
2206 $termios->setispeed( &POSIX::B9600 );
2208 Returns "undef" on failure.
2210 "setlflag"
2212 Set the "c_lflag" field of a "termios" object.
2213 $termios->setlflag( $c_lflag | &POSIX::ECHO );
2215 "setoflag"
2217 Set the "c_oflag" field of a "termios" object.
2218 $termios->setoflag( $c_oflag | &POSIX::OPOST );
2220 "setospeed"
2222 Set the output baud rate.
2223 $termios->setospeed( &POSIX::B9600 );
2225 Returns "undef" on failure.
2227 Baud rate values
2229 "B38400" "B75" "B200" "B134" "B300" "B1800" "B150" "B0"
2230 "B19200" "B1200" "B9600" "B600" "B4800" "B50" "B2400" "B110"
2231 Terminal interface values
2233 "TCSADRAIN" "TCSANOW" "TCOON" "TCIOFLUSH" "TCOFLUSH" "TCION"
2234 "TCIFLUSH" "TCSAFLUSH" "TCIOFF" "TCOOFF"
2235 "c_cc" field values
2237 "VEOF" "VEOL" "VERASE" "VINTR" "VKILL" "VQUIT" "VSUSP" "VSTART"
2238 "VSTOP" "VMIN" "VTIME" "NCCS"
2239 "c_cflag" field values
2241 "CLOCAL" "CREAD" "CSIZE" "CS5" "CS6" "CS7" "CS8" "CSTOPB"
2242 "HUPCL" "PARENB" "PARODD"
2243 "c_iflag" field values
2245 "BRKINT" "ICRNL" "IGNBRK" "IGNCR" "IGNPAR" "INLCR" "INPCK"
2246 "ISTRIP" "IXOFF" "IXON" "PARMRK"
2247 "c_lflag" field values
2249 "ECHO" "ECHOE" "ECHOK" "ECHONL" "ICANON" "IEXTEN" "ISIG"
2250 "NOFLSH" "TOSTOP"
2251 "c_oflag" field values
2253 "OPOST"
2254
2256 Constants
2257 "_PC_CHOWN_RESTRICTED" "_PC_LINK_MAX" "_PC_MAX_CANON"
2258 "_PC_MAX_INPUT" "_PC_NAME_MAX" "_PC_NO_TRUNC" "_PC_PATH_MAX"
2259 "_PC_PIPE_BUF" "_PC_VDISABLE"
2260
2262 Constants
2263 "_POSIX_ARG_MAX" "_POSIX_CHILD_MAX" "_POSIX_CHOWN_RESTRICTED"
2264 "_POSIX_JOB_CONTROL" "_POSIX_LINK_MAX" "_POSIX_MAX_CANON"
2265 "_POSIX_MAX_INPUT" "_POSIX_NAME_MAX" "_POSIX_NGROUPS_MAX"
2266 "_POSIX_NO_TRUNC" "_POSIX_OPEN_MAX" "_POSIX_PATH_MAX"
2267 "_POSIX_PIPE_BUF" "_POSIX_SAVED_IDS" "_POSIX_SSIZE_MAX"
2268 "_POSIX_STREAM_MAX" "_POSIX_TZNAME_MAX" "_POSIX_VDISABLE"
2269 "_POSIX_VERSION"
