


POSIX(3p)        Perl Programmers Reference Guide       POSIX(3p)


NAME
       POSIX - Perl interface to IEEE Std 1003.1

SYNOPSIS
           use POSIX;
           use POSIX qw(setsid);
           use POSIX qw(:errno_h :fcntl_h);

           printf "EINTR is %d\n", EINTR;

           $sess_id = POSIX::setsid();

           $fd = POSIX::open($path, O_CREAT|O_EXCL|O_WRONLY, 0644);
               # note: that's a filedescriptor, *NOT* a filehandle


DESCRIPTION
       The POSIX module permits you to access all (or nearly all)
       the standard POSIX 1003.1 identifiers.  Many of these
       identifiers have been given Perl-ish interfaces.  Things
       which are "#defines" in C, like EINTR or O_NDELAY, are
       automatically exported into your namespace.  All functions
       are only exported if you ask for them explicitly.  Most
       likely people will prefer to use the fully-qualified func-
       tion names.

       This document gives a condensed list of the features
       available in the POSIX module.  Consult your operating
       system's manpages for general information on most fea-
       tures.  Consult the perlfunc manpage for functions which
       are noted as being identical to Perl's builtin functions.

       The first section describes POSIX functions from the
       1003.1 specification.  The second section describes some
       classes for signal objects, TTY objects, and other miscel-
       laneous objects.  The remaining sections list various con-
       stants and macros in an organization which roughly follows
       IEEE Std 1003.1b-1993.

NOTE
       The POSIX module is probably the most complex Perl module
       supplied with the standard distribution.  It incorporates
       autoloading, namespace games, and dynamic loading of code
       that's in Perl, C, or both.  It's a great source of wis-
       dom.

CAVEATS
       A few functions are not implemented because they are C
       specific.  If you attempt to call these, they will print a
       message telling you that they aren't implemented, and sug-
       gest using the Perl equivalent should one exist.  For
       example, trying to access the setjmp() call will elicit
       the message "setjmp() is C-specific: use eval {} instead".




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       Furthermore, some evil vendors will claim 1003.1 compli-
       ance, but in fact are not so: they will not pass the PCTS
       (POSIX Compliance Test Suites).  For example, one vendor
       may not define EDEADLK, or the semantics of the errno val-
       ues set by open(2) might not be quite right.  Perl does
       not attempt to verify POSIX compliance.  That means you
       can currently successfully say "use POSIX",  and then
       later in your program you find that your vendor has been
       lax and there's no usable ICANON macro after all.  This
       could be construed to be a bug.

FUNCTIONS
       _exit   This is identical to the C function "_exit()".  It
               exits the program immediately which means among
               other things buffered I/O is not flushed.

       abort   This is identical to the C function "abort()".  It
               terminates the process with a "SIGABRT" signal
               unless caught by a signal handler or if the han-
               dler does not return normally (it e.g.  does a
               "longjmp").

       abs     This is identical to Perl's builtin "abs()" func-
               tion, returning the absolute value of its numeri-
               cal argument.

       access  Determines the accessibility of a file.

                       if( POSIX::access( "/", &POSIX::R_OK ) ){
                               print "have read permission\n";
                       }

               Returns "undef" on failure.  Note: do not use
               "access()" for security purposes.  Between the
               "access()" call and the operation you are prepar-
               ing for the permissions might change: a classic
               race condition.

       acos    This is identical to the C function "acos()",
               returning the arcus cosine of its numerical argu-
               ment.  See also the Math::Trig manpage.

       alarm   This is identical to Perl's builtin "alarm()"
               function, either for arming or disarming the
               "SIGARLM" timer.

       asctime This is identical to the C function "asctime()".
               It returns a string of the form

                       "Fri Jun  2 18:22:13 2000\n\0"

               and it is called thusly





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                       $asctime = asctime($sec, $min, $hour, $mday, $mon, $year,
                                          $wday, $yday, $isdst);

               The "$mon" is zero-based: January equals "0".  The
               "$year" is 1900-based: 2001 equals "101".  The
               "$wday", "$yday", and "$isdst" default to zero
               (and the first two are usually ignored anyway).

       asin    This is identical to the C function "asin()",
               returning the arcus sine of its numerical argu-
               ment.  See also the Math::Trig manpage.

       assert  Unimplemented, but you can use the die entry in
               the perlfunc manpage and the the Carp manpage mod-
               ule to achieve similar things.

       atan    This is identical to the C function "atan()",
               returning the arcus tangent of its numerical argu-
               ment.  See also the Math::Trig manpage.

       atan2   This is identical to Perl's builtin "atan2()"
               function, returning the arcus tangent defined by
               its two numerical arguments, the y coordinate and
               the x coordinate.  See also the Math::Trig man-
               page.

       atexit  atexit() is C-specific: use "END {}" instead, see
               the perlsub manpage.

       atof    atof() is C-specific.  Perl converts strings to
               numbers transparently.  If you need to force a
               scalar to a number, add a zero to it.

       atoi    atoi() is C-specific.  Perl converts strings to
               numbers transparently.  If you need to force a
               scalar to a number, add a zero to it.  If you need
               to have just the integer part, see the int entry
               in the perlfunc manpage.

       atol    atol() is C-specific.  Perl converts strings to
               numbers transparently.  If you need to force a
               scalar to a number, add a zero to it.  If you need
               to have just the integer part, see the int entry
               in the perlfunc manpage.

       bsearch bsearch() not supplied.  For doing binary search
               on wordlists, see the Search::Dict manpage.

       calloc  calloc() is C-specific.  Perl does memory manage-
               ment transparently.

       ceil    This is identical to the C function "ceil()",
               returning the smallest integer value greater than
               or equal to the given numerical argument.



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       chdir   This is identical to Perl's builtin "chdir()"
               function, allowing one to change the working
               (default) directory, see the chdir entry in the
               perlfunc manpage.

       chmod   This is identical to Perl's builtin "chmod()"
               function, allowing one to change file and direc-
               tory permissions, see the chmod entry in the perl-
               func manpage.

       chown   This is identical to Perl's builtin "chown()"
               function, allowing one to change file and direc-
               tory owners and groups, see the chown entry in the
               perlfunc manpage.

       clearerr
               Use the method the IO::Handle::clearerr() entry
               elsewhere in this document instead, to reset the
               error state (if any) and EOF state (if any) of the
               given stream.

       clock   This is identical to the C function "clock()",
               returning the amount of spent processor time in
               microseconds.

       close   Close the file.  This uses file descriptors such
               as those obtained by calling "POSIX::open".

                       $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
                       POSIX::close( $fd );

               Returns "undef" on failure.

               See also the close entry in the perlfunc manpage.

       closedir
               This is identical to Perl's builtin "closedir()"
               function for closing a directory handle, see the
               closedir entry in the perlfunc manpage.

       cos     This is identical to Perl's builtin "cos()" func-
               tion, for returning the cosine of its numerical
               argument, see the cos entry in the perlfunc man-
               page.  See also the Math::Trig manpage.

       cosh    This is identical to the C function "cosh()", for
               returning the hyperbolic cosine of its numeric
               argument.  See also the Math::Trig manpage.

       creat   Create a new file.  This returns a file descriptor
               like the ones returned by "POSIX::open".  Use
               "POSIX::close" to close the file.





