1File::Spec(3pm)        Perl Programmers Reference Guide        File::Spec(3pm)
2
3
4

NAME

6       File::Spec - portably perform operations on file names
7

SYNOPSIS

9               use File::Spec;
10
11               $x=File::Spec->catfile('a', 'b', 'c');
12
13       which returns 'a/b/c' under Unix. Or:
14
15               use File::Spec::Functions;
16
17               $x = catfile('a', 'b', 'c');
18

DESCRIPTION

20       This module is designed to support operations commonly performed on
21       file specifications (usually called "file names", but not to be
22       confused with the contents of a file, or Perl's file handles), such as
23       concatenating several directory and file names into a single path, or
24       determining whether a path is rooted. It is based on code directly
25       taken from MakeMaker 5.17, code written by Andreas Koenig, Andy
26       Dougherty, Charles Bailey, Ilya Zakharevich, Paul Schinder, and others.
27
28       Since these functions are different for most operating systems, each
29       set of OS specific routines is available in a separate module,
30       including:
31
32               File::Spec::Unix
33               File::Spec::Mac
34               File::Spec::OS2
35               File::Spec::Win32
36               File::Spec::VMS
37
38       The module appropriate for the current OS is automatically loaded by
39       File::Spec. Since some modules (like VMS) make use of facilities
40       available only under that OS, it may not be possible to load all
41       modules under all operating systems.
42
43       Since File::Spec is object oriented, subroutines should not be called
44       directly, as in:
45
46               File::Spec::catfile('a','b');
47
48       but rather as class methods:
49
50               File::Spec->catfile('a','b');
51
52       For simple uses, File::Spec::Functions provides convenient functional
53       forms of these methods.
54

