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 ldexp This is identical to the C function "ldexp()" for multiplying
543 floating point numbers with powers of two.
544 $x_quadrupled = POSIX::ldexp($x, 2);
546 ldiv (For computing dividends of long integers.) ldiv() is
548 C-specific, use "/" and "int()" instead.
549 link This is identical to Perl's builtin "link()" function for
551 creating hard links into files, see "link" in perlfunc.
552 localeconv
554 Get numeric formatting information. Returns a reference to a
555 hash containing the current locale formatting values.
556 Here is how to query the database for the de (Deutsch or
558 German) locale.
559 $loc = POSIX::setlocale( &POSIX::LC_ALL, "de" );
561 print "Locale = $loc\n";
562 $lconv = POSIX::localeconv();
563 print "decimal_point = ", $lconv->{decimal_point}, "\n";
564 print "thousands_sep = ", $lconv->{thousands_sep}, "\n";
565 print "grouping = ", $lconv->{grouping}, "\n";
566 print "int_curr_symbol = ", $lconv->{int_curr_symbol}, "\n";
567 print "currency_symbol = ", $lconv->{currency_symbol}, "\n";
568 print "mon_decimal_point = ", $lconv->{mon_decimal_point}, "\n";
569 print "mon_thousands_sep = ", $lconv->{mon_thousands_sep}, "\n";
570 print "mon_grouping = ", $lconv->{mon_grouping}, "\n";
571 print "positive_sign = ", $lconv->{positive_sign}, "\n";
572 print "negative_sign = ", $lconv->{negative_sign}, "\n";
573 print "int_frac_digits = ", $lconv->{int_frac_digits}, "\n";
574 print "frac_digits = ", $lconv->{frac_digits}, "\n";
575 print "p_cs_precedes = ", $lconv->{p_cs_precedes}, "\n";
576 print "p_sep_by_space = ", $lconv->{p_sep_by_space}, "\n";
577 print "n_cs_precedes = ", $lconv->{n_cs_precedes}, "\n";
578 print "n_sep_by_space = ", $lconv->{n_sep_by_space}, "\n";
579 print "p_sign_posn = ", $lconv->{p_sign_posn}, "\n";
580 print "n_sign_posn = ", $lconv->{n_sign_posn}, "\n";
581 localtime
583 This is identical to Perl's builtin "localtime()" function for
584 converting seconds since the epoch to a date see "localtime" in
585 perlfunc.
586 log This is identical to Perl's builtin "log()" function, returning
588 the natural (e-based) logarithm of the numerical argument, see
589 "log" in perlfunc.
590 log10 This is identical to the C function "log10()", returning the
592 10-base logarithm of the numerical argument. You can also use
593 sub log10 { log($_[0]) / log(10) }
595 or
597 sub log10 { log($_[0]) / 2.30258509299405 }
599 or
601 sub log10 { log($_[0]) * 0.434294481903252 }
603 longjmp longjmp() is C-specific: use "die" in perlfunc instead.
605 lseek Move the file's read/write position. This uses file
607 descriptors such as those obtained by calling "POSIX::open".
608 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
610 $off_t = POSIX::lseek( $fd, 0, &POSIX::SEEK_SET );
611 Returns "undef" on failure.
613 malloc malloc() is C-specific. Perl does memory management
615 transparently.
616 mblen This is identical to the C function "mblen()". Perl does not
618 have any support for the wide and multibyte characters of the C
619 standards, so this might be a rather useless function.
620 mbstowcs
622 This is identical to the C function "mbstowcs()". Perl does
623 not have any support for the wide and multibyte characters of
624 the C standards, so this might be a rather useless function.
625 mbtowc This is identical to the C function "mbtowc()". Perl does not
627 have any support for the wide and multibyte characters of the C
628 standards, so this might be a rather useless function.
629 memchr memchr() is C-specific, see "index" in perlfunc instead.
631 memcmp memcmp() is C-specific, use "eq" instead, see perlop.
633 memcpy memcpy() is C-specific, use "=", see perlop, or see "substr" in
635 perlfunc.
636 memmove memmove() is C-specific, use "=", see perlop, or see "substr"
638 in perlfunc.
639 memset memset() is C-specific, use "x" instead, see perlop.
641 mkdir This is identical to Perl's builtin "mkdir()" function for
643 creating directories, see "mkdir" in perlfunc.
644 mkfifo This is similar to the C function "mkfifo()" for creating FIFO
646 special files.
647 if (mkfifo($path, $mode)) { ....
649 Returns "undef" on failure. The $mode is similar to the mode
651 of "mkdir()", see "mkdir" in perlfunc, though for "mkfifo" you
652 must specify the $mode.
653 mktime Convert date/time info to a calendar time.
655 Synopsis:
657 mktime(sec, min, hour, mday, mon, year, wday = 0, yday = 0, isdst = -1)
659 The month ("mon"), weekday ("wday"), and yearday ("yday") begin
661 at zero. I.e. January is 0, not 1; Sunday is 0, not 1; January
662 1st is 0, not 1. The year ("year") is given in years since
663 1900. I.e. The year 1995 is 95; the year 2001 is 101. Consult
664 your system's "mktime()" manpage for details about these and
665 the other arguments.
666 Calendar time for December 12, 1995, at 10:30 am.
668 $time_t = POSIX::mktime( 0, 30, 10, 12, 11, 95 );
670 print "Date = ", POSIX::ctime($time_t);
671 Returns "undef" on failure.
673 modf Return the integral and fractional parts of a floating-point
675 number.