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                       $fd = POSIX::creat( "foo", 0611 );
                       POSIX::close( $fd );

               See also the sysopen entry in the perlfunc manpage
               and its "O_CREAT" flag.

       ctermid Generates the path name for the controlling termi-
               nal.

                       $path = POSIX::ctermid();


       ctime   This is identical to the C function "ctime()" and
               equivalent to "asctime(localtime(...))", see the
               asctimeand localtime entries elsewhere in this
               document.

       cuserid Get the login name of the owner of the current
               process.

                       $name = POSIX::cuserid();


       difftime
               This is identical to the C function "difftime()",
               for returning the time difference (in seconds)
               between two times (as returned by "time()"), see
               the time entry elsewhere in this document.

       div     div() is C-specific, use the int entry in the
               perlfunc manpage on the usual "/" division and the
               modulus "%".

       dup     This is similar to the C function "dup()", for
               duplicating a file descriptor.

               This uses file descriptors such as those obtained
               by calling "POSIX::open".

               Returns "undef" on failure.

       dup2    This is similar to the C function "dup2()", for
               duplicating a file descriptor to an another known
               file descriptor.

               This uses file descriptors such as those obtained
               by calling "POSIX::open".

               Returns "undef" on failure.

       errno   Returns the value of errno.

                       $errno = POSIX::errno();




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               This identical to the numerical values of the
               "$!", see the section on "$ERRNO" in the perlvar
               manpage.

       execl   execl() is C-specific, see the exec entry in the
               perlfunc manpage.

       execle  execle() is C-specific, see the exec entry in the
               perlfunc manpage.

       execlp  execlp() is C-specific, see the exec entry in the
               perlfunc manpage.

       execv   execv() is C-specific, see the exec entry in the
               perlfunc manpage.

       execve  execve() is C-specific, see the exec entry in the
               perlfunc manpage.

       execvp  execvp() is C-specific, see the exec entry in the
               perlfunc manpage.

       exit    This is identical to Perl's builtin "exit()" func-
               tion for exiting the program, see the exit entry
               in the perlfunc manpage.

       exp     This is identical to Perl's builtin "exp()" func-
               tion for returning the exponent (e-based) of the
               numerical argument, see the exp entry in the perl-
               func manpage.

       fabs    This is identical to Perl's builtin "abs()" func-
               tion for returning the absolute value of the
               numerical argument, see the abs entry in the perl-
               func manpage.

       fclose  Use method "IO::Handle::close()" instead, or see
               the close entry in the perlfunc manpage.

       fcntl   This is identical to Perl's builtin "fcntl()"
               function, see the fcntl entry in the perlfunc man-
               page.

       fdopen  Use method "IO::Handle::new_from_fd()" instead, or
               see the open entry in the perlfunc manpage.

       feof    Use method "IO::Handle::eof()" instead, or see the
               eof entry in the perlfunc manpage.

       ferror  Use method "IO::Handle::error()" instead.

       fflush  Use method "IO::Handle::flush()" instead.  See
               also the section on "$OUTPUT_AUTOFLUSH" in the
               perlvar manpage.



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       fgetc   Use method "IO::Handle::getc()" instead, or see
               the read entry in the perlfunc manpage.

       fgetpos Use method "IO::Seekable::getpos()" instead, or
               see the seek entry in the L manpage.

       fgets   Use method "IO::Handle::gets()" instead.  Similar
               to <>, also known as the readline entry in the
               perlfunc manpage.

       fileno  Use method "IO::Handle::fileno()" instead, or see
               the fileno entry in the perlfunc manpage.

       floor   This is identical to the C function "floor()",
               returning the largest integer value less than or
               equal to the numerical argument.

       fmod    This is identical to the C function "fmod()".

                       $r = modf($x, $y);

               It returns the remainder "$r = $x - $n*$y", where
               "$n = trunc($x/$y)".  The "$r" has the same sign
               as "$x" and magnitude (absolute value) less than
               the magnitude of "$y".

       fopen   Use method "IO::File::open()" instead, or see the
               open entry in the perlfunc manpage.

       fork    This is identical to Perl's builtin "fork()" func-
               tion for duplicating the current process, see the
               fork entry in the perlfunc manpage and the perl-
               fork manpage if you are in Windows.

       fpathconf
               Retrieves the value of a configurable limit on a
               file or directory.  This uses file descriptors
               such as those obtained by calling "POSIX::open".

               The following will determine the maximum length of
               the longest allowable pathname on the filesystem
               which holds "/tmp/foo".

                       $fd = POSIX::open( "/tmp/foo", &POSIX::O_RDONLY );
                       $path_max = POSIX::fpathconf( $fd, &POSIX::_PC_PATH_MAX );

               Returns "undef" on failure.

       fprintf fprintf() is C-specific, see the printf entry in
               the perlfunc manpage instead.

       fputc   fputc() is C-specific, see the print entry in the
               perlfunc manpage instead.




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       fputs   fputs() is C-specific, see the print entry in the
               perlfunc manpage instead.

       fread   fread() is C-specific, see the read entry in the
               perlfunc manpage instead.

       free    free() is C-specific.  Perl does memory management
               transparently.

       freopen freopen() is C-specific, see the open entry in the
               perlfunc manpage instead.

       frexp   Return the mantissa and exponent of a floating-
               point number.

                       ($mantissa, $exponent) = POSIX::frexp( 1.234e56 );


       fscanf  fscanf() is C-specific, use <> and regular expres-
               sions instead.

       fseek   Use method "IO::Seekable::seek()" instead, or see
               the seek entry in the perlfunc manpage.

       fsetpos Use method "IO::Seekable::setpos()" instead, or
               seek the seek entry in the perlfunc manpage.

       fstat   Get file status.  This uses file descriptors such
               as those obtained by calling "POSIX::open".  The
               data returned is identical to the data from Perl's
               builtin "stat" function.

