package File
::Spec
::Unix
;
File::Spec::Unix - File::Spec for Unix, base for other File::Spec modules
require File::Spec::Unix; # Done automatically by File::Spec
Methods for manipulating file specifications. Other File::Spec
modules, such as File::Spec::Mac, inherit from File::Spec::Unix and
override specific methods.
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 F<x/../y> sections into F<y>. This
is by design. If F</foo> on your system is a symlink to F</bar/baz>,
then F</foo/../quux> is actually F</bar/quux>, not F</quux> as a naive
F<../>-removal would give you. If you want to do this kind of
processing, you probably want C<Cwd>'s C<realpath()> function to
actually traverse the filesystem cleaning up paths like this.
# Handle POSIX-style node names beginning with double slash (qnx, nto)
# Handle network path names beginning with double slash (cygwin)
# (POSIX says: "a pathname that begins with two successive slashes
# may be interpreted in an implementation-defined manner, although
# more than two leading slashes shall be treated as a single slash.")
if ( $^O =~ m/^(?:qnx|nto|cygwin)$/ && $path =~ s:^(//[^/]+)(/|\z):/:s ) {
# $path =~ s|/+|/|g unless($^O eq 'cygwin');
# but that made tests 29, 30, 35, 46, and 213 (as of #13272) to fail
# (Mainly because trailing "" directories didn't get stripped).
# Why would cygwin avoid collapsing multiple slashes into one? --jhi
$path =~ s|/+|/|g; # xx////xx -> xx/xx
$path =~ s@(/\.)+(/|\Z(?!\n))@/@g; # xx/././xx -> xx/xx
$path =~ s|^(\./)+||s unless $path eq "./"; # ./xx -> xx
$path =~ s|^/(\.\./)+|/|; # /../../xx -> xx
$path =~ s|^/\.\.$|/|; # /.. -> /
$path =~ s|/\Z(?!\n)|| unless $path eq "/"; # xx/ -> xx
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
$self->canonpath(join('/', @_, '')); # '' because need a trailing '/'
Concatenate one or more directory names and a filename to form a
complete path ending with a filename
my $file = $self->canonpath(pop @_);
my $dir = $self->catdir(@_);
$dir .= "/" unless substr($dir,-1) eq "/";
Returns a string representation of the current directory. "." on UNIX.
Returns a string representation of the null device. "/dev/null" on UNIX.
sub devnull () { '/dev/null' }
Returns a string representation of the root directory. "/" on UNIX.
Returns a string representation of the first writable directory from
the following list or the current directory if none from the list are
Since perl 5.8.0, if running under taint mode, and if $ENV{TMPDIR}
is tainted, it is not used.
return $tmpdir if defined $tmpdir;
if (${"\cTAINT"}) { # Check for taint mode on perl >= 5.8.0
@dirlist = grep { ! Scalar::Util::tainted($_) } @dirlist;
next unless defined && -d && -w _;
$tmpdir = $self->curdir unless defined $tmpdir;
$tmpdir = defined $tmpdir && $self->canonpath($tmpdir);
return $tmpdir if defined $tmpdir;
$tmpdir = $_[0]->_tmpdir( $ENV{TMPDIR}, "/tmp" );
Returns a string representation of the parent directory. ".." on UNIX.
Given a list of file names, strip out those that refer to a parent
directory. (Does not strip symlinks, only '.', '..', and equivalents.)
return grep(!/^\.{1,2}\Z(?!\n)/s, @_);
Returns a true or false value indicating, respectively, that alphabetic
is not or is significant when comparing file specifications.
sub case_tolerant () { 0 }
=item file_name_is_absolute
Takes as argument a path and returns true if it is an absolute path.
This does not consult the local filesystem on Unix, Win32, OS/2 or Mac
OS (Classic). It does consult the working environment for VMS (see
L<File::Spec::VMS/file_name_is_absolute>).
sub file_name_is_absolute {
return scalar($file =~ m:^/:s);
Takes no argument, returns the environment variable PATH as an array.
return () unless exists $ENV{PATH};
my @path = split(':', $ENV{PATH});
foreach (@path) { $_ = '.' if $_ eq '' }
join is the same as catfile.
return $self->catfile(@_);
($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 ( '', $path, '' ).
