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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.

       Everything is exported by default with the exception of any POSIX functions with the same name as a
       built-in Perl function, such as "abs", "alarm", "rmdir", "write", etc.., which will be exported only if
       you ask for them explicitly.  This is an unfortunate backwards compatibility feature.  You can stop the
       exporting by saying "use POSIX ()" and then use the fully qualified names (ie. "POSIX::SEEK_END"), or by
       giving an explicit import list.  If you do neither, and opt for the default, "use POSIX;" has to import
       553 symbols.

       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 features.  Consult perlfunc 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 miscellaneous objects.  The remaining sections
       list various constants and macros in an organization which roughly follows IEEE Std 1003.1b-1993.

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 suggest 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".

       Furthermore, some evil vendors will claim 1003.1 compliance, 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 values 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.

               Note that when using threads and in Linux this is not a good way to  exit  a  thread  because  in
               Linux  processes  and  threads  are  kind of the same thing (Note: while this is the situation in
               early 2003 there are projects under way to have threads with more POSIXly  semantics  in  Linux).
               If you want not to return from a thread, detach the thread.

       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 handler does not return normally (it e.g.  does a
               "longjmp").

       abs     This is identical to Perl's builtin  "abs()"  function,  returning  the  absolute  value  of  its
               numerical 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 preparing 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
               argument.  See also Math::Trig.

       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

                       $asctime = asctime($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.  $wday and
               $yday default to zero (and are usually ignored anyway), and $isdst defaults to -1.

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

       assert  Unimplemented, but you can use "die" in perlfunc and the Carp module to achieve similar things.

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

       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 Math::Trig.

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

       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  "int"  in
               perlfunc.

       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  "int"  in
               perlfunc.

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

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

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

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

       chmod   This is identical to Perl's builtin "chmod()" function, allowing one to change file and directory
               permissions, see "chmod" in perlfunc.

       chown   This is identical to Perl's builtin "chown()" function, allowing one to change file and directory
               owners and groups, see "chown" in perlfunc.

       clearerr
               Use  the method "IO::Handle::clearerr()" 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 "close" in perlfunc.

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

       cos     This is identical to Perl's builtin "cos()" function, for returning the cosine of  its  numerical
               argument, see "cos" in perlfunc.  See also Math::Trig.

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

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

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

               See also "sysopen" in perlfunc and its "O_CREAT" flag.

       ctermid Generates the path name for the controlling terminal.

                       $path = POSIX::ctermid();

       ctime   This  is  identical  to the C function "ctime()" and equivalent to "asctime(localtime(...))", see
               "asctime" and "localtime".

       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 "time".

       div     div() is C-specific, use "int" in perlfunc 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();

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

       execl   execl() is C-specific, see "exec" in perlfunc.

       execle  execle() is C-specific, see "exec" in perlfunc.

       execlp  execlp() is C-specific, see "exec" in perlfunc.

       execv   execv() is C-specific, see "exec" in perlfunc.

       execve  execve() is C-specific, see "exec" in perlfunc.

       execvp  execvp() is C-specific, see "exec" in perlfunc.

       exit    This  is  identical  to  Perl's  builtin "exit()" function for exiting the program, see "exit" in
               perlfunc.

       exp     This is identical to Perl's builtin "exp()" function for returning the exponent (e-based) of  the
               numerical argument, see "exp" in perlfunc.

       fabs    This  is  identical  to  Perl's  builtin "abs()" function for returning the absolute value of the
               numerical argument, see "abs" in perlfunc.

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

       fcntl   This is identical to Perl's builtin "fcntl()" function, see "fcntl" in perlfunc.

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

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

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

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

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

       fgetpos Use method "IO::Seekable::getpos()" instead, or see "seek" in perlfunc.

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

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

       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()".

                       $r = fmod($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 "open" in perlfunc.

       fork    This is identical to Perl's builtin "fork()" function for duplicating the  current  process,  see
               "fork" in perlfunc and perlfork 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 /var/foo.

