POSIX 1003.1 identifiers. Many of these identifiers have been given Perl-ish
interfaces.
-I<Everything is exported by default> with the exception of any POSIX
-functions with the same name as a built-in Perl function, such as
-C<abs>, C<alarm>, C<rmdir>, C<write>, etc.., which will be exported
-only if you ask for them explicitly. This is an unfortunate backwards
-compatibility feature. You can stop the exporting by saying C<use
-POSIX ()> and then use the fully qualified names (ie. C<POSIX::SEEK_END>),
-or by giving an explicit import list. If you do neither, and opt for the
-default, C<use POSIX;> has to import I<553 symbols>.
-
This document gives a condensed list of the features available in the POSIX
module. Consult your operating system's manpages for general information on
most features. Consult L<perlfunc> for functions which are noted as being
-identical to Perl's builtin functions.
+identical or almost 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,
constants and macros in an organization which roughly follows IEEE Std
1003.1b-1993.
+The notation C<[C99]> indicates functions that were added in the ISO/IEC
+9899:1999 version of the C language standard. Some may not be available
+on your system if it adheres to an earlier standard. Attempts to use
+any missing one will result in a fatal runtime error message.
+
=head1 CAVEATS
+I<Everything is exported by default> (with a handful of exceptions).
+This is an unfortunate backwards compatibility feature and its use is
+B<strongly L<discouraged|perlpolicy/discouraged>>.
+You should either prevent the exporting (by saying S<C<use POSIX ();>>,
+as usual) and then use fully qualified names (e.g. C<POSIX::SEEK_END>),
+or give an explicit import list.
+If you do neither and opt for the default (as in S<C<use POSIX;>>), you
+will import I<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".
+aren't implemented, and suggest using the Perl equivalent, should one
+exist. For example, trying to access the C<setjmp()> call will elicit the
+message "C<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
+For example, one vendor may not define C<EDEADLK>, or the semantics of the
+errno values set by C<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
+that your vendor has been lax and there's no usable C<ICANON> macro after
all. This could be construed to be a bug.
=head1 FUNCTIONS
=over 8
-=item _exit
+=item C<_exit>
This is identical to the C function C<_exit()>. It exits the program
immediately which means among other things buffered I/O is B<not> flushed.
projects under way to have threads with more POSIXly semantics in Linux).
If you want not to return from a thread, detach the thread.
-=item abort
+=item C<abort>
This is identical to the C function C<abort()>. It terminates the
process with a C<SIGABRT> signal unless caught by a signal handler or
if the handler does not return normally (it e.g. does a C<longjmp>).
-=item abs
+=item C<abs>
+
+This is identical to Perl's builtin C<abs()> function, returning the absolute
+value of its numerical argument (except that C<POSIX::abs()> must be provided
+an explicit value (rather than relying on an implicit C<$_>):
-This is identical to Perl's builtin C<abs()> function, returning
-the absolute value of its numerical argument.
+ $absolute_value = POSIX::abs(42); # good
-=item access
+ $absolute_value = POSIX::abs(); # throws exception
+
+=item C<access>
Determines the accessibility of a file.
you are preparing for the permissions might change: a classic
I<race condition>.
-=item acos
+=item C<acos>
This is identical to the C function C<acos()>, returning
the arcus cosine of its numerical argument. See also L<Math::Trig>.
-=item alarm
+=item C<acosh>
+
+This is identical to the C function C<acosh()>, returning the
+hyperbolic arcus cosine of its numerical argument [C99]. See also
+L<Math::Trig>. Added in Perl v5.22.
+
+=item C<alarm>
+
+This is identical to Perl's builtin C<alarm()> function, either for arming or
+disarming the C<SIGARLM> timer, except that C<POSIX::alarm()> must be provided
+an explicit value (rather than relying on an implicit C<$_>):
-This is identical to Perl's builtin C<alarm()> function,
-either for arming or disarming the C<SIGARLM> timer.
+ POSIX::alarm(3) # good
-=item asctime
+ POSIX::alarm() # throws exception
+
+=item C<asctime>
This is identical to the C function C<asctime()>. It returns
a string of the form
and it is called thusly
- $asctime = asctime($sec, $min, $hour, $mday, $mon, $year,
- $wday, $yday, $isdst);
+ $asctime = asctime($sec, $min, $hour, $mday, $mon,
+ $year, $wday, $yday, $isdst);
The C<$mon> is zero-based: January equals C<0>. The C<$year> is
1900-based: 2001 equals C<101>. C<$wday> and C<$yday> default to zero
(and are usually ignored anyway), and C<$isdst> defaults to -1.
-=item asin
+Note the result is always in English. Use C<L</strftime>> instead to
+get a result suitable for the current locale. That function's C<%c>
+format yields the locale's preferred representation.
+
+=item C<asin>
This is identical to the C function C<asin()>, returning
the arcus sine of its numerical argument. See also L<Math::Trig>.
-=item assert
+=item C<asinh>
+
+This is identical to the C function C<asinh()>, returning the
+hyperbolic arcus sine of its numerical argument [C99]. See also
+L<Math::Trig>. Added in Perl v5.22.
+
+=item C<assert>
Unimplemented, but you can use L<perlfunc/die> and the L<Carp> module
to achieve similar things.
-=item atan
+=item C<atan>
This is identical to the C function C<atan()>, returning the
arcus tangent of its numerical argument. See also L<Math::Trig>.
-=item atan2
+=item C<atanh>
+
+This is identical to the C function C<atanh()>, returning the
+hyperbolic arcus tangent of its numerical argument [C99]. See also
+L<Math::Trig>. Added in Perl v5.22.
+
+=item C<atan2>
This is identical to Perl's builtin C<atan2()> function, returning
the arcus tangent defined by its two numerical arguments, the I<y>
coordinate and the I<x> coordinate. See also L<Math::Trig>.
-=item atexit
+=item C<atexit>
-atexit() is C-specific: use C<END {}> instead, see L<perlsub>.
+Not implemented. C<atexit()> is C-specific: use C<END {}> instead, see L<perlmod>.
-=item atof
+=item C<atof>
-atof() is C-specific. Perl converts strings to numbers transparently.
+Not implemented. C<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.
-=item atoi
+=item C<atoi>
-atoi() is C-specific. Perl converts strings to numbers transparently.
+Not implemented. C<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 L<perlfunc/int>.
-=item atol
+=item C<atol>
-atol() is C-specific. Perl converts strings to numbers transparently.
+Not implemented. C<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 L<perlfunc/int>.
-=item bsearch
+=item C<bsearch>
-bsearch() not supplied. For doing binary search on wordlists,
+C<bsearch()> not supplied. For doing binary search on wordlists,
see L<Search::Dict>.
-=item calloc
+=item C<calloc>
+
+Not implemented. C<calloc()> is C-specific. Perl does memory management transparently.
-calloc() is C-specific. Perl does memory management transparently.
+=item C<cbrt>
-=item ceil
+The cube root [C99]. Added in Perl v5.22.
+
+=item C<ceil>
This is identical to the C function C<ceil()>, returning the smallest
integer value greater than or equal to the given numerical argument.
-=item chdir
+=item C<chdir>
+
+This is identical to Perl's builtin C<chdir()> function, allowing one to
+change the working (default) directory -- see L<perlfunc/chdir> -- with the
+exception that C<POSIX::chdir()> must be provided an explicit value (rather
+than relying on an implicit C<$_>):
-This is identical to Perl's builtin C<chdir()> function, allowing
-one to change the working (default) directory, see L<perlfunc/chdir>.
+ $rv = POSIX::chdir('path/to/dir'); # good
-=item chmod
+ $rv = POSIX::chdir(); # throws exception
+
+=item C<chmod>
This is identical to Perl's builtin C<chmod()> function, allowing
-one to change file and directory permissions, see L<perlfunc/chmod>.
+one to change file and directory permissions -- see L<perlfunc/chmod> -- with
+the exception that C<POSIX::chmod()> can only change one file at a time
+(rather than a list of files):
+
+ $c = chmod 0664, $file1, $file2; # good
-=item chown
+ $c = POSIX::chmod 0664, $file1; # throws exception
+
+ $c = POSIX::chmod 0664, $file1, $file2; # throws exception
+
+As with the built-in C<chmod()>, C<$file> may be a filename or a file
+handle.
+
+=item C<chown>
This is identical to Perl's builtin C<chown()> function, allowing one
to change file and directory owners and groups, see L<perlfunc/chown>.
-=item clearerr
+=item C<clearerr>
-Use the method C<IO::Handle::clearerr()> instead, to reset the error
+Not implemented. Use the method C<IO::Handle::clearerr()> instead, to reset the error
state (if any) and EOF state (if any) of the given stream.
-=item clock
+=item C<clock>
This is identical to the C function C<clock()>, returning the
amount of spent processor time in microseconds.
-=item close
+=item C<close>
Close the file. This uses file descriptors such as those obtained by calling
C<POSIX::open>.
See also L<perlfunc/close>.
-=item closedir
+=item C<closedir>
This is identical to Perl's builtin C<closedir()> function for closing
a directory handle, see L<perlfunc/closedir>.
-=item cos
+=item C<cos>
This is identical to Perl's builtin C<cos()> function, for returning
the cosine of its numerical argument, see L<perlfunc/cos>.
See also L<Math::Trig>.
-=item cosh
+=item C<cosh>
This is identical to the C function C<cosh()>, for returning
the hyperbolic cosine of its numeric argument. See also L<Math::Trig>.
-=item creat
+=item C<copysign>
+
+Returns C<x> but with the sign of C<y> [C99]. Added in Perl v5.22.
+
+ $x_with_sign_of_y = POSIX::copysign($x, $y);
+
+See also L</signbit>.
+
+=item C<creat>
Create a new file. This returns a file descriptor like the ones returned by
C<POSIX::open>. Use C<POSIX::close> to close the file.
See also L<perlfunc/sysopen> and its C<O_CREAT> flag.
-=item ctermid
+=item C<ctermid>
Generates the path name for the controlling terminal.
$path = POSIX::ctermid();
-=item ctime
+=item C<ctime>
This is identical to the C function C<ctime()> and equivalent
to C<asctime(localtime(...))>, see L</asctime> and L</localtime>.
-=item cuserid
+=item C<cuserid> [POSIX.1-1988]
Get the login name of the owner of the current process.
$name = POSIX::cuserid();
-=item difftime
+Note: this function has not been specified by POSIX since 1990 and is included
+only for backwards compatibility. New code should use L<C<getlogin()>|perlfunc/getlogin> instead.
+
+=item C<difftime>
This is identical to the C function C<difftime()>, for returning
the time difference (in seconds) between two times (as returned
by C<time()>), see L</time>.
-=item div
+=item C<div>
-
div() is C-specific, use L<perlfunc/int> on the usual C</> division and
+
Not implemented. C<div()> is C-specific, use L<perlfunc/int> on the usual C</> division and
the modulus C<%>.
-=item dup
+=item C<dup>
This is similar to the C function C<dup()>, for duplicating a file
descriptor.
Returns C<undef> on failure.
-=item dup2
+=item C<dup2>
This is similar to the C function C<dup2()>, for duplicating a file
descriptor to an another known file descriptor.
Returns C<undef> on failure.
-=item errno
+=item C<erf>
+
+The error function [C99]. Added in Perl v5.22.
+
+=item C<erfc>
+
+The complementary error function [C99]. Added in Perl v5.22.
+
+=item C<errno>
Returns the value of errno.
This identical to the numerical values of the C<$!>, see L<perlvar/$ERRNO>.
-=item execl
+=item C<execl>
-
execl() is C-specific, see L<perlfunc/exec>.
+
Not implemented. C<execl()> is C-specific, see L<perlfunc/exec>.
-=item execle
+=item C<execle>
-
execle() is C-specific, see L<perlfunc/exec>.
+
Not implemented. C<execle()> is C-specific, see L<perlfunc/exec>.
-=item execlp
+=item C<execlp>
-
execlp() is C-specific, see L<perlfunc/exec>.
+
Not implemented. C<execlp()> is C-specific, see L<perlfunc/exec>.
-=item execv
+=item C<execv>
-
execv() is C-specific, see L<perlfunc/exec>.
+
Not implemented. C<execv()> is C-specific, see L<perlfunc/exec>.
-=item execve
+=item C<execve>
-
execve() is C-specific, see L<perlfunc/exec>.
+
Not implemented. C<execve()> is C-specific, see L<perlfunc/exec>.
-=item execvp
+=item C<execvp>
-
execvp() is C-specific, see L<perlfunc/exec>.
+
Not implemented. C<execvp()> is C-specific, see L<perlfunc/exec>.
-=item exit
+=item C<exit>
This is identical to Perl's builtin C<exit()> function for exiting the
program, see L<perlfunc/exit>.
-=item exp
+=item C<exp>
This is identical to Perl's builtin C<exp()> function for
returning the exponent (I<e>-based) of the numerical argument,
see L<perlfunc/exp>.
-=item fabs
+=item C<expm1>
+
+Equivalent to C<exp(x) - 1>, but more precise for small argument values [C99].
+Added in Perl v5.22.
+
+See also L</log1p>.
+
+=item C<fabs>
This is identical to Perl's builtin C<abs()> function for returning
the absolute value of the numerical argument, see L<perlfunc/abs>.
