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




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.

       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

       Everything is exported by default (with a handful of exceptions).  This
       is an unfortunate backwards compatibility feature and its use is
       strongly discouraged.  You should either prevent the exporting (by
       saying "use POSIX ();", as usual) and then use fully qualified names
       (e.g. "POSIX::SEEK_END"), or give an explicit import list.  If you do
       neither and opt for the default (as in "use POSIX;"), you will import
       hundreds and hundreds of symbols into your namespace.

       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.

       "acosh" This is identical to the C function "acosh()", returning the
               hyperbolic arcus cosine of its numerical argument [C99].  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.

       "asinh" This is identical to the C function "asinh()", returning the
               hyperbolic arcus sine of its numerical argument [C99].  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.

       "atanh" This is identical to the C function "atanh()", returning the
               hyperbolic arcus tangent of its numerical argument [C99].  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"
               Not implemented.  "atexit()" is C-specific: use "END {}"
               instead, see perlmod.

       "atof"  Not implemented.  "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"  Not implemented.  "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"  Not implemented.  "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"
               Not implemented.  "calloc()" is C-specific.  Perl does memory
               management transparently.

       "cbrt"  The cube root [C99].

       "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"
               Not implemented.  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.

       "copysign"
               Returns "x" but with the sign of "y" [C99].

                $x_with_sign_of_y = POSIX::copysign($x, $y);

               See also "signbit".

       "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"   Not implemented.  "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.

       "erf"   The error function [C99].

       "erfc"  The complementary error function [C99].

       "errno" Returns the value of errno.

                       $errno = POSIX::errno();

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

       "execl" Not implemented.  "execl()" is C-specific, see "exec" in
               perlfunc.

       "execle"
               Not implemented.  "execle()" is C-specific, see "exec" in
               perlfunc.

       "execlp"
               Not implemented.  "execlp()" is C-specific, see "exec" in
               perlfunc.

       "execv" Not implemented.  "execv()" is C-specific, see "exec" in
               perlfunc.

       "execve"
               Not implemented.  "execve()" is C-specific, see "exec" in
               perlfunc.

       "execvp"
               Not implemented.  "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.

       "expm1" Equivalent to "exp(x) - 1", but more precise for small argument
               values [C99].

               See also "log1p".

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

       "fclose"
               Not implemented.  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"
               Not implemented.  Use method "IO::Handle::new_from_fd()"
               instead, or see "open" in perlfunc.

       "feof"  Not implemented.  Use method "IO::Handle::eof()" instead, or
               see "eof" in perlfunc.

       "ferror"
               Not implemented.  Use method "IO::Handle::error()" instead.

       "fflush"
               Not implemented.  Use method "IO::Handle::flush()" instead.
               See also ""$OUTPUT_AUTOFLUSH" in perlvar".

       "fgetc" Not implemented.  Use method "IO::Handle::getc()" instead, or
               see "read" in perlfunc.

       "fgetpos"
               Not implemented.  Use method "IO::Seekable::getpos()" instead,
               or see "seek" in perlfunc.

       "fgets" Not implemented.  Use method "IO::Handle::gets()" instead.
               Similar to <>, also known as "readline" in perlfunc.

       "fileno"
               Not implemented.  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.

       "fdim"  "Positive difference", "x - y" if "x > y", zero otherwise
               [C99].

       "fegetround"
               Returns the current floating point rounding mode, one of

                 FE_TONEAREST FE_TOWARDZERO FE_UPWARD FE_UPWARD

               "FE_TONEAREST" is like "round", "FE_TOWARDZERO" is like "trunc"
               [C99].

       "fesetround"
               Sets the floating point rounding mode, see "fegetround" [C99].

       "fma"   "Fused multiply-add", "x * y + z", possibly faster (and less
               lossy) than the explicit two operations [C99].

                my $fused = POSIX::fma($x, $y, $z);

       "fmax"  Maximum of "x" and "y", except when either is "NaN", returns
               the other [C99].

                my $min = POSIX::fmax($x, $y);

       "fmin"  Minimum of "x" and "y", except when either is "NaN", returns
               the other [C99].

                my $min = POSIX::fmin($x, $y);

       "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" Not implemented.  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.

