File/Spec/Unix.pm

package File::Spec::Unix;

use strict;
use vars qw($VERSION);

$VERSION = '1.5';

=head1 NAME

File::Spec::Unix - File::Spec for Unix, base for other File::Spec modules

=head1 SYNOPSIS

 require File::Spec::Unix; # Done automatically by File::Spec

=head1 DESCRIPTION

Methods for manipulating file specifications.  Other File::Spec
modules, such as File::Spec::Mac, inherit from File::Spec::Unix and
override specific methods.

=head1 METHODS

=over 2

=item 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 ) ;

=cut

sub canonpath {
    my ($self,$path) = @_;
    
    # 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.")
    my $node = '';
    if ( $^O =~ m/^(?:qnx|nto|cygwin)$/ && $path =~ s:^(//[^/]+)(/|\z):/:s ) {
      $node = $1;
    }
    # This used to be
    # $path =~ s|/+|/|g unless($^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|^/(\.\./)+|/|s;                     # /../../xx -> xx
    $path =~ s|/\Z(?!\n)|| unless $path eq "/";          # xx/       -> xx
    return "$node$path";
}

=item 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 :-)

=cut

sub catdir {
    my $self = shift;

    $self->canonpath(join('/', @_, '')); # '' because need a trailing '/'
}

=item catfile

Concatenate one or more directory names and a filename to form a
complete path ending with a filename

=cut

sub catfile {
    my $self = shift;
    my $file = $self->canonpath(pop @_);
    return $file unless @_;
    my $dir = $self->catdir(@_);
    $dir .= "/" unless substr($dir,-1) eq "/";
    return $dir.$file;
}

=item curdir

Returns a string representation of the current directory.  "." on UNIX.

=cut

sub curdir () { '.' }

=item devnull

Returns a string representation of the null device. "/dev/null" on UNIX.

=cut

sub devnull () { '/dev/null' }

=item rootdir

Returns a string representation of the root directory.  "/" on UNIX.

=cut

sub rootdir () { '/' }

=item 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

Since perl 5.8.0, if running under taint mode, and if $ENV{TMPDIR}
is tainted, it is not used.

=cut

my $tmpdir;
sub _tmpdir {
    return $tmpdir if defined $tmpdir;
    my $self = shift;
    my @dirlist = @_;
    {
        no strict 'refs';
        if (${"\cTAINT"}) { # Check for taint mode on perl >= 5.8.0
            require Scalar::Util;
            @dirlist = grep { ! Scalar::Util::tainted($_) } @dirlist;
        }
    }
    foreach (@dirlist) {
        next unless defined && -d && -w _;
        $tmpdir = $_;
        last;
    }
    $tmpdir = $self->curdir unless defined $tmpdir;
    $tmpdir = defined $tmpdir && $self->canonpath($tmpdir);
    return $tmpdir;
}

sub tmpdir {
    return $tmpdir if defined $tmpdir;
    my $self = shift;
    $tmpdir = $self->_tmpdir( $ENV{TMPDIR}, "/tmp" );
}

=item updir

Returns a string representation of the parent directory.  ".." on UNIX.

=cut

sub updir () { '..' }

=item no_upwards

Given a list of file names, strip out those that refer to a parent
directory. (Does not strip symlinks, only '.', '..', and equivalents.)

=cut

sub no_upwards {
    my $self = shift;
    return grep(!/^\.{1,2}\Z(?!\n)/s, @_);
}

=item case_tolerant

Returns a true or false value indicating, respectively, that alphabetic
is not or is significant when comparing file specifications.

=cut

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>).

=cut

sub file_name_is_absolute {
    my ($self,$file) = @_;
    return scalar($file =~ m:^/:s);
}

=item path

Takes no argument, returns the environment variable PATH as an array.

=cut

sub path {
    return () unless exists $ENV{PATH};
    my @path = split(':', $ENV{PATH});
    foreach (@path) { $_ = '.' if $_ eq '' }
    return @path;
}

=item join

join is the same as catfile.

=cut

sub join {
    my $self = shift;
    return $self->catfile(@_);
}

=item 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 L</catpath()> to get back a path equivalent to
(usually identical to) the original path.

=cut

sub splitpath {
    my ($self,$path, $nofile) = @_;

    my ($volume,$directory,$file) = ('','','');

    if ( $nofile ) {
        $directory = $path;
    }
    else {
        $path =~ m|^ ( (?: .* / (?: \.\.?\Z(?!\n) )? )? ) ([^/]*) |xs;
        $directory = $1;
        $file      = $2;
    }

    return ($volume,$directory,$file);
}


=item splitdir

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
files from directories.

Unlike just splitting the directories on the separator, empty
directory names (C<''>) can be returned, because these are significant
on some OSs.

On Unix,

    File::Spec->splitdir( "/a/b//c/" );

Yields:

    ( '', 'a', 'b', '', 'c', '' )

=cut

sub splitdir {
    return split m|/|, $_[1], -1;  # Preserve trailing fields
}


=item 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.