-=item fclose
+=item C<fclose>
-Use method C<IO::Handle::close()> instead, or see L<perlfunc/close>.
+
Not implemented. Use method C<IO::Handle::close()> instead, or see L<perlfunc/close>.
-=item fcntl
+=item C<fcntl>
This is identical to Perl's builtin C<fcntl()> function,
see L<perlfunc/fcntl>.
-=item fdopen
+=item C<fdopen>
-Use method C<IO::Handle::new_from_fd()> instead, or see L<perlfunc/open>.
+
Not implemented. Use method C<IO::Handle::new_from_fd()> instead, or see L<perlfunc/open>.
-=item feof
+=item C<feof>
-Use method C<IO::Handle::eof()> instead, or see L<perlfunc/eof>.
+
Not implemented. Use method C<IO::Handle::eof()> instead, or see L<perlfunc/eof>.
-=item ferror
+=item C<ferror>
-Use method C<IO::Handle::error()> instead.
+Not implemented. Use method C<IO::Handle::error()> instead.
-=item fflush
+=item C<fflush>
-Use method C<IO::Handle::flush()> instead.
-See also L<perlvar/$OUTPUT_AUTOFLUSH>.
+Not implemented. Use method C<IO::Handle::flush()> instead.
+See also C<L<perlvar/$OUTPUT_AUTOFLUSH>>.
-=item fgetc
+=item C<fgetc>
-Use method C<IO::Handle::getc()> instead, or see L<perlfunc/read>.
+
Not implemented. Use method C<IO::Handle::getc()> instead, or see L<perlfunc/read>.
-=item fgetpos
+=item C<fgetpos>
-Use method C<IO::Seekable::getpos()> instead, or see L<perlfunc/seek>.
+
Not implemented. Use method C<IO::Seekable::getpos()> instead, or see L<perlfunc/seek>.
-=item fgets
+=item C<fgets>
-Use method C<IO::Handle::gets()> instead. Similar to E<lt>E<gt>, also known
+Not implemented. Use method C<IO::Handle::gets()> instead. Similar to E<lt>E<gt>, also known
as L<perlfunc/readline>.
-=item fileno
+=item C<fileno>
-Use method C<IO::Handle::fileno()> instead, or see L<perlfunc/fileno>.
+
Not implemented. Use method C<IO::Handle::fileno()> instead, or see L<perlfunc/fileno>.
-=item floor
+=item C<floor>
This is identical to the C function C<floor()>, returning the largest
integer value less than or equal to the numerical argument.
-=item fmod
+=item C<fdim>
+
+"Positive difference", S<C<x - y>> if S<C<x E<gt> y>>, zero otherwise [C99].
+Added in Perl v5.22.
+
+=item C<fegetround>
+
+Returns the current floating point rounding mode, one of
+
+ FE_TONEAREST FE_TOWARDZERO FE_UPWARD FE_DOWNWARD
+
+C<FE_TONEAREST> is like L</round>, C<FE_TOWARDZERO> is like L</trunc> [C99].
+Added in Perl v5.22.
+
+=item C<fesetround>
+
+Sets the floating point rounding mode, see L</fegetround> [C99]. Added in
+Perl v5.22.
+
+=item C<fma>
+
+"Fused multiply-add", S<C<x * y + z>>, possibly faster (and less lossy)
+than the explicit two operations [C99]. Added in Perl v5.22.
+
+ my $fused = POSIX::fma($x, $y, $z);
+
+=item C<fmax>
+
+Maximum of C<x> and C<y>, except when either is C<NaN>, returns the other [C99].
+Added in Perl v5.22.
+
+ my $min = POSIX::fmax($x, $y);
+
+=item C<fmin>
+
+Minimum of C<x> and C<y>, except when either is C<NaN>, returns the other [C99].
+Added in Perl v5.22.
+
+ my $min = POSIX::fmin($x, $y);
+
+=item C<fmod>
This is identical to the C function C<fmod()>.
$r = fmod($x, $y);
-It returns the remainder C<$r = $x - $n*$y>, where C<$n = trunc($x/$y)>.
+It returns the remainder S<C<$r = $x - $n*$y>>, where S<C<$n = trunc($x/$y)>>.
The C<$r> has the same sign as C<$x> and magnitude (absolute value)
less than the magnitude of C<$y>.
-=item fopen
+=item C<fopen>
-Use method C<IO::File::open()> instead, or see L<perlfunc/open>.
+
Not implemented. Use method C<IO::File::open()> instead, or see L<perlfunc/open>.
-=item fork
+=item C<fork>
This is identical to Perl's builtin C<fork()> function
for duplicating the current process, see L<perlfunc/fork>
and L<perlfork> if you are in Windows.
-=item fpathconf
+=item C<fpathconf>
Retrieves the value of a configurable limit on a file or directory. This
uses file descriptors such as those obtained by calling C<POSIX::open>.
The following will determine the maximum length of the longest allowable
-pathname on the filesystem which holds C</var/foo>.
+pathname on the filesystem which holds F</var/foo>.
$fd = POSIX::open( "/var/foo", &POSIX::O_RDONLY );
- $path_max = POSIX::fpathconf( $fd, &POSIX::_PC_PATH_MAX );
+ $path_max = POSIX::fpathconf($fd, &POSIX::_PC_PATH_MAX);
Returns C<undef> on failure.
-=item fprintf
+=item C<fpclassify>
+
+Returns one of
+
+ FP_NORMAL FP_ZERO FP_SUBNORMAL FP_INFINITE FP_NAN
-fprintf() is C-specific, see L<perlfunc/printf> instead.
+telling the class of the argument [C99]. C<FP_INFINITE> is positive
+or negative infinity, C<FP_NAN> is not-a-number. C<FP_SUBNORMAL>
+means subnormal numbers (also known as denormals), very small numbers
+with low precision. C<FP_ZERO> is zero. C<FP_NORMAL> is all the rest.
+Added in Perl v5.22.
-=item fputc
+=item C<fprintf>
-fputc() is C-specific, see L<perlfunc/print> instead.
+Not implemented. C<fprintf()> is C-specific, see L<perlfunc/printf> instead.
-=item fputs
+=item C<fputc>
-
fputs() is C-specific, see L<perlfunc/print> instead.
+
Not implemented. C<fputc()> is C-specific, see L<perlfunc/print> instead.
-=item fread
+=item C<fputs>
-fread() is C-specific, see L<perlfunc/read> instead.
+Not implemented. C<fputs()> is C-specific, see L<perlfunc/print> instead.
-=item free
+=item C<fread>
-free() is C-specific. Perl does memory management transparently.
+Not implemented. C<fread()> is C-specific, see L<perlfunc/read> instead.
-=item freopen
+=item C<free>
-freopen() is C-specific, see L<perlfunc/open> instead.
+Not implemented. C<free()> is C-specific. Perl does memory management transparently.
-=item frexp
+=item C<freopen>
+
+Not implemented. C<freopen()> is C-specific, see L<perlfunc/open> instead.
+
+=item C<frexp>
Return the mantissa and exponent of a floating-point number.
($mantissa, $exponent) = POSIX::frexp( 1.234e56 );
-=item fscanf
+=item C<fscanf>
-fscanf() is C-specific, use E<lt>E<gt> and regular expressions instead.
+Not implemented. C<fscanf()> is C-specific, use E<lt>E<gt> and regular expressions instead.
-=item fseek
+=item C<fseek>
-Use method C<IO::Seekable::seek()> instead, or see L<perlfunc/seek>.
+
Not implemented. Use method C<IO::Seekable::seek()> instead, or see L<perlfunc/seek>.
-=item fsetpos
+=item C<fsetpos>
-Use method C<IO::Seekable::setpos()> instead, or seek L<perlfunc/seek>.
+
Not implemented. Use method C<IO::Seekable::setpos()> instead, or seek L<perlfunc/seek>.
-=item fstat
+=item C<fstat>
Get file status. This uses file descriptors such as those obtained by
calling C<POSIX::open>. The data returned is identical to the data from
$fd = POSIX::open( "foo", &POSIX::O_RDONLY );
@stats = POSIX::fstat( $fd );
-=item fsync
+=item C<fsync>
-Use method C<IO::Handle::sync()> instead.
+Not implemented. Use method C<IO::Handle::sync()> instead.
-=item ftell
+=item C<ftell>
-Use method C<IO::Seekable::tell()> instead, or see L<perlfunc/tell>.
+
Not implemented. Use method C<IO::Seekable::tell()> instead, or see L<perlfunc/tell>.
-=item fwrite
+=item C<fwrite>
-
fwrite() is C-specific, see L<perlfunc/print> instead.
+
Not implemented. C<fwrite()> is C-specific, see L<perlfunc/print> instead.
-=item getc
+=item C<getc>
This is identical to Perl's builtin C<getc()> function,
see L<perlfunc/getc>.
-=item getchar
+=item C<getchar>
Returns one character from STDIN. Identical to Perl's C<getc()>,
see L<perlfunc/getc>.
-=item getcwd
+=item C<getcwd>
Returns the name of the current working directory.
See also L<Cwd>.
-=item getegid
+=item C<getegid>
Returns the effective group identifier. Similar to Perl' s builtin
variable C<$(>, see L<perlvar/$EGID>.
-=item getenv
+=item C<getenv>
Returns the value of the specified environment variable.
The same information is available through the C<%ENV> array.
-=item geteuid
+=item C<geteuid>
Returns the effective user identifier. Identical to Perl's builtin C<$E<gt>>
variable, see L<perlvar/$EUID>.
-=item getgid
+=item C<getgid>
Returns the user's real group identifier. Similar to Perl's builtin
variable C<$)>, see L<perlvar/$GID>.
-=item getgrgid
+=item C<getgrgid>
This is identical to Perl's builtin C<getgrgid()> function for
returning group entries by group identifiers, see
L<perlfunc/getgrgid>.
-=item getgrnam
+=item C<getgrnam>
This is identical to Perl's builtin C<getgrnam()> function for
returning group entries by group names, see L<perlfunc/getgrnam>.
-=item getgroups
+=item C<getgroups>
Returns the ids of the user's supplementary groups. Similar to Perl's
builtin variable C<$)>, see L<perlvar/$GID>.
-=item getlogin
+=item C<getlogin>
This is identical to Perl's builtin C<getlogin()> function for
returning the user name associated with the current session, see
L<perlfunc/getlogin>.
-=item getpgrp
+=item C<getpayload>
+
+ use POSIX ':nan_payload';
+ getpayload($var)
+
+Returns the C<NaN> payload. Added in Perl v5.24.
+
+Note the API instability warning in L</setpayload>.
+
+See L</nan> for more discussion about C<NaN>.
+
+=item C<getpgrp>
This is identical to Perl's builtin C<getpgrp()> function for
returning the process group identifier of the current process, see
L<perlfunc/getpgrp>.
-=item getpid
+=item C<getpid>
Returns the process identifier. Identical to Perl's builtin
variable C<$$>, see L<perlvar/$PID>.
-=item getppid
+=item C<getppid>
This is identical to Perl's builtin C<getppid()> function for
returning the process identifier of the parent process of the current
process , see L<perlfunc/getppid>.
-=item getpwnam
+=item C<getpwnam>
This is identical to Perl's builtin C<getpwnam()> function for
returning user entries by user names, see L<perlfunc/getpwnam>.
-=item getpwuid
+=item C<getpwuid>
This is identical to Perl's builtin C<getpwuid()> function for
returning user entries by user identifiers, see L<perlfunc/getpwuid>.
-=item gets
+=item C<gets>
Returns one line from C<STDIN>, similar to E<lt>E<gt>, also known
as the C<readline()> function, see L<perlfunc/readline>.
it has no buffer overrun checks. It should B<never> be used. The
C<fgets()> function should be preferred instead.
-=item getuid
+=item C<getuid>
Returns the user's identifier. Identical to Perl's builtin C<$E<lt>> variable,
see L<perlvar/$UID>.
-=item gmtime
+=item C<gmtime>
This is identical to Perl's builtin C<gmtime()> function for
converting seconds since the epoch to a date in Greenwich Mean Time,
see L<perlfunc/gmtime>.
-=item isalnum
+=item C<hypot>
-This is identical to the C function, except that it can apply to a
-single character or to a whole string. Note that locale settings may
-affect what characters are considered C<isalnum>. Does not work on
-Unicode characters code point 256 or higher. Consider using regular
-expressions and the C</[[:alnum:]]/> construct instead, or possibly
-the C</\w/> construct.
+Equivalent to C<S<sqrt(x * x + y * y)>> except more stable on very large
+or very small arguments [C99]. Added in Perl v5.22.
-=item isalpha
+=item C<ilogb>
-This is identical to the C function, except that it can apply to
-a single character or to a whole string. Note that locale settings
-may affect what characters are considered C<isalpha>. Does not work
-on Unicode characters code point 256 or higher. Consider using regular
-expressions and the C</[[:alpha:]]/> construct instead.
+Integer binary logarithm [C99]. Added in Perl v5.22.
-=item isatty
+For example C<ilogb(20)> is 4, as an integer.
+
+See also L</logb>.
+
+=item C<Inf>
+
+The infinity as a constant:
+
+ use POSIX qw(Inf);
+ my $pos_inf = +Inf; # Or just Inf.
+ my $neg_inf = -Inf;
+
+See also L</isinf>, and L</fpclassify>.