       "fpclassify"
               Returns one of

                 FP_NORMAL FP_ZERO FP_SUBNORMAL FP_INFINITE FP_NAN

               telling the class of the argument [C99].  "FP_INFINITE" is
               positive or negative infinity, "FP_NAN" is not-a-number.
               "FP_SUBNORMAL" means subnormal numbers (also known as
               denormals), very small numbers with low precision. "FP_ZERO" is
               zero.  "FP_NORMAL" is all the rest.

       "fprintf"
               Not implemented.  "fprintf()" is C-specific, see "printf" in
               perlfunc instead.

       "fputc" Not implemented.  "fputc()" is C-specific, see "print" in
               perlfunc instead.

       "fputs" Not implemented.  "fputs()" is C-specific, see "print" in
               perlfunc instead.

       "fread" Not implemented.  "fread()" is C-specific, see "read" in
               perlfunc instead.

       "free"  Not implemented.  "free()" is C-specific.  Perl does memory
               management transparently.

       "freopen"
               Not implemented.  "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"
               Not implemented.  "fscanf()" is C-specific, use <> and regular
               expressions instead.

       "fseek" Not implemented.  Use method "IO::Seekable::seek()" instead, or
               see "seek" in perlfunc.

       "fsetpos"
               Not implemented.  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" Not implemented.  Use method "IO::Handle::sync()" instead.

       "ftell" Not implemented.  Use method "IO::Seekable::tell()" instead, or
               see "tell" in perlfunc.

       "fwrite"
               Not implemented.  "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.

       "getpayload"
                       use POSIX ':nan_payload';
                       getpayload($var)

               Returns the "NaN" payload.

               Note the API instability warning in "setpayload".

               See "nan" for more discussion about "NaN".

       "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.

       "hypot" Equivalent to "sqrt(x * x + y * y)" except more stable on very
               large or very small arguments [C99].

       "ilogb" Integer binary logarithm [C99]

               For example "ilogb(20)" is 4, as an integer.

               See also "logb".

       "Inf"   The infinity as a constant:

                  use POSIX qw(Inf);
                  my $pos_inf = +Inf;  # Or just Inf.
                  my $neg_inf = -Inf;

               See also "isinf", and "fpclassify".

       "isalnum"
               This function has been removed as of v5.24.  It was very
               similar to matching against "qr/ ^ [[:alnum:]]+ $ /x", which
               you should convert to use instead.  See "POSIX Character
               Classes" in perlrecharclass.

       "isalpha"
               This function has been removed as of v5.24.  It was very
               similar to matching against "qr/ ^ [[:alpha:]]+ $ /x", which
               you should convert to use instead.  See "POSIX Character
               Classes" in perlrecharclass.

       "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 function has been removed as of v5.24.  It was very
               similar to matching against "qr/ ^ [[:cntrl:]]+ $ /x", which
               you should convert to use instead.  See "POSIX Character
               Classes" in perlrecharclass.

       "isdigit"
               This function has been removed as of v5.24.  It was very
               similar to matching against "qr/ ^ [[:digit:]]+ $ /x", which
               you should convert to use instead.  See "POSIX Character
               Classes" in perlrecharclass.

       "isfinite"
               Returns true if the argument is a finite number (that is, not
               an infinity, or the not-a-number) [C99].

               See also "isinf", "isnan", and "fpclassify".

       "isgraph"
               This function has been removed as of v5.24.  It was very
               similar to matching against "qr/ ^ [[:graph:]]+ $ /x", which
               you should convert to use instead.  See "POSIX Character
               Classes" in perlrecharclass.

       "isgreater"
               (Also "isgreaterequal", "isless", "islessequal",
               "islessgreater", "isunordered")

               Floating point comparisons which handle the "NaN" [C99].

