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File::Spec(3)		       User Contributed Perl Documentation		    File::Spec(3)

NAME
       File::Spec - portably perform operations on file names

SYNOPSIS
	       use File::Spec;

	       $x=File::Spec->catfile('a', 'b', 'c');

       which returns 'a/b/c' under Unix. Or:

	       use File::Spec::Functions;

	       $x = catfile('a', 'b', 'c');

DESCRIPTION
       This module is designed to support operations commonly performed on file specifications
       (usually called "file names", but not to be confused with the contents of a file, or
       Perl's file handles), such as concatenating several directory and file names into a single
       path, or determining whether a path is rooted. It is based on code directly taken from
       MakeMaker 5.17, code written by Andreas Koenig, Andy Dougherty, Charles Bailey, Ilya
       Zakharevich, Paul Schinder, and others.

       Since these functions are different for most operating systems, each set of OS specific
       routines is available in a separate module, including:

	       File::Spec::Unix
	       File::Spec::Mac
	       File::Spec::OS2
	       File::Spec::Win32
	       File::Spec::VMS

       The module appropriate for the current OS is automatically loaded by File::Spec. Since
       some modules (like VMS) make use of facilities available only under that OS, it may not be
       possible to load all modules under all operating systems.

       Since File::Spec is object oriented, subroutines should not be called directly, as in:

	       File::Spec::catfile('a','b');

       but rather as class methods:

	       File::Spec->catfile('a','b');

       For simple uses, File::Spec::Functions provides convenient functional forms of these
       methods.

METHODS
       canonpath
	 No physical check on the filesystem, but a logical cleanup of a path.

	     $cpath = File::Spec->canonpath( $path ) ;

	 Note that this does *not* collapse x/../y sections into y.  This is by design.  If /foo
	 on your system is a symlink to /bar/baz, then /foo/../quux is actually /bar/quux, not
	 /quux as a naive ../-removal would give you.  If you want to do this kind of processing,
	 you probably want "Cwd"'s "realpath()" function to actually traverse the filesystem
	 cleaning up paths like this.

       catdir
	 Concatenate two or more directory names to form a complete path ending with a directory.
	 But remove the trailing slash from the resulting string, because it doesn't look good,
	 isn't necessary and confuses OS/2. Of course, if this is the root directory, don't cut
	 off the trailing slash :-)

	     $path = File::Spec->catdir( @directories );

       catfile
	 Concatenate one or more directory names and a filename to form a complete path ending
	 with a filename

	     $path = File::Spec->catfile( @directories, $filename );

       curdir
	 Returns a string representation of the current directory.

	     $curdir = File::Spec->curdir();

       devnull
	 Returns a string representation of the null device.

	     $devnull = File::Spec->devnull();

       rootdir
	 Returns a string representation of the root directory.

	     $rootdir = File::Spec->rootdir();

       tmpdir
	 Returns a string representation of the first writable directory from a list of possible
	 temporary directories.  Returns the current directory if no writable temporary
	 directories are found.  The list of directories checked depends on the platform; e.g.
	 File::Spec::Unix checks $ENV{TMPDIR} (unless taint is on) and /tmp.

	     $tmpdir = File::Spec->tmpdir();

       updir
	 Returns a string representation of the parent directory.

	     $updir = File::Spec->updir();

       no_upwards
	 Given a list of file names, strip out those that refer to a parent directory. (Does not
	 strip symlinks, only '.', '..', and equivalents.)

	     @paths = File::Spec->no_upwards( @paths );

       case_tolerant
	 Returns a true or false value indicating, respectively, that alphabetic case is not or
	 is significant when comparing file specifications.  Cygwin and Win32 accept an optional
	 drive argument.

	     $is_case_tolerant = File::Spec->case_tolerant();

       file_name_is_absolute
	 Takes as its argument a path, and returns true if it is an absolute path.

	     $is_absolute = File::Spec->file_name_is_absolute( $path );

	 This does not consult the local filesystem on Unix, Win32, OS/2, or Mac OS (Classic).
	 It does consult the working environment for VMS (see "file_name_is_absolute" in
	 File::Spec::VMS).

       path
	 Takes no argument.  Returns the environment variable "PATH" (or the local platform's
	 equivalent) as a list.

	     @PATH = File::Spec->path();

       join
	 join is the same as catfile.

       splitpath
	 Splits a path in to volume, directory, and filename portions. On systems with no concept
	 of volume, returns '' for volume.

	     ($volume,$directories,$file) =
				File::Spec->splitpath( $path );
	     ($volume,$directories,$file) =
				File::Spec->splitpath( $path, $no_file );

	 For systems with no syntax differentiating filenames from directories, assumes that the
	 last file is a path unless $no_file is true or a trailing separator or /. or /.. is
	 present. On Unix, this means that $no_file true makes this return ( '', $path, '' ).