METHODS

56       canonpath
57         No physical check on the filesystem, but a logical cleanup of a path.
58
59             $cpath = File::Spec->canonpath( $path ) ;
60
61         Note that this does *not* collapse x/../y sections into y.  This is
62         by design.  If /foo on your system is a symlink to /bar/baz, then
63         /foo/../quux is actually /bar/quux, not /quux as a naive ../-removal
64         would give you.  If you want to do this kind of processing, you
65         probably want "Cwd"'s "realpath()" function to actually traverse the
66         filesystem cleaning up paths like this.
67
68       catdir
69         Concatenate two or more directory names to form a complete path
70         ending with a directory. But remove the trailing slash from the
71         resulting string, because it doesn't look good, isn't necessary and
72         confuses OS/2. Of course, if this is the root directory, don't cut
73         off the trailing slash :-)
74
75             $path = File::Spec->catdir( @directories );
76
77       catfile
78         Concatenate one or more directory names and a filename to form a
79         complete path ending with a filename
80
81             $path = File::Spec->catfile( @directories, $filename );
82
83       curdir
84         Returns a string representation of the current directory.
85
86             $curdir = File::Spec->curdir();
87
88       devnull
89         Returns a string representation of the null device.
90
91             $devnull = File::Spec->devnull();
92
93       rootdir
94         Returns a string representation of the root directory.
95
96             $rootdir = File::Spec->rootdir();
97
98       tmpdir
99         Returns a string representation of the first writable directory from
100         a list of possible temporary directories.  Returns the current
101         directory if no writable temporary directories are found.  The list
102         of directories checked depends on the platform; e.g. File::Spec::Unix
103         checks $ENV{TMPDIR} (unless taint is on) and /tmp.
104
105             $tmpdir = File::Spec->tmpdir();
106
107       updir
108         Returns a string representation of the parent directory.
109
110             $updir = File::Spec->updir();
111
112       no_upwards
113         Given a list of file names, strip out those that refer to a parent
114         directory. (Does not strip symlinks, only '.', '..', and
115         equivalents.)
116
117             @paths = File::Spec->no_upwards( @paths );
118
119       case_tolerant
120         Returns a true or false value indicating, respectively, that
121         alphabetic case is not or is significant when comparing file
122         specifications.
123
124             $is_case_tolerant = File::Spec->case_tolerant();
125
126       file_name_is_absolute
127         Takes as its argument a path, and returns true if it is an absolute
128         path.
129
130             $is_absolute = File::Spec->file_name_is_absolute( $path );
131
132         This does not consult the local filesystem on Unix, Win32, OS/2, or
133         Mac OS (Classic).  It does consult the working environment for VMS
134         (see "file_name_is_absolute" in File::Spec::VMS).
135
136       path
137         Takes no argument.  Returns the environment variable "PATH" (or the
138         local platform's equivalent) as a list.
139
140             @PATH = File::Spec->path();
141
142       join
143         join is the same as catfile.
144
145       splitpath
146         Splits a path in to volume, directory, and filename portions. On
147         systems with no concept of volume, returns '' for volume.
148
149             ($volume,$directories,$file) = File::Spec->splitpath( $path );
150             ($volume,$directories,$file) = File::Spec->splitpath( $path, $no_file );
151
152         For systems with no syntax differentiating filenames from
153         directories, assumes that the last file is a path unless $no_file is
154         true or a trailing separator or /. or /.. is present. On Unix, this
155         means that $no_file true makes this return ( '', $path, '' ).
156
157         The directory portion may or may not be returned with a trailing '/'.
158
159         The results can be passed to "catpath()" to get back a path
160         equivalent to (usually identical to) the original path.
161
162       splitdir
163         The opposite of "catdir()".
164
165             @dirs = File::Spec->splitdir( $directories );
166
167         $directories must be only the directory portion of the path on
168         systems that have the concept of a volume or that have path syntax
169         that differentiates files from directories.
170
171         Unlike just splitting the directories on the separator, empty
172         directory names ('') can be returned, because these are significant
173         on some OSes.
174
175       catpath()
176         Takes volume, directory and file portions and returns an entire path.
177         Under Unix, $volume is ignored, and directory and file are
178         concatenated.  A '/' is inserted if need be.  On other OSes, $volume
179         is significant.
180
181             $full_path = File::Spec->catpath( $volume, $directory, $file );
182
183       abs2rel
184         Takes a destination path and an optional base path returns a relative
185         path from the base path to the destination path:
186
187             $rel_path = File::Spec->abs2rel( $path ) ;
188             $rel_path = File::Spec->abs2rel( $path, $base ) ;
189
190         If $base is not present or '', then Cwd::cwd() is used. If $base is
191         relative, then it is converted to absolute form using "rel2abs()".
192         This means that it is taken to be relative to Cwd::cwd().
193
194         On systems with the concept of volume, if $path and $base appear to
195         be on two different volumes, we will not attempt to resolve the two
196         paths, and we will instead simply return $path.  Note that previous
197         versions of this module ignored the volume of $base, which resulted
198         in garbage results part of the time.
199
200         On systems that have a grammar that indicates filenames, this ignores
201         the $base filename as well. Otherwise all path components are assumed
202         to be directories.
203
204         If $path is relative, it is converted to absolute form using
205         "rel2abs()".  This means that it is taken to be relative to
206         Cwd::cwd().
207
208         No checks against the filesystem are made.  On VMS, there is
209         interaction with the working environment, as logicals and macros are
210         expanded.
211
212         Based on code written by Shigio Yamaguchi.
213
214       rel2abs()
215         Converts a relative path to an absolute path.
216
217             $abs_path = File::Spec->rel2abs( $path ) ;
218             $abs_path = File::Spec->rel2abs( $path, $base ) ;
219
220         If $base is not present or '', then Cwd::cwd() is used. If $base is
221         relative, then it is converted to absolute form using "rel2abs()".
222         This means that it is taken to be relative to Cwd::cwd().
223
224         On systems with the concept of volume, if $path and $base appear to
225         be on two different volumes, we will not attempt to resolve the two
226         paths, and we will instead simply return $path.  Note that previous
227         versions of this module ignored the volume of $base, which resulted
228         in garbage results part of the time.
229
230         On systems that have a grammar that indicates filenames, this ignores
231         the $base filename as well. Otherwise all path components are assumed
232         to be directories.
233
234         If $path is absolute, it is cleaned up and returned using
235         "canonpath()".
236
237         No checks against the filesystem are made.  On VMS, there is
238         interaction with the working environment, as logicals and macros are
239         expanded.
240
241         Based on code written by Shigio Yamaguchi.
242
243       For further information, please see File::Spec::Unix, File::Spec::Mac,
244       File::Spec::OS2, File::Spec::Win32, or File::Spec::VMS.
245

SEE ALSO

247       File::Spec::Unix, File::Spec::Mac, File::Spec::OS2, File::Spec::Win32,
248       File::Spec::VMS, File::Spec::Functions, ExtUtils::MakeMaker
249

AUTHOR

251       Currently maintained by Ken Williams "<KWILLIAMS@cpan.org>".
252
253       The vast majority of the code was written by Kenneth Albanowski
254       "<kjahds@kjahds.com>", Andy Dougherty "<doughera@lafayette.edu>",
255       Andreas Koenig "<A.Koenig@franz.ww.TU-Berlin.DE>", Tim Bunce
256       "<Tim.Bunce@ig.co.uk>".  VMS support by Charles Bailey
257       "<bailey@newman.upenn.edu>".  OS/2 support by Ilya Zakharevich
258       "<ilya@math.ohio-state.edu>".  Mac support by Paul Schinder
259       "<schinder@pobox.com>", and Thomas Wegner "<wegner_thomas@yahoo.com>".
260       abs2rel() and rel2abs() written by Shigio Yamaguchi
261       "<shigio@tamacom.com>", modified by Barrie Slaymaker
262       "<barries@slaysys.com>".  splitpath(), splitdir(), catpath() and
263       catdir() by Barrie Slaymaker.
264
266       Copyright (c) 2004 by the Perl 5 Porters.  All rights reserved.
267
268       This program is free software; you can redistribute it and/or modify it
269       under the same terms as Perl itself.
270
271
272
273perl v5.12.4                      2011-06-20                   File::Spec(3pm)
Impressum