File::Spec::Unix(3perl) Perl Programmers Reference GuideFile::Spec::Unix(3perl)
NAME
File::Spec::Unix - File::Spec for Unix, base for other File::Spec
modules
SYNOPSIS
require File::Spec::Unix; # Done automatically by File::Spec
DESCRIPTION
Methods for manipulating file specifications. Other File::Spec modules,
such as File::Spec::Mac, inherit from File::Spec::Unix and override
specific methods.
METHODS
canonpath()
No physical check on the filesystem, but a logical cleanup of a path.
On UNIX eliminates successive slashes and successive "/.".
$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
OS2. Of course, if this is the root directory, don't cut off the
trailing slash :-)
catfile
Concatenate one or more directory names and a filename to form a
complete path ending with a filename
curdir
Returns a string representation of the current directory. "." on
UNIX.
devnull
Returns a string representation of the null device. "/dev/null" on
UNIX.
rootdir
Returns a string representation of the root directory. "/" on UNIX.
tmpdir
Returns a string representation of the first writable directory from
the following list or the current directory if none from the list are
writable:
$ENV{TMPDIR}
/tmp
If running under taint mode, and if $ENV{TMPDIR} is tainted, it is not
used.
updir
Returns a string representation of the parent directory. ".." on
UNIX.
no_upwards
Given a list of file names, strip out those that refer to a parent
directory. (Does not strip symlinks, only '.', '..', and equivalents.)
case_tolerant
Returns a true or false value indicating, respectively, that
alphabetic is not or is significant when comparing file
specifications.
file_name_is_absolute
Takes as argument a path and returns true if it is an absolute path.
This does not consult the local filesystem on Unix, Win32, OS/2 or Mac
OS (Classic). It does consult the working environment for VMS (see
"file_name_is_absolute" in File::Spec::VMS).
path
Takes no argument, returns the environment variable PATH as an array.
join
join is the same as catfile.
splitpath
($volume,$directories,$file) = File::Spec->splitpath( $path );
($volume,$directories,$file) = File::Spec->splitpath( $path,
$no_file );
Splits a path into volume, directory, and filename portions. On
systems with no concept of volume, returns '' for volume.
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 OSs.
On Unix,
File::Spec->splitdir( "/a/b//c/" );
Yields:
( '', 'a', 'b', '', 'c', '' )
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 needed (though if the directory
portion doesn't start with '/' it is not added). On other OSs,
$volume is significant.
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() 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 that have a grammar that indicates filenames, this ignores
the $base filename. 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, so the result may not be
correct if $base contains symbolic links. (Apply Cwd::abs_path()
beforehand if that is a concern.) 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 that have a grammar that indicates filenames, this ignores
the $base filename. 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.
COPYRIGHT
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.
Please submit bug reports at <https://github.com/Perl/perl5/issues>.
SEE ALSO
File::Spec
perl v5.40.1 2026-08-30 File::Spec::Unix(3perl)
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