2270
2272 Imported with the ":sys_resource_h" tag.
2273 Constants
2275 Added in Perl v5.28:
2276 "PRIO_PROCESS" "PRIO_PGRP" "PRIO_USER"
2278
2280 Constants
2281 "_SC_ARG_MAX" "_SC_CHILD_MAX" "_SC_CLK_TCK" "_SC_JOB_CONTROL"
2282 "_SC_NGROUPS_MAX" "_SC_OPEN_MAX" "_SC_PAGESIZE" "_SC_SAVED_IDS"
2283 "_SC_STREAM_MAX" "_SC_TZNAME_MAX" "_SC_VERSION"
2284
2286 Constants
2287 "E2BIG" "EACCES" "EADDRINUSE" "EADDRNOTAVAIL" "EAFNOSUPPORT"
2288 "EAGAIN" "EALREADY" "EBADF" "EBADMSG" "EBUSY" "ECANCELED"
2289 "ECHILD" "ECONNABORTED" "ECONNREFUSED" "ECONNRESET" "EDEADLK"
2290 "EDESTADDRREQ" "EDOM" "EDQUOT" "EEXIST" "EFAULT" "EFBIG"
2291 "EHOSTDOWN" "EHOSTUNREACH" "EIDRM" "EILSEQ" "EINPROGRESS"
2292 "EINTR" "EINVAL" "EIO" "EISCONN" "EISDIR" "ELOOP" "EMFILE"
2293 "EMLINK" "EMSGSIZE" "ENAMETOOLONG" "ENETDOWN" "ENETRESET"
2294 "ENETUNREACH" "ENFILE" "ENOBUFS" "ENODATA" "ENODEV" "ENOENT"
2295 "ENOEXEC" "ENOLCK" "ENOLINK" "ENOMEM" "ENOMSG" "ENOPROTOOPT"
2296 "ENOSPC" "ENOSR" "ENOSTR" "ENOSYS" "ENOTBLK" "ENOTCONN"
2297 "ENOTDIR" "ENOTEMPTY" "ENOTRECOVERABLE" "ENOTSOCK" "ENOTSUP"
2298 "ENOTTY" "ENXIO" "EOPNOTSUPP" "EOTHER" "EOVERFLOW" "EOWNERDEAD"
2299 "EPERM" "EPFNOSUPPORT" "EPIPE" "EPROCLIM" "EPROTO"
2300 "EPROTONOSUPPORT" "EPROTOTYPE" "ERANGE" "EREMOTE" "ERESTART"
2301 "EROFS" "ESHUTDOWN" "ESOCKTNOSUPPORT" "ESPIPE" "ESRCH" "ESTALE"
2302 "ETIME" "ETIMEDOUT" "ETOOMANYREFS" "ETXTBSY" "EUSERS"
2303 "EWOULDBLOCK" "EXDEV"
2304
2306 Constants
2307 "FD_CLOEXEC" "F_DUPFD" "F_GETFD" "F_GETFL" "F_GETLK" "F_OK"
2308 "F_RDLCK" "F_SETFD" "F_SETFL" "F_SETLK" "F_SETLKW" "F_UNLCK"
2309 "F_WRLCK" "O_ACCMODE" "O_APPEND" "O_CREAT" "O_EXCL" "O_NOCTTY"
2310 "O_NONBLOCK" "O_RDONLY" "O_RDWR" "O_TRUNC" "O_WRONLY"
2311
2313 Constants
2314 "DBL_DIG" "DBL_EPSILON" "DBL_MANT_DIG" "DBL_MAX"
2315 "DBL_MAX_10_EXP" "DBL_MAX_EXP" "DBL_MIN" "DBL_MIN_10_EXP"
2316 "DBL_MIN_EXP" "FLT_DIG" "FLT_EPSILON" "FLT_MANT_DIG" "FLT_MAX"
2317 "FLT_MAX_10_EXP" "FLT_MAX_EXP" "FLT_MIN" "FLT_MIN_10_EXP"
2318 "FLT_MIN_EXP" "FLT_RADIX" "FLT_ROUNDS" "LDBL_DIG"
2319 "LDBL_EPSILON" "LDBL_MANT_DIG" "LDBL_MAX" "LDBL_MAX_10_EXP"
2320 "LDBL_MAX_EXP" "LDBL_MIN" "LDBL_MIN_10_EXP" "LDBL_MIN_EXP"
2321
2323 Constants
2324 "FE_DOWNWARD" "FE_TONEAREST" "FE_TOWARDZERO" "FE_UPWARD" on
2325 systems that support them.