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

               Returns "undef" on failure.

       fprintf fprintf() is C-specific, see "printf" in perlfunc instead.

       fputc   fputc() is C-specific, see "print" in perlfunc instead.

       fputs   fputs() is C-specific, see "print" in perlfunc instead.

       fread   fread() is C-specific, see "read" in perlfunc instead.

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

       freopen freopen() is C-specific, see "open" in perlfunc 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 expressions instead.

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

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

       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 );

       fsync   Use method "IO::Handle::sync()" instead.

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

       fwrite  fwrite() is C-specific, see "print" in perlfunc instead.

       getc    This is identical to Perl's builtin "getc()" function, see "getc" in perlfunc.

       getchar Returns one character from STDIN.  Identical to Perl's "getc()", see "getc" in perlfunc.

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

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

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

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

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

       getgrgid
               This is identical to Perl's builtin "getgrgid()" function for returning group  entries  by  group
               identifiers, see "getgrgid" in perlfunc.

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

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

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

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

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

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

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

       getpwuid
               This  is  identical  to  Perl's  builtin "getpwuid()" function for returning user entries by user
               identifiers, see "getpwuid" in perlfunc.

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

               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 $< variable, see "$UID" in perlvar.

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

       isalnum This is identical to the C function, except that it can apply to a single character or to a whole
               string.  Note that locale settings may affect what characters are considered "isalnum".  Does not
               work on Unicode characters code point 256 or higher.  Consider using regular expressions and  the
               "/[[:alnum:]]/" construct instead, or possibly 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.  Note that locale settings may affect what characters are considered "isalpha".  Does not
               work  on Unicode characters code point 256 or higher.  Consider using regular expressions and the
               "/[[:alpha:]]/" construct instead.

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

       iscntrl This is identical to the C function, except that it can apply to a single character or to a whole
               string.  Note that locale settings may affect what characters are considered "iscntrl".  Does not
               work  on Unicode characters code point 256 or higher.  Consider using regular expressions and the
               "/[[:cntrl:]]/" construct instead.

       isdigit This is identical to the C function, except that it can apply to a single character or to a whole
               string.  Note that locale settings may affect what characters are considered "isdigit" (unlikely,
               but still possible). Does not work on Unicode characters code  point  256  or  higher.   Consider
               using regular expressions and the "/[[:digit:]]/" construct instead, or the "/\d/" construct.

       isgraph This is identical to the C function, except that it can apply to a single character or to a whole
               string.  Note that locale settings may affect what characters are considered "isgraph".  Does not
               work  on Unicode characters code point 256 or higher.  Consider using regular expressions and the
               "/[[:graph:]]/" construct instead.

       islower This is identical to the C function, except that it can apply to a single character or to a whole
               string.  Note that locale settings may affect what characters are considered "islower".  Does not
               work on Unicode characters code point 256 or higher.  Consider using regular expressions and  the
               "/[[:lower:]]/" 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.  Note that locale settings may affect what characters are considered "isprint".  Does not
               work  on Unicode characters code point 256 or higher.  Consider using regular expressions and the
               "/[[:print:]]/" construct instead.

       ispunct This is identical to the C function, except that it can apply to a single character or to a whole
               string.  Note that locale settings may affect what characters are considered "ispunct".  Does not
               work on Unicode characters code point 256 or higher.  Consider using regular expressions and  the
               "/[[:punct:]]/" construct instead.

       isspace This is identical to the C function, except that it can apply to a single character or to a whole
               string.  Note that locale settings may affect what characters are considered "isspace".  Does not
               work  on Unicode characters code point 256 or higher.  Consider using regular expressions and the
               "/[[:space:]]/"  construct  instead,  or  the  "/\s/"   construct.    (Note   that   "/\s/"   and
               "/[[:space:]]/" are slightly different in that "/[[:space:]]/" can normally match a vertical tab,
               while "/\s/" does not.)