       "isinf" Returns true if the argument is an infinity (positive or
               negative) [C99].

               See also "Inf", "isnan", "isfinite", and "fpclassify".

       "islower"
               This function has been removed as of v5.24.  It was very
               similar to matching against "qr/ ^ [[:lower:]]+ $ /x", which
               you should convert to use instead.  See "POSIX Character
               Classes" in perlrecharclass.

       "isnan" Returns true if the argument is "NaN" (not-a-number) [C99].

               Note that you cannot test for ""NaN"-ness" with

                  $x == $x

               since the "NaN" is not equivalent to anything, including
               itself.

               See also "nan", "NaN", "isinf", and "fpclassify".

       "isnormal"
               Returns true if the argument is normal (that is, not a
               subnormal/denormal, and not an infinity, or a not-a-number)
               [C99].

               See also "isfinite", and "fpclassify".

       "isprint"
               This function has been removed as of v5.24.  It was very
               similar to matching against "qr/ ^ [[:print:]]+ $ /x", which
               you should convert to use instead.  See "POSIX Character
               Classes" in perlrecharclass.

       "ispunct"
               This function has been removed as of v5.24.  It was very
               similar to matching against "qr/ ^ [[:punct:]]+ $ /x", which
               you should convert to use instead.  See "POSIX Character
               Classes" in perlrecharclass.

       "issignaling"
                       use POSIX ':nan_payload';
                       issignaling($var, $payload)

               Return true if the argument is a signaling NaN.

               Note the API instability warning in "setpayload".

               See "nan" for more discussion about "NaN".

       "isspace"
               This function has been removed as of v5.24.  It was very
               similar to matching against "qr/ ^ [[:space:]]+ $ /x", which
               you should convert to use instead.  See "POSIX Character
               Classes" in perlrecharclass.

       "isupper"
               This function has been removed as of v5.24.  It was very
               similar to matching against "qr/ ^ [[:upper:]]+ $ /x", which
               you should convert to use instead.  See "POSIX Character
               Classes" in perlrecharclass.

       "isxdigit"
               This function has been removed as of v5.24.  It was very
               similar to matching against "qr/ ^ [[:xdigit:]]+ $ /x", which
               you should convert to use instead.  See "POSIX Character
               Classes" in perlrecharclass.

       "j0"
       "j1"
       "jn"
       "y0"
       "y1"
       "yn"    The Bessel function of the first kind of the order zero.

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

       "labs"  Not implemented.  (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 a 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.

                POSIX::lchown($uid, $gid, $file_path);

       "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"  Not implemented.  (For computing dividends of long integers.)
               "ldiv()" is C-specific, use "/" and "int()" instead.

       "lgamma"
               The logarithm of the Gamma function [C99].

               See also "tgamma".

       "log1p" Equivalent to "log(1 + x)", but more stable results for small
               argument values [C99].

       "log2"  Logarithm base two [C99].

               See also "expm1".

       "logb"  Integer binary logarithm [C99].

               For example "logb(20)" is 4, as a floating point number.

               See also "ilogb".

       "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 underlying locale's formatting
               values.  Users of this function should also read perllocale,
               which provides a comprehensive discussion of Perl locale
               handling, including a section devoted to this function.

               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
                               int_p_cs_precedes
                               int_p_sep_by_space
                               int_n_cs_precedes
                               int_n_sep_by_space
                               int_p_sign_posn
                               int_n_sign_posn
                       ))
                       {
                               printf qq(%s: "%s",\n),
                                       $property, $lconv->{$property};
                       }

               The members whose names begin with "int_p_" and "int_n_" were
               added by POSIX.1-2008 and are only available on systems that
               support them.

       "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"
               Not implemented.  "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.

       "lrint" Depending on the current floating point rounding mode, rounds
               the argument either toward nearest (like "round"), toward zero
               (like "trunc"), downward (toward negative infinity), or upward
               (toward positive infinity) [C99].