+
+=item C<isalnum>
+
+This function has been removed as of Perl v5.24. It was very similar to
+matching against S<C<qr/ ^ [[:alnum:]]+ $ /x>>, which you should convert
+to use instead. See L<perlrecharclass/POSIX Character Classes>.
+
+=item C<isalpha>
+
+This function has been removed as of Perl v5.24. It was very similar to
+matching against S<C<qr/ ^ [[:alpha:]]+ $ /x>>, which you should convert
+to use instead. See L<perlrecharclass/POSIX Character Classes>.
+
+=item C<isatty>
Returns a boolean indicating whether the specified filehandle is connected
to a tty. Similar to the C<-t> operator, see L<perlfunc/-X>.
-=item iscntrl
+=item C<iscntrl>
-This is identical to the C function, except that it can apply to
-a single character or to a whole string. Note that locale settings
-may affect what characters are considered C<iscntrl>. Does not work
-on Unicode characters code point 256 or higher. Consider using regular
-expressions and the C</[[:cntrl:]]/> construct instead.
+This function has been removed as of Perl v5.24. It was very similar to
+matching against S<C<qr/ ^ [[:cntrl:]]+ $ /x>>, which you should convert
+to use instead. See L<perlrecharclass/POSIX Character Classes>.
-=item isdigit
+=item C<isdigit>
-This is identical to the C function, except that it can apply to
-a single character or to a whole string. Note that locale settings
-may affect what characters are considered C<isdigit> (unlikely, but
-still possible). Does not work on Unicode characters code point 256
-or higher. Consider using regular expressions and the C</[[:digit:]]/>
-construct instead, or the C</\d/> construct.
+This function has been removed as of Perl v5.24. It was very similar to
+matching against S<C<qr/ ^ [[:digit:]]+ $ /x>>, which you should convert
+to use instead. See L<perlrecharclass/POSIX Character Classes>.
-=item isgraph
+=item C<isfinite>
-This is identical to the C function, except that it can apply to
-a single character or to a whole string. Note that locale settings
-may affect what characters are considered C<isgraph>. Does not work
-on Unicode characters code point 256 or higher. Consider using regular
-expressions and the C</[[:graph:]]/> construct instead.
+Returns true if the argument is a finite number (that is, not an
+infinity, or the not-a-number) [C99]. Added in Perl v5.22.
-=item islower
+See also L</isinf>, L</isnan>, and L</fpclassify>.
-This is identical to the C function, except that it can apply to
-a single character or to a whole string. Note that locale settings
-may affect what characters are considered C<islower>. Does not work
-on Unicode characters code point 256 or higher. Consider using regular
-expressions and the C</[[:lower:]]/> construct instead. Do B<not> use
-C</[a-z]/>.
+=item C<isgraph>
-=item isprint
+This function has been removed as of Perl v5.24. It was very similar to
+matching against S<C<qr/ ^ [[:graph:]]+ $ /x>>, which you should convert
+to use instead. See L<perlrecharclass/POSIX Character Classes>.
-This is identical to the C function, except that it can apply to
-a single character or to a whole string. Note that locale settings
-may affect what characters are considered C<isprint>. Does not work
-on Unicode characters code point 256 or higher. Consider using regular
-expressions and the C</[[:print:]]/> construct instead.
+=item C<isgreater>
-=item ispunct
+(Also C<isgreaterequal>, C<isless>, C<islessequal>, C<islessgreater>,
+C<isunordered>)
-This is identical to the C function, except that it can apply to
-a single character or to a whole string. Note that locale settings
-may affect what characters are considered C<ispunct>. Does not work
-on Unicode characters code point 256 or higher. Consider using regular
-expressions and the C</[[:punct:]]/> construct instead.
+Floating point comparisons which handle the C<NaN> [C99]. Added in Perl
+v5.22.
-=item isspace
+=item C<isinf>
-This is identical to the C function, except that it can apply to
-a single character or to a whole string. Note that locale settings
-may affect what characters are considered C<isspace>. Does not work
-on Unicode characters code point 256 or higher. Consider using regular
-expressions and the C</[[:space:]]/> construct instead, or the C</\s/>
-construct. (Note that C</\s/> and C</[[:space:]]/> are slightly
-different in that C</[[:space:]]/> can normally match a vertical tab,
-while C</\s/> does not.)
+Returns true if the argument is an infinity (positive or negative) [C99].
+Added in Perl v5.22.
-=item isupper
+See also L</Inf>, L</isnan>, L</isfinite>, and L</fpclassify>.
-This is identical to the C function, except that it can apply to
-a single character or to a whole string. Note that locale settings
-may affect what characters are considered C<isupper>. Does not work
-on Unicode characters code point 256 or higher. Consider using regular
-expressions and the C</[[:upper:]]/> construct instead. Do B<not> use
-C</[A-Z]/>.
+=item C<islower>
-=item isxdigit
+This function has been removed as of Perl v5.24. It was very similar to
+matching against S<C<qr/ ^ [[:lower:]]+ $ /x>>, which you should convert
+to use instead. See L<perlrecharclass/POSIX Character Classes>.
-This is identical to the C function, except that it can apply to a single
-character or to a whole string. Note that locale settings may affect what
-characters are considered C<isxdigit> (unlikely, but still possible).
-Does not work on Unicode characters code point 256 or higher.
-Consider using regular expressions and the C</[[:xdigit:]]/>
-construct instead, or simply C</[0-9a-f]/i>.
+=item C<isnan>
+
+Returns true if the argument is C<NaN> (not-a-number) [C99]. Added in
+Perl v5.22.
+
+Note that you cannot test for "C<NaN>-ness" with
+
+ $x == $x
+
+since the C<NaN> is not equivalent to anything, B<including itself>.
+
+See also L</nan>, L</NaN>, L</isinf>, and L</fpclassify>.
+
+=item C<isnormal>
+
+Returns true if the argument is normal (that is, not a subnormal/denormal,
+and not an infinity, or a not-a-number) [C99]. Added in Perl v5.22.
+
+See also L</isfinite>, and L</fpclassify>.
+
+=item C<isprint>
+
+This function has been removed as of Perl v5.24. It was very similar to
+matching against S<C<qr/ ^ [[:print:]]+ $ /x>>, which you should convert
+to use instead. See L<perlrecharclass/POSIX Character Classes>.
+
+=item C<ispunct>
+
+This function has been removed as of Perl v5.24. It was very similar to
+matching against S<C<qr/ ^ [[:punct:]]+ $ /x>>, which you should convert
+to use instead. See L<perlrecharclass/POSIX Character Classes>.
+
+=item C<issignaling>
+
+ use POSIX ':nan_payload';
+ issignaling($var, $payload)
+
+Return true if the argument is a I<signaling> NaN. Added in Perl v5.24.
+
+Note the API instability warning in L</setpayload>.
+
+See L</nan> for more discussion about C<NaN>.
+
+=item C<isspace>
+
+This function has been removed as of Perl v5.24. It was very similar to
+matching against S<C<qr/ ^ [[:space:]]+ $ /x>>, which you should convert
+to use instead. See L<perlrecharclass/POSIX Character Classes>.
-=item kill
+=item C<isupper>
+
+This function has been removed as of Perl v5.24. It was very similar to
+matching against S<C<qr/ ^ [[:upper:]]+ $ /x>>, which you should convert
+to use instead. See L<perlrecharclass/POSIX Character Classes>.
+
+=item C<isxdigit>
+
+This function has been removed as of Perl v5.24. It was very similar to
+matching against S<C<qr/ ^ [[:xdigit:]]+ $ /x>>, which you should
+convert to use instead. See L<perlrecharclass/POSIX Character Classes>.
+
+=item C<j0>
+
+=item C<j1>
+
+=item C<jn>
+
+=item C<y0>
+
+=item C<y1>
+
+=item C<yn>
+
+The Bessel function of the first kind of the order zero.
+
+=item C<kill>
This is identical to Perl's builtin C<kill()> function for sending
signals to processes (often to terminate them), see L<perlfunc/kill>.
-=item labs
+=item C<labs>
-(For returning absolute values of long integers.)
-
labs() is C-specific, see L<perlfunc/abs> instead.
+Not implemented. (For returning absolute values of long integers.)
+
C<labs()> is C-specific, see L<perlfunc/abs> instead.
-=item lchown
+=item C<lchown>
This is identical to the C function, except the order of arguments is
consistent with Perl's builtin C<chown()> with the added restriction
-of only one path, not an list of paths. Does the same thing as the
-C<chown()> function but changes the owner of a symbolic link instead
+of only one path, not a list of paths. Does the same thing as the
+C<chown()> function but changes the owner of a symbolic link instead
of the file the symbolic link points to.
-=item ldexp
+ POSIX::lchown($uid, $gid, $file_path);
+
+=item C<ldexp>
This is identical to the C function C<ldexp()>
for multiplying floating point numbers with powers of two.
$x_quadrupled = POSIX::ldexp($x, 2);
-=item ldiv
+=item C<ldiv>
+
+Not implemented. (For computing dividends of long integers.)
+C<ldiv()> is C-specific, use C</> and C<int()> instead.
+
+=item C<lgamma>
+
+The logarithm of the Gamma function [C99]. Added in Perl v5.22.
-(For computing dividends of long integers.)
-ldiv() is C-specific, use C</> and C<int()> instead.
+See also L</tgamma>.
-=item link
+=item C<log1p>
+
+Equivalent to S<C<log(1 + x)>>, but more stable results for small argument
+values [C99]. Added in Perl v5.22.
+
+=item C<log2>
+
+Logarithm base two [C99]. Added in Perl v5.22.
+
+See also L</expm1>.
+
+=item C<logb>
+
+Integer binary logarithm [C99]. Added in Perl v5.22.
+
+For example C<logb(20)> is 4, as a floating point number.
+
+See also L</ilogb>.
+
+=item C<link>
This is identical to Perl's builtin C<link()> function
for creating hard links into files, see L<perlfunc/link>.
-=item localeconv
+=item C<localeconv>
Get numeric formatting information. Returns a reference to a hash
-containing the current locale formatting values.
+containing the formatting values of the locale that currently underlies
+the program, regardless of whether or not it is called from within the
+scope of a S<C<use locale>>. Users of this function should also read
+L<perllocale>, which provides a comprehensive discussion of Perl locale
+handling, including
+L<a section devoted to this function|perllocale/The localeconv function>.
+Prior to Perl 5.28, or when operating in a non thread-safe environment,
+it should not be used in a threaded application unless it's certain that
+the underlying locale is C or POSIX. This is because it otherwise
+changes the locale, which globally affects all threads simultaneously.
+Windows platforms starting with Visual Studio 2005 are mostly
+thread-safe, but use of this function in those prior to Visual Studio
+2015 can interfere with a thread that has called
+L<perlapi/switch_to_global_locale>.
Here is how to query the database for the B<de> (Deutsch or German) locale.
- $loc = POSIX::setlocale( &POSIX::LC_ALL, "de" );
- print "Locale = $loc\n";
- $lconv = POSIX::localeconv();
- print "decimal_point = ", $lconv->{decimal_point}, "\n";
- print "thousands_sep = ", $lconv->{thousands_sep}, "\n";
- print "grouping = ", $lconv->{grouping}, "\n";
- print "int_curr_symbol = ", $lconv->{int_curr_symbol}, "\n";
- print "currency_symbol = ", $lconv->{currency_symbol}, "\n";
- print "mon_decimal_point = ", $lconv->{mon_decimal_point}, "\n";
- print "mon_thousands_sep = ", $lconv->{mon_thousands_sep}, "\n";
- print "mon_grouping = ", $lconv->{mon_grouping}, "\n";
- print "positive_sign = ", $lconv->{positive_sign}, "\n";
- print "negative_sign = ", $lconv->{negative_sign}, "\n";
- print "int_frac_digits = ", $lconv->{int_frac_digits}, "\n";
- print "frac_digits = ", $lconv->{frac_digits}, "\n";
- print "p_cs_precedes = ", $lconv->{p_cs_precedes}, "\n";
- print "p_sep_by_space = ", $lconv->{p_sep_by_space}, "\n";
- print "n_cs_precedes = ", $lconv->{n_cs_precedes}, "\n";
- print "n_sep_by_space = ", $lconv->{n_sep_by_space}, "\n";
- print "p_sign_posn = ", $lconv->{p_sign_posn}, "\n";
- print "n_sign_posn = ", $lconv->{n_sign_posn}, "\n";
-
-=item localtime
+ 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 C<int_p_> and C<int_n_> were added by
+POSIX.1-2008 and are only available on systems that support them.
+
+=item C<localtime>
This is identical to Perl's builtin C<localtime()> function for
-converting seconds since the epoch to a date see L<perlfunc/localtime>.
+converting seconds since the epoch to a date see L<perlfunc/localtime> except
+that C<POSIX::localtime()> must be provided an explicit value (rather than
+relying on an implicit C<$_>):
+
+ @localtime = POSIX::localtime(time); # good
+
+ @localtime = localtime(); # good
+
+ @localtime = POSIX::localtime(); # throws exception
-=item log
+=item C<log>
This is identical to Perl's builtin C<log()> function,
returning the natural (I<e>-based) logarithm of the numerical argument,
see L<perlfunc/log>.