The directory portion may or may not be returned with a trailing '/'.
The results can be passed to L</catpath()> to get back a path equivalent to
(usually identical to) the original path.
my ($self,$path, $nofile) = @_;
my ($volume,$directory,$file) = ('','','');
$path =~ m|^ ( (?: .* / (?: \.\.?\Z(?!\n) )? )? ) ([^/]*) |xs;
return ($volume,$directory,$file);
The opposite of L</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
Unlike just splitting the directories on the separator, empty
directory names (C<''>) can be returned, because these are significant
File::Spec->splitdir( "/a/b//c/" );
( '', 'a', 'b', '', 'c', '' )
return split m|/|, $_[1], -1; # Preserve trailing fields
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, $volume is significant.
my ($self,$volume,$directory,$file) = @_;
substr( $directory, -1 ) ne '/' &&
substr( $file, 0, 1 ) ne '/'
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 L<cwd()|Cwd> is used. If $base is
relative, then it is converted to absolute form using
L</rel2abs()>. This means that it is taken to be relative to
On systems that have a grammar that indicates filenames, this ignores the
$base filename. Otherwise all path components are assumed to be
If $path is relative, it is converted to absolute form using L</rel2abs()>.
This means that it is taken to be relative to L<cwd()|Cwd>.
No checks against the filesystem are made. On VMS, there is
interaction with the working environment, as logicals and
Based on code written by Shigio Yamaguchi.
my($self,$path,$base) = @_;
if ( ! $self->file_name_is_absolute( $path ) ) {
$path = $self->rel2abs( $path ) ;
$path = $self->canonpath( $path ) ;
# Figure out the effective $base and clean it up.
if ( !defined( $base ) || $base eq '' ) {
elsif ( ! $self->file_name_is_absolute( $base ) ) {
$base = $self->rel2abs( $base ) ;
$base = $self->canonpath( $base ) ;
# Now, remove all leading components that are the same
my @pathchunks = $self->splitdir( $path);
my @basechunks = $self->splitdir( $base);
while (@pathchunks && @basechunks && $pathchunks[0] eq $basechunks[0]) {
$path = CORE::join( '/', @pathchunks );
$base = CORE::join( '/', @basechunks );
# $base now contains the directories the resulting relative path
# must ascend out of before it can descend to $path_directory. So,
# replace all names with $parentDir
# Glue the two together, using a separator if necessary, and preventing an
if ( $path ne '' && $base ne '' ) {
return $self->canonpath( $path ) ;
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 L<cwd()|Cwd> is used. If $base is
relative, then it is converted to absolute form using
L</rel2abs()>. This means that it is taken to be relative to
On systems that have a grammar that indicates filenames, this ignores
the $base filename. Otherwise all path components are assumed to be
If $path is absolute, it is cleaned up and returned using L</canonpath()>.
No checks against the filesystem are made. On VMS, there is
interaction with the working environment, as logicals and
Based on code written by Shigio Yamaguchi.
my ($self,$path,$base ) = @_;
if ( ! $self->file_name_is_absolute( $path ) ) {
# Figure out the effective $base and clean it up.
if ( !defined( $base ) || $base eq '' ) {
elsif ( ! $self->file_name_is_absolute( $base ) ) {
$base = $self->rel2abs( $base ) ;
$base = $self->canonpath( $base ) ;
$path = $self->catdir( $base, $path ) ;
return $self->canonpath( $path ) ;
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.
# Internal routine to File::Spec, no point in making this public since
# it is the standard Cwd interface. Most of the platform-specific
# File::Spec subclasses use this.
# Internal method to reduce xx\..\yy -> yy
my $curdir = $fs->curdir;
my($vol, $dirs, $file) = $fs->splitpath($path);
my @dirs = $fs->splitdir($dirs);
foreach my $dir (@dirs) {
if( $dir eq $updir and # if we have an updir
@collapsed and # and something to collapse
length $collapsed[-1] and # and its not the rootdir
$collapsed[-1] ne $updir and # nor another updir
$collapsed[-1] ne $curdir # nor the curdir
pop @collapsed; # collapse
push @collapsed, $dir; # just hang onto it
return $fs->catpath($vol,