               For the rounding mode, see "fegetround".

       "lround"
               Like "round", but as integer, as opposed to floating point
               [C99].

               See also "ceil", "floor", "trunc".

               Owing to an oversight, this is not currently exported by
               default, or as part of the ":math_h_c99" export tag; importing
               it must therefore be done by explicit name.

       "malloc"
               Not implemented.  "malloc()" is C-specific.  Perl does memory
               management transparently.

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

               Core Perl does not have any support for the wide and multibyte
               characters of the C standards, except under UTF-8 locales, so
               this might be a rather useless function.

               However, Perl supports Unicode, see perluniintro.

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

               See "mblen".

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

               See "mblen".

       "memchr"
               Not implemented.  "memchr()" is C-specific, see "index" in
               perlfunc instead.

       "memcmp"
               Not implemented.  "memcmp()" is C-specific, use "eq" instead,
               see perlop.

       "memcpy"
               Not implemented.  "memcpy()" is C-specific, use "=", see
               perlop, or see "substr" in perlfunc.

       "memmove"
               Not implemented.  "memmove()" is C-specific, use "=", see
               perlop, or see "substr" in perlfunc.

       "memset"
               Not implemented.  "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 );

               See also "round".

       "NaN"   The not-a-number as a constant:

                  use POSIX qw(NaN);
                  my $nan = NaN;

               See also "nan", "/isnan", and "fpclassify".

       "nan"
                  my $nan = nan();

               Returns "NaN", not-a-number [C99].

               The returned NaN is always a quiet NaN, as opposed to
               signaling.

               With an argument, can be used to generate a NaN with payload.
               The argument is first interpreted as a floating point number,
               but then any fractional parts are truncated (towards zero), and
               the value is interpreted as an unsigned integer.  The bits of
               this integer are stored in the unused bits of the NaN.

               The result has a dual nature: it is a NaN, but it also carries
               the integer inside it.  The integer can be retrieved with
               "getpayload".  Note, though, that the payload is not
               propagated, not even on copies, and definitely not in
               arithmetic operations.

               How many bits fit in the NaN depends on what kind of floating
               points are being used, but on the most common platforms (64-bit
               IEEE 754, or the x86 80-bit long doubles) there are 51 and 61
               bits available, respectively.  (There would be 52 and 62, but
               the quiet/signaling bit of NaNs takes away one.)  However,
               because of the floating-point-to- integer-and-back conversions,
               please test carefully whether you get back what you put in.  If
               your integers are only 32 bits wide, you probably should not
               rely on more than 32 bits of payload.

               Whether a "signaling" NaN is in any way different from a
               "quiet" NaN, depends on the platform.  Also note that the
               payload of the default NaN (no argument to nan()) is not
               necessarily zero, use "setpayload" to explicitly set the
               payload.  On some platforms like the 32-bit x86, (unless using
               the 80-bit long doubles) the signaling bit is not supported at
               all.

               See also "isnan", "NaN", "setpayload" and "issignaling".

       "nearbyint"
               Returns the nearest integer to the argument, according to the
               current rounding mode (see "fegetround") [C99].

       "nextafter"
               Returns the next representable floating point number after "x"
               in the direction of "y" [C99].

                my $nextafter = POSIX::nextafter($x, $y);

               Like "nexttoward", but potentially less accurate.

       "nexttoward"
               Returns the next representable floating point number after "x"
               in the direction of "y" [C99].

                my $nexttoward = POSIX::nexttoward($x, $y);

               Like "nextafter", but potentially more accurate.

       "nice"  This is similar to the C function "nice()", for changing the
               scheduling preference of the current process.  Positive
               arguments mean a more polite process, negative values a more
               needy process.  Normal (non-root) user processes can only
               change towards being more polite.

               Returns "undef" on failure.

       "offsetof"
               Not implemented.  "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"  Not implemented.  "putc()" is C-specific, see "print" in
               perlfunc instead.