-=item log10
+=item C<log10>
This is identical to the C function C<log10()>,
returning the 10-base logarithm of the numerical argument.
sub log10 { log($_[0]) * 0.434294481903252 }
-=item longjmp
+=item C<longjmp>
-
longjmp() is C-specific: use L<perlfunc/die> instead.
+
Not implemented. C<longjmp()> is C-specific: use L<perlfunc/die> instead.
-=item lseek
+=item C<lseek>
Move the file's read/write position. This uses file descriptors such as
those obtained by calling C<POSIX::open>.
Returns C<undef> on failure.
-=item malloc
+=item C<lrint>
-malloc() is C-specific. Perl does memory management transparently.
+Depending on the current floating point rounding mode, rounds the
+argument either toward nearest (like L</round>), toward zero (like
+L</trunc>), downward (toward negative infinity), or upward (toward
+positive infinity) [C99]. Added in Perl v5.22.
-=item mblen
+For the rounding mode, see L</fegetround>.
-This is identical to the C function C<mblen()>.
-Perl does not have any support for the wide and multibyte
-characters of the C standards, so this might be a rather
-useless function.
+=item C<lround>
-=item mbstowcs
+Like L</round>, but as integer, as opposed to floating point [C99]. Added
+in Perl v5.22.
-This is identical to the C function C<mbstowcs()>.
-Perl does not have any support for the wide and multibyte
-characters of the C standards, so this might be a rather
-useless function.
+See also L</ceil>, L</floor>, L</trunc>.
-=item mbtowc
+Owing to an oversight, this is not currently exported by default, or as part of
+the C<:math_h_c99> export tag; importing it must therefore be done by explicit
+name.
-This is identical to the C function C<mbtowc()>.
-Perl does not have any support for the wide and multibyte
-characters of the C standards, so this might be a rather
-useless function.
+=item C<malloc>
-=item memchr
+Not implemented. C<malloc()> is C-specific. Perl does memory management transparently.
-memchr() is C-specific, see L<perlfunc/index> instead.
+=item C<mblen>
-=item memcmp
+This is the same as the C function C<mblen()> on unthreaded perls. On
+threaded perls, it transparently (almost) substitutes the more
+thread-safe L<C<mbrlen>(3)>, if available, instead of C<mblen>.
-memcmp() is C-specific, use C<eq> instead, see L<perlop>.
+Core Perl does not have any support for wide and multibyte locales,
+except Unicode UTF-8 locales. This function, in conjunction with
+L</mbtowc> and L</wctomb> may be used to roll your own decoding/encoding
+of other types of multi-byte locales.
-=item memcpy
+Use C<undef> as the first parameter to this function to get the effect
+of passing NULL as the first parameter to C<mblen>. This resets any
+shift state to its initial value. The return value is undefined if
+C<mbrlen> was substituted, so you should never rely on it.
-memcpy() is C-specific, use C<=>, see L<perlop>, or see L<perlfunc/substr>.
+When the first parameter is a scalar containing a value that either is a
+PV string or can be forced into one, the return value is the number of
+bytes occupied by the first character of that string; or 0 if that first
+character is the wide NUL character; or negative if there is an error.
+This is based on the locale that currently underlies the program,
+regardless of whether or not the function is called from Perl code that
+is within the scope of S<C<use locale>>. Perl makes no attempt at
+hiding from your code any differences in the C<errno> setting between
+C<mblen> and C<mbrlen>. It does set C<errno> to 0 before calling them.
-=item memmove
+The optional second parameter is ignored if it is larger than the
+actual length of the first parameter string.
-memmove() is C-specific, use C<=>, see L<perlop>, or see L<perlfunc/substr>.
+=item C<mbtowc>
-=item memset
+This is the same as the C function C<mbtowc()> on unthreaded perls. On
+threaded perls, it transparently (almost) substitutes the more
+thread-safe L<C<mbrtowc>(3)>, if available, instead of C<mbtowc>.
-memset() is C-specific, use C<x> instead, see L<perlop>.
+Core Perl does not have any support for wide and multibyte locales,
+except Unicode UTF-8 locales. This function, in conjunction with
+L</mblen> and L</wctomb> may be used to roll your own decoding/encoding
+of other types of multi-byte locales.
-=item mkdir
+The first parameter is a scalar into which, upon success, the wide
+character represented by the multi-byte string contained in the second
+parameter is stored. The optional third parameter is ignored if it is
+larger than the actual length of the second parameter string.
+
+Use C<undef> as the second parameter to this function to get the effect
+of passing NULL as the second parameter to C<mbtowc>. This resets any
+shift state to its initial value. The return value is undefined if
+C<mbrtowc> was substituted, so you should never rely on it.
+
+When the second parameter is a scalar containing a value that either is
+a PV string or can be forced into one, the return value is the number of
+bytes occupied by the first character of that string; or 0 if that first
+character is the wide NUL character; or negative if there is an error.
+This is based on the locale that currently underlies the program,
+regardless of whether or not the function is called from Perl code that
+is within the scope of S<C<use locale>>. Perl makes no attempt at
+hiding from your code any differences in the C<errno> setting between
+C<mbtowc> and C<mbrtowc>. It does set C<errno> to 0 before calling
+them.
+
+=item C<memchr>
+
+Not implemented. C<memchr()> is C-specific, see L<perlfunc/index> instead.
+
+=item C<memcmp>
+
+Not implemented. C<memcmp()> is C-specific, use C<eq> instead, see L<perlop>.
+
+=item C<memcpy>
+
+Not implemented. C<memcpy()> is C-specific, use C<=>, see L<perlop>, or see L<perlfunc/substr>.
+
+=item C<memmove>
+
+Not implemented. C<memmove()> is C-specific, use C<=>, see L<perlop>, or see L<perlfunc/substr>.
+
+=item C<memset>
+
+Not implemented. C<memset()> is C-specific, use C<x> instead, see L<perlop>.
+
+=item C<mkdir>
This is identical to Perl's builtin C<mkdir()> function
for creating directories, see L<perlfunc/mkdir>.
-=item mkfifo
+=item C<mkfifo>
This is similar to the C function C<mkfifo()> for creating
FIFO special files.
mode of C<mkdir()>, see L<perlfunc/mkdir>, though for C<mkfifo>
you B<must> specify the C<$mode>.
-=item mktime
+=item C<mktime>
Convert date/time info to a calendar time.
Synopsis:
- mktime(sec, min, hour, mday, mon, year, wday = 0, yday = 0, isdst = -1)
+ mktime(sec, min, hour, mday, mon, year, wday = 0,
+ yday = 0, isdst = -1)
-The month (C<mon>), weekday (C<wday>), and yearday (C<yday>) begin at zero.
-I.e. January is 0, not 1; Sunday is 0, not 1; January 1st is 0, not 1. The
-year (C<year>) is given in years since 1900. I.e. The year 1995 is 95; the
+The month (C<mon>), weekday (C<wday>), and yearday (C<yday>) begin at zero,
+I<i.e.>, January is 0, not 1; Sunday is 0, not 1; January 1st is 0, not 1. The
+year (C<year>) is given in years since 1900; I<i.e.>, the year 1995 is 95; the
year 2001 is 101. Consult your system's C<mktime()> manpage for details
about these and the other arguments.
Returns C<undef> on failure.
-=item modf
+=item C<modf>
Return the integral and fractional parts of a floating-point number.
($fractional, $integral) = POSIX::modf( 3.14 );
-=item nice
+See also L</round>.
+
+=item C<NaN>
+
+The not-a-number as a constant:
+
+ use POSIX qw(NaN);
+ my $nan = NaN;
+
+See also L</nan>, C</isnan>, and L</fpclassify>.
+
+=item C<nan>
+
+ my $nan = nan();
+
+Returns C<NaN>, not-a-number [C99]. Added in Perl v5.22.
+
+The returned NaN is always a I<quiet> NaN, as opposed to I<signaling>.
+
+With an argument, can be used to generate a NaN with I<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 L</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 C<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 L</isnan>, L</NaN>, L</setpayload> and L</issignaling>.
+
+=item C<nearbyint>
+
+Returns the nearest integer to the argument, according to the current
+rounding mode (see L</fegetround>) [C99]. Added in Perl v5.22.
+
+=item C<nextafter>
+
+Returns the next representable floating point number after C<x> in the
+direction of C<y> [C99]. Added in Perl v5.22.
+
+ my $nextafter = POSIX::nextafter($x, $y);
+
+Like L</nexttoward>, but potentially less accurate.
+
+=item C<nexttoward>
+
+Returns the next representable floating point number after C<x> in the
+direction of C<y> [C99]. Added in Perl v5.22.
+
+ my $nexttoward = POSIX::nexttoward($x, $y);
+
+Like L</nextafter>, but potentially more accurate.
+
+=item C<nice>
This is similar to the C function C<nice()>, for changing
the scheduling preference of the current process. Positive
-arguments mean more polite process, negative values more
-needy process. Normal user processes can only be more polite.
+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 C<undef> on failure.
-=item offsetof
+=item C<offsetof>
-
offsetof() is C-specific, you probably want to see L<perlfunc/pack> instead.
+
Not implemented. C<offsetof()> is C-specific, you probably want to see L<perlfunc/pack> instead.
-=item open
+=item C<open>
Open a file for reading for writing. This returns file descriptors, not
Perl filehandles. Use C<POSIX::close> to close the file.
Open a file for write, with truncation.
- $fd = POSIX::open( "foo", &POSIX::O_WRONLY | &POSIX::O_TRUNC );
+ $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 );
+ $fd = POSIX::open(
+ "foo", &POSIX::O_CREAT | &POSIX::O_WRONLY, 0640
+ );
Returns C<undef> on failure.
See also L<perlfunc/sysopen>.
-=item opendir
+=item C<opendir>
Open a directory for reading.
Returns C<undef> on failure.
-=item pathconf
+=item C<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 C</var>.
- $path_max = POSIX::pathconf( "/var", &POSIX::_PC_PATH_MAX );
+ $path_max = POSIX::pathconf( "/var",
+ &POSIX::_PC_PATH_MAX );
Returns C<undef> on failure.
-=item pause
+=item C<pause>
This is similar to the C function C<pause()>, which suspends
the execution of the current process until a signal is received.
Returns C<undef> on failure.
-=item perror
+=item C<perror>
This is identical to the C function C<perror()>, which outputs to the
-standard error stream the specified message followed by ": " and the
+standard error stream the specified message followed by C<": "> and the
current error string. Use the C<warn()> function and the C<$!>
variable instead, see L<perlfunc/warn> and L<perlvar/$ERRNO>.
-=item pipe
+=item C<pipe>
Create an interprocess channel. This returns file descriptors like those
returned by C<POSIX::open>.
See also L<perlfunc/pipe>.
-=item pow
+=item C<pow>
Computes C<$x> raised to the power C<$exponent>.
You can also use the C<**> operator, see L<perlop>.
-=item printf
+=item C<printf>
-Formats and prints the specified arguments to STDOUT.
+Formats and prints the specified arguments to C<STDOUT>.
See also L<perlfunc/printf>.
-=item putc
+=item C<putc>
-
putc() is C-specific, see L<perlfunc/print> instead.
+
Not implemented. C<putc()> is C-specific, see L<perlfunc/print> instead.
-=item putchar
+=item C<putchar>
-
putchar() is C-specific, see L<perlfunc/print> instead.
+
Not implemented. C<putchar()> is C-specific, see L<perlfunc/print> instead.
-=item puts
+=item C<puts>
-
puts() is C-specific, see L<perlfunc/print> instead.
+
Not implemented. C<puts()> is C-specific, see L<perlfunc/print> instead.
-=item qsort
+=item C<qsort>
-
qsort() is C-specific, see L<perlfunc/sort> instead.
+
Not implemented. C<qsort()> is C-specific, see L<perlfunc/sort> instead.
-=item raise
+=item C<raise>
Sends the specified signal to the current process.
See also L<perlfunc/kill> and the C<$$> in L<perlvar/$PID>.
-=item rand
+=item C<rand>
-C<rand()> is non-portable, see L<perlfunc/rand> instead.
+
Not implemented. C<rand()> is non-portable, see L<perlfunc/rand> instead.
-=item read
+=item C<read>
Read from a file. This uses file descriptors such as those obtained by
calling C<POSIX::open>. If the buffer C<$buf> is not large enough for the
See also L<perlfunc/sysread>.
-=item readdir
+=item C<readdir>
This is identical to Perl's builtin C<readdir()> function
for reading directory entries, see L<perlfunc/readdir>.
-=item realloc
+=item C<realloc>
-realloc() is C-specific. Perl does memory management transparently.
+Not implemented. C<realloc()> is C-specific. Perl does memory management transparently.
-=item remove
+=item C<remainder>
-This is identical to Perl's builtin C<unlink()> function
-for removing files, see L<perlfunc/unlink>.
+Given C<x> and C<y>, returns the value S<C<x - n*y>>, where C<n> is the integer
+closest to C<x>/C<y> [C99]. Added in Perl v5.22.
+
+ my $remainder = POSIX::remainder($x, $y)
+
+See also L</remquo>.
+
+=item C<remove>
+
+Deletes a name from the filesystem. Calls L<perlfunc/unlink> for
+files and L<perlfunc/rmdir> for directories.
+
+=item C<remquo>
+
+Like L</remainder> but also returns the low-order bits of the quotient (n)
+[C99]. Added in Perl v5.22.