       isupper This is identical to the C function, except that it can apply to a single character or to a whole
               string.  Note that locale settings may affect what characters are considered "isupper".  Does not
               work  on Unicode characters code point 256 or higher.  Consider using regular expressions and the
               "/[[:upper:]]/" 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.  Note  that  locale  settings  may  affect  what  characters  are  considered  "isxdigit"
               (unlikely,  but  still  possible).  Does not work on Unicode characters code point 256 or higher.
               Consider using  regular  expressions  and  the  "/[[:xdigit:]]/"  construct  instead,  or  simply
               "/[0-9a-f]/i".

       kill    This  is identical to Perl's builtin "kill()" function for sending signals to processes (often to
               terminate them), see "kill" in perlfunc.

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

       lchown  This  is  identical  to  the  C function, except the order of arguments is consistent with Perl's
               builtin "chown()" with the added restriction of only one path, not an list of  paths.   Does  the
               same thing as the "chown()" function but changes the owner of a symbolic link instead of the file
               the symbolic link points to.

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

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

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

       link    This is identical to Perl's builtin "link()" function for creating hard  links  into  files,  see
               "link" in perlfunc.

       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.

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

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

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

       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) }

               or

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

               or

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

       longjmp longjmp() is C-specific: use "die" in perlfunc 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 management 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 "index" in perlfunc instead.

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

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

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

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

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

       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  similar to the mode of "mkdir()", see "mkdir" in
               perlfunc, though for "mkfifo" you must specify the $mode.

       mktime  Convert date/time info to a calendar time.

               Synopsis:

                       mktime(sec, min, hour, mday, mon, year, wday = 0, yday = 0, isdst = -1)

               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.  Consult 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  process,  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 "pack" in perlfunc instead.

       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 "sysopen" in perlfunc.

       opendir Open a directory for reading.

                       $dir = POSIX::opendir( "/var" );
                       @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 "/var".

                       $path_max = POSIX::pathconf( "/var", &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
               specified message followed by ": " and the current error string.  Use the "warn()"  function  and
               the $!  variable instead, see "warn" in perlfunc and "$ERRNO" in perlvar.

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

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

               See also "pipe" in perlfunc.

       pow     Computes $x raised to the power $exponent.

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

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

       printf  Formats and prints the specified arguments to STDOUT.  See also "printf" in perlfunc.

       putc    putc() is C-specific, see "print" in perlfunc instead.

       putchar putchar() is C-specific, see "print" in perlfunc instead.

       puts    puts() is C-specific, see "print" in perlfunc instead.

       qsort   qsort() is C-specific, see "sort" in perlfunc instead.

       raise   Sends the specified signal to the current process.  See also "kill" in perlfunc  and  the  $$  in
               "$PID" in perlvar.

       rand    "rand()" is non-portable, see "rand" in perlfunc 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 );

               Returns "undef" on failure.

               See also "sysread" in perlfunc.

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

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

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

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

       rewind  Seeks to the beginning of the file.

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

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

       scanf   scanf() is C-specific, use <> and regular expressions instead, see perlre.

       setgid  Sets the real group identifier and the effective group identifier for this process.   Similar  to
               assigning  a  value  to  the  Perl's builtin $) variable, see "$EGID" in perlvar, except that the
               latter will change only the real user identifier, and  that  the  setgid()  uses  only  a  single
               numeric argument, as opposed to a space-separated list of numbers.

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

       setlocale
               Modifies and queries program's locale.  The following 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" );

               The following will query the current LC_CTYPE category.  (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
               environment variables' meaning or consult perllocale.

                       $loc = setlocale( LC_CTYPE, "" );

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

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

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

               Returns "undef" on failure.