2326
2328 Constants
2329 "ARG_MAX" "CHAR_BIT" "CHAR_MAX" "CHAR_MIN" "CHILD_MAX"
2330 "INT_MAX" "INT_MIN" "LINK_MAX" "LONG_MAX" "LONG_MIN"
2331 "MAX_CANON" "MAX_INPUT" "MB_LEN_MAX" "NAME_MAX" "NGROUPS_MAX"
2332 "OPEN_MAX" "PATH_MAX" "PIPE_BUF" "SCHAR_MAX" "SCHAR_MIN"
2333 "SHRT_MAX" "SHRT_MIN" "SSIZE_MAX" "STREAM_MAX" "TZNAME_MAX"
2334 "UCHAR_MAX" "UINT_MAX" "ULONG_MAX" "USHRT_MAX"
2335
2337 Constants
2338 "LC_ALL" "LC_COLLATE" "LC_CTYPE" "LC_MONETARY" "LC_NUMERIC"
2339 "LC_TIME" "LC_MESSAGES" on systems that support them.
2340
2342 Constants
2343 "HUGE_VAL"
2344 Added in Perl v5.22:
2346 "FP_ILOGB0" "FP_ILOGBNAN" "FP_INFINITE" "FP_NAN" "FP_NORMAL"
2348 "FP_SUBNORMAL" "FP_ZERO" "INFINITY" "NAN" "Inf" "NaN" "M_1_PI"
2349 "M_2_PI" "M_2_SQRTPI" "M_E" "M_LN10" "M_LN2" "M_LOG10E"
2350 "M_LOG2E" "M_PI" "M_PI_2" "M_PI_4" "M_SQRT1_2" "M_SQRT2" on
2351 systems with C99 support.
2352
2354 Constants
2355 "SA_NOCLDSTOP" "SA_NOCLDWAIT" "SA_NODEFER" "SA_ONSTACK"
2356 "SA_RESETHAND" "SA_RESTART" "SA_SIGINFO" "SIGABRT" "SIGALRM"
2357 "SIGCHLD" "SIGCONT" "SIGFPE" "SIGHUP" "SIGILL" "SIGINT"
2358 "SIGKILL" "SIGPIPE" "SIGQUIT" "SIGSEGV" "SIGSTOP" "SIGTERM"
2359 "SIGTSTP" "SIGTTIN" "SIGTTOU" "SIGUSR1" "SIGUSR2" "SIG_BLOCK"
2360 "SIG_DFL" "SIG_ERR" "SIG_IGN" "SIG_SETMASK" "SIG_UNBLOCK"
2361 Added in Perl v5.24:
2363 "ILL_ILLOPC" "ILL_ILLOPN" "ILL_ILLADR" "ILL_ILLTRP"
2365 "ILL_PRVOPC" "ILL_PRVREG" "ILL_COPROC" "ILL_BADSTK"
2366 "FPE_INTDIV" "FPE_INTOVF" "FPE_FLTDIV" "FPE_FLTOVF"
2367 "FPE_FLTUND" "FPE_FLTRES" "FPE_FLTINV" "FPE_FLTSUB"
2368 "SEGV_MAPERR" "SEGV_ACCERR" "BUS_ADRALN" "BUS_ADRERR"
2369 "BUS_OBJERR" "TRAP_BRKPT" "TRAP_TRACE" "CLD_EXITED"
2370 "CLD_KILLED" "CLD_DUMPED" "CLD_TRAPPED" "CLD_STOPPED"
2371 "CLD_CONTINUED" "POLL_IN" "POLL_OUT" "POLL_MSG" "POLL_ERR"
2372 "POLL_PRI" "POLL_HUP" "SI_USER" "SI_QUEUE" "SI_TIMER"
2373 "SI_ASYNCIO" "SI_MESGQ"
2374
2376 Constants
2377 "S_IRGRP" "S_IROTH" "S_IRUSR" "S_IRWXG" "S_IRWXO" "S_IRWXU"
2378 "S_ISGID" "S_ISUID" "S_IWGRP" "S_IWOTH" "S_IWUSR" "S_IXGRP"
2379 "S_IXOTH" "S_IXUSR"
2380 Macros "S_ISBLK" "S_ISCHR" "S_ISDIR" "S_ISFIFO" "S_ISREG"
2382
2384 Constants
2385 "EXIT_FAILURE" "EXIT_SUCCESS" "MB_CUR_MAX" "RAND_MAX"
2386
2388 Constants
2389 "BUFSIZ" "EOF" "FILENAME_MAX" "L_ctermid" "L_cuserid" "TMP_MAX"
2390
2392 Constants
2393 "CLK_TCK" "CLOCKS_PER_SEC"
2394
2396 Constants
2397 "R_OK" "SEEK_CUR" "SEEK_END" "SEEK_SET" "STDIN_FILENO"
2398 "STDOUT_FILENO" "STDERR_FILENO" "W_OK" "X_OK"
2399
2401 Constants
2402 "WNOHANG" "WUNTRACED"
2403 "WNOHANG" Do not suspend the calling process until a
2405 child process changes state but instead return
2406 immediately.