676 ($fractional, $integral) = POSIX::modf( 3.14 );
678 nice This is similar to the C function "nice()", for changing the
680 scheduling preference of the current process. Positive
681 arguments mean more polite process, negative values more needy
682 process. Normal user processes can only be more polite.
683 Returns "undef" on failure.
685 offsetof
687 offsetof() is C-specific, you probably want to see "pack" in
688 perlfunc instead.
689 open Open a file for reading for writing. This returns file
691 descriptors, not Perl filehandles. Use "POSIX::close" to close
692 the file.
693 Open a file read-only with mode 0666.
695 $fd = POSIX::open( "foo" );
697 Open a file for read and write.
699 $fd = POSIX::open( "foo", &POSIX::O_RDWR );
701 Open a file for write, with truncation.
703 $fd = POSIX::open( "foo", &POSIX::O_WRONLY | &POSIX::O_TRUNC );
705 Create a new file with mode 0640. Set up the file for writing.
707 $fd = POSIX::open( "foo", &POSIX::O_CREAT | &POSIX::O_WRONLY, 0640 );
709 Returns "undef" on failure.
711 See also "sysopen" in perlfunc.
713 opendir Open a directory for reading.
715 $dir = POSIX::opendir( "/var" );
717 @files = POSIX::readdir( $dir );
718 POSIX::closedir( $dir );
719 Returns "undef" on failure.
721 pathconf
723 Retrieves the value of a configurable limit on a file or
724 directory.
725 The following will determine the maximum length of the longest
727 allowable pathname on the filesystem which holds "/var".
728 $path_max = POSIX::pathconf( "/var", &POSIX::_PC_PATH_MAX );
730 Returns "undef" on failure.
732 pause This is similar to the C function "pause()", which suspends the
734 execution of the current process until a signal is received.
735 Returns "undef" on failure.
737 perror This is identical to the C function "perror()", which outputs
739 to the standard error stream the specified message followed by
740 ": " and the current error string. Use the "warn()" function
741 and the $! variable instead, see "warn" in perlfunc and
742 "$ERRNO" in perlvar.
743 pipe Create an interprocess channel. This returns file descriptors
745 like those returned by "POSIX::open".
746 my ($read, $write) = POSIX::pipe();
748 POSIX::write( $write, "hello", 5 );
749 POSIX::read( $read, $buf, 5 );
750 See also "pipe" in perlfunc.
752 pow Computes $x raised to the power $exponent.
754 $ret = POSIX::pow( $x, $exponent );
756 You can also use the "**" operator, see perlop.
758 printf Formats and prints the specified arguments to STDOUT. See also
760 "printf" in perlfunc.
761 putc putc() is C-specific, see "print" in perlfunc instead.
763 putchar putchar() is C-specific, see "print" in perlfunc instead.
765 puts puts() is C-specific, see "print" in perlfunc instead.
767 qsort qsort() is C-specific, see "sort" in perlfunc instead.
769 raise Sends the specified signal to the current process. See also
771 "kill" in perlfunc and the $$ in "$PID" in perlvar.
772 rand "rand()" is non-portable, see "rand" in perlfunc instead.
774 read Read from a file. This uses file descriptors such as those
776 obtained by calling "POSIX::open". If the buffer $buf is not
777 large enough for the read then Perl will extend it to make room
778 for the request.
779 $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
781 $bytes = POSIX::read( $fd, $buf, 3 );
782 Returns "undef" on failure.
784 See also "sysread" in perlfunc.
786 readdir This is identical to Perl's builtin "readdir()" function for
788 reading directory entries, see "readdir" in perlfunc.
789 realloc realloc() is C-specific. Perl does memory management
791 transparently.
792 remove This is identical to Perl's builtin "unlink()" function for
794 removing files, see "unlink" in perlfunc.
795 rename This is identical to Perl's builtin "rename()" function for
797 renaming files, see "rename" in perlfunc.
798 rewind Seeks to the beginning of the file.
800 rewinddir
802 This is identical to Perl's builtin "rewinddir()" function for
803 rewinding directory entry streams, see "rewinddir" in perlfunc.
804 rmdir This is identical to Perl's builtin "rmdir()" function for
806 removing (empty) directories, see "rmdir" in perlfunc.
807 scanf scanf() is C-specific, use <> and regular expressions instead,
809 see perlre.
810 setgid Sets the real group identifier and the effective group
812 identifier for this process. Similar to assigning a value to
813 the Perl's builtin $) variable, see "$EGID" in perlvar, except
814 that the latter will change only the real user identifier, and
815 that the setgid() uses only a single numeric argument, as
816 opposed to a space-separated list of numbers.
817 setjmp "setjmp()" is C-specific: use "eval {}" instead, see "eval" in
819 perlfunc.
820 setlocale
822 Modifies and queries program's locale. The following examples
823 assume
824 use POSIX qw(setlocale LC_ALL LC_CTYPE);
826 has been issued.
828 The following will set the traditional UNIX system locale
830 behavior (the second argument "C").
831 $loc = setlocale( LC_ALL, "C" );
833 The following will query the current LC_CTYPE category. (No
835 second argument means 'query'.)
836 $loc = setlocale( LC_CTYPE );
838 The following will set the LC_CTYPE behaviour according to the
840 locale environment variables (the second argument ""). Please
841 see your systems setlocale(3) documentation for the locale
842 environment variables' meaning or consult perllocale.
843 $loc = setlocale( LC_CTYPE, "" );
845 The following will set the LC_COLLATE behaviour to Argentinian
847 Spanish. NOTE: The naming and availability of locales depends
848 on your operating system. Please consult perllocale for how to
849 find out which locales are available in your system.