       "putchar"
               Not implemented.  "putchar()" is C-specific, see "print" in
               perlfunc instead.

       "puts"  Not implemented.  "puts()" is C-specific, see "print" in
               perlfunc instead.

       "qsort" Not implemented.  "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"  Not implemented.  "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"
               Not implemented.  "realloc()" is C-specific.  Perl does memory
               management transparently.

       "remainder"
               Given "x" and "y", returns the value "x - n*y", where "n" is
               the integer closest to "x"/"y". [C99]

                my $remainder = POSIX::remainder($x, $y)

               See also "remquo".

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

       "remquo"
               Like "remainder" but also returns the low-order bits of the
               quotient (n) [C99]

               (This is quite esoteric interface, mainly used to implement
               numerical algorithms.)

       "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.

       "rint"  Identical to "lrint".

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

       "round" Returns the integer (but still as floating point) nearest to
               the argument [C99].

               See also "ceil", "floor", "lround", "modf", and "trunc".

       "scalbn"
               Returns "x * 2**y" [C99].

               See also "frexp" and "ldexp".

       "scanf" Not implemented.  "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"
               Not implemented.  "setjmp()" is C-specific: use "eval {}"
               instead, see "eval" in perlfunc.

       "setlocale"
               WARNING!  Do NOT use this function in a thread.  The locale
               will change in all other threads at the same time, and should
               your thread get paused by the operating system, and another
               started, that thread will not have the locale it is expecting.
               On some platforms, there can be a race leading to segfaults if
               two threads call this function nearly simultaneously.

               Modifies and queries the program's underlying locale.  Users of
               this function should read perllocale, whch provides a
               comprehensive discussion of Perl locale handling, knowledge of
               which is necessary to properly use this function.  It contains
               a section devoted to this function.  The discussion here is
               merely a summary reference for "setlocale()".  Note that Perl
               itself is almost entirely unaffected by the locale except
               within the scope of "use locale".  (Exceptions are listed in
               "Not within the scope of "use locale"" in perllocale.)

               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 system's 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" );

       "setpayload"
                       use POSIX ':nan_payload';
                       setpayload($var, $payload);

               Sets the "NaN" payload of var.

               NOTE: the NaN payload APIs are based on the latest (as of June
               2015) proposed ISO C interfaces, but they are not yet a
               standard.  Things may change.

               See "nan" for more discussion about "NaN".

               See also "setpayloadsig", "isnan", "getpayload", and
               "issignaling".

       "setpayloadsig"
                       use POSIX ':nan_payload';
                       setpayloadsig($var, $payload);

               Like "setpayload" but also makes the NaN signaling.

               Depending on the platform the NaN may or may not behave
               differently.

               Note the API instability warning in "setpayload".

               Note that because how the floating point formats work out, on
               the most common platforms signaling payload of zero is best
               avoided, since it might end up being identical to "+Inf".

               See also "nan", "isnan", "getpayload", and "issignaling".

       "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 constants for specific "code" values can be imported
               individually or using the ":signal_h_si_code" tag.

               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
                   addr        address of faulting instruction or memory
                               reference for SIGILL, SIGFPE, SIGSEGV or SIGBUS

               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"
               Not implemented.  "siglongjmp()" is C-specific: use "die" in
               perlfunc instead.

       "signbit"
               Returns zero for positive arguments, non-zero for negative
               arguments [C99].

       "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"
               Not implemented.  "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"
               Not implemented.  "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"
               Not implemented.  "strcat()" is C-specific, use ".=" instead,
               see perlop.

       "strchr"
               Not implemented.  "strchr()" is C-specific, see "index" in
               perlfunc instead.

       "strcmp"
               Not implemented.  "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.

               Beware that in a UTF-8 locale, anything you pass to this
               function must be in UTF-8; and when not in a UTF-8 locale,
               anything passed must not be UTF-8 encoded.

       "strcpy"
               Not implemented.  "strcpy()" is C-specific, use "=" instead,
               see perlop.