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

       setuid  Sets  the  real  user  identifier and the effective user identifier for this process.  Similar to
               assigning a value to the Perl's builtin $< variable, see  "$UID"  in  perlvar,  except  that  the
               latter will change only the real user identifier.

       sigaction
               Detailed   signal  management.   This  uses  "POSIX::SigAction"  objects  for  the  "action"  and
               "oldaction" arguments (the oldaction can also be just a hash reference).  Consult  your  system's
               "sigaction" manpage for details, see also "POSIX::SigRt".

               Synopsis:

                       sigaction(signal, action, oldaction = 0)

               Returns  "undef"  on  failure.   The  "signal" must be a number (like SIGHUP), not a string (like
               "SIGHUP"), though Perl does try hard to understand you.

               If you use the SA_SIGINFO flag, the signal handler will in addition to the  first  argument,  the
               signal  name,  also  receive  a second argument, a hash reference, inside which are the following
               keys with the following semantics, as defined by POSIX/SUSv3:

                   signo       the signal number
                   errno       the error number
                   code        if this is zero or less, the signal was sent by
                               a user process and the uid and pid make sense,
                               otherwise the signal was sent by the kernel

               The following are also defined by POSIX/SUSv3, but unfortunately not very widely implemented:

                   pid         the process id generating the signal
                   uid         the uid of the process id generating the signal
                   status      exit value or signal for SIGCHLD
                   band        band event for SIGPOLL

               A third argument is also passed to the handler, which contains a copy of the raw binary  contents
               of  the siginfo structure: if a system has some non-POSIX fields, this third argument is where to
               unpack() them from.

               Note that not all siginfo values make sense simultaneously  (some  are  valid  only  for  certain
               signals, for example), and not all values make sense from Perl perspective, you should to consult
               your system's "sigaction" and possibly also "siginfo" documentation.

       siglongjmp
               siglongjmp() is C-specific: use "die" in perlfunc instead.

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

               Note that you can't reliably block or unblock a signal from its  own  signal  handler  if  you're
               using safe signals. Other signals can be blocked or unblocked reliably.

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

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

               Synopsis:

                       sigsuspend(signal_mask)

               Returns "undef" on failure.

       sin     This is identical to Perl's builtin "sin()" function for returning  the  sine  of  the  numerical
               argument, see "sin" in perlfunc.  See also Math::Trig.

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

       sleep   This is functionally identical to Perl's builtin "sleep()" function for suspending the  execution
               of  the current for process for certain number of seconds, see "sleep" in perlfunc.  There is one
               significant difference, however: "POSIX::sleep()" returns the number of  unslept  seconds,  while
               the "CORE::sleep()" returns the number of slept seconds.

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

       sqrt    This is identical to Perl's builtin "sqrt()" function.  for returning  the  square  root  of  the
               numerical argument, see "sqrt" in perlfunc.

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

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

       stat    This  is  identical to Perl's builtin "stat()" function for returning information about files and
               directories.

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

       strchr  strchr() is C-specific, see "index" in perlfunc instead.

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

       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
               perllocale.

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

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

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

       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)

               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.  Consult 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   (C89,   to   play   safe).    These   are
               "aAbBcdHIjmMpSUwWxXyYZ%".   But  even  then, the results of some of the conversion specifiers are
               non-portable.  For example, the specifiers "aAbBcpZ" change according to the locale  settings  of
               the  user,  and  both  how  to  set locales (the locale names) and what output to expect are non-
               standard.  The specifier "c" changes according to the timezone  settings  of  the  user  and  the
               timezone  computation rules of the operating system.  The "Z" specifier is notoriously unportable
               since the names of timezones are non-standard. Sticking to the numeric specifiers is  the  safest
               route.

               The  given  arguments  are  made  consistent  as though by calling "mktime()" before calling your
               system's "strftime()" 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 "length" in perlfunc.

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

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

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

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

       strrchr strrchr() is C-specific, see "rindex" in perlfunc instead.