850 $loc = setlocale( LC_ALL, "es_AR.ISO8859-1" );
852 setpgid This is similar to the C function "setpgid()" for setting the
854 process group identifier of the current process.
855 Returns "undef" on failure.
857 setsid This is identical to the C function "setsid()" for setting the
859 session identifier of the current process.
860 setuid Sets the real user identifier and the effective user identifier
862 for this process. Similar to assigning a value to the Perl's
863 builtin $< variable, see "$UID" in perlvar, except that the
864 latter will change only the real user identifier.
865 sigaction
867 Detailed signal management. This uses "POSIX::SigAction"
868 objects for the "action" and "oldaction" arguments (the
869 oldaction can also be just a hash reference). Consult your
870 system's "sigaction" manpage for details, see also
871 "POSIX::SigRt".
872 Synopsis:
874 sigaction(signal, action, oldaction = 0)
876 Returns "undef" on failure. The "signal" must be a number
878 (like SIGHUP), not a string (like "SIGHUP"), though Perl does
879 try hard to understand you.
880 If you use the SA_SIGINFO flag, the signal handler will in
882 addition to the first argument, the signal name, also receive a
883 second argument, a hash reference, inside which are the
884 following keys with the following semantics, as defined by
885 POSIX/SUSv3:
886 signo the signal number
888 errno the error number
889 code if this is zero or less, the signal was sent by
890 a user process and the uid and pid make sense,
891 otherwise the signal was sent by the kernel
892 The following are also defined by POSIX/SUSv3, but
894 unfortunately not very widely implemented:
895 pid the process id generating the signal
897 uid the uid of the process id generating the signal
898 status exit value or signal for SIGCHLD
899 band band event for SIGPOLL
900 A third argument is also passed to the handler, which contains
902 a copy of the raw binary contents of the siginfo structure: if
903 a system has some non-POSIX fields, this third argument is
904 where to unpack() them from.
905 Note that not all siginfo values make sense simultaneously
907 (some are valid only for certain signals, for example), and not
908 all values make sense from Perl perspective, you should to
909 consult your system's "sigaction" and possibly also "siginfo"
910 documentation.
911 siglongjmp
913 siglongjmp() is C-specific: use "die" in perlfunc instead.
914 sigpending
916 Examine signals that are blocked and pending. This uses
917 "POSIX::SigSet" objects for the "sigset" argument. Consult
918 your system's "sigpending" manpage for details.
919 Synopsis:
921 sigpending(sigset)
923 Returns "undef" on failure.
925 sigprocmask
927 Change and/or examine calling process's signal mask. This uses
928 "POSIX::SigSet" objects for the "sigset" and "oldsigset"
929 arguments. Consult your system's "sigprocmask" manpage for
930 details.
931 Synopsis:
933 sigprocmask(how, sigset, oldsigset = 0)
935 Returns "undef" on failure.
937 sigsetjmp
939 "sigsetjmp()" is C-specific: use "eval {}" instead, see "eval"
940 in perlfunc.
941 sigsuspend
943 Install a signal mask and suspend process until signal arrives.
944 This uses "POSIX::SigSet" objects for the "signal_mask"
945 argument. Consult your system's "sigsuspend" manpage for
946 details.
947 Synopsis:
949 sigsuspend(signal_mask)
951 Returns "undef" on failure.
953 sin This is identical to Perl's builtin "sin()" function for
955 returning the sine of the numerical argument, see "sin" in
956 perlfunc. See also Math::Trig.
957 sinh This is identical to the C function "sinh()" for returning the
959 hyperbolic sine of the numerical argument. See also
960 Math::Trig.
961 sleep This is functionally identical to Perl's builtin "sleep()"
963 function for suspending the execution of the current for
964 process for certain number of seconds, see "sleep" in perlfunc.
965 There is one significant difference, however: "POSIX::sleep()"
966 returns the number of unslept seconds, while the
967 "CORE::sleep()" returns the number of slept seconds.
968 sprintf This is similar to Perl's builtin "sprintf()" function for
970 returning a string that has the arguments formatted as
971 requested, see "sprintf" in perlfunc.
972 sqrt This is identical to Perl's builtin "sqrt()" function. for
974 returning the square root of the numerical argument, see "sqrt"
975 in perlfunc.
976 srand Give a seed the pseudorandom number generator, see "srand" in
978 perlfunc.
979 sscanf sscanf() is C-specific, use regular expressions instead, see
981 perlre.
982 stat This is identical to Perl's builtin "stat()" function for
984 returning information about files and directories.
985 strcat strcat() is C-specific, use ".=" instead, see perlop.
987 strchr strchr() is C-specific, see "index" in perlfunc instead.
989 strcmp strcmp() is C-specific, use "eq" or "cmp" instead, see perlop.
991 strcoll This is identical to the C function "strcoll()" for collating
993 (comparing) strings transformed using the "strxfrm()" function.
994 Not really needed since Perl can do this transparently, see
995 perllocale.
996 strcpy strcpy() is C-specific, use "=" instead, see perlop.
998 strcspn strcspn() is C-specific, use regular expressions instead, see
1000 perlre.
1001 strerror
1003 Returns the error string for the specified errno. Identical to
1004 the string form of the $!, see "$ERRNO" in perlvar.
1005 strftime
1007 Convert date and time information to string. Returns the
1008 string.