       "strcspn"
               Not implemented.  "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 $!, see "$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"
               Not implemented.  "strlen()" is C-specific, use "length()"
               instead, see "length" in perlfunc.

       "strncat"
               Not implemented.  "strncat()" is C-specific, use ".=" instead,
               see perlop.

       "strncmp"
               Not implemented.  "strncmp()" is C-specific, use "eq" instead,
               see perlop.

       "strncpy"
               Not implemented.  "strncpy()" is C-specific, use "=" instead,
               see perlop.

       "strpbrk"
               Not implemented.  "strpbrk()" is C-specific, use regular
               expressions instead, see perlre.

       "strrchr"
               Not implemented.  "strrchr()" is C-specific, see "rindex" in
               perlfunc instead.

       "strspn"
               Not implemented.  "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" respects any POSIX "setlocale()" "LC_TIME" settings,
               regardless of whether or not it is called from Perl code that
               is within the scope of "use locale".

               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"
               Not implemented.  "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.

       "strtold"
               Like "strtod" but for long doubles.  Defined only if the system
               supports long doubles.

       "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.

               Beware that in a UTF-8 locale, anything you pass to this
               function must be in UTF-8; and when not in a UTF-8 locale,
               anything passed must not be UTF-8 encoded.

       "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.

       "tgamma"
               The Gamma function [C99].

               See also "lgamma".

       "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"
               Not implemented.  Use method "IO::File::new_tmpfile()" instead,
               or see File::Temp.

       "tmpnam"
               For security reasons, which are probably detailed in your
               system's documentation for the C library "tmpnam()" function,
               this interface is no longer available; instead use File::Temp.

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

       "toupper"
               This is similar to the C function, except that it can apply to
               a single character or to a whole string, and currently operates
               as if the locale always is "C".  Consider using the "uc()"
               function, see "uc" in perlfunc, or the equivalent "\U" operator
               inside doublequotish strings.

       "trunc" Returns the integer toward zero from the argument [C99].

               See also "ceil", "floor", and "round".

       "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"
               Not implemented.  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"
               Not implemented.  "vfprintf()" is C-specific, see "printf" in
               perlfunc instead.

       "vprintf"
               Not implemented.  "vprintf()" is C-specific, see "printf" in
               perlfunc instead.

       "vsprintf"
               Not implemented.  "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()".

               See "mblen".

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

               See "mblen".

       "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" "EBADMSG" "EBUSY" "ECANCELED"
               "ECHILD" "ECONNABORTED" "ECONNREFUSED" "ECONNRESET" "EDEADLK"
               "EDESTADDRREQ" "EDOM" "EDQUOT" "EEXIST" "EFAULT" "EFBIG"
               "EHOSTDOWN" "EHOSTUNREACH" "EIDRM" "EILSEQ" "EINPROGRESS"
               "EINTR" "EINVAL" "EIO" "EISCONN" "EISDIR" "ELOOP" "EMFILE"
               "EMLINK" "EMSGSIZE" "ENAMETOOLONG" "ENETDOWN" "ENETRESET"
               "ENETUNREACH" "ENFILE" "ENOBUFS" "ENODATA" "ENODEV" "ENOENT"
               "ENOEXEC" "ENOLCK" "ENOLINK" "ENOMEM" "ENOMSG" "ENOPROTOOPT"
               "ENOSPC" "ENOSR" "ENOSTR" "ENOSYS" "ENOTBLK" "ENOTCONN"
               "ENOTDIR" "ENOTEMPTY" "ENOTRECOVERABLE" "ENOTSOCK" "ENOTSUP"
               "ENOTTY" "ENXIO" "EOPNOTSUPP" "EOTHER" "EOVERFLOW" "EOWNERDEAD"
               "EPERM" "EPFNOSUPPORT" "EPIPE" "EPROCLIM" "EPROTO"
               "EPROTONOSUPPORT" "EPROTOTYPE" "ERANGE" "EREMOTE" "ERESTART"
               "EROFS" "ESHUTDOWN" "ESOCKTNOSUPPORT" "ESPIPE" "ESRCH" "ESTALE"
               "ETIME" "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"


FLOATING-POINT ENVIRONMENT

       Constants
               "FE_DOWNWARD" "FE_TONEAREST" "FE_TOWARDZERO" "FE_UPWARD" on
               systems that support them.