2407 "WUNTRACED" Catch stopped child processes.
2409 Macros "WIFEXITED" "WEXITSTATUS" "WIFSIGNALED" "WTERMSIG" "WIFSTOPPED"
2411 "WSTOPSIG"
2412 "WIFEXITED" "WIFEXITED(${^CHILD_ERROR_NATIVE})" returns
2414 true if the child process exited normally
2415 ("exit()" or by falling off the end of
2416 "main()")
2417 "WEXITSTATUS" "WEXITSTATUS(${^CHILD_ERROR_NATIVE})" returns
2419 the normal exit status of the child process
2420 (only meaningful if
2421 "WIFEXITED(${^CHILD_ERROR_NATIVE})" is true)
2422 "WIFSIGNALED" "WIFSIGNALED(${^CHILD_ERROR_NATIVE})" returns
2424 true if the child process terminated because of
2425 a signal
2426 "WTERMSIG" "WTERMSIG(${^CHILD_ERROR_NATIVE})" returns the
2428 signal the child process terminated for (only
2429 meaningful if
2430 "WIFSIGNALED(${^CHILD_ERROR_NATIVE})" is true)
2431 "WIFSTOPPED" "WIFSTOPPED(${^CHILD_ERROR_NATIVE})" returns
2433 true if the child process is currently stopped
2434 (can happen only if you specified the WUNTRACED
2435 flag to "waitpid()")
2436 "WSTOPSIG" "WSTOPSIG(${^CHILD_ERROR_NATIVE})" returns the
2438 signal the child process was stopped for (only
2439 meaningful if
2440 "WIFSTOPPED(${^CHILD_ERROR_NATIVE})" is true)
2441
2443 (Windows only.)
2444 Constants
2446 Added in Perl v5.24:
2447 "WSAEINTR" "WSAEBADF" "WSAEACCES" "WSAEFAULT" "WSAEINVAL"
2449 "WSAEMFILE" "WSAEWOULDBLOCK" "WSAEINPROGRESS" "WSAEALREADY"
2450 "WSAENOTSOCK" "WSAEDESTADDRREQ" "WSAEMSGSIZE" "WSAEPROTOTYPE"
2451 "WSAENOPROTOOPT" "WSAEPROTONOSUPPORT" "WSAESOCKTNOSUPPORT"
2452 "WSAEOPNOTSUPP" "WSAEPFNOSUPPORT" "WSAEAFNOSUPPORT"
2453 "WSAEADDRINUSE" "WSAEADDRNOTAVAIL" "WSAENETDOWN"
2454 "WSAENETUNREACH" "WSAENETRESET" "WSAECONNABORTED"
2455 "WSAECONNRESET" "WSAENOBUFS" "WSAEISCONN" "WSAENOTCONN"
2456 "WSAESHUTDOWN" "WSAETOOMANYREFS" "WSAETIMEDOUT"
2457 "WSAECONNREFUSED" "WSAELOOP" "WSAENAMETOOLONG" "WSAEHOSTDOWN"
2458 "WSAEHOSTUNREACH" "WSAENOTEMPTY" "WSAEPROCLIM" "WSAEUSERS"
2459 "WSAEDQUOT" "WSAESTALE" "WSAEREMOTE" "WSAEDISCON" "WSAENOMORE"
2460 "WSAECANCELLED" "WSAEINVALIDPROCTABLE" "WSAEINVALIDPROVIDER"
2461 "WSAEPROVIDERFAILEDINIT" "WSAEREFUSED"
2462perl v5.36.0 2022-08-30 POSIX(3pm)