1009 Synopsis:
1011 strftime(fmt, sec, min, hour, mday, mon, year, wday = -1, yday = -1, isdst = -1)
1013 The month ("mon"), weekday ("wday"), and yearday ("yday") begin
1015 at zero. I.e. January is 0, not 1; Sunday is 0, not 1; January
1016 1st is 0, not 1. The year ("year") is given in years since
1017 1900. I.e., the year 1995 is 95; the year 2001 is 101.
1018 Consult your system's "strftime()" manpage for details about
1019 these and the other arguments.
1020 If you want your code to be portable, your format ("fmt")
1022 argument should use only the conversion specifiers defined by
1023 the ANSI C standard (C89, to play safe). These are
1024 "aAbBcdHIjmMpSUwWxXyYZ%". But even then, the results of some
1025 of the conversion specifiers are non-portable. For example,
1026 the specifiers "aAbBcpZ" change according to the locale
1027 settings of the user, and both how to set locales (the locale
1028 names) and what output to expect are non-standard. The
1029 specifier "c" changes according to the timezone settings of the
1030 user and the timezone computation rules of the operating
1031 system. The "Z" specifier is notoriously unportable since the
1032 names of timezones are non-standard. Sticking to the numeric
1033 specifiers is the safest route.
1034 The given arguments are made consistent as though by calling
1036 "mktime()" before calling your system's "strftime()" function,
1037 except that the "isdst" value is not affected.
1038 The string for Tuesday, December 12, 1995.
1040 $str = POSIX::strftime( "%A, %B %d, %Y", 0, 0, 0, 12, 11, 95, 2 );
1042 print "$str\n";
1043 strlen strlen() is C-specific, use "length()" instead, see "length" in
1045 perlfunc.
1046 strncat strncat() is C-specific, use ".=" instead, see perlop.
1048 strncmp strncmp() is C-specific, use "eq" instead, see perlop.
1050 strncpy strncpy() is C-specific, use "=" instead, see perlop.
1052 strpbrk strpbrk() is C-specific, use regular expressions instead, see
1054 perlre.
1055 strrchr strrchr() is C-specific, see "rindex" in perlfunc instead.
1057 strspn strspn() is C-specific, use regular expressions instead, see
1059 perlre.
1060 strstr This is identical to Perl's builtin "index()" function, see
1062 "index" in perlfunc.
1063 strtod String to double translation. Returns the parsed number and the
1065 number of characters in the unparsed portion of the string.
1066 Truly POSIX-compliant systems set $! ($ERRNO) to indicate a
1067 translation error, so clear $! before calling strtod. However,
1068 non-POSIX systems may not check for overflow, and therefore
1069 will never set $!.
1070 strtod should respect any POSIX setlocale() settings.
1072 To parse a string $str as a floating point number use
1074 $! = 0;
1076 ($num, $n_unparsed) = POSIX::strtod($str);
1077 The second returned item and $! can be used to check for valid
1079 input:
1080 if (($str eq '') || ($n_unparsed != 0) || $!) {
1082 die "Non-numeric input $str" . ($! ? ": $!\n" : "\n");
1083 }
1084 When called in a scalar context strtod returns the parsed
1086 number.
1087 strtok strtok() is C-specific, use regular expressions instead, see
1089 perlre, or "split" in perlfunc.
1090 strtol String to (long) integer translation. Returns the parsed
1092 number and the number of characters in the unparsed portion of
1093 the string. Truly POSIX-compliant systems set $! ($ERRNO) to
1094 indicate a translation error, so clear $! before calling
1095 strtol. However, non-POSIX systems may not check for overflow,
1096 and therefore will never set $!.
1097 strtol should respect any POSIX setlocale() settings.
1099 To parse a string $str as a number in some base $base use
1101 $! = 0;
1103 ($num, $n_unparsed) = POSIX::strtol($str, $base);
1104 The base should be zero or between 2 and 36, inclusive. When
1106 the base is zero or omitted strtol will use the string itself
1107 to determine the base: a leading "0x" or "0X" means
1108 hexadecimal; a leading "0" means octal; any other leading
1109 characters mean decimal. Thus, "1234" is parsed as a decimal
1110 number, "01234" as an octal number, and "0x1234" as a
1111 hexadecimal number.
1112 The second returned item and $! can be used to check for valid
1114 input:
1115 if (($str eq '') || ($n_unparsed != 0) || !$!) {
1117 die "Non-numeric input $str" . $! ? ": $!\n" : "\n";
1118 }
1119 When called in a scalar context strtol returns the parsed
1121 number.
1122 strtoul String to unsigned (long) integer translation. strtoul() is
1124 identical to strtol() except that strtoul() only parses
1125 unsigned integers. See "strtol" for details.
1126 Note: Some vendors supply strtod() and strtol() but not
1128 strtoul(). Other vendors that do supply strtoul() parse "-1"
1129 as a valid value.
1130 strxfrm String transformation. Returns the transformed string.
1132 $dst = POSIX::strxfrm( $src );
1134 Used in conjunction with the "strcoll()" function, see
1136 "strcoll".
1137 Not really needed since Perl can do this transparently, see
1139 perllocale.
1140 sysconf Retrieves values of system configurable variables.
1142 The following will get the machine's clock speed.
1144 $clock_ticks = POSIX::sysconf( &POSIX::_SC_CLK_TCK );
1146 Returns "undef" on failure.
1148 system This is identical to Perl's builtin "system()" function, see
1150 "system" in perlfunc.
1151 tan This is identical to the C function "tan()", returning the
1153 tangent of the numerical argument. See also Math::Trig.