=cut

sub catpath {
    my ($self,$volume,$directory,$file) = @_;

    if ( $directory ne ''                && 
         $file ne ''                     && 
         substr( $directory, -1 ) ne '/' && 
         substr( $file, 0, 1 ) ne '/' 
    ) {
        $directory .= "/$file" ;
    }
    else {
        $directory .= $file ;
    }

    return $directory ;
}

=item 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 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
L<cwd()|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 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
macros are expanded.

Based on code written by Shigio Yamaguchi.

=cut

sub abs2rel {
    my($self,$path,$base) = @_;

    # Clean up $path
    if ( ! $self->file_name_is_absolute( $path ) ) {
        $path = $self->rel2abs( $path ) ;
    }
    else {
        $path = $self->canonpath( $path ) ;
    }

    # Figure out the effective $base and clean it up.
    if ( !defined( $base ) || $base eq '' ) {
        $base = $self->_cwd();
    }
    elsif ( ! $self->file_name_is_absolute( $base ) ) {
        $base = $self->rel2abs( $base ) ;
    }
    else {
        $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]) {
        shift @pathchunks ;
        shift @basechunks ;
    }

    $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
    $base =~ s|[^/]+|..|g ;

    # Glue the two together, using a separator if necessary, and preventing an
    # empty result.
    if ( $path ne '' && $base ne '' ) {
        $path = "$base/$path" ;
    } else {
        $path = "$base$path" ;
    }

    return $self->canonpath( $path ) ;
}

=item 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 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
L<cwd()|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 L</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.

=cut

sub rel2abs {
    my ($self,$path,$base ) = @_;

    # Clean up $path
    if ( ! $self->file_name_is_absolute( $path ) ) {
        # Figure out the effective $base and clean it up.
        if ( !defined( $base ) || $base eq '' ) {
            $base = $self->_cwd();
        }
        elsif ( ! $self->file_name_is_absolute( $base ) ) {
            $base = $self->rel2abs( $base ) ;
        }
        else {
            $base = $self->canonpath( $base ) ;
        }

        # Glom them together
        $path = $self->catdir( $base, $path ) ;
    }

    return $self->canonpath( $path ) ;
}

=back

=head1 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.

