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 König, 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 files in a directory (such as from "readdir()"), strip out '.' and '..'.

         SECURITY NOTE: This does NOT filter paths containing '..', like
         '../../../../etc/passwd', only literal matches to '.' and '..'.

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

       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

       Maintained by perl5-porters <perl5-porters@perl.org>.

       The vast majority of the code was written by Kenneth Albanowski "<kjahds@kjahds.com>",
       Andy Dougherty "<doughera@lafayette.edu>", Andreas König
       "<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.