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" "LC_MESSAGES" on systems that support them.


MATH

       Constants
               "HUGE_VAL"

               "FP_ILOGB0" "FP_ILOGBNAN" "FP_INFINITE" "FP_NAN" "FP_NORMAL"
               "FP_SUBNORMAL" "FP_ZERO" "INFINITY" "NAN" "Inf" "NaN" "M_1_PI"
               "M_2_PI" "M_2_SQRTPI" "M_E" "M_LN10" "M_LN2" "M_LOG10E"
               "M_LOG2E" "M_PI" "M_PI_2" "M_PI_4" "M_SQRT1_2" "M_SQRT2" on
               systems with C99 support.


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"
               "ILL_ILLOPC" "ILL_ILLOPN" "ILL_ILLADR" "ILL_ILLTRP"
               "ILL_PRVOPC" "ILL_PRVREG" "ILL_COPROC" "ILL_BADSTK"
               "FPE_INTDIV" "FPE_INTOVF" "FPE_FLTDIV" "FPE_FLTOVF"
               "FPE_FLTUND" "FPE_FLTRES" "FPE_FLTINV" "FPE_FLTSUB"
               "SEGV_MAPERR" "SEGV_ACCERR" "BUS_ADRALN" "BUS_ADRERR"
               "BUS_OBJERR" "TRAP_BRKPT" "TRAP_TRACE" "CLD_EXITED"
               "CLD_KILLED" "CLD_DUMPED" "CLD_TRAPPED" "CLD_STOPPED"
               "CLD_CONTINUED" "POLL_IN" "POLL_OUT" "POLL_MSG" "POLL_ERR"
               "POLL_PRI" "POLL_HUP" "SI_USER" "SI_QUEUE" "SI_TIMER"
               "SI_ASYNCIO" "SI_MESGQ"


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" "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)


WINSOCK

       (Windows only.)

       Constants
               "WSAEINTR" "WSAEBADF" "WSAEACCES" "WSAEFAULT" "WSAEINVAL"
               "WSAEMFILE" "WSAEWOULDBLOCK" "WSAEINPROGRESS" "WSAEALREADY"
               "WSAENOTSOCK" "WSAEDESTADDRREQ" "WSAEMSGSIZE" "WSAEPROTOTYPE"
               "WSAENOPROTOOPT" "WSAEPROTONOSUPPORT" "WSAESOCKTNOSUPPORT"
               "WSAEOPNOTSUPP" "WSAEPFNOSUPPORT" "WSAEAFNOSUPPORT"
               "WSAEADDRINUSE" "WSAEADDRNOTAVAIL" "WSAENETDOWN"
               "WSAENETUNREACH" "WSAENETRESET" "WSAECONNABORTED"
               "WSAECONNRESET" "WSAENOBUFS" "WSAEISCONN" "WSAENOTCONN"
               "WSAESHUTDOWN" "WSAETOOMANYREFS" "WSAETIMEDOUT"
               "WSAECONNREFUSED" "WSAELOOP" "WSAENAMETOOLONG" "WSAEHOSTDOWN"
               "WSAEHOSTUNREACH" "WSAENOTEMPTY" "WSAEPROCLIM" "WSAEUSERS"
               "WSAEDQUOT" "WSAESTALE" "WSAEREMOTE" "WSAEDISCON" "WSAENOMORE"
               "WSAECANCELLED" "WSAEINVALIDPROCTABLE" "WSAEINVALIDPROVIDER"
               "WSAEPROVIDERFAILEDINIT" "WSAEREFUSED"



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