1154 tanh This is identical to the C function "tanh()", returning the
1156 hyperbolic tangent of the numerical argument. See also
1157 Math::Trig.
1158 tcdrain This is similar to the C function "tcdrain()" for draining the
1160 output queue of its argument stream.
1161 Returns "undef" on failure.
1163 tcflow This is similar to the C function "tcflow()" for controlling
1165 the flow of its argument stream.
1166 Returns "undef" on failure.
1168 tcflush This is similar to the C function "tcflush()" for flushing the
1170 I/O buffers of its argument stream.
1171 Returns "undef" on failure.
1173 tcgetpgrp
1175 This is identical to the C function "tcgetpgrp()" for returning
1176 the process group identifier of the foreground process group of
1177 the controlling terminal.
1178 tcsendbreak
1180 This is similar to the C function "tcsendbreak()" for sending a
1181 break on its argument stream.
1182 Returns "undef" on failure.
1184 tcsetpgrp
1186 This is similar to the C function "tcsetpgrp()" for setting the
1187 process group identifier of the foreground process group of the
1188 controlling terminal.
1189 Returns "undef" on failure.
1191 time This is identical to Perl's builtin "time()" function for
1193 returning the number of seconds since the epoch (whatever it is
1194 for the system), see "time" in perlfunc.
1195 times The times() function returns elapsed realtime since some point
1197 in the past (such as system startup), user and system times for
1198 this process, and user and system times used by child
1199 processes. All times are returned in clock ticks.
1200 ($realtime, $user, $system, $cuser, $csystem) = POSIX::times();
1202 Note: Perl's builtin "times()" function returns four values,
1204 measured in seconds.
1205 tmpfile Use method "IO::File::new_tmpfile()" instead, or see
1207 File::Temp.
1208 tmpnam Returns a name for a temporary file.
1210 $tmpfile = POSIX::tmpnam();
1212 For security reasons, which are probably detailed in your
1214 system's documentation for the C library tmpnam() function,
1215 this interface should not be used; instead see File::Temp.
1216 tolower This is identical to the C function, except that it can apply
1218 to a single character or to a whole string. Consider using the
1219 "lc()" function, see "lc" in perlfunc, or the equivalent "\L"
1220 operator inside doublequotish strings.
1221 toupper This is identical to the C function, except that it can apply
1223 to a single character or to a whole string. Consider using the
1224 "uc()" function, see "uc" in perlfunc, or the equivalent "\U"
1225 operator inside doublequotish strings.
1226 ttyname This is identical to the C function "ttyname()" for returning
1228 the name of the current terminal.
1229 tzname Retrieves the time conversion information from the "tzname"
1231 variable.
1232 POSIX::tzset();
1234 ($std, $dst) = POSIX::tzname();
1235 tzset This is identical to the C function "tzset()" for setting the
1237 current timezone based on the environment variable "TZ", to be
1238 used by "ctime()", "localtime()", "mktime()", and "strftime()"
1239 functions.
1240 umask This is identical to Perl's builtin "umask()" function for
1242 setting (and querying) the file creation permission mask, see
1243 "umask" in perlfunc.
1244 uname Get name of current operating system.
1246 ($sysname, $nodename, $release, $version, $machine) = POSIX::uname();
1248 Note that the actual meanings of the various fields are not
1250 that well standardized, do not expect any great portability.
1251 The $sysname might be the name of the operating system, the
1252 $nodename might be the name of the host, the $release might be
1253 the (major) release number of the operating system, the
1254 $version might be the (minor) release number of the operating
1255 system, and the $machine might be a hardware identifier.
1256 Maybe.
1257 ungetc Use method "IO::Handle::ungetc()" instead.
1259 unlink This is identical to Perl's builtin "unlink()" function for
1261 removing files, see "unlink" in perlfunc.
1262 utime This is identical to Perl's builtin "utime()" function for
1264 changing the time stamps of files and directories, see "utime"
1265 in perlfunc.
1266 vfprintf
1268 vfprintf() is C-specific, see "printf" in perlfunc instead.
1269 vprintf vprintf() is C-specific, see "printf" in perlfunc instead.
1271 vsprintf
1273 vsprintf() is C-specific, see "sprintf" in perlfunc instead.
1274 wait This is identical to Perl's builtin "wait()" function, see
1276 "wait" in perlfunc.
1277 waitpid Wait for a child process to change state. This is identical to
1279 Perl's builtin "waitpid()" function, see "waitpid" in perlfunc.
1280 $pid = POSIX::waitpid( -1, POSIX::WNOHANG );
1282 print "status = ", ($? / 256), "\n";
1283 wcstombs
1285 This is identical to the C function "wcstombs()". Perl does
1286 not have any support for the wide and multibyte characters of
1287 the C standards, so this might be a rather useless function.
1288 wctomb This is identical to the C function "wctomb()". Perl does not
1290 have any support for the wide and multibyte characters of the C
1291 standards, so this might be a rather useless function.
1292 write Write to a file. This uses file descriptors such as those
1294 obtained by calling "POSIX::open".
1295 $fd = POSIX::open( "foo", &POSIX::O_WRONLY );
1297 $buf = "hello";
1298 $bytes = POSIX::write( $fd, $buf, 5 );
1299 Returns "undef" on failure.
1301 See also "syswrite" in perlfunc.
1303
1305 POSIX::SigAction
1306 new Creates a new "POSIX::SigAction" object which corresponds to
1307 the C "struct sigaction". This object will be destroyed
1308 automatically when it is no longer needed. The first parameter
1309 is the handler, a sub reference. The second parameter is a
1310 "POSIX::SigSet" object, it defaults to the empty set. The
1311 third parameter contains the "sa_flags", it defaults to 0.