                       $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
                       @stats = POSIX::fstat( $fd );


       ftell   Use method "IO::Seekable::tell()" instead, or see
               the tell entry in the perlfunc manpage.

       fwrite  fwrite() is C-specific, see the print entry in the
               perlfunc manpage instead.

       getc    This is identical to Perl's builtin "getc()" func-
               tion, see the getc entry in the perlfunc manpage.

       getchar Returns one character from STDIN.  Identical to
               Perl's "getc()", see the getc entry in the perl-
               func manpage.

       getcwd  Returns the name of the current working directory.
               See also the Cwd manpage.

       getegid Returns the effective group identifier.  Similar
               to Perl' s builtin variable "$(", see the section



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               on "$EGID" in the perlvar manpage.

       getenv  Returns the value of the specified enironment
               variable.  The same information is available
               through the "%ENV" array.

       geteuid Returns the effective user identifier.  Identical
               to Perl's builtin "$>" variable, see the section
               on "$EUID" in the perlvar manpage.

       getgid  Returns the user's real group identifier.  Similar
               to Perl's builtin variable "$)", see the section
               on "$GID" in the perlvar manpage.

       getgrgid
               This is identical to Perl's builtin "getgrgid()"
               function for returning group entries by group
               identifiers, see the getgrgid entry in the perl-
               func manpage.

       getgrnam
               This is identical to Perl's builtin "getgrnam()"
               function for returning group entries by group
               names, see the getgrnam entry in the perlfunc man-
               page.

       getgroups
               Returns the ids of the user's supplementary
               groups.  Similar to Perl's builtin variable "$)",
               see the section on "$GID" in the perlvar manpage.

       getlogin
               This is identical to Perl's builtin "getlogin()"
               function for returning the user name associated
               with the current session, see the getlogin entry
               in the perlfunc manpage.

       getpgrp This is identical to Perl's builtin "getpgrp()"
               function for returning the prcess group identifier
               of the current process, see the getpgrp entry in
               the perlfunc manpage.

       getpid  Returns the process identifier.  Identical to
               Perl's builtin variable "$$", see the section on
               "$PID" in the perlvar manpage.

       getppid This is identical to Perl's builtin "getppid()"
               function for returning the process identifier of
               the parent process of the current process , see
               the getppid entry in the perlfunc manpage.

       getpwnam
               This is identical to Perl's builtin "getpwnam()"
               function for returning user entries by user names,



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               see the getpwnam entry in the perlfunc manpage.

       getpwuid
               This is identical to Perl's builtin "getpwuid()"
               function for returning user entries by user iden-
               tifiers, see the getpwuid entry in the perlfunc
               manpage.

       gets    Returns one line from "STDIN", similar to <>, also
               known as the "readline()" function, see the read-
               line entry in the perlfunc manpage.

               NOTE: if you have C programs that still use
               "gets()", be very afraid.  The "gets()" function
               is a source of endless grief because it has no
               buffer overrun checks.  It should never be used.
               The "fgets()" function should be preferred
               instead.

       getuid  Returns the user's identifier.  Identical to
               Perl's builtin "$<" variable, see the section on
               "$UID" in the perlvar manpage.

       gmtime  This is identical to Perl's builtin "gmtime()"
               function for converting seconds since the epoch to
               a date in Greenwich Mean Time, see the gmtime
               entry in the perlfunc manpage.

       isalnum This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using regular expressions and
               the "/[[:isalnum:]]/" construct instead, or possi-
               bly the "/\w/" construct.

       isalpha This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using regular expressions and
               the "/[[:isalpha:]]/" construct instead.

       isatty  Returns a boolean indicating whether the specified
               filehandle is connected to a tty.  Similar to the
               "-t" operator, see the section on "-X" in the
               perlfunc manpage.

       iscntrl This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using regular expressions and
               the "/[[:iscntrl:]]/" construct instead.

       isdigit This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using regular expressions and
               the "/[[:isdigit:]]/" construct instead, or the
               "/\d/" construct.



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       isgraph This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using regular expressions and
               the "/[[:isgraph:]]/" construct instead.

       islower This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using regular expressions and
               the "/[[:islower:]]/" construct instead.  Do not
               use "/a-z/".

       isprint This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using regular expressions and
               the "/[[:isprint:]]/" construct instead.

       ispunct This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using regular expressions and
               the "/[[:ispunct:]]/" construct instead.

       isspace This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using regular expressions and
               the "/[[:isspace:]]/" construct instead, or the
               "/\s/" construct.

       isupper This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using regular expressions and
               the "/[[:isupper:]]/" construct instead.  Do not
               use "/A-Z/".

       isxdigit
               This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using regular expressions and
               the "/[[:isxdigit:]]/" construct instead, or sim-
               ply "/[0-9a-f]/i".

       kill    This is identical to Perl's builtin "kill()" func-
               tion for sending signals to processes (often to
               terminate them), see the kill entry in the perl-
               func manpage.

       labs    (For returning absolute values of long integers.)
               labs() is C-specific, see the abs entry in the
               perlfunc manpage instead.

       ldexp   This is identical to the C function "ldexp()" for
               multiplying floating point numbers with powers of
               two.

                       $x_quadrupled = POSIX::ldexp($x, 2);



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       ldiv    (For computing dividends of long integers.)
               ldiv() is C-specific, use "/" and "int()" instead.

       link    This is identical to Perl's builtin "link()" func-
               tion for creating hard links into files, see the
               link entry in the perlfunc manpage.

       localeconv
               Get numeric formatting information.  Returns a
               reference to a hash containing the current locale
               formatting values.

               Here is how to query the database for the de
               (Deutsch or German) locale.

                       $loc = POSIX::setlocale( &POSIX::LC_ALL, "de" );
                       print "Locale = $loc\n";
                       $lconv = POSIX::localeconv();
                       print "decimal_point    = ", $lconv->{decimal_point},   "\n";
                       print "thousands_sep    = ", $lconv->{thousands_sep},   "\n";
                       print "grouping = ", $lconv->{grouping},        "\n";
                       print "int_curr_symbol  = ", $lconv->{int_curr_symbol}, "\n";
                       print "currency_symbol  = ", $lconv->{currency_symbol}, "\n";
                       print "mon_decimal_point = ", $lconv->{mon_decimal_point}, "\n";
                       print "mon_thousands_sep = ", $lconv->{mon_thousands_sep}, "\n";
                       print "mon_grouping     = ", $lconv->{mon_grouping},    "\n";
                       print "positive_sign    = ", $lconv->{positive_sign},   "\n";
                       print "negative_sign    = ", $lconv->{negative_sign},   "\n";
                       print "int_frac_digits  = ", $lconv->{int_frac_digits}, "\n";
                       print "frac_digits      = ", $lconv->{frac_digits},     "\n";
                       print "p_cs_precedes    = ", $lconv->{p_cs_precedes},   "\n";
                       print "p_sep_by_space   = ", $lconv->{p_sep_by_space},  "\n";
                       print "n_cs_precedes    = ", $lconv->{n_cs_precedes},   "\n";
                       print "n_sep_by_space   = ", $lconv->{n_sep_by_space},  "\n";
                       print "p_sign_posn      = ", $lconv->{p_sign_posn},     "\n";
                       print "n_sign_posn      = ", $lconv->{n_sign_posn},     "\n";


       localtime
               This is identical to Perl's builtin "localtime()"
               function for converting seconds since the epoch to
               a date see the localtime entry in the perlfunc
               manpage.

       log     This is identical to Perl's builtin "log()" func-
               tion, returning the natural (e-based) logarithm of
               the numerical argument, see the log entry in the
               perlfunc manpage.

       log10   This is identical to the C function "log10()",
               returning the 10-base logarithm of the numerical
               argument.  You can also use

                   sub log10 { log($_[0]) / log(10) }



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               or

                   sub log10 { log($_[0]) / 2.30258509299405 }

               or

                   sub log10 { log($_[0]) * 0.434294481903252 }


       longjmp longjmp() is C-specific: use the die entry in the
               perlfunc manpage instead.

       lseek   Move the file's read/write position.  This uses
               file descriptors such as those obtained by calling
               "POSIX::open".