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

       strstr  This is identical to Perl's builtin "index()" function, see "index" in perlfunc.

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

               strtod should respect any POSIX setlocale() settings.

               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 perlre, or "split" in perlfunc.

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

               strtol should respect any POSIX setlocale() settings.

               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  strtol
               will  use  the  string  itself to determine the base: a leading "0x" or "0X" means hexadecimal; a
               leading "0" means octal; any other leading characters 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:

                   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 "strtol" 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 "strcoll".

               Not really needed since Perl can do this transparently, see perllocale.

       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 "system" in perlfunc.

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

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

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

               Returns "undef" on failure.

       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  argument
               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 terminal.

       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 terminal.

               Returns "undef" on failure.

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

       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 File::Temp.

       tmpnam  Returns a name for a temporary file.

                       $tmpfile = POSIX::tmpnam();

               For security reasons, which are probably detailed  in  your  system's  documentation  for  the  C
               library tmpnam() function, this interface should not be used; instead see File::Temp.

       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  "lc"  in perlfunc, 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  "uc"  in  perlfunc,  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
               environment variable "TZ", to be used by "ctime()", "localtime()", "mktime()",  and  "strftime()"
               functions.

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

       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.

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

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

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

       vfprintf
               vfprintf() is C-specific, see "printf" in perlfunc instead.

       vprintf vprintf() is C-specific, see "printf" in perlfunc instead.

       vsprintf
               vsprintf() is C-specific, see "sprintf" in perlfunc instead.

       wait    This is identical to Perl's builtin "wait()" function, see "wait" in perlfunc.

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

                       $pid = POSIX::waitpid( -1, POSIX::WNOHANG );
                       print "status = ", ($? / 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( $fd, $buf, 5 );

               Returns "undef" on failure.

               See also "syswrite" in perlfunc.

CLASSES

   POSIX::SigAction
       new     Creates a new "POSIX::SigAction" object which corresponds to  the  C  "struct  sigaction".   This
               object  will  be destroyed automatically when it is no longer needed.  The first parameter is the
               handler, a sub reference.  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( \&handler, $sigset, &POSIX::SA_NOCLDSTOP );

               This "POSIX::SigAction" object is intended for use with the "POSIX::sigaction()" function.

       handler
       mask
       flags   accessor functions to get/set the values of a SigAction object.

                       $sigset = $sigaction->mask;
                       $sigaction->flags(&POSIX::SA_RESTART);

       safe    accessor  function  for  the  "safe  signals" flag of a SigAction object; see perlipc for general
               information on safe (a.k.a. "deferred") signals.  If you wish to handle a signal safely, use this
               accessor to set the "safe" flag in the "POSIX::SigAction" object:

                       $sigaction->safe(1);

               You may also examine the "safe" flag on the output action object which is filled in when given as
               the third parameter to "POSIX::sigaction()":

                       sigaction(SIGINT, $new_action, $old_action);
                       if ($old_action->safe) {
                           # previous SIGINT handler used safe signals
                       }

   POSIX::SigRt
       %SIGRT  A hash of the POSIX realtime signal handlers.  It is an  extension  of  the  standard  %SIG,  the
               $POSIX::SIGRT{SIGRTMIN}  is  roughly equivalent to $SIG{SIGRTMIN}, but the right POSIX moves (see
               below) are made with the POSIX::SigSet and POSIX::sigaction instead of accessing the %SIG.

               You can set the %POSIX::SIGRT elements to set the POSIX realtime signal  handlers,  use  "delete"
               and  "exists"  on  the elements, and use "scalar" on the %POSIX::SIGRT to find out how many POSIX
               realtime signals there are available (SIGRTMAX - SIGRTMIN + 1, the  SIGRTMAX  is  a  valid  POSIX
               realtime signal).