-=item rename
+(This is quite esoteric interface, mainly used to implement numerical
+algorithms.)
+
+=item C<rename>
This is identical to Perl's builtin C<rename()> function
for renaming files, see L<perlfunc/rename>.
-=item rewind
+=item C<rewind>
Seeks to the beginning of the file.
-=item rewinddir
+=item C<rewinddir>
This is identical to Perl's builtin C<rewinddir()> function for
rewinding directory entry streams, see L<perlfunc/rewinddir>.
-=item rmdir
+=item C<rint>
+
+Identical to L</lrint>.
+
+=item C<rmdir>
This is identical to Perl's builtin C<rmdir()> function
for removing (empty) directories, see L<perlfunc/rmdir>.
-=item scanf
+=item C<round>
+
+Returns the integer (but still as floating point) nearest to the
+argument [C99]. Added in Perl v5.22.
+
+See also L</ceil>, L</floor>, L</lround>, L</modf>, and L</trunc>.
+
+=item C<scalbn>
+
+Returns S<C<x * 2**y>> [C99]. Added in Perl v5.22.
+
+See also L</frexp> and L</ldexp>.
-scanf() is C-specific, use E<lt>E<gt> and regular expressions instead,
+=item C<scanf>
+
+Not implemented. C<scanf()> is C-specific, use E<lt>E<gt> and regular expressions instead,
see L<perlre>.
-=item setgid
+=item C<setgid>
Sets the real group identifier and the effective group identifier for
this process. Similar to assigning a value to the Perl's builtin
uses only a single numeric argument, as opposed to a space-separated
list of numbers.
-=item setjmp
+=item C<setjmp>
-C<setjmp()> is C-specific: use C<eval {}> instead,
+Not implemented. C<setjmp()> is C-specific: use C<eval {}> instead,
see L<perlfunc/eval>.
-=item setlocale
-
-Modifies and queries program's locale. The following examples assume
+=item C<setlocale>
+
+WARNING! Prior to Perl 5.28 or on a system that does not support
+thread-safe locale operations, do NOT use this function in a
+L<thread|threads>. 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. This warning
+does not apply on unthreaded builds, or on perls where
+C<${^SAFE_LOCALES}> exists and is non-zero; namely Perl 5.28 and later
+compiled to be locale-thread-safe.
+
+This function
+modifies and queries the program's underlying locale. Users of this
+function should read L<perllocale>, whch provides a comprehensive
+discussion of Perl locale handling, knowledge of which is necessary to
+properly use this function. It contains
+L<a section devoted to this function|perllocale/The setlocale function>.
+The discussion here is merely a summary reference for C<setlocale()>.
+Note that Perl itself is almost entirely unaffected by the locale
+except within the scope of S<C<"use locale">>. (Exceptions are listed
+in L<perllocale/Not within the scope of "use locale">, and
+locale-dependent functions within the POSIX module ARE always affected
+by the current locale.)
+
+The following examples assume
use POSIX qw(setlocale LC_ALL LC_CTYPE);
$loc = setlocale( LC_ALL, "C" );
-The following will query the current LC_CTYPE category. (No second
+The following will query the current C<LC_CTYPE> category. (No second
argument means 'query'.)
$loc = setlocale( LC_CTYPE );
-The following will set the LC_CTYPE behaviour according to the locale
+The following will set the C<LC_CTYPE> behaviour according to the locale
environment variables (the second argument C<"">).
-Please see your systems C<setlocale(3)> documentation for the locale
+Please see your system's C<setlocale(3)> documentation for the locale
environment variables' meaning or consult L<perllocale>.
$loc = setlocale( LC_CTYPE, "" );
-The following will set the LC_COLLATE behaviour to Argentinian
+The following will set the C<LC_COLLATE> behaviour to Argentinian
Spanish. B<NOTE>: The naming and availability of locales depends on
your operating system. Please consult L<perllocale> for how to find
out which locales are available in your system.
$loc = setlocale( LC_COLLATE, "es_AR.ISO8859-1" );
-=item setpgid
+=item C<setpayload>
+
+ use POSIX ':nan_payload';
+ setpayload($var, $payload);
+
+Sets the C<NaN> payload of var. Added in Perl v5.24.
+
+NOTE: the NaN payload APIs are based on the latest (as of June 2015)
+proposed ISO C interfaces, but they are not yet a standard. Things
+may change.
+
+See L</nan> for more discussion about C<NaN>.
+
+See also L</setpayloadsig>, L</isnan>, L</getpayload>, and L</issignaling>.
+
+=item C<setpayloadsig>
+
+ use POSIX ':nan_payload';
+ setpayloadsig($var, $payload);
+
+Like L</setpayload> but also makes the NaN I<signaling>. Added in Perl
+v5.24.
+
+Depending on the platform the NaN may or may not behave differently.
+
+Note the API instability warning in L</setpayload>.
+
+Note that because how the floating point formats work out, on the most
+common platforms signaling payload of zero is best avoided,
+since it might end up being identical to C<+Inf>.
+
+See also L</nan>, L</isnan>, L</getpayload>, and L</issignaling>.
+
+=item C<setpgid>
This is similar to the C function C<setpgid()> for
setting the process group identifier of the current process.
Returns C<undef> on failure.
-=item setsid
+=item C<setsid>
This is identical to the C function C<setsid()> for
setting the session identifier of the current process.
-=item setuid
+=item C<setuid>
Sets the real user identifier and the effective user identifier for
this process. Similar to assigning a value to the Perl's builtin
C<$E<lt>> variable, see L<perlvar/$UID>, except that the latter
will change only the real user identifier.
-=item sigaction
+=item C<sigaction>
Detailed signal management. This uses C<POSIX::SigAction> objects for
the C<action> and C<oldaction> arguments (the oldaction can also be
sigaction(signal, action, oldaction = 0)
Returns C<undef> on failure. The C<signal> must be a number (like
-SIGHUP), not a string (like "SIGHUP"), though Perl does try hard
+C<SIGHUP>), not a string (like C<"SIGHUP">), though Perl does try hard
to understand you.
-If you use the SA_SIGINFO flag, the signal handler will in addition to
+If you use the C<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:
a user process and the uid and pid make sense,
otherwise the signal was sent by the kernel
+The constants for specific C<code> values can be imported individually
+or using the C<:signal_h_si_code> tag, since Perl v5.24.
+
The following are also defined by POSIX/SUSv3, but unfortunately
not very widely implemented:
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
+of the raw binary contents of the C<siginfo> structure: if a system has
+some non-POSIX fields, this third argument is where to C<unpack()> them
from.
-Note that not all siginfo values make sense simultaneously (some are
+Note that not all C<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
C<sigaction> and possibly also C<siginfo> documentation.
-=item siglongjmp
+=item C<siglongjmp>
+
+Not implemented. C<siglongjmp()> is C-specific: use L<perlfunc/die> instead.
-siglongjmp() is C-specific: use L<perlfunc/die> instead.
+=item C<signbit>
-=item sigpending
+Returns zero for positive arguments, non-zero for negative arguments [C99].
+Added in Perl v5.22.
+
+=item C<sigpending>
Examine signals that are blocked and pending. This uses C<POSIX::SigSet>
objects for the C<sigset> argument. Consult your system's C<sigpending>
Returns C<undef> on failure.
-=item sigprocmask
+=item C<sigprocmask>
Change and/or examine calling process's signal mask. This uses
C<POSIX::SigSet> objects for the C<sigset> and C<oldsigset> arguments.
handler if you're using safe signals. Other signals can be blocked or unblocked
reliably.
-=item sigsetjmp
+=item C<sigsetjmp>
-C<sigsetjmp()> is C-specific: use C<eval {}> instead,
+Not implemented. C<sigsetjmp()> is C-specific: use C<eval {}> instead,
see L<perlfunc/eval>.
-=item sigsuspend
+=item C<sigsuspend>
Install a signal mask and suspend process until signal arrives. This uses
C<POSIX::SigSet> objects for the C<signal_mask> argument. Consult your
Returns C<undef> on failure.
-=item sin
+=item C<sin>
This is identical to Perl's builtin C<sin()> function
for returning the sine of the numerical argument,
see L<perlfunc/sin>. See also L<Math::Trig>.
-=item sinh
+=item C<sinh>
This is identical to the C function C<sinh()>
for returning the hyperbolic sine of the numerical argument.
See also L<Math::Trig>.
-=item sleep
+=item C<sleep>
This is functionally identical to Perl's builtin C<sleep()> function
for suspending the execution of the current for process for certain
B<unslept> seconds, while the C<CORE::sleep()> returns the
number of slept seconds.
-=item sprintf
+=item C<sprintf>
This is similar to Perl's builtin C<sprintf()> function
for returning a string that has the arguments formatted as requested,
see L<perlfunc/sprintf>.
-=item sqrt
+=item C<sqrt>
This is identical to Perl's builtin C<sqrt()> function.
for returning the square root of the numerical argument,
see L<perlfunc/sqrt>.
-=item srand
+=item C<srand>
Give a seed the pseudorandom number generator, see L<perlfunc/srand>.
-=item sscanf
+=item C<sscanf>
-sscanf() is C-specific, use regular expressions instead,
+Not implemented. C<sscanf()> is C-specific, use regular expressions instead,
see L<perlre>.
-=item stat
+=item C<stat>
This is identical to Perl's builtin C<stat()> function
for returning information about files and directories.
-=item strcat
+=item C<strcat>
-
strcat() is C-specific, use C<.=> instead, see L<perlop>.
+
Not implemented. C<strcat()> is C-specific, use C<.=> instead, see L<perlop>.
-=item strchr
+=item C<strchr>
-
strchr() is C-specific, see L<perlfunc/index> instead.
+
Not implemented. C<strchr()> is C-specific, see L<perlfunc/index> instead.
-=item strcmp
+=item C<strcmp>
-
strcmp() is C-specific, use C<eq> or C<cmp> instead, see L<perlop>.
+
Not implemented. C<strcmp()> is C-specific, use C<eq> or C<cmp> instead, see L<perlop>.
-=item strcoll
+=item C<strcoll>
This is identical to the C function C<strcoll()>
for collating (comparing) strings transformed using
the C<strxfrm()> function. Not really needed since
Perl can do this transparently, see L<perllocale>.
-=item strcpy
+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.
+
+=item C<strcpy>
-
strcpy() is C-specific, use C<=> instead, see L<perlop>.
+
Not implemented. C<strcpy()> is C-specific, use C<=> instead, see L<perlop>.
-=item strcspn
+=item C<strcspn>
-strcspn() is C-specific, use regular expressions instead,
+Not implemented. C<strcspn()> is C-specific, use regular expressions instead,
see L<perlre>.
-=item strerror
+=item C<strerror>
Returns the error string for the specified errno.
-Identical to the string form of
the C<$!>, see L<perlvar/$ERRNO>.
+Identical to the string form of C<$!>, see L<perlvar/$ERRNO>.
-=item strftime
+=item C<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)
+ strftime(fmt, sec, min, hour, mday, mon, year,
+ wday = -1, yday = -1, isdst = -1)
-The month (C<mon>), weekday (C<wday>), and yearday (C<yday>) begin at zero.
-I.e. January is 0, not 1; Sunday is 0, not 1; January 1st is 0, not 1. The
-year (C<year>) is given in years since 1900. I.e., the year 1995 is 95; the
+The month (C<mon>), weekday (C<wday>), and yearday (C<yday>) begin at zero,
+I<i.e.>, January is 0, not 1; Sunday is 0, not 1; January 1st is 0, not 1. The
+year (C<year>) is given in years since 1900, I<i.e.>, the year 1995 is 95; the
year 2001 is 101. Consult your system's C<strftime()> manpage for details
about these and the other arguments.
The string for Tuesday, December 12, 1995.
- $str = POSIX::strftime( "%A, %B %d, %Y", 0, 0, 0, 12, 11, 95, 2 );
+ $str = POSIX::strftime( "%A, %B %d, %Y",
+ 0, 0, 0, 12, 11, 95, 2 );
print "$str\n";
-=item strlen
+=item C<strlen>
-
strlen() is C-specific, use C<length()> instead, see L<perlfunc/length>.
+
Not implemented. C<strlen()> is C-specific, use C<length()> instead, see L<perlfunc/length>.
-=item strncat
+=item C<strncat>
-
strncat() is C-specific, use C<.=> instead, see L<perlop>.
+
Not implemented. C<strncat()> is C-specific, use C<.=> instead, see L<perlop>.
-=item strncmp
+=item C<strncmp>
-
strncmp() is C-specific, use C<eq> instead, see L<perlop>.
+
Not implemented. C<strncmp()> is C-specific, use C<eq> instead, see L<perlop>.
-=item strncpy
+=item C<strncpy>
-
strncpy() is C-specific, use C<=> instead, see L<perlop>.
+
Not implemented. C<strncpy()> is C-specific, use C<=> instead, see L<perlop>.
-=item strpbrk
+=item C<strpbrk>
-strpbrk() is C-specific, use regular expressions instead,
+Not implemented. C<strpbrk()> is C-specific, use regular expressions instead,
see L<perlre>.
-=item strrchr
+=item C<strrchr>
-
strrchr() is C-specific, see L<perlfunc/rindex> instead.
+
Not implemented. C<strrchr()> is C-specific, see L<perlfunc/rindex> instead.
