NAME
PerlIO::Util - A selection of general PerlIO utilities
VERSION
This document describes PerlIO::Util version 0.60
SYNOPSIS
use PerlIO::Util;
# utility layers
open $in, '+<:flock', ...; # with flock(IN, LOCK_EX)
open $in, '+<:creat :excl', ...; # with O_CREAT | O_EXCL
open $out, '>:tee', 'file.txt', \$scalar, \*STDERR;
print $out 'foo'; # print to 'file.txt', $scalar and *STDERR
# utility routines
$fh = PerlIO::Util->open('<', $file); # it dies on fail
*STDOUT->push_layer(scalar => \$s); # it dies on fail
print 'foo';
print *STDOUT->pop_layer(); # => scalar
print $s; # => foo
DESCRIPTION
PerlIO::Util
provides general PerlIO utilities: utility layers and utility methods.
Utility layers are a part of PerlIO::Util
, but you don't need to say use PerlIO::Util
for loading them. They will be automatically loaded.
UTILITY LAYERS
:flock
Easy interface to flock()
.
See PerlIO::flock.
:creat
Use of O_CREAT without Fcntl
.
See PerlIO::creat.
:excl
Use of O_EXCL without Fcntl
.
See PerlIO::excl.
:tee
Multiplex output stream.
See PerlIO::tee.
:dir
PerlIO interface to directory functions.
See PerlIO::dir.
:reverse
Reverse input stream.
See PerlIO::reverse.
:fse
Mediation of filesystem encoding.
See PerlIO::fse.
UTILITY METHODS
PerlIO::Util->open(mode, args)
Calls built-in open()
, and returns an anonymous IO::Handle
instance. It dies on fail.
Unlike Perl's open()
(nor IO::File
's), mode is always required.
PerlIO::Util->known_layers( )
Returns the known layer names.
FILEHANDLE->get_layers( )
Returns the names of the PerlIO layers on FILEHANDLE.
See "Querying the layers of filehandles" in PerlIO.
FILEHANDLE->push_layer(layer [ => arg])
Almost equivalent to binmode(FILEHANDLE, ':layer(arg)')
, but accepts any type of arg, e.g. a scalar reference to the :scalar
layer.
This method dies on fail. Otherwise, it returns FILEHANDLE.
FILEHANDLE->pop_layer( )
Equivalent to binmode(FILEHANDLE, ':pop')
. It removes a top level layer from FILEHANDLE, but note that you cannot remove dummy layers such as :utf8
or :flock
.
This method returns the name of the popped layer.
DEPENDENCIES
Perl 5.8.1 or later, and a C compiler.
BUGS
No bugs have been reported.
Please report any bugs or feature requests to <gfuji(at)cpan.org>, or through the web interface at http://rt.cpan.org/.
SEE ALSO
PerlIO::flock, PerlIO::creat, PerlIO::excl, PerlIO::tee, PerlIO::dir, PerlIO::reverse, PerlIO::fse.
PerlIO for push_layer()
and pop_layer()
.
perliol for implementation details.
AUTHOR
Goro Fuji (藤 吾郎) <gfuji(at)cpan.org>
LICENSE AND COPYRIGHT
Copyright (c) 2008, Goro Fuji <gfuji(at)cpan.org>. Some rights reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.