1312 $sigset = POSIX::SigSet->new(SIGINT, SIGQUIT);
1314 $sigaction = POSIX::SigAction->new( \&handler, $sigset, &POSIX::SA_NOCLDSTOP );
1315 This "POSIX::SigAction" object is intended for use with the
1317 "POSIX::sigaction()" function.
1318 handler
1320 mask
1321 flags accessor functions to get/set the values of a SigAction object.
1322 $sigset = $sigaction->mask;
1324 $sigaction->flags(&POSIX::SA_RESTART);
1325 safe accessor function for the "safe signals" flag of a SigAction
1327 object; see perlipc for general information on safe (a.k.a.
1328 "deferred") signals. If you wish to handle a signal safely,
1329 use this accessor to set the "safe" flag in the
1330 "POSIX::SigAction" object:
1331 $sigaction->safe(1);
1333 You may also examine the "safe" flag on the output action
1335 object which is filled in when given as the third parameter to
1336 "POSIX::sigaction()":
1337 sigaction(SIGINT, $new_action, $old_action);
1339 if ($old_action->safe) {
1340 # previous SIGINT handler used safe signals
1341 }
1342 POSIX::SigRt
1344 %SIGRT A hash of the POSIX realtime signal handlers. It is an
1345 extension of the standard %SIG, the $POSIX::SIGRT{SIGRTMIN} is
1346 roughly equivalent to $SIG{SIGRTMIN}, but the right POSIX moves
1347 (see below) are made with the POSIX::SigSet and
1348 POSIX::sigaction instead of accessing the %SIG.
1349 You can set the %POSIX::SIGRT elements to set the POSIX
1351 realtime signal handlers, use "delete" and "exists" on the
1352 elements, and use "scalar" on the %POSIX::SIGRT to find out how
1353 many POSIX realtime signals there are available (SIGRTMAX -
1354 SIGRTMIN + 1, the SIGRTMAX is a valid POSIX realtime signal).
1355 Setting the %SIGRT elements is equivalent to calling this:
1357 sub new {
1359 my ($rtsig, $handler, $flags) = @_;
1360 my $sigset = POSIX::SigSet($rtsig);
1361 my $sigact = POSIX::SigAction->new($handler, $sigset, $flags);
1362 sigaction($rtsig, $sigact);
1363 }
1364 The flags default to zero, if you want something different you
1366 can either use "local" on $POSIX::SigRt::SIGACTION_FLAGS, or
1367 you can derive from POSIX::SigRt and define your own "new()"
1368 (the tied hash STORE method of the %SIGRT calls "new($rtsig,
1369 $handler, $SIGACTION_FLAGS)", where the $rtsig ranges from zero
1370 to SIGRTMAX - SIGRTMIN + 1).
1371 Just as with any signal, you can use sigaction($rtsig, undef,
1373 $oa) to retrieve the installed signal handler (or, rather, the
1374 signal action).
1375 NOTE: whether POSIX realtime signals really work in your
1377 system, or whether Perl has been compiled so that it works with
1378 them, is outside of this discussion.
1379 SIGRTMIN
1381 Return the minimum POSIX realtime signal number available, or
1382 "undef" if no POSIX realtime signals are available.
1383 SIGRTMAX
1385 Return the maximum POSIX realtime signal number available, or
1386 "undef" if no POSIX realtime signals are available.
1387 POSIX::SigSet
1389 new Create a new SigSet object. This object will be destroyed
1390 automatically when it is no longer needed. Arguments may be
1391 supplied to initialize the set.
1392 Create an empty set.
1394 $sigset = POSIX::SigSet->new;
1396 Create a set with SIGUSR1.
1398 $sigset = POSIX::SigSet->new( &POSIX::SIGUSR1 );
1400 addset Add a signal to a SigSet object.
1402 $sigset->addset( &POSIX::SIGUSR2 );
1404 Returns "undef" on failure.
1406 delset Remove a signal from the SigSet object.
1408 $sigset->delset( &POSIX::SIGUSR2 );
1410 Returns "undef" on failure.
1412 emptyset
1414 Initialize the SigSet object to be empty.
1415 $sigset->emptyset();
1417 Returns "undef" on failure.
1419 fillset Initialize the SigSet object to include all signals.
1421 $sigset->fillset();
1423 Returns "undef" on failure.
1425 ismember
1427 Tests the SigSet object to see if it contains a specific
1428 signal.
1429 if( $sigset->ismember( &POSIX::SIGUSR1 ) ){
1431 print "contains SIGUSR1\n";
1432 }
1433 POSIX::Termios
1435 new Create a new Termios object. This object will be destroyed
1436 automatically when it is no longer needed. A Termios object
1437 corresponds to the termios C struct. new() mallocs a new one,
1438 getattr() fills it from a file descriptor, and setattr() sets a
1439 file descriptor's parameters to match Termios' contents.
1440 $termios = POSIX::Termios->new;
1442 getattr Get terminal control attributes.
1444 Obtain the attributes for stdin.
1446 $termios->getattr( 0 ) # Recommended for clarity.
1448 $termios->getattr()
1449 Obtain the attributes for stdout.
1451 $termios->getattr( 1 )
1453 Returns "undef" on failure.
1455 getcc Retrieve a value from the c_cc field of a termios object. The
1457 c_cc field is an array so an index must be specified.