-=item strspn
+=item C<strspn>
-strspn() is C-specific, use regular expressions instead,
+Not implemented. C<strspn()> is C-specific, use regular expressions instead,
see L<perlre>.
-=item strstr
+=item C<strstr>
This is identical to Perl's builtin C<index()> function,
see L<perlfunc/index>.
-=item strtod
+=item C<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 $!.
+POSIX-compliant systems set C<$!> (C<$ERRNO>) to indicate a translation
+error, so clear C<$!> before calling C<strtod>. However, non-POSIX systems
+may not check for overflow, and therefore will never set C<$!>.
-strtod should respect any POSIX I<setlocale()> settings.
+C<strtod> respects any POSIX C<setlocale()> C<LC_NUMERIC> settings,
+regardless of whether or not it is called from Perl code that is within
+the scope of S<C<use locale>>. Prior to Perl 5.28, or when operating in
+a non thread-safe environment, it should not be used in a threaded
+application unless it's certain that the underlying locale is C
+or POSIX. This is because it otherwise changes the locale, which
+globally affects all threads simultaneously.
-To parse a string $str as a floating point number use
+To parse a string C<$str> as a floating point number use
$! = 0;
($num, $n_unparsed) = POSIX::strtod($str);
-The second returned item and $! can be used to check for valid input:
+The second returned item and C<$!> 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.
+When called in a scalar context C<strtod> returns the parsed number.
-=item strtok
+=item C<strtok>
-strtok() is C-specific, use regular expressions instead, see
+Not implemented. C<strtok()> is C-specific, use regular expressions instead, see
L<perlre>, or L<perlfunc/split>.
-=item strtol
+=item C<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 $!.
+POSIX-compliant systems set C<$!> (C<$ERRNO>) to indicate a translation
+error, so clear C<$!> before calling C<strtol>. However, non-POSIX systems
+may not check for overflow, and therefore will never set C<$!>.
-strtol should respect any POSIX I<setlocale()> settings.
+C<strtol> should respect any POSIX I<setlocale()> settings.
-To parse a string $str as a number in some base $base use
+To parse a string C<$str> as a number in some base C<$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
+is zero or omitted C<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 $! can be used to check for valid input:
+The second returned item and C<$!> 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.
+When called in a scalar context C<strtol> returns the parsed number.
-=item strtoul
+=item C<strtold>
-String to unsigned (long) integer translation. strtoul() is identical
-to strtol() except that strtoul() only parses unsigned integers. See
+Like L</strtod> but for long doubles. Defined only if the
+system supports long doubles.
+
+=item C<strtoul>
+
+String to unsigned (long) integer translation. C<strtoul()> is identical
+to C<strtol()> except that C<strtoul()> only parses unsigned integers. See
L</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.
+Note: Some vendors supply C<strtod()> and C<strtol()> but not C<strtoul()>.
+Other vendors that do supply C<strtoul()> parse "-1" as a valid value.
-=item strxfrm
+=item C<strxfrm>
String transformation. Returns the transformed string.
Not really needed since Perl can do this transparently, see
L<perllocale>.
-=item sysconf
+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.
+
+=item C<sysconf>
Retrieves values of system configurable variables.
Returns C<undef> on failure.
-=item system
+=item C<system>
This is identical to Perl's builtin C<system()> function, see
L<perlfunc/system>.
-=item tan
+=item C<tan>
This is identical to the C function C<tan()>, returning the
tangent of the numerical argument. See also L<Math::Trig>.
-=item tanh
+=item C<tanh>
This is identical to the C function C<tanh()>, returning the
hyperbolic tangent of the numerical argument. See also L<Math::Trig>.
-=item tcdrain
+=item C<tcdrain>
This is similar to the C function C<tcdrain()> for draining
the output queue of its argument stream.
Returns C<undef> on failure.
-=item tcflow
+=item C<tcflow>
This is similar to the C function C<tcflow()> for controlling
the flow of its argument stream.
Returns C<undef> on failure.
-=item tcflush
+=item C<tcflush>
This is similar to the C function C<tcflush()> for flushing
the I/O buffers of its argument stream.
Returns C<undef> on failure.
-=item tcgetpgrp
+=item C<tcgetpgrp>
This is identical to the C function C<tcgetpgrp()> for returning the
process group identifier of the foreground process group of the controlling
terminal.
-=item tcsendbreak
+=item C<tcsendbreak>
This is similar to the C function C<tcsendbreak()> for sending
a break on its argument stream.
Returns C<undef> on failure.
-=item tcsetpgrp
+=item C<tcsetpgrp>
This is similar to the C function C<tcsetpgrp()> for setting the
process group identifier of the foreground process group of the controlling
Returns C<undef> on failure.
-=item time
+=item C<tgamma>
+
+The Gamma function [C99]. Added in Perl v5.22.
+
+See also L</lgamma>.
+
+=item C<time>
This is identical to Perl's builtin C<time()> function
for returning the number of seconds since the epoch
(whatever it is for the system), see L<perlfunc/time>.
-=item times
+=item C<times>
-The times() function returns elapsed realtime since some point in the past
+The C<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, $csystem) = POSIX::times();
+ ($realtime, $user, $system, $cuser, $csystem)
+ = POSIX::times();
Note: Perl's builtin C<times()> function returns four values, measured in
seconds.
-=item tmpfile
-
-Use method C<IO::File::new_tmpfile()> instead, or see L<File::Temp>.
+=item C<tmpfile>
-=item tmpnam
+Not implemented. Use method C<IO::File::new_tmpfile()> instead, or see L<File::Temp>.
-Returns a name for a temporary file.
-
- $tmpfile = POSIX::tmpnam();
+=item C<tmpnam>
For security reasons, which are probably detailed in your system's
-documentation for the C library tmpnam() function, this interface
-should not be used; instead see L<File::Temp>.
+documentation for the C library C<tmpnam()> function, this interface
+is no longer available since Perl v5.26; instead use L<File::Temp>.
-=item tolower
+=item C<tolower>
+This function has been removed as of Perl v5.26.
This is identical to the C function, except that it can apply to a single
-character or to a whole string. Consider using the C<lc()> function,
+character or to a whole string, and currently operates as if the locale
+always is "C". Consider using the C<lc()> function, see L<perlfunc/lc>,
see L<perlfunc/lc>, or the equivalent C<\L> operator inside doublequotish
strings.
-=item toupper
+=item C<toupper>
-This is identical to the C function, except that it can apply to a single
-character or to a whole string. Consider using the C<uc()> function,
-see L<perlfunc/uc>, or the equivalent C<\U> operator inside doublequotish
-strings.
+This function has been removed as of Perl v5.26.
+This is similar to the C function, except that it can apply to a single
+character or to a whole string, and currently operates as if the locale
+always is "C". Consider using the C<uc()> function, see L<perlfunc/uc>,
+or the equivalent C<\U> operator inside doublequotish strings.
+
+=item C<trunc>
-=item ttyname
+Returns the integer toward zero from the argument [C99]. Added in Perl
+v5.22.
+
+See also L</ceil>, L</floor>, and L</round>.
+
+=item C<ttyname>
This is identical to the C function C<ttyname()> for returning the
name of the current terminal.
-=item tzname
+=item C<tzname>
Retrieves the time conversion information from the C<tzname> variable.
POSIX::tzset();
($std, $dst) = POSIX::tzname();
-=item tzset
+=item C<tzset>
This is identical to the C function C<tzset()> for setting
the current timezone based on the environment variable C<TZ>,
to be used by C<ctime()>, C<localtime()>, C<mktime()>, and C<strftime()>
functions.
-=item umask
+=item C<umask>
This is identical to Perl's builtin C<umask()> function
for setting (and querying) the file creation permission mask,
see L<perlfunc/umask>.
-=item uname
+=item C<uname>
Get name of current operating system.
- ($sysname, $nodename, $release, $version, $machine) = POSIX::uname();
+ ($sysname, $nodename, $release, $version, $machine)
+ = POSIX::uname();
Note that the actual meanings of the various fields are not
that well standardized, do not expect any great portability.
operating system, and the C<$machine> might be a hardware identifier.
Maybe.
-=item ungetc
+=item C<ungetc>
-Use method C<IO::Handle::ungetc()> instead.
+Not implemented. Use method C<IO::Handle::ungetc()> instead.
-=item unlink
+=item C<unlink>
This is identical to Perl's builtin C<unlink()> function
for removing files, see L<perlfunc/unlink>.
-=item utime
+=item C<utime>
This is identical to Perl's builtin C<utime()> function
for changing the time stamps of files and directories,
see L<perlfunc/utime>.
-=item vfprintf
+=item C<vfprintf>
-
vfprintf() is C-specific, see L<perlfunc/printf> instead.
+
Not implemented. C<vfprintf()> is C-specific, see L<perlfunc/printf> instead.
-=item vprintf
+=item C<vprintf>
-
vprintf() is C-specific, see L<perlfunc/printf> instead.
+
Not implemented. C<vprintf()> is C-specific, see L<perlfunc/printf> instead.
-=item vsprintf
+=item C<vsprintf>
-
vsprintf() is C-specific, see L<perlfunc/sprintf> instead.
+
Not implemented. C<vsprintf()> is C-specific, see L<perlfunc/sprintf> instead.
-=item wait
+=item C<wait>
This is identical to Perl's builtin C<wait()> function,
see L<perlfunc/wait>.
-=item waitpid
+=item C<waitpid>
Wait for a child process to change state. This is identical to Perl's
builtin C<waitpid()> function, see L<perlfunc/waitpid>.
$pid = POSIX::waitpid( -1, POSIX::WNOHANG );
print "status = ", ($? / 256), "\n";
-=item wcstombs
+See L</mblen>.
+
+=item C<wctomb>
+
+This is the same as the C function C<wctomb()> on unthreaded perls. On
+threaded perls, it transparently (almost) substitutes the more
+thread-safe L<C<wcrtomb>(3)>, if available, instead of C<wctomb>.
-This is identical to the C function C<wcstombs()>.
-Perl does not have any support for the wide and multibyte
-characters of the C standards, so this might be a rather
-useless function.
+Core Perl does not have any support for wide and multibyte locales,
+except Unicode UTF-8 locales. This function, in conjunction with
+L</mblen> and L</mbtowc> may be used to roll your own decoding/encoding
+of other types of multi-byte locales.
-=item wctomb
+Use C<undef> as the first parameter to this function to get the effect
+of passing NULL as the first parameter to C<wctomb>. This resets any
+shift state to its initial value. The return value is undefined if
+C<wcrtomb> was substituted, so you should never rely on it.
-This is identical to the C function C<wctomb()>.
-Perl does not have any support for the wide and multibyte
-characters of the C standards, so this might be a rather
-useless function.
+When the first parameter is a scalar, the code point contained in the
+scalar second parameter is converted into a multi-byte string and stored
+into the first parameter scalar. This is based on the locale that
+currently underlies the program, regardless of whether or not the
+function is called from Perl code that is within the scope of S<C<use
+locale>>. The return value is the number of bytes stored; or negative
+if the code point isn't representable in the current locale. Perl makes
+no attempt at hiding from your code any differences in the C<errno>
+setting between C<wctomb> and C<wcrtomb>. It does set C<errno> to 0
+before calling them.
-=item write
+=item C<write>
Write to a file. This uses file descriptors such as those obtained by
calling C<POSIX::open>.
=head1 CLASSES
-=head2 POSIX::SigAction
+=head2 C<POSIX::SigAction>
=over 8
-=item new
+=item C<new>
Creates a new C<POSIX::SigAction> object which corresponds to the C
C<struct sigaction>. This object will be destroyed automatically when
C<sa_flags>, it defaults to 0.
$sigset = POSIX::SigSet->new(SIGINT, SIGQUIT);
- $sigaction = POSIX::SigAction->new( \&handler, $sigset, &POSIX::SA_NOCLDSTOP );
+ $sigaction = POSIX::SigAction->new(
+ \&handler, $sigset, &POSIX::SA_NOCLDSTOP
+ );
This C<POSIX::SigAction> object is intended for use with the C<POSIX::sigaction()>
function.
=over 8
-=item handler
+=item C<handler>
-=item mask
+=item C<mask>
-=item flags
+=item C<flags>
accessor functions to get/set the values of a SigAction object.
$sigset = $sigaction->mask;
$sigaction->flags(&POSIX::SA_RESTART);
-=item safe
+=item C<safe>
accessor function for the "safe signals" flag of a SigAction object; see
L<perlipc> for general information on safe (a.k.a. "deferred") signals. If
=back
-=head2 POSIX::SigRt
+=head2 C<POSIX::SigRt>
=over 8
-=item %SIGRT
+=item C<%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 $SIG{SIGRTMIN}, but the right POSIX moves (see below) are made with
-the POSIX::SigSet and POSIX::sigaction instead of accessing the %SIG.
+the standard C<%SIG>, the C<$POSIX::SIGRT{SIGRTMIN}> is roughly equivalent
+to C<$SIG{SIGRTMIN}>, but the right POSIX moves (see below) are made with
+the C<POSIX::SigSet> and C<POSIX::sigaction> instead of accessing the C<%SIG>.