                       $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
                       $off_t = POSIX::lseek( $fd, 0, &POSIX::SEEK_SET );

               Returns "undef" on failure.

       malloc  malloc() is C-specific.  Perl does memory manage-
               ment transparently.

       mblen   This is identical to the C function "mblen()".
               Perl does not have any support for the wide and
               multibyte characters of the C standards, so this
               might be a rather useless function.

       mbstowcs
               This is identical to the C function "mbstowcs()".
               Perl does not have any support for the wide and
               multibyte characters of the C standards, so this
               might be a rather useless function.

       mbtowc  This is identical to the C function "mbtowc()".
               Perl does not have any support for the wide and
               multibyte characters of the C standards, so this
               might be a rather useless function.

       memchr  memchr() is C-specific, see the index entry in the
               perlfunc manpage instead.

       memcmp  memcmp() is C-specific, use "eq" instead, see the
               perlop manpage.

       memcpy  memcpy() is C-specific, use "=", see the perlop
               manpage, or see the substr entry in the perlfunc
               manpage.

       memmove memmove() is C-specific, use "=", see the perlop
               manpage, or see the substr entry in the perlfunc
               manpage.




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       memset  memset() is C-specific, use "x" instead, see the
               perlop manpage.

       mkdir   This is identical to Perl's builtin "mkdir()"
               function for creating directories, see the mkdir
               entry in the perlfunc manpage.

       mkfifo  This is similar to the C function "mkfifo()" for
               creating FIFO special files.

                       if (mkfifo($path, $mode)) { ....

               Returns "undef" on failure.  The "$mode" is simi-
               lar to the mode of "mkdir()", see the mkdir entry
               in the perlfunc manpage.

       mktime  Convert date/time info to a calendar time.

               Synopsis:

                       mktime(sec, min, hour, mday, mon, year, wday = 0, yday = 0, isdst = 0)

               The month ("mon"), weekday ("wday"), and yearday
               ("yday") begin at zero.  I.e. January is 0, not 1;
               Sunday is 0, not 1; January 1st is 0, not 1.  The
               year ("year") is given in years since 1900.  I.e.
               The year 1995 is 95; the year 2001 is 101.  Con-
               sult your system's "mktime()" manpage for details
               about these and the other arguments.

               Calendar time for December 12, 1995, at 10:30 am.

                       $time_t = POSIX::mktime( 0, 30, 10, 12, 11, 95 );
                       print "Date = ", POSIX::ctime($time_t);

               Returns "undef" on failure.

       modf    Return the integral and fractional parts of a
               floating-point number.

                       ($fractional, $integral) = POSIX::modf( 3.14 );


       nice    This is similar to the C function "nice()", for
               changing the scheduling preference of the current
               process.  Positive arguments mean more polite pro-
               cess, negative values more needy process.  Normal
               user processes can only be more polite.

               Returns "undef" on failure.

       offsetof
               offsetof() is C-specific, you probably want to see
               the pack entry in the perlfunc manpage instead.



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       open    Open a file for reading for writing.  This returns
               file descriptors, not Perl filehandles.  Use
               "POSIX::close" to close the file.

               Open a file read-only with mode 0666.

                       $fd = POSIX::open( "foo" );

               Open a file for read and write.

                       $fd = POSIX::open( "foo", &POSIX::O_RDWR );

               Open a file for write, with truncation.

                       $fd = POSIX::open( "foo", &POSIX::O_WRONLY | &POSIX::O_TRUNC );

               Create a new file with mode 0640.  Set up the file
               for writing.

                       $fd = POSIX::open( "foo", &POSIX::O_CREAT | &POSIX::O_WRONLY, 0640 );

               Returns "undef" on failure.

               See also the sysopen entry in the perlfunc man-
               page.

       opendir Open a directory for reading.

                       $dir = POSIX::opendir( "/tmp" );
                       @files = POSIX::readdir( $dir );
                       POSIX::closedir( $dir );

               Returns "undef" on failure.

       pathconf
               Retrieves the value of a configurable limit on a
               file or directory.

               The following will determine the maximum length of
               the longest allowable pathname on the filesystem
               which holds "/tmp".

                       $path_max = POSIX::pathconf( "/tmp", &POSIX::_PC_PATH_MAX );

               Returns "undef" on failure.

       pause   This is similar to the C function "pause()", which
               suspends the execution of the current process
               until a signal is received.

               Returns "undef" on failure.

       perror  This is identical to the C function "perror()",
               which outputs to the standard error stream the



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               specified message followed by ": " and the current
               error string.  Use the "warn()" function and the
               "$!"  variable instead, see the warn entry in the
               perlfunc manpage and the section on "$ERRNO" in
               the perlvar manpage.

       pipe    Create an interprocess channel.  This returns file
               descriptors like those returned by "POSIX::open".

                       ($fd0, $fd1) = POSIX::pipe();
                       POSIX::write( $fd0, "hello", 5 );
                       POSIX::read( $fd1, $buf, 5 );

               See also the pipe entry in the perlfunc manpage.

       pow     Computes "$x" raised to the power "$exponent".

                       $ret = POSIX::pow( $x, $exponent );

               You can also use the "**" operator, see the perlop
               manpage.

       printf  Formats and prints the specified arguments to STD-
               OUT.  See also the printf entry in the perlfunc
               manpage.

       putc    putc() is C-specific, see the print entry in the
               perlfunc manpage instead.

       putchar putchar() is C-specific, see the print entry in
               the perlfunc manpage instead.

       puts    puts() is C-specific, see the print entry in the
               perlfunc manpage instead.

       qsort   qsort() is C-specific, see the sort entry in the
               perlfunc manpage instead.

       raise   Sends the specified signal to the current process.
               See also the kill entry in the perlfunc manpage
               and the "$$" in the section on "$PID" in the perl-
               var manpage.

       rand    "rand()" is non-portable, see the rand entry in
               the perlfunc manpage instead.

       read    Read from a file.  This uses file descriptors such
               as those obtained by calling "POSIX::open".  If
               the buffer "$buf" is not large enough for the read
               then Perl will extend it to make room for the
               request.

                       $fd = POSIX::open( "foo", &POSIX::O_RDONLY );
                       $bytes = POSIX::read( $fd, $buf, 3 );



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               Returns "undef" on failure.