               Setting the %SIGRT elements is equivalent to calling this:

                 sub new {
                   my ($rtsig, $handler, $flags) = @_;
                   my $sigset = POSIX::SigSet($rtsig);
                   my $sigact = POSIX::SigAction->new($handler, $sigset, $flags);
                   sigaction($rtsig, $sigact);
                 }

               The  flags  default  to  zero,  if  you  want  something  different you can either use "local" on
               $POSIX::SigRt::SIGACTION_FLAGS, or you can derive from POSIX::SigRt and define your  own  "new()"
               (the  tied hash STORE method of the %SIGRT calls "new($rtsig, $handler, $SIGACTION_FLAGS)", where
               the $rtsig ranges from zero to SIGRTMAX - SIGRTMIN + 1).

               Just as with any signal, you can use sigaction($rtsig, undef,  $oa)  to  retrieve  the  installed
               signal handler (or, rather, the signal action).

               NOTE:  whether  POSIX  realtime  signals  really  work  in  your system, or whether Perl has been
               compiled so that it works with them, is outside of this discussion.

       SIGRTMIN
               Return the minimum POSIX realtime signal number  available,  or  "undef"  if  no  POSIX  realtime
               signals are available.

       SIGRTMAX
               Return  the  maximum  POSIX  realtime  signal  number  available, or "undef" if no POSIX realtime
               signals are available.

   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();

               Returns "undef" on failure.

       fillset Initialize the SigSet object to include all signals.

                       $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( 0 ) # Recommended for clarity.
                       $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.

                       $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 );

       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 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_VDISABLE _POSIX_VERSION

SYSTEM CONFIGURATION

       Constants
               _SC_ARG_MAX  _SC_CHILD_MAX  _SC_CLK_TCK _SC_JOB_CONTROL _SC_NGROUPS_MAX _SC_OPEN_MAX _SC_PAGESIZE
               _SC_SAVED_IDS _SC_STREAM_MAX _SC_TZNAME_MAX _SC_VERSION

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  ENETRESET  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

       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_tmpname TMP_MAX

TIME

       Constants
               CLK_TCK CLOCKS_PER_SEC

UNISTD

       Constants
               R_OK SEEK_CUR SEEK_END SEEK_SET STDIN_FILENO STDOUT_FILENO STDERR_FILENO W_OK X_OK

WAIT

       Constants
               WNOHANG WUNTRACED

               WNOHANG         Do  not  suspend  the  calling  process  until  a child process changes state but
                               instead return immediately.

               WUNTRACED       Catch stopped child processes.

       Macros  WIFEXITED WEXITSTATUS WIFSIGNALED WTERMSIG WIFSTOPPED WSTOPSIG

               WIFEXITED       WIFEXITED(${^CHILD_ERROR_NATIVE})  returns  true  if  the  child  process  exited
                               normally ("exit()" or by falling off the end of "main()")

               WEXITSTATUS     WEXITSTATUS(${^CHILD_ERROR_NATIVE})  returns  the normal exit status of the child
                               process (only meaningful if WIFEXITED(${^CHILD_ERROR_NATIVE}) is true)

               WIFSIGNALED     WIFSIGNALED(${^CHILD_ERROR_NATIVE}) returns true if the child process  terminated
                               because of a signal

               WTERMSIG        WTERMSIG(${^CHILD_ERROR_NATIVE})  returns the signal the child process terminated
                               for (only meaningful if WIFSIGNALED(${^CHILD_ERROR_NATIVE}) is true)

               WIFSTOPPED      WIFSTOPPED(${^CHILD_ERROR_NATIVE}) returns true if the child process is currently
                               stopped (can happen only if you specified the WUNTRACED flag to waitpid())

               WSTOPSIG        WSTOPSIG(${^CHILD_ERROR_NATIVE}) returns the signal the child process was stopped
                               for (only meaningful if WIFSTOPPED(${^CHILD_ERROR_NATIVE}) is true)

perl v5.18.2                                       2014-01-06                                       POSIX(3perl)