	 The directory portion may or may not be returned with a trailing '/'.

	 The results can be passed to "catpath()" to get back a path equivalent to (usually
	 identical to) the original path.

       splitdir
	 The opposite of "catdir".

	     @dirs = File::Spec->splitdir( $directories );

	 $directories must be only the directory portion of the path on systems that have the
	 concept of a volume or that have path syntax that differentiates files from directories.

	 Unlike just splitting the directories on the separator, empty directory names ('') can
	 be returned, because these are significant on some OSes.

       catpath()
	 Takes volume, directory and file portions and returns an entire path. Under Unix,
	 $volume is ignored, and directory and file are concatenated.  A '/' is inserted if need
	 be.  On other OSes, $volume is significant.

	     $full_path = File::Spec->catpath( $volume, $directory, $file );

       abs2rel
	 Takes a destination path and an optional base path returns a relative path from the base
	 path to the destination path:

	     $rel_path = File::Spec->abs2rel( $path ) ;
	     $rel_path = File::Spec->abs2rel( $path, $base ) ;

	 If $base is not present or '', then Cwd::cwd() is used. If $base is relative, then it is
	 converted to absolute form using "rel2abs()". This means that it is taken to be relative
	 to Cwd::cwd().

	 On systems with the concept of volume, if $path and $base appear to be on two different
	 volumes, we will not attempt to resolve the two paths, and we will instead simply return
	 $path.  Note that previous versions of this module ignored the volume of $base, which
	 resulted in garbage results part of the time.

	 On systems that have a grammar that indicates filenames, this ignores the $base filename
	 as well. Otherwise all path components are assumed to be directories.

	 If $path is relative, it is converted to absolute form using "rel2abs()".  This means
	 that it is taken to be relative to Cwd::cwd().

	 No checks against the filesystem are made.  On VMS, there is interaction with the
	 working environment, as logicals and macros are expanded.

	 Based on code written by Shigio Yamaguchi.

       rel2abs()
	 Converts a relative path to an absolute path.

	     $abs_path = File::Spec->rel2abs( $path ) ;
	     $abs_path = File::Spec->rel2abs( $path, $base ) ;

	 If $base is not present or '', then Cwd::cwd() is used. If $base is relative, then it is
	 converted to absolute form using "rel2abs()". This means that it is taken to be relative
	 to Cwd::cwd().

	 On systems with the concept of volume, if $path and $base appear to be on two different
	 volumes, we will not attempt to resolve the two paths, and we will instead simply return
	 $path.  Note that previous versions of this module ignored the volume of $base, which
	 resulted in garbage results part of the time.

	 On systems that have a grammar that indicates filenames, this ignores the $base filename
	 as well. Otherwise all path components are assumed to be directories.

	 If $path is absolute, it is cleaned up and returned using "canonpath".

	 No checks against the filesystem are made.  On VMS, there is interaction with the
	 working environment, as logicals and macros are expanded.

	 Based on code written by Shigio Yamaguchi.

       For further information, please see File::Spec::Unix, File::Spec::Mac, File::Spec::OS2,
       File::Spec::Win32, or File::Spec::VMS.

SEE ALSO
       File::Spec::Unix, File::Spec::Mac, File::Spec::OS2, File::Spec::Win32, File::Spec::VMS,
       File::Spec::Functions, ExtUtils::MakeMaker

AUTHOR
       Currently maintained by Ken Williams "<KWILLIAMS@cpan.org>".

       The vast majority of the code was written by Kenneth Albanowski "<kjahds@kjahds.com>",
       Andy Dougherty "<doughera@lafayette.edu>", Andreas Koenig
       "<A.Koenig@franz.ww.TU-Berlin.DE>", Tim Bunce "<Tim.Bunce@ig.co.uk>".  VMS support by
       Charles Bailey "<bailey@newman.upenn.edu>".  OS/2 support by Ilya Zakharevich
       "<ilya@math.ohio-state.edu>".  Mac support by Paul Schinder "<schinder@pobox.com>", and
       Thomas Wegner "<wegner_thomas@yahoo.com>".  abs2rel() and rel2abs() written by Shigio
       Yamaguchi "<shigio@tamacom.com>", modified by Barrie Slaymaker "<barries@slaysys.com>".
       splitpath(), splitdir(), catpath() and catdir() by Barrie Slaymaker.

COPYRIGHT
       Copyright (c) 2004-2013 by the Perl 5 Porters.  All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same
       terms as Perl itself.

perl v5.16.3				    2013-01-16				    File::Spec(3)
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