               See also the sysread entry in the perlfunc man-
               page.

       readdir This is identical to Perl's builtin "readdir()"
               function for reading directory entries, see the
               readdir entry in the perlfunc manpage.

       realloc realloc() is C-specific.  Perl does memory manage-
               ment transparently.

       remove  This is identical to Perl's builtin "unlink()"
               function for removing files, see the unlink entry
               in the perlfunc manpage.

       rename  This is identical to Perl's builtin "rename()"
               function for renaming files, see the rename entry
               in the perlfunc manpage.

       rewind  Seeks to the beginning of the file.

       rewinddir
               This is identical to Perl's builtin "rewinddir()"
               function for rewinding directory entry streams,
               see the rewinddir entry in the perlfunc manpage.

       rmdir   This is identical to Perl's builtin "rmdir()"
               function for removing (empty) directories, see the
               rmdir entry in the perlfunc manpage.

       scanf   scanf() is C-specific, use <> and regular expres-
               sions instead, see the perlre manpage.

       setgid  Sets the real group identifier for this process.
               Identical to assigning a value to the Perl's
               builtin "$)" variable, see the section on "$UID"
               in the perlvar manpage.

       setjmp  "setjmp()" is C-specific: use "eval {}" instead,
               see the eval entry in the perlfunc manpage.

       setlocale
               Modifies and queries program's locale.  The fol-
               lowing examples assume

                       use POSIX qw(setlocale LC_ALL LC_CTYPE);

               has been issued.

               The following will set the traditional UNIX system
               locale behavior (the second argument ""C"").

                       $loc = setlocale( LC_ALL, "C" );



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               The following will query the current LC_CTYPE cat-
               egory.  (No second argument means 'query'.)

                       $loc = setlocale( LC_CTYPE );

               The following will set the LC_CTYPE behaviour
               according to the locale environment variables (the
               second argument """").  Please see your systems
               setlocale(3) documentation for the locale environ-
               ment variables' meaning or consult the perllocale
               manpage.

                       $loc = setlocale( LC_CTYPE, "" );

               The following will set the LC_COLLATE behaviour to
               Argentinian Spanish. NOTE: The naming and avail-
               ability of locales depends on your operating sys-
               tem. Please consult the perllocale manpage for how
               to find out which locales are available in your
               system.

                       $loc = setlocale( LC_ALL, "es_AR.ISO8859-1" );


       setpgid This is similar to the C function "setpgid()" for
               setting the process group identifier of the cur-
               rent process.

               Returns "undef" on failure.

       setsid  This is identical to the C function "setsid()" for
               setting the session identifier of the current pro-
               cess.

       setuid  Sets the real user identifier for this process.
               Identical to assigning a value to the Perl's
               builtin "$<" variable, see the section on "$UID"
               in the perlvar manpage.

       sigaction
               Detailed signal management.  This uses
               "POSIX::SigAction" objects for the "action" and
               "oldaction" arguments.  Consult your system's
               "sigaction" manpage for details.

               Synopsis:

                       sigaction(sig, action, oldaction = 0)

               Returns "undef" on failure.

       siglongjmp
               siglongjmp() is C-specific: use the die entry in
               the perlfunc manpage instead.



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       sigpending
               Examine signals that are blocked and pending.
               This uses "POSIX::SigSet" objects for the "sigset"
               argument.  Consult your system's "sigpending" man-
               page for details.

               Synopsis:

                       sigpending(sigset)

               Returns "undef" on failure.

       sigprocmask
               Change and/or examine calling process's signal
               mask.  This uses "POSIX::SigSet" objects for the
               "sigset" and "oldsigset" arguments.  Consult your
               system's "sigprocmask" manpage for details.

               Synopsis:

                       sigprocmask(how, sigset, oldsigset = 0)

               Returns "undef" on failure.

       sigsetjmp
               "sigsetjmp()" is C-specific: use "eval {}"
               instead, see the eval entry in the perlfunc man-
               page.

       sigsuspend
               Install a signal mask and suspend process until
               signal arrives.  This uses "POSIX::SigSet" objects
               for the "signal_mask" argument.  Consult your sys-
               tem's "sigsuspend" manpage for details.

               Synopsis:

                       sigsuspend(signal_mask)

               Returns "undef" on failure.

       sin     This is identical to Perl's builtin "sin()" func-
               tion for returning the sine of the numerical argu-
               ment, see the sin entry in the perlfunc manpage.
               See also the Math::Trig manpage.

       sinh    This is identical to the C function "sinh()" for
               returning the hyperbolic sine of the numerical
               argument.  See also the Math::Trig manpage.

       sleep   This is identical to Perl's builtin "sleep()"
               function for suspending the execution of the cur-
               rent for process for certain number of seconds,
               see the sleep entry in the perlfunc manpage.



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       sprintf This is similar to Perl's builtin "sprintf()"
               function for returning a string that has the argu-
               ments formatted as requested, see the sprintf
               entry in the perlfunc manpage.

       sqrt    This is identical to Perl's builtin "sqrt()" func-
               tion.  for returning the square root of the numer-
               ical argument, see the sqrt entry in the perlfunc
               manpage.

       srand   Give a seed the pseudorandom number generator, see
               the srand entry in the perlfunc manpage.

       sscanf  sscanf() is C-specific, use regular expressions
               instead, see the perlre manpage.

       stat    This is identical to Perl's builtin "stat()" func-
               tion for retutning information about files and
               directories.

       strcat  strcat() is C-specific, use ".=" instead, see the
               perlop manpage.

       strchr  strchr() is C-specific, see the index entry in the
               perlfunc manpage instead.

       strcmp  strcmp() is C-specific, use "eq" or "cmp" instead,
               see the perlop manpage.

       strcoll This is identical to the C function "strcoll()"
               for collating (comparing) strings transformed
               using the "strxfrm()" function.  Not really needed
               since Perl can do this transparently, see the per-
               llocale manpage.

       strcpy  strcpy() is C-specific, use "=" instead, see the
               perlop manpage.

       strcspn strcspn() is C-specific, use regular expressions
               instead, see the perlre manpage.

       strerror
               Returns the error string for the specified errno.
               Identical to the string form of the "$!", see the
               section on "$ERRNO" in the perlvar manpage.

       strftime
               Convert date and time information to string.
               Returns the string.

               Synopsis:

                       strftime(fmt, sec, min, hour, mday, mon, year, wday = -1, yday = -1, isdst = -1)




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               The month ("mon"), weekday ("wday"), and yearday
               ("yday") begin at zero.  I.e. January is 0, not 1;
               Sunday is 0, not 1; January 1st is 0, not 1.  The
               year ("year") is given in years since 1900.  I.e.,
               the year 1995 is 95; the year 2001 is 101.  Con-
               sult your system's "strftime()" manpage for
               details about these and the other arguments.  If
               you want your code to be portable, your format
               ("fmt") argument should use only the conversion
               specifiers defined by the ANSI C standard.  These
               are "aAbBcdHIjmMpSUwWxXyYZ%".  The given arguments
               are made consistent as though by calling
               "mktime()" before calling your system's "strf-
               time()" function, except that the "isdst" value is
               not affected.

               The string for Tuesday, December 12, 1995.