1458 $c_cc[1] = $termios->getcc(1);
1460 getcflag
1462 Retrieve the c_cflag field of a termios object.
1463 $c_cflag = $termios->getcflag;
1465 getiflag
1467 Retrieve the c_iflag field of a termios object.
1468 $c_iflag = $termios->getiflag;
1470 getispeed
1472 Retrieve the input baud rate.
1473 $ispeed = $termios->getispeed;
1475 getlflag
1477 Retrieve the c_lflag field of a termios object.
1478 $c_lflag = $termios->getlflag;
1480 getoflag
1482 Retrieve the c_oflag field of a termios object.
1483 $c_oflag = $termios->getoflag;
1485 getospeed
1487 Retrieve the output baud rate.
1488 $ospeed = $termios->getospeed;
1490 setattr Set terminal control attributes.
1492 Set attributes immediately for stdout.
1494 $termios->setattr( 1, &POSIX::TCSANOW );
1496 Returns "undef" on failure.
1498 setcc Set a value in the c_cc field of a termios object. The c_cc
1500 field is an array so an index must be specified.
1501 $termios->setcc( &POSIX::VEOF, 1 );
1503 setcflag
1505 Set the c_cflag field of a termios object.
1506 $termios->setcflag( $c_cflag | &POSIX::CLOCAL );
1508 setiflag
1510 Set the c_iflag field of a termios object.
1511 $termios->setiflag( $c_iflag | &POSIX::BRKINT );
1513 setispeed
1515 Set the input baud rate.
1516 $termios->setispeed( &POSIX::B9600 );
1518 Returns "undef" on failure.
1520 setlflag
1522 Set the c_lflag field of a termios object.
1523 $termios->setlflag( $c_lflag | &POSIX::ECHO );
1525 setoflag
1527 Set the c_oflag field of a termios object.
1528 $termios->setoflag( $c_oflag | &POSIX::OPOST );
1530 setospeed
1532 Set the output baud rate.
1533 $termios->setospeed( &POSIX::B9600 );
1535 Returns "undef" on failure.
1537 Baud rate values
1539 B38400 B75 B200 B134 B300 B1800 B150 B0 B19200 B1200 B9600 B600
1540 B4800 B50 B2400 B110
1541 Terminal interface values
1543 TCSADRAIN TCSANOW TCOON TCIOFLUSH TCOFLUSH TCION TCIFLUSH
1544 TCSAFLUSH TCIOFF TCOOFF
1545 c_cc field values
1547 VEOF VEOL VERASE VINTR VKILL VQUIT VSUSP VSTART VSTOP VMIN
1548 VTIME NCCS
1549 c_cflag field values
1551 CLOCAL CREAD CSIZE CS5 CS6 CS7 CS8 CSTOPB HUPCL PARENB PARODD
1552 c_iflag field values
1554 BRKINT ICRNL IGNBRK IGNCR IGNPAR INLCR INPCK ISTRIP IXOFF IXON
1555 PARMRK
1556 c_lflag field values
1558 ECHO ECHOE ECHOK ECHONL ICANON IEXTEN ISIG NOFLSH TOSTOP
1559 c_oflag field values
1561 OPOST
1562
1564 Constants
1565 _PC_CHOWN_RESTRICTED _PC_LINK_MAX _PC_MAX_CANON _PC_MAX_INPUT
1566 _PC_NAME_MAX _PC_NO_TRUNC _PC_PATH_MAX _PC_PIPE_BUF
1567 _PC_VDISABLE
1568
1570 Constants
1571 _POSIX_ARG_MAX _POSIX_CHILD_MAX _POSIX_CHOWN_RESTRICTED
1572 _POSIX_JOB_CONTROL _POSIX_LINK_MAX _POSIX_MAX_CANON
1573 _POSIX_MAX_INPUT _POSIX_NAME_MAX _POSIX_NGROUPS_MAX
1574 _POSIX_NO_TRUNC _POSIX_OPEN_MAX _POSIX_PATH_MAX _POSIX_PIPE_BUF
1575 _POSIX_SAVED_IDS _POSIX_SSIZE_MAX _POSIX_STREAM_MAX
1576 _POSIX_TZNAME_MAX _POSIX_VDISABLE _POSIX_VERSION
1577
1579 Constants
1580 _SC_ARG_MAX _SC_CHILD_MAX _SC_CLK_TCK _SC_JOB_CONTROL
1581 _SC_NGROUPS_MAX _SC_OPEN_MAX _SC_PAGESIZE _SC_SAVED_IDS
1582 _SC_STREAM_MAX _SC_TZNAME_MAX _SC_VERSION
1583
1585 Constants
1586 E2BIG EACCES EADDRINUSE EADDRNOTAVAIL EAFNOSUPPORT EAGAIN
1587 EALREADY EBADF EBUSY ECHILD ECONNABORTED ECONNREFUSED
1588 ECONNRESET EDEADLK EDESTADDRREQ EDOM EDQUOT EEXIST EFAULT EFBIG
1589 EHOSTDOWN EHOSTUNREACH EINPROGRESS EINTR EINVAL EIO EISCONN
1590 EISDIR ELOOP EMFILE EMLINK EMSGSIZE ENAMETOOLONG ENETDOWN
