|
|
File::Spec - portably perform operations on file names
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');
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, the File::Spec::Functions manpage provides convenient functional forms of these methods.
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.
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 );
Concatenate one or more directory names and a filename to form a complete path ending with a filename
$path = File::Spec->catfile( @directories, $filename );
Returns a string representation of the current directory.
$curdir = File::Spec->curdir();
Returns a string representation of the null device.
$devnull = File::Spec->devnull();
Returns a string representation of the root directory.
$rootdir = File::Spec->rootdir();
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();
Returns a string representation of the parent directory.
$updir = File::Spec->updir();
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 );
Returns a true or false value indicating, respectively, that alphabetic case is not or is significant when comparing file specifications.
$is_case_tolerant = File::Spec->case_tolerant();
Takes as its argument a path, and returns true if it is an absolute path.
$is_absolute = File::Spec->file_name_is_absolute( $path );
This does not consult the local filesystem on Unix, Win32, OS/2, or Mac OS (Classic). It does consult the working environment for VMS (see file_name_is_absolute in the File::Spec::VMS manpage).
Takes no argument. Returns the environment variable PATH (or the local
platform's equivalent) as a list.
@PATH = File::Spec->path();
join is the same as catfile.
Splits a path in to volume, directory, and filename portions. On systems with no concept of volume, returns '' for volume.
($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.
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 );
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() 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().
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().
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() 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().
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 the File::Spec::Unix manpage, the File::Spec::Mac manpage, the File::Spec::OS2 manpage, the File::Spec::Win32 manpage, or the File::Spec::VMS manpage.
the File::Spec::Unix manpage, the File::Spec::Mac manpage, the File::Spec::OS2 manpage, the File::Spec::Win32 manpage, the File::Spec::VMS manpage, the File::Spec::Functions manpage, the ExtUtils::MakeMaker manpage
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 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 (c) 2004 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.