                       $str = POSIX::strftime( "%A, %B %d, %Y", 0, 0, 0, 12, 11, 95, 2 );
                       print "$str\n";


       strlen  strlen() is C-specific, use "length()" instead,
               see the length entry in the perlfunc manpage.

       strncat strncat() is C-specific, use ".=" instead, see the
               perlop manpage.

       strncmp strncmp() is C-specific, use "eq" instead, see the
               perlop manpage.

       strncpy strncpy() is C-specific, use "=" instead, see the
               perlop manpage.

       strpbrk strpbrk() is C-specific, use regular expressions
               instead, see the perlre manpage.

       strrchr strrchr() is C-specific, see the rindex entry in
               the perlfunc manpage instead.

       strspn  strspn() is C-specific, use regular expressions
               instead, see the perlre manpage.

       strstr  This is identical to Perl's builtin "index()"
               function, see the index entry in the perlfunc man-
               page.

       strtod  String to double translation. Returns the parsed
               number and the number of characters in the
               unparsed portion of the string.  Truly POSIX-com-
               pliant systems set $! ($ERRNO) to indicate a
               translation error, so clear $! before calling str-
               tod.  However, non-POSIX systems may not check for
               overflow, and therefore will never set $!.



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               strtod should respect any POSIX setlocale() set-
               tings.

               To parse a string $str as a floating point number
               use

                   $! = 0;
                   ($num, $n_unparsed) = POSIX::strtod($str);

               The second returned item and $! can be used to
               check for valid input:

                   if (($str eq '') || ($n_unparsed != 0) || !$!) {
                       die "Non-numeric input $str" . $! ? ": $!\n" : "\n";
                   }

               When called in a scalar context strtod returns the
               parsed number.

       strtok  strtok() is C-specific, use regular expressions
               instead, see the perlre manpage, or the split
               entry in the perlfunc manpage.

       strtol  String to (long) integer translation.  Returns the
               parsed number and the number of characters in the
               unparsed portion of the string.  Truly POSIX-com-
               pliant systems set $! ($ERRNO) to indicate a
               translation error, so clear $! before calling str-
               tol.  However, non-POSIX systems may not check for
               overflow, and therefore will never set $!.

               strtol should respect any POSIX setlocale() set-
               tings.

               To parse a string $str as a number in some base
               $base use

                   $! = 0;
                   ($num, $n_unparsed) = POSIX::strtol($str, $base);

               The base should be zero or between 2 and 36,
               inclusive.  When the base is zero or omitted str-
               tol will use the string itself to determine the
               base: a leading "0x" or "0X" means hexadecimal; a
               leading "0" means octal; any other leading charac-
               ters mean decimal.  Thus, "1234" is parsed as a
               decimal number, "01234" as an octal number, and
               "0x1234" as a hexadecimal number.

               The second returned item and $! can be used to
               check for valid input:






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                   if (($str eq '') || ($n_unparsed != 0) || !$!) {
                       die "Non-numeric input $str" . $! ? ": $!\n" : "\n";
                   }

               When called in a scalar context strtol returns the
               parsed number.

       strtoul String to unsigned (long) integer translation.
               strtoul() is identical to strtol() except that
               strtoul() only parses unsigned integers.  See the
               strtol entry elsewhere in this document for
               details.

               Note: Some vendors supply strtod() and strtol()
               but not strtoul().  Other vendors that do supply
               strtoul() parse "-1" as a valid value.

       strxfrm String transformation.  Returns the transformed
               string.

                       $dst = POSIX::strxfrm( $src );

               Used in conjunction with the "strcoll()" function,
               see the strcoll entry elsewhere in this document.

               Not really needed since Perl can do this transpar-
               ently, see the perllocale manpage.

       sysconf Retrieves values of system configurable variables.

               The following will get the machine's clock speed.

                       $clock_ticks = POSIX::sysconf( &POSIX::_SC_CLK_TCK );

               Returns "undef" on failure.

       system  This is identical to Perl's builtin "system()"
               function, see the system entry in the perlfunc
               manpage.

       tan     This is identical to the C function "tan()",
               returning the tangent of the numerical argument.
               See also the Math::Trig manpage.

       tanh    This is identical to the C function "tanh()",
               returning the hyperbolic tangent of the numerical
               argument.   See also the Math::Trig manpage.

       tcdrain This is similar to the C function "tcdrain()" for
               draining the output queue of its argument stream.

               Returns "undef" on failure.





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       tcflow  This is similar to the C function "tcflow()" for
               controlling the flow of its argument stream.

               Returns "undef" on failure.

       tcflush This is similar to the C function "tcflush()" for
               flushing the I/O buffers of its argumeny stream.

               Returns "undef" on failure.

       tcgetpgrp
               This is identical to the C function "tcgetpgrp()"
               for returning the process group identifier of the
               foreground process group of the controlling termi-
               nal.

       tcsendbreak
               This is similar to the C function "tcsendbreak()"
               for sending a break on its argument stream.

               Returns "undef" on failure.

       tcsetpgrp
               This is similar to the C function "tcsetpgrp()"
               for setting the process group identifier of the
               foreground process group of the controlling termi-
               nal.

               Returns "undef" on failure.

       time    This is identical to Perl's builtin "time()" func-
               tion for returning the number of seconds since the
               epoch (whatever it is for the system), see the
               time entry in the perlfunc manpage.

       times   The times() function returns elapsed realtime
               since some point in the past (such as system
               startup), user and system times for this process,
               and user and system times used by child processes.
               All times are returned in clock ticks.

                   ($realtime, $user, $system, $cuser, $csystem) = POSIX::times();

               Note: Perl's builtin "times()" function returns
               four values, measured in seconds.

       tmpfile Use method "IO::File::new_tmpfile()" instead, or
               see the File::Temp manpage.

       tmpnam  Returns a name for a temporary file.

                       $tmpfile = POSIX::tmpnam();

               For security reasons, which are probably detailed



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               in your system's documentation for the C library
               tmpnam() function, this interface should not be
               used; instead see the File::Temp manpage.

       tolower This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using the "lc()" function, see
               the lc entry in the perlfunc manpage, or the
               equivalent "\L" operator inside doublequotish
               strings.

       toupper This is identical to the C function, except that
               it can apply to a single character or to a whole
               string.  Consider using the "uc()" function, see
               the uc entry in the perlfunc manpage, or the
               equivalent "\U" operator inside doublequotish
               strings.

       ttyname This is identical to the C function "ttyname()"
               for returning the name of the current terminal.

       tzname  Retrieves the time conversion information from the
               "tzname" variable.

                       POSIX::tzset();
                       ($std, $dst) = POSIX::tzname();


       tzset   This is identical to the C function "tzset()" for
               setting the current timezone based on the environ-
               ment variable "TZ", to be used by "ctime()",
               "localtime()", "mktime()", and "strftime()" func-
               tions.

       umask   This is identical to Perl's builtin "umask()"
               function for setting (and querying) the file cre-
               ation permission mask, see the umask entry in the
               perlfunc manpage.

       uname   Get name of current operating system.

                       ($sysname, $nodename, $release, $version, $machine) = POSIX::uname();

               Note that the actual meanings of the various
               fields are not that well standardized, do not
               expect any great portability.  The "$sysname"
               might be the name of the operating system, the
               "$nodename" might be the name of the host, the
               "$release" might be the (major) release number of
               the operating system, the "$version" might be the
               (minor) release number of the operating system,
               and the "$machine" might be a hardware identifier.
               Maybe.