1591 ENETRESET ENETUNREACH ENFILE ENOBUFS ENODEV ENOENT ENOEXEC
1592 ENOLCK ENOMEM ENOPROTOOPT ENOSPC ENOSYS ENOTBLK ENOTCONN
1593 ENOTDIR ENOTEMPTY ENOTSOCK ENOTTY ENXIO EOPNOTSUPP EPERM
1594 EPFNOSUPPORT EPIPE EPROCLIM EPROTONOSUPPORT EPROTOTYPE ERANGE
1595 EREMOTE ERESTART EROFS ESHUTDOWN ESOCKTNOSUPPORT ESPIPE ESRCH
1596 ESTALE ETIMEDOUT ETOOMANYREFS ETXTBSY EUSERS EWOULDBLOCK EXDEV
1597
1599 Constants
1600 FD_CLOEXEC F_DUPFD F_GETFD F_GETFL F_GETLK F_OK F_RDLCK F_SETFD
1601 F_SETFL F_SETLK F_SETLKW F_UNLCK F_WRLCK O_ACCMODE O_APPEND
1602 O_CREAT O_EXCL O_NOCTTY O_NONBLOCK O_RDONLY O_RDWR O_TRUNC
1603 O_WRONLY
1604
1606 Constants
1607 DBL_DIG DBL_EPSILON DBL_MANT_DIG DBL_MAX DBL_MAX_10_EXP
1608 DBL_MAX_EXP DBL_MIN DBL_MIN_10_EXP DBL_MIN_EXP FLT_DIG
1609 FLT_EPSILON FLT_MANT_DIG FLT_MAX FLT_MAX_10_EXP FLT_MAX_EXP
1610 FLT_MIN FLT_MIN_10_EXP FLT_MIN_EXP FLT_RADIX FLT_ROUNDS
1611 LDBL_DIG LDBL_EPSILON LDBL_MANT_DIG LDBL_MAX LDBL_MAX_10_EXP
1612 LDBL_MAX_EXP LDBL_MIN LDBL_MIN_10_EXP LDBL_MIN_EXP
1613
1615 Constants
1616 ARG_MAX CHAR_BIT CHAR_MAX CHAR_MIN CHILD_MAX INT_MAX INT_MIN
1617 LINK_MAX LONG_MAX LONG_MIN MAX_CANON MAX_INPUT MB_LEN_MAX
1618 NAME_MAX NGROUPS_MAX OPEN_MAX PATH_MAX PIPE_BUF SCHAR_MAX
1619 SCHAR_MIN SHRT_MAX SHRT_MIN SSIZE_MAX STREAM_MAX TZNAME_MAX
1620 UCHAR_MAX UINT_MAX ULONG_MAX USHRT_MAX
1621
1623 Constants
1624 LC_ALL LC_COLLATE LC_CTYPE LC_MONETARY LC_NUMERIC LC_TIME
1625
1627 Constants
1628 HUGE_VAL
1629
1631 Constants
1632 SA_NOCLDSTOP SA_NOCLDWAIT SA_NODEFER SA_ONSTACK SA_RESETHAND
1633 SA_RESTART SA_SIGINFO SIGABRT SIGALRM SIGCHLD SIGCONT SIGFPE
1634 SIGHUP SIGILL SIGINT SIGKILL SIGPIPE SIGQUIT SIGSEGV SIGSTOP
1635 SIGTERM SIGTSTP SIGTTIN SIGTTOU SIGUSR1 SIGUSR2 SIG_BLOCK
1636 SIG_DFL SIG_ERR SIG_IGN SIG_SETMASK SIG_UNBLOCK
1637
1639 Constants
1640 S_IRGRP S_IROTH S_IRUSR S_IRWXG S_IRWXO S_IRWXU S_ISGID S_ISUID
1641 S_IWGRP S_IWOTH S_IWUSR S_IXGRP S_IXOTH S_IXUSR
1642 Macros S_ISBLK S_ISCHR S_ISDIR S_ISFIFO S_ISREG
1644
1646 Constants
1647 EXIT_FAILURE EXIT_SUCCESS MB_CUR_MAX RAND_MAX
1648
1650 Constants
1651 BUFSIZ EOF FILENAME_MAX L_ctermid L_cuserid L_tmpname TMP_MAX
1652
1654 Constants
1655 CLK_TCK CLOCKS_PER_SEC
1656
1658 Constants
1659 R_OK SEEK_CUR SEEK_END SEEK_SET STDIN_FILENO STDOUT_FILENO
1660 STDERR_FILENO W_OK X_OK
1661
1663 Constants
1664 WNOHANG WUNTRACED
1665 WNOHANG Do not suspend the calling process until a
1667 child process changes state but instead return
1668 immediately.
1669 WUNTRACED Catch stopped child processes.
1671 Macros WIFEXITED WEXITSTATUS WIFSIGNALED WTERMSIG WIFSTOPPED WSTOPSIG
1673 WIFEXITED WIFEXITED($?) returns true if the child process
1675 exited normally ("exit()" or by falling off the
1676 end of "main()")
1677 WEXITSTATUS WEXITSTATUS($?) returns the normal exit status
1679 of the child process (only meaningful if
1680 WIFEXITED($?) is true)
1681 WIFSIGNALED WIFSIGNALED($?) returns true if the child
1683 process terminated because of a signal
1684 WTERMSIG WTERMSIG($?) returns the signal the child
1686 process terminated for (only meaningful if
1687 WIFSIGNALED($?) is true)
1688 WIFSTOPPED WIFSTOPPED($?) returns true if the child
1690 process is currently stopped (can happen only
1691 if you specified the WUNTRACED flag to
1692 waitpid())
1693 WSTOPSIG WSTOPSIG($?) returns the signal the child
1695 process was stopped for (only meaningful if
1696 WIFSTOPPED($?) is true)
1697perl v5.10.1 2009-04-12 POSIX(3pm)