-You can set the %POSIX::SIGRT elements to set the POSIX realtime
+You can set the C<%POSIX::SIGRT> elements to set the POSIX realtime
signal handlers, use C<delete> and C<exists> on the elements, and use
C<scalar> on the C<%POSIX::SIGRT> to find out how many POSIX realtime
-signals there are available (SIGRTMAX - SIGRTMIN + 1, the SIGRTMAX is
+signals there are available S<C<(SIGRTMAX - SIGRTMIN + 1>>, the C<SIGRTMAX> is
a valid POSIX realtime signal).
-Setting the %SIGRT elements is equivalent to calling this:
+Setting the C<%SIGRT> elements is equivalent to calling this:
sub new {
my ($rtsig, $handler, $flags) = @_;
my $sigset = POSIX::SigSet($rtsig);
- my $sigact = POSIX::SigAction->new($handler, $sigset, $flags);
+ 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 C<local> on $POSIX::SigRt::SIGACTION_FLAGS, or you can
+either use C<local> on C<$POSIX::SigRt::SIGACTION_FLAGS>, or you can
derive from POSIX::SigRt and define your own C<new()> (the tied hash
-STORE method of the %SIGRT calls C<new($rtsig, $handler, $SIGACTION_FLAGS)>,
-where the $rtsig ranges from zero to SIGRTMAX - SIGRTMIN + 1).
+STORE method of the C<%SIGRT> calls C<new($rtsig, $handler, $SIGACTION_FLAGS)>,
+where the C<$rtsig> ranges from zero to S<C<SIGRTMAX - SIGRTMIN + 1)>>.
-Just as with any signal, you can use sigaction($rtsig, undef, $oa) to
+Just as with any signal, you can use C<sigaction($rtsig, undef, $oa)> to
retrieve the installed signal handler (or, rather, the signal action).
B<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.
-=item SIGRTMIN
+=item C<SIGRTMIN>
Return the minimum POSIX realtime signal number available, or C<undef>
if no POSIX realtime signals are available.
-=item SIGRTMAX
+=item C<SIGRTMAX>
Return the maximum POSIX realtime signal number available, or C<undef>
if no POSIX realtime signals are available.
=back
-=head2 POSIX::SigSet
+=head2 C<POSIX::SigSet>
=over 8
-=item new
+=item C<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
$sigset = POSIX::SigSet->new;
-Create a set with SIGUSR1.
+Create a set with C<SIGUSR1>.
$sigset = POSIX::SigSet->new( &POSIX::SIGUSR1 );
-=item addset
+Throws an error if any of the signals supplied cannot be added to the
+set.
+
+=item C<addset>
Add a signal to a SigSet object.
Returns C<undef> on failure.
-=item delset
+=item C<delset>
Remove a signal from the SigSet object.
Returns C<undef> on failure.
-=item emptyset
+=item C<emptyset>
Initialize the SigSet object to be empty.
Returns C<undef> on failure.
-=item fillset
+=item C<fillset>
Initialize the SigSet object to include all signals.
Returns C<undef> on failure.
-=item ismember
+=item C<ismember>
Tests the SigSet object to see if it contains a specific signal.
=back
-=head2 POSIX::Termios
+=head2 C<POSIX::Termios>
=over 8
-=item new
+=item C<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.
+when it is no longer needed. A Termios object corresponds to the C<termios>
+C struct. C<new()> mallocs a new one, C<getattr()> fills it from a file descriptor,
+and C<setattr()> sets a file descriptor's parameters to match Termios' contents.
$termios = POSIX::Termios->new;
-=item getattr
+=item C<getattr>
Get terminal control attributes.
-Obtain the attributes for stdin.
+Obtain the attributes for C<stdin>.
$termios->getattr( 0 ) # Recommended for clarity.
$termios->getattr()
Returns C<undef> on failure.
-=item getcc
+=item C<getcc>
-Retrieve a value from the c_cc field of a termios object. The c_cc field is
+Retrieve a value from the C<c_cc> field of a C<termios> object. The C<c_cc> field is
an array so an index must be specified.
$c_cc[1] = $termios->getcc(1);
-=item getcflag
+=item C<getcflag>
-Retrieve the c_cflag field of a termios object.
+Retrieve the C<c_cflag> field of a C<termios> object.
$c_cflag = $termios->getcflag;
-=item getiflag
+=item C<getiflag>
-Retrieve the c_iflag field of a termios object.
+Retrieve the C<c_iflag> field of a C<termios> object.
$c_iflag = $termios->getiflag;
-=item getispeed
+=item C<getispeed>
Retrieve the input baud rate.
$ispeed = $termios->getispeed;
-=item getlflag
+=item C<getlflag>
-Retrieve the c_lflag field of a termios object.
+Retrieve the C<c_lflag> field of a C<termios> object.
$c_lflag = $termios->getlflag;
-=item getoflag
+=item C<getoflag>
-Retrieve the c_oflag field of a termios object.
+Retrieve the C<c_oflag> field of a C<termios> object.
$c_oflag = $termios->getoflag;
-=item getospeed
+=item C<getospeed>
Retrieve the output baud rate.
$ospeed = $termios->getospeed;
-=item setattr
+=item C<setattr>
Set terminal control attributes.
Returns C<undef> on failure.
-=item setcc
+=item C<setcc>
-Set a value in the c_cc field of a termios object. The c_cc field is an
+Set a value in the C<c_cc> field of a C<termios> object. The C<c_cc> field is an
array so an index must be specified.
$termios->setcc( &POSIX::VEOF, 1 );
-=item setcflag
+=item C<setcflag>
-Set the c_cflag field of a termios object.
+Set the C<c_cflag> field of a C<termios> object.
$termios->setcflag( $c_cflag | &POSIX::CLOCAL );
-=item setiflag
+=item C<setiflag>
-Set the c_iflag field of a termios object.
+Set the C<c_iflag> field of a C<termios> object.
$termios->setiflag( $c_iflag | &POSIX::BRKINT );
-=item setispeed
+=item C<setispeed>
Set the input baud rate.
Returns C<undef> on failure.
-=item setlflag
+=item C<setlflag>
-Set the c_lflag field of a termios object.
+Set the C<c_lflag> field of a C<termios> object.
$termios->setlflag( $c_lflag | &POSIX::ECHO );
-=item setoflag
+=item C<setoflag>
-Set the c_oflag field of a termios object.
+Set the C<c_oflag> field of a C<termios> object.
$termios->setoflag( $c_oflag | &POSIX::OPOST );
-=item setospeed
+=item C<setospeed>
Set the output baud rate.
=item Baud rate values
-B38400 B75 B200 B134 B300 B1800 B150 B0 B19200 B1200 B9600 B600 B4800 B50 B2400 B110
+C<B38400> C<B75> C<B200> C<B134> C<B300> C<B1800> C<B150> C<B0> C<B19200> C<B1200> C<B9600> C<B600> C<B4800> C<B50> C<B2400> C<B110>
=item Terminal interface values
-TCSADRAIN TCSANOW TCOON TCIOFLUSH TCOFLUSH TCION TCIFLUSH TCSAFLUSH TCIOFF TCOOFF
+C<TCSADRAIN> C<TCSANOW> C<TCOON> C<TCIOFLUSH> C<TCOFLUSH> C<TCION> C<TCIFLUSH> C<TCSAFLUSH> C<TCIOFF> C<TCOOFF>
-=item c_cc field values
+=item C<c_cc> field values
-VEOF VEOL VERASE VINTR VKILL VQUIT VSUSP VSTART VSTOP VMIN VTIME NCCS
+C<VEOF> C<VEOL> C<VERASE> C<VINTR> C<VKILL> C<VQUIT> C<VSUSP> C<VSTART> C<VSTOP> C<VMIN> C<VTIME> C<NCCS>
-=item c_cflag field values
+=item C<c_cflag> field values
-CLOCAL CREAD CSIZE CS5 CS6 CS7 CS8 CSTOPB HUPCL PARENB PARODD
+C<CLOCAL> C<CREAD> C<CSIZE> C<CS5> C<CS6> C<CS7> C<CS8> C<CSTOPB> C<HUPCL> C<PARENB> C<PARODD>
-=item c_iflag field values
+=item C<c_iflag> field values
-BRKINT ICRNL IGNBRK IGNCR IGNPAR INLCR INPCK ISTRIP IXOFF IXON PARMRK
+C<BRKINT> C<ICRNL> C<IGNBRK> C<IGNCR> C<IGNPAR> C<INLCR> C<INPCK> C<ISTRIP> C<IXOFF> C<IXON> C<PARMRK>
-=item c_lflag field values
+=item C<c_lflag> field values
-ECHO ECHOE ECHOK ECHONL ICANON IEXTEN ISIG NOFLSH TOSTOP
+C<ECHO> C<ECHOE> C<ECHOK> C<ECHONL> C<ICANON> C<IEXTEN> C<ISIG> C<NOFLSH> C<TOSTOP>
-=item c_oflag field values
+=item C<c_oflag> field values
-OPOST
+C<OPOST>
=back
=item 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
+C<_PC_CHOWN_RESTRICTED> C<_PC_LINK_MAX> C<_PC_MAX_CANON> C<_PC_MAX_INPUT> C<_PC_NAME_MAX>
+C<_PC_NO_TRUNC> C<_PC_PATH_MAX> C<_PC_PIPE_BUF> C<_PC_VDISABLE>
=back
=item 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
+C<_POSIX_ARG_MAX> C<_POSIX_CHILD_MAX> C<_POSIX_CHOWN_RESTRICTED> C<_POSIX_JOB_CONTROL>
+C<_POSIX_LINK_MAX> C<_POSIX_MAX_CANON> C<_POSIX_MAX_INPUT> C<_POSIX_NAME_MAX>
+C<_POSIX_NGROUPS_MAX> C<_POSIX_NO_TRUNC> C<_POSIX_OPEN_MAX> C<_POSIX_PATH_MAX>
+C<_POSIX_PIPE_BUF> C<_POSIX_SAVED_IDS> C<_POSIX_SSIZE_MAX> C<_POSIX_STREAM_MAX>
+C<_POSIX_TZNAME_MAX> C<_POSIX_VDISABLE> C<_POSIX_VERSION>
+
+=back
+
+=head1 RESOURCE CONSTANTS
+
+Imported with the C<:sys_resource_h> tag.
+
+=over 8
+
+=item Constants
+
+Added in Perl v5.28:
+
+C<PRIO_PROCESS> C<PRIO_PGRP> C<PRIO_USER>
=back
=item 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
+C<_SC_ARG_MAX> C<_SC_CHILD_MAX> C<_SC_CLK_TCK> C<_SC_JOB_CONTROL> C<_SC_NGROUPS_MAX>
+C<_SC_OPEN_MAX> C<_SC_PAGESIZE> C<_SC_SAVED_IDS> C<_SC_STREAM_MAX> C<_SC_TZNAME_MAX>
+C<_SC_VERSION>
=back
=item Constants
-E2BIG EACCES EADDRINUSE EADDRNOTAVAIL EAFNOSUPPORT EAGAIN EALREADY EBADF
-EBUSY ECHILD ECONNABORTED ECONNREFUSED ECONNRESET EDEADLK EDESTADDRREQ
-EDOM EDQUOT EEXIST EFAULT EFBIG EHOSTDOWN EHOSTUNREACH EINPROGRESS EINTR
-EINVAL EIO EISCONN EISDIR ELOOP EMFILE EMLINK EMSGSIZE ENAMETOOLONG
-ENETDOWN ENETRESET ENETUNREACH ENFILE ENOBUFS ENODEV ENOENT ENOEXEC
-ENOLCK ENOMEM ENOPROTOOPT ENOSPC ENOSYS ENOTBLK ENOTCONN ENOTDIR
-ENOTEMPTY ENOTSOCK ENOTTY ENXIO EOPNOTSUPP EPERM EPFNOSUPPORT EPIPE
-EPROCLIM EPROTONOSUPPORT EPROTOTYPE ERANGE EREMOTE ERESTART EROFS
-ESHUTDOWN ESOCKTNOSUPPORT ESPIPE ESRCH ESTALE ETIMEDOUT ETOOMANYREFS
-ETXTBSY EUSERS EWOULDBLOCK EXDEV
+C<E2BIG> C<EACCES> C<EADDRINUSE> C<EADDRNOTAVAIL> C<EAFNOSUPPORT> C<EAGAIN> C<EALREADY> C<EBADF> C<EBADMSG>
+C<EBUSY> C<ECANCELED> C<ECHILD> C<ECONNABORTED> C<ECONNREFUSED> C<ECONNRESET> C<EDEADLK> C<EDESTADDRREQ>
+C<EDOM> C<EDQUOT> C<EEXIST> C<EFAULT> C<EFBIG> C<EHOSTDOWN> C<EHOSTUNREACH> C<EIDRM> C<EILSEQ> C<EINPROGRESS>
+C<EINTR> C<EINVAL> C<EIO> C<EISCONN> C<EISDIR> C<ELOOP> C<EMFILE> C<EMLINK> C<EMSGSIZE> C<ENAMETOOLONG>
+C<ENETDOWN> C<ENETRESET> C<ENETUNREACH> C<ENFILE> C<ENOBUFS> C<ENODATA> C<ENODEV> C<ENOENT> C<ENOEXEC>
+C<ENOLCK> C<ENOLINK> C<ENOMEM> C<ENOMSG> C<ENOPROTOOPT> C<ENOSPC> C<ENOSR> C<ENOSTR> C<ENOSYS> C<ENOTBLK>
+C<ENOTCONN> C<ENOTDIR> C<ENOTEMPTY> C<ENOTRECOVERABLE> C<ENOTSOCK> C<ENOTSUP> C<ENOTTY> C<ENXIO>
+C<EOPNOTSUPP> C<EOTHER> C<EOVERFLOW> C<EOWNERDEAD> C<EPERM> C<EPFNOSUPPORT> C<EPIPE> C<EPROCLIM> C<EPROTO>
+C<EPROTONOSUPPORT> C<EPROTOTYPE> C<ERANGE> C<EREMOTE> C<ERESTART> C<EROFS> C<ESHUTDOWN>
+C<ESOCKTNOSUPPORT> C<ESPIPE> C<ESRCH> C<ESTALE> C<ETIME> C<ETIMEDOUT> C<ETOOMANYREFS> C<ETXTBSY> C<EUSERS>
+C<EWOULDBLOCK> C<EXDEV>
=back
=item 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
+C<FD_CLOEXEC> C<F_DUPFD> C<F_GETFD> C<F_GETFL> C<F_GETLK> C<F_OK> C<F_RDLCK> C<F_SETFD> C<F_SETFL> C<F_SETLK>
+C<F_SETLKW> C<F_UNLCK> C<F_WRLCK> C<O_ACCMODE> C<O_APPEND> C<O_CREAT> C<O_EXCL> C<O_NOCTTY> C<O_NONBLOCK>
+C<O_RDONLY> C<O_RDWR> C<O_TRUNC> C<O_WRONLY>
=back
=item 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
+C<DBL_DIG> C<DBL_EPSILON> C<DBL_MANT_DIG> C<DBL_MAX> C<DBL_MAX_10_EXP> C<DBL_MAX_EXP> C<DBL_MIN>
+C<DBL_MIN_10_EXP> C<DBL_MIN_EXP> C<FLT_DIG> C<FLT_EPSILON> C<FLT_MANT_DIG> C<FLT_MAX>
+C<FLT_MAX_10_EXP> C<FLT_MAX_EXP> C<FLT_MIN> C<FLT_MIN_10_EXP> C<FLT_MIN_EXP> C<FLT_RADIX>
+C<FLT_ROUNDS> C<LDBL_DIG> C<LDBL_EPSILON> C<LDBL_MANT_DIG> C<LDBL_MAX> C<LDBL_MAX_10_EXP>
+C<LDBL_MAX_EXP> C<LDBL_MIN> C<LDBL_MIN_10_EXP> C<LDBL_MIN_EXP>
+
+=back
+
+=head1 FLOATING-POINT ENVIRONMENT
+
+=over 8
+
+=item Constants
+
+C<FE_DOWNWARD> C<FE_TONEAREST> C<FE_TOWARDZERO> C<FE_UPWARD>
+on systems that support them.