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       ungetc  Use method "IO::Handle::ungetc()" instead.

       unlink  This is identical to Perl's builtin "unlink()"
               function for removing files, see the unlink entry
               in the perlfunc manpage.

       utime   This is identical to Perl's builtin "utime()"
               function for changing the time stamps of files and
               directories, see the utime entry in the perlfunc
               manpage.

       vfprintf
               vfprintf() is C-specific, see the printf entry in
               the perlfunc manpage instead.

       vprintf vprintf() is C-specific, see the printf entry in
               the perlfunc manpage instead.

       vsprintf
               vsprintf() is C-specific, see the sprintf entry in
               the perlfunc manpage instead.

       wait    This is identical to Perl's builtin "wait()" func-
               tion, see the wait entry in the perlfunc manpage.

       waitpid Wait for a child process to change state.  This is
               identical to Perl's builtin "waitpid()" function,
               see the waitpid entry in the perlfunc manpage.

                       $pid = POSIX::waitpid( -1, &POSIX::WNOHANG );
                       print "status = ", ($? / 256), "\n";


       wcstombs
               This is identical to the C function "wcstombs()".
               Perl does not have any support for the wide and
               multibyte characters of the C standards, so this
               might be a rather useless function.

       wctomb  This is identical to the C function "wctomb()".
               Perl does not have any support for the wide and
               multibyte characters of the C standards, so this
               might be a rather useless function.

       write   Write to a file.  This uses file descriptors such
               as those obtained by calling "POSIX::open".

                       $fd = POSIX::open( "foo", &POSIX::O_WRONLY );
                       $buf = "hello";
                       $bytes = POSIX::write( $b, $buf, 5 );

               Returns "undef" on failure.

               See also the syswrite entry in the perlfunc



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               manpage.

CLASSES
       POSIX::SigAction


       new     Creates a new "POSIX::SigAction" object which cor-
               responds to the C "struct sigaction".  This object
               will be destroyed automatically when it is no
               longer needed.  The first parameter is the fully-
               qualified name of a sub which is a signal-handler.
               The second parameter is a "POSIX::SigSet" object,
               it defaults to the empty set.  The third parameter
               contains the "sa_flags", it defaults to 0.

                       $sigset = POSIX::SigSet->new(SIGINT, SIGQUIT);
                       $sigaction = POSIX::SigAction->new( 'main::handler', $sigset, &POSIX::SA_NOCLDSTOP );

               This "POSIX::SigAction" object should be used with
               the "POSIX::sigaction()" function.

       POSIX::SigSet


       new     Create a new SigSet object.  This object will be
               destroyed automatically when it is no longer
               needed.  Arguments may be supplied to initialize
               the set.

               Create an empty set.

                       $sigset = POSIX::SigSet->new;

               Create a set with SIGUSR1.

                       $sigset = POSIX::SigSet->new( &POSIX::SIGUSR1 );


       addset  Add a signal to a SigSet object.

                       $sigset->addset( &POSIX::SIGUSR2 );

               Returns "undef" on failure.

       delset  Remove a signal from the SigSet object.

                       $sigset->delset( &POSIX::SIGUSR2 );

               Returns "undef" on failure.

       emptyset
               Initialize the SigSet object to be empty.

                       $sigset->emptyset();



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               Returns "undef" on failure.

       fillset Initialize the SigSet object to include all sig-
               nals.

                       $sigset->fillset();

               Returns "undef" on failure.

       ismember
               Tests the SigSet object to see if it contains a
               specific signal.

                       if( $sigset->ismember( &POSIX::SIGUSR1 ) ){
                               print "contains SIGUSR1\n";
                       }


       POSIX::Termios


       new     Create a new Termios object.  This object will be
               destroyed automatically when it is no longer
               needed.  A Termios object corresponds to the
               termios C struct.  new() mallocs a new one,
               getattr() fills it from a file descriptor, and
               setattr() sets a file descriptor's parameters to
               match Termios' contents.

                       $termios = POSIX::Termios->new;


       getattr Get terminal control attributes.

               Obtain the attributes for stdin.

                       $termios->getattr()

               Obtain the attributes for stdout.

                       $termios->getattr( 1 )

               Returns "undef" on failure.

       getcc   Retrieve a value from the c_cc field of a termios
               object.  The c_cc field is an array so an index
               must be specified.

                       $c_cc[1] = $termios->getcc(1);


       getcflag
               Retrieve the c_cflag field of a termios object.




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                       $c_cflag = $termios->getcflag;


       getiflag
               Retrieve the c_iflag field of a termios object.

                       $c_iflag = $termios->getiflag;


       getispeed
               Retrieve the input baud rate.

                       $ispeed = $termios->getispeed;


       getlflag
               Retrieve the c_lflag field of a termios object.

                       $c_lflag = $termios->getlflag;


       getoflag
               Retrieve the c_oflag field of a termios object.

                       $c_oflag = $termios->getoflag;


       getospeed
               Retrieve the output baud rate.

                       $ospeed = $termios->getospeed;


       setattr Set terminal control attributes.

               Set attributes immediately for stdout.

                       $termios->setattr( 1, &POSIX::TCSANOW );

               Returns "undef" on failure.

       setcc   Set a value in the c_cc field of a termios object.
               The c_cc field is an array so an index must be
               specified.

                       $termios->setcc( &POSIX::VEOF, 1 );


       setcflag
               Set the c_cflag field of a termios object.

                       $termios->setcflag( $c_cflag | &POSIX::CLOCAL );





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       setiflag
               Set the c_iflag field of a termios object.

                       $termios->setiflag( $c_iflag | &POSIX::BRKINT );


       setispeed
               Set the input baud rate.

                       $termios->setispeed( &POSIX::B9600 );

               Returns "undef" on failure.

       setlflag
               Set the c_lflag field of a termios object.

                       $termios->setlflag( $c_lflag | &POSIX::ECHO );


       setoflag
               Set the c_oflag field of a termios object.

                       $termios->setoflag( $c_oflag | &POSIX::OPOST );


       setospeed
               Set the output baud rate.

                       $termios->setospeed( &POSIX::B9600 );

               Returns "undef" on failure.

