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File::Spec(3pm)        Perl Programmers Reference Guide        File::Spec(3pm)




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 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(3), File::Spec::Mac(3), File::Spec::OS2(3),
       File::Spec::Win32(3), File::Spec::VMS(3), File::Spec::Functions(3),
       ExtUtils::MakeMaker(3)


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 v5.26.1                      2017-07-18                   File::Spec(3pm)

perl 5.26.1 - Generated Sun Nov 5 10:47:58 CST 2017
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