=back
=item 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
+C<ARG_MAX> C<CHAR_BIT> C<CHAR_MAX> C<CHAR_MIN> C<CHILD_MAX> C<INT_MAX> C<INT_MIN> C<LINK_MAX> C<LONG_MAX>
+C<LONG_MIN> C<MAX_CANON> C<MAX_INPUT> C<MB_LEN_MAX> C<NAME_MAX> C<NGROUPS_MAX> C<OPEN_MAX> C<PATH_MAX>
+C<PIPE_BUF> C<SCHAR_MAX> C<SCHAR_MIN> C<SHRT_MAX> C<SHRT_MIN> C<SSIZE_MAX> C<STREAM_MAX> C<TZNAME_MAX>
+C<UCHAR_MAX> C<UINT_MAX> C<ULONG_MAX> C<USHRT_MAX>
=back
=item Constants
-LC_ALL LC_COLLATE LC_CTYPE LC_MONETARY LC_NUMERIC LC_TIME
+C<LC_ALL> C<LC_COLLATE> C<LC_CTYPE> C<LC_MONETARY> C<LC_NUMERIC> C<LC_TIME> C<LC_MESSAGES>
+on systems that support them.
=back
=item Constants
-HUGE_VAL
+C<HUGE_VAL>
+
+Added in Perl v5.22:
+
+C<FP_ILOGB0> C<FP_ILOGBNAN> C<FP_INFINITE> C<FP_NAN> C<FP_NORMAL> C<FP_SUBNORMAL> C<FP_ZERO>
+C<INFINITY> C<NAN> C<Inf> C<NaN>
+C<M_1_PI> C<M_2_PI> C<M_2_SQRTPI> C<M_E> C<M_LN10> C<M_LN2> C<M_LOG10E> C<M_LOG2E> C<M_PI>
+C<M_PI_2> C<M_PI_4> C<M_SQRT1_2> C<M_SQRT2>
+on systems with C99 support.
=back
=item 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
+C<SA_NOCLDSTOP> C<SA_NOCLDWAIT> C<SA_NODEFER> C<SA_ONSTACK> C<SA_RESETHAND> C<SA_RESTART>
+C<SA_SIGINFO> C<SIGABRT> C<SIGALRM> C<SIGCHLD> C<SIGCONT> C<SIGFPE> C<SIGHUP> C<SIGILL> C<SIGINT>
+C<SIGKILL> C<SIGPIPE> C<SIGQUIT> C<SIGSEGV> C<SIGSTOP> C<SIGTERM> C<SIGTSTP> C<SIGTTIN> C<SIGTTOU>
+C<SIGUSR1> C<SIGUSR2> C<SIG_BLOCK> C<SIG_DFL> C<SIG_ERR> C<SIG_IGN> C<SIG_SETMASK>
+C<SIG_UNBLOCK>
+
+Added in Perl v5.24:
+
+C<ILL_ILLOPC> C<ILL_ILLOPN> C<ILL_ILLADR> C<ILL_ILLTRP> C<ILL_PRVOPC> C<ILL_PRVREG> C<ILL_COPROC>
+C<ILL_BADSTK> C<FPE_INTDIV> C<FPE_INTOVF> C<FPE_FLTDIV> C<FPE_FLTOVF> C<FPE_FLTUND> C<FPE_FLTRES>
+C<FPE_FLTINV> C<FPE_FLTSUB> C<SEGV_MAPERR> C<SEGV_ACCERR> C<BUS_ADRALN> C<BUS_ADRERR>
+C<BUS_OBJERR> C<TRAP_BRKPT> C<TRAP_TRACE> C<CLD_EXITED> C<CLD_KILLED> C<CLD_DUMPED> C<CLD_TRAPPED>
+C<CLD_STOPPED> C<CLD_CONTINUED> C<POLL_IN> C<POLL_OUT> C<POLL_MSG> C<POLL_ERR> C<POLL_PRI>
+C<POLL_HUP> C<SI_USER> C<SI_QUEUE> C<SI_TIMER> C<SI_ASYNCIO> C<SI_MESGQ>
=back
=item 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
+C<S_IRGRP> C<S_IROTH> C<S_IRUSR> C<S_IRWXG> C<S_IRWXO> C<S_IRWXU> C<S_ISGID> C<S_ISUID> C<S_IWGRP> C<S_IWOTH>
+C<S_IWUSR> C<S_IXGRP> C<S_IXOTH> C<S_IXUSR>
=item Macros
-S_ISBLK S_ISCHR S_ISDIR S_ISFIFO S_ISREG
+C<S_ISBLK> C<S_ISCHR> C<S_ISDIR> C<S_ISFIFO> C<S_ISREG>
=back
=item Constants
-EXIT_FAILURE EXIT_SUCCESS MB_CUR_MAX RAND_MAX
+C<EXIT_FAILURE> C<EXIT_SUCCESS> C<MB_CUR_MAX> C<RAND_MAX>
=back
=item Constants
-BUFSIZ EOF FILENAME_MAX L_ctermid L_cuserid L_tmpname TMP_MAX
+C<BUFSIZ> C<EOF> C<FILENAME_MAX> C<L_ctermid> C<L_cuserid> C<TMP_MAX>
=back
=item Constants
-CLK_TCK CLOCKS_PER_SEC
+C<CLK_TCK> C<CLOCKS_PER_SEC>
=back
=item Constants
-R_OK SEEK_CUR SEEK_END SEEK_SET STDIN_FILENO STDOUT_FILENO STDERR_FILENO W_OK X_OK
+C<R_OK> C<SEEK_CUR> C<SEEK_END> C<SEEK_SET> C<STDIN_FILENO> C<STDOUT_FILENO> C<STDERR_FILENO> C<W_OK> C<X_OK>
=back
=item Constants
-WNOHANG WUNTRACED
+C<WNOHANG> C<WUNTRACED>
=over 16
-=item WNOHANG
+=item C<WNOHANG>
Do not suspend the calling process until a child process
changes state but instead return immediately.
-=item WUNTRACED
+=item C<WUNTRACED>
Catch stopped child processes.
=item Macros
-WIFEXITED WEXITSTATUS WIFSIGNALED WTERMSIG WIFSTOPPED WSTOPSIG
+C<WIFEXITED> C<WEXITSTATUS> C<WIFSIGNALED> C<WTERMSIG> C<WIFSTOPPED> C<WSTOPSIG>
=over 16
-=item WIFEXITED
+=item C<WIFEXITED>
-WIFEXITED(${^CHILD_ERROR_NATIVE}) returns true if the child process
+C<WIFEXITED(${^CHILD_ERROR_NATIVE})> returns true if the child process
exited normally (C<exit()> or by falling off the end of C<main()>)
-=item WEXITSTATUS
+=item C<WEXITSTATUS>
-WEXITSTATUS(${^CHILD_ERROR_NATIVE}) returns the normal exit status of
-the child process (only meaningful if WIFEXITED(${^CHILD_ERROR_NATIVE})
+C<WEXITSTATUS(${^CHILD_ERROR_NATIVE})> returns the normal exit status of
+the child process (only meaningful if C<WIFEXITED(${^CHILD_ERROR_NATIVE})>
is true)
-=item WIFSIGNALED
+=item C<WIFSIGNALED>
-WIFSIGNALED(${^CHILD_ERROR_NATIVE}) returns true if the child process
+C<WIFSIGNALED(${^CHILD_ERROR_NATIVE})> returns true if the child process
terminated because of a signal
-=item WTERMSIG
+=item C<WTERMSIG>
-WTERMSIG(${^CHILD_ERROR_NATIVE}) returns the signal the child process
-terminated for (only meaningful if WIFSIGNALED(${^CHILD_ERROR_NATIVE})
+C<WTERMSIG(${^CHILD_ERROR_NATIVE})> returns the signal the child process
+terminated for (only meaningful if
+C<WIFSIGNALED(${^CHILD_ERROR_NATIVE})>
is true)
-=item WIFSTOPPED
+=item C<WIFSTOPPED>
-WIFSTOPPED(${^CHILD_ERROR_NATIVE}) returns true if the child process is
+C<WIFSTOPPED(${^CHILD_ERROR_NATIVE})> returns true if the child process is
currently stopped (can happen only if you specified the WUNTRACED flag
-to waitpid())
+to C<waitpid()>)
-=item WSTOPSIG
+=item C<WSTOPSIG>
-WSTOPSIG(${^CHILD_ERROR_NATIVE}) returns the signal the child process
-was stopped for (only meaningful if WIFSTOPPED(${^CHILD_ERROR_NATIVE})
+C<WSTOPSIG(${^CHILD_ERROR_NATIVE})> returns the signal the child process
+was stopped for (only meaningful if
+C<WIFSTOPPED(${^CHILD_ERROR_NATIVE})>
is true)
=back
=back
+=head1 WINSOCK
+
+(Windows only.)
+
+=over 8
+
+=item Constants
+
+Added in Perl v5.24:
+
+C<WSAEINTR> C<WSAEBADF> C<WSAEACCES> C<WSAEFAULT> C<WSAEINVAL> C<WSAEMFILE> C<WSAEWOULDBLOCK>
+C<WSAEINPROGRESS> C<WSAEALREADY> C<WSAENOTSOCK> C<WSAEDESTADDRREQ> C<WSAEMSGSIZE>
+C<WSAEPROTOTYPE> C<WSAENOPROTOOPT> C<WSAEPROTONOSUPPORT> C<WSAESOCKTNOSUPPORT>
+C<WSAEOPNOTSUPP> C<WSAEPFNOSUPPORT> C<WSAEAFNOSUPPORT> C<WSAEADDRINUSE>
+C<WSAEADDRNOTAVAIL> C<WSAENETDOWN> C<WSAENETUNREACH> C<WSAENETRESET> C<WSAECONNABORTED>
+C<WSAECONNRESET> C<WSAENOBUFS> C<WSAEISCONN> C<WSAENOTCONN> C<WSAESHUTDOWN>
+C<WSAETOOMANYREFS> C<WSAETIMEDOUT> C<WSAECONNREFUSED> C<WSAELOOP> C<WSAENAMETOOLONG>
+C<WSAEHOSTDOWN> C<WSAEHOSTUNREACH> C<WSAENOTEMPTY> C<WSAEPROCLIM> C<WSAEUSERS>
+C<WSAEDQUOT> C<WSAESTALE> C<WSAEREMOTE> C<WSAEDISCON> C<WSAENOMORE> C<WSAECANCELLED>
+C<WSAEINVALIDPROCTABLE> C<WSAEINVALIDPROVIDER> C<WSAEPROVIDERFAILEDINIT>
+C<WSAEREFUSED>
+
+=back
+
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