       Baud rate values
               B38400 B75 B200 B134 B300 B1800 B150 B0 B19200
               B1200 B9600 B600 B4800 B50 B2400 B110

       Terminal interface values
               TCSADRAIN TCSANOW TCOON TCIOFLUSH TCOFLUSH TCION
               TCIFLUSH TCSAFLUSH TCIOFF TCOOFF

       c_cc field values
               VEOF VEOL VERASE VINTR VKILL VQUIT VSUSP VSTART
               VSTOP VMIN VTIME NCCS

       c_cflag field values
               CLOCAL CREAD CSIZE CS5 CS6 CS7 CS8 CSTOPB HUPCL
               PARENB PARODD

       c_iflag field values
               BRKINT ICRNL IGNBRK IGNCR IGNPAR INLCR INPCK
               ISTRIP IXOFF IXON PARMRK

       c_lflag field values
               ECHO ECHOE ECHOK ECHONL ICANON IEXTEN ISIG NOFLSH



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               TOSTOP

       c_oflag field values
               OPOST

PATHNAME CONSTANTS
       Constants
               _PC_CHOWN_RESTRICTED _PC_LINK_MAX _PC_MAX_CANON
               _PC_MAX_INPUT _PC_NAME_MAX _PC_NO_TRUNC
               _PC_PATH_MAX _PC_PIPE_BUF _PC_VDISABLE

POSIX CONSTANTS
       Constants
               _POSIX_ARG_MAX _POSIX_CHILD_MAX
               _POSIX_CHOWN_RESTRICTED _POSIX_JOB_CONTROL
               _POSIX_LINK_MAX _POSIX_MAX_CANON _POSIX_MAX_INPUT
               _POSIX_NAME_MAX _POSIX_NGROUPS_MAX _POSIX_NO_TRUNC
               _POSIX_OPEN_MAX _POSIX_PATH_MAX _POSIX_PIPE_BUF
               _POSIX_SAVED_IDS _POSIX_SSIZE_MAX
               _POSIX_STREAM_MAX _POSIX_TZNAME_MAX _POSIX_VDIS-
               ABLE _POSIX_VERSION

SYSTEM CONFIGURATION
       Constants
               _SC_ARG_MAX _SC_CHILD_MAX _SC_CLK_TCK _SC_JOB_CON-
               TROL _SC_NGROUPS_MAX _SC_OPEN_MAX _SC_SAVED_IDS
               _SC_STREAM_MAX _SC_TZNAME_MAX _SC_VERSION

ERRNO
       Constants
               E2BIG EACCES EADDRINUSE EADDRNOTAVAIL EAFNOSUPPORT
               EAGAIN EALREADY EBADF EBUSY ECHILD ECONNABORTED
               ECONNREFUSED ECONNRESET EDEADLK EDESTADDRREQ EDOM
               EDQUOT EEXIST EFAULT EFBIG EHOSTDOWN EHOSTUNREACH
               EINPROGRESS EINTR EINVAL EIO EISCONN EISDIR ELOOP
               EMFILE EMLINK EMSGSIZE ENAMETOOLONG ENETDOWN ENE-
               TRESET ENETUNREACH ENFILE ENOBUFS ENODEV ENOENT
               ENOEXEC ENOLCK ENOMEM ENOPROTOOPT ENOSPC ENOSYS
               ENOTBLK ENOTCONN ENOTDIR ENOTEMPTY ENOTSOCK ENOTTY
               ENXIO EOPNOTSUPP EPERM EPFNOSUPPORT EPIPE EPROCLIM
               EPROTONOSUPPORT EPROTOTYPE ERANGE EREMOTE ERESTART
               EROFS ESHUTDOWN ESOCKTNOSUPPORT ESPIPE ESRCH
               ESTALE ETIMEDOUT ETOOMANYREFS ETXTBSY EUSERS
               EWOULDBLOCK EXDEV

FCNTL
       Constants
               FD_CLOEXEC F_DUPFD F_GETFD F_GETFL F_GETLK F_OK
               F_RDLCK F_SETFD F_SETFL F_SETLK F_SETLKW F_UNLCK
               F_WRLCK O_ACCMODE O_APPEND O_CREAT O_EXCL O_NOCTTY
               O_NONBLOCK O_RDONLY O_RDWR O_TRUNC O_WRONLY

FLOAT




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       Constants
               DBL_DIG DBL_EPSILON DBL_MANT_DIG DBL_MAX
               DBL_MAX_10_EXP DBL_MAX_EXP DBL_MIN DBL_MIN_10_EXP
               DBL_MIN_EXP FLT_DIG FLT_EPSILON FLT_MANT_DIG
               FLT_MAX FLT_MAX_10_EXP FLT_MAX_EXP FLT_MIN
               FLT_MIN_10_EXP FLT_MIN_EXP FLT_RADIX FLT_ROUNDS
               LDBL_DIG LDBL_EPSILON LDBL_MANT_DIG LDBL_MAX
               LDBL_MAX_10_EXP LDBL_MAX_EXP LDBL_MIN
               LDBL_MIN_10_EXP LDBL_MIN_EXP

LIMITS
       Constants
               ARG_MAX CHAR_BIT CHAR_MAX CHAR_MIN CHILD_MAX
               INT_MAX INT_MIN LINK_MAX LONG_MAX LONG_MIN
               MAX_CANON MAX_INPUT MB_LEN_MAX NAME_MAX
               NGROUPS_MAX OPEN_MAX PATH_MAX PIPE_BUF SCHAR_MAX
               SCHAR_MIN SHRT_MAX SHRT_MIN SSIZE_MAX STREAM_MAX
               TZNAME_MAX UCHAR_MAX UINT_MAX ULONG_MAX USHRT_MAX

LOCALE
       Constants
               LC_ALL LC_COLLATE LC_CTYPE LC_MONETARY LC_NUMERIC
               LC_TIME

MATH
       Constants
               HUGE_VAL

SIGNAL
       Constants
               SA_NOCLDSTOP SA_NOCLDWAIT SA_NODEFER SA_ONSTACK
               SA_RESETHAND SA_RESTART SA_SIGINFO SIGABRT SIGALRM
               SIGCHLD SIGCONT SIGFPE SIGHUP SIGILL SIGINT
               SIGKILL SIGPIPE SIGQUIT SIGSEGV SIGSTOP SIGTERM
               SIGTSTP SIGTTIN SIGTTOU SIGUSR1 SIGUSR2 SIG_BLOCK
               SIG_DFL SIG_ERR SIG_IGN SIG_SETMASK SIG_UNBLOCK

STAT
       Constants
               S_IRGRP S_IROTH S_IRUSR S_IRWXG S_IRWXO S_IRWXU
               S_ISGID S_ISUID S_IWGRP S_IWOTH S_IWUSR S_IXGRP
               S_IXOTH S_IXUSR

       Macros  S_ISBLK S_ISCHR S_ISDIR S_ISFIFO S_ISREG

STDLIB
       Constants
               EXIT_FAILURE EXIT_SUCCESS MB_CUR_MAX RAND_MAX

STDIO
       Constants
               BUFSIZ EOF FILENAME_MAX L_ctermid L_cuserid L_tmp-
               name TMP_MAX




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POSIX(3p)        Perl Programmers Reference Guide       POSIX(3p)


TIME
       Constants
               CLK_TCK CLOCKS_PER_SEC

UNISTD
       Constants
               R_OK SEEK_CUR SEEK_END SEEK_SET STDIN_FILENO STD-
               OUT_FILENO STDERR_FILENO W_OK X_OK

WAIT
       Constants
               WNOHANG WUNTRACED

       Macros  WIFEXITED WEXITSTATUS WIFSIGNALED WTERMSIG WIF-
               STOPPED WSTOPSIG










































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