=head1 SEE ALSO

L<File::Spec>

=cut

# 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.
sub _cwd {
    require Cwd;
    Cwd::cwd();
}

1;
Revision:	1.1
Committed:	Thu Jun 30 14:27:12 2005 UTC (21 years, 3 months ago) by root
Branch:	MAIN
CVS Tags:	PERL-5-8-7, HEAD
Branch point for:	PERL
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	package File::Spec::Unix;
2
3			use strict;
4			use vars qw($VERSION);
5
6			$VERSION = '1.5';
7
8			=head1 NAME
9
10			File::Spec::Unix - File::Spec for Unix, base for other File::Spec modules
11
12			=head1 SYNOPSIS
13
14			require File::Spec::Unix; # Done automatically by File::Spec
15
16			=head1 DESCRIPTION
17
18			Methods for manipulating file specifications. Other File::Spec
19			modules, such as File::Spec::Mac, inherit from File::Spec::Unix and
20			override specific methods.
21
22			=head1 METHODS
23
24			=over 2
25
26			=item canonpath()
27
28			No physical check on the filesystem, but a logical cleanup of a
29			path. On UNIX eliminates successive slashes and successive "/.".
30
31			$cpath = File::Spec->canonpath( $path ) ;
32
33			=cut
34
35			sub canonpath {
36			my ($self,$path) = @_;
37
38			# Handle POSIX-style node names beginning with double slash (qnx, nto)
39			# Handle network path names beginning with double slash (cygwin)
40			# (POSIX says: "a pathname that begins with two successive slashes
41			# may be interpreted in an implementation-defined manner, although
42			# more than two leading slashes shall be treated as a single slash.")
43			my $node = '';
44			if ( $^O =~ m/^(?:qnx\|nto\|cygwin)$/ && $path =~ s:^(//[^/]+)(/\|\z):/:s ) {
45			$node = $1;
46			}
47			# This used to be
48			# $path =~ s\|/+\|/\|g unless($^O eq 'cygwin');
49			# but that made tests 29, 30, 35, 46, and 213 (as of #13272) to fail
50			# (Mainly because trailing "" directories didn't get stripped).
51			# Why would cygwin avoid collapsing multiple slashes into one? --jhi
52			$path =~ s\|/+\|/\|g; # xx////xx -> xx/xx
53			$path =~ s@(/\.)+(/\|\Z(?!\n))@/@g; # xx/././xx -> xx/xx
54			$path =~ s\|^(\./)+\|\|s unless $path eq "./"; # ./xx -> xx
55			$path =~ s\|^/(\.\./)+\|/\|s; # /../../xx -> xx
56			$path =~ s\|/\Z(?!\n)\|\| unless $path eq "/"; # xx/ -> xx
57			return "$node$path";
58			}
59
60			=item catdir()
61
62			Concatenate two or more directory names to form a complete path ending
63			with a directory. But remove the trailing slash from the resulting
64			string, because it doesn't look good, isn't necessary and confuses
65			OS2. Of course, if this is the root directory, don't cut off the
66			trailing slash :-)
67
68			=cut
69
70			sub catdir {
71			my $self = shift;
72
73			$self->canonpath(join('/', @_, '')); # '' because need a trailing '/'
74			}
75
76			=item catfile
77
78			Concatenate one or more directory names and a filename to form a
79			complete path ending with a filename
80
81			=cut
82
83			sub catfile {
84			my $self = shift;
85			my $file = $self->canonpath(pop @_);
86			return $file unless @_;
87			my $dir = $self->catdir(@_);
88			$dir .= "/" unless substr($dir,-1) eq "/";
89			return $dir.$file;
90			}
91
92			=item curdir
93
94			Returns a string representation of the current directory. "." on UNIX.
95
96			=cut
97
98			sub curdir () { '.' }
99
100			=item devnull
101
102			Returns a string representation of the null device. "/dev/null" on UNIX.
103
104			=cut
105
106			sub devnull () { '/dev/null' }
107
108			=item rootdir
109
110			Returns a string representation of the root directory. "/" on UNIX.
111
112			=cut
113
114			sub rootdir () { '/' }
115
116			=item tmpdir
117
118			Returns a string representation of the first writable directory from
119			the following list or the current directory if none from the list are
120			writable:
121
122			$ENV{TMPDIR}
123			/tmp
124
125			Since perl 5.8.0, if running under taint mode, and if $ENV{TMPDIR}
126			is tainted, it is not used.
127
128			=cut
129
130			my $tmpdir;
131			sub _tmpdir {
132			return $tmpdir if defined $tmpdir;
133			my $self = shift;
134			my @dirlist = @_;
135			{
136			no strict 'refs';
137			if (${"\cTAINT"}) { # Check for taint mode on perl >= 5.8.0
138			require Scalar::Util;
139			@dirlist = grep { ! Scalar::Util::tainted($_) } @dirlist;
140			}
141			}
142			foreach (@dirlist) {
143			next unless defined && -d && -w _;
144			$tmpdir = $_;
145			last;
146			}
147			$tmpdir = $self->curdir unless defined $tmpdir;
148			$tmpdir = defined $tmpdir && $self->canonpath($tmpdir);
149			return $tmpdir;
150			}
151
152			sub tmpdir {
153			return $tmpdir if defined $tmpdir;
154			my $self = shift;
155			$tmpdir = $self->_tmpdir( $ENV{TMPDIR}, "/tmp" );
156			}
157
158			=item updir
159
160			Returns a string representation of the parent directory. ".." on UNIX.
161
162			=cut
163
164			sub updir () { '..' }
165
166			=item no_upwards
167
168			Given a list of file names, strip out those that refer to a parent
169			directory. (Does not strip symlinks, only '.', '..', and equivalents.)
170
171			=cut
172
173			sub no_upwards {
174			my $self = shift;
175			return grep(!/^\.{1,2}\Z(?!\n)/s, @_);
176			}
177
178			=item case_tolerant
179
180			Returns a true or false value indicating, respectively, that alphabetic
181			is not or is significant when comparing file specifications.
182
183			=cut
184
185			sub case_tolerant () { 0 }
186
187			=item file_name_is_absolute
188
189			Takes as argument a path and returns true if it is an absolute path.
190
191			This does not consult the local filesystem on Unix, Win32, OS/2 or Mac
192			OS (Classic). It does consult the working environment for VMS (see
193			L<File::Spec::VMS/file_name_is_absolute>).
194
195			=cut
196
197			sub file_name_is_absolute {
198			my ($self,$file) = @_;
199			return scalar($file =~ m:^/:s);
200			}
201
202			=item path
203
204			Takes no argument, returns the environment variable PATH as an array.
205
206			=cut
207
208			sub path {
209			return () unless exists $ENV{PATH};
210			my @path = split(':', $ENV{PATH});
211			foreach (@path) { $_ = '.' if $_ eq '' }
212			return @path;
213			}
214
215			=item join
216
217			join is the same as catfile.
218
219			=cut
220
221			sub join {
222			my $self = shift;
223			return $self->catfile(@_);
224			}
225
226			=item splitpath
227
228			($volume,$directories,$file) = File::Spec->splitpath( $path );
229			($volume,$directories,$file) = File::Spec->splitpath( $path, $no_file );
230
231			Splits a path into volume, directory, and filename portions. On systems
232			with no concept of volume, returns '' for volume.
233
234			For systems with no syntax differentiating filenames from directories,
235			assumes that the last file is a path unless $no_file is true or a
236			trailing separator or /. or /.. is present. On Unix this means that $no_file
237			true makes this return ( '', $path, '' ).
238
239			The directory portion may or may not be returned with a trailing '/'.
240
241			The results can be passed to L</catpath()> to get back a path equivalent to
242			(usually identical to) the original path.
243
244			=cut
245
246			sub splitpath {
247			my ($self,$path, $nofile) = @_;
248
249			my ($volume,$directory,$file) = ('','','');
250
251			if ( $nofile ) {
252			$directory = $path;
253			}
254			else {
255			$path =~ m\|^ ( (?: .* / (?: \.\.?\Z(?!\n) )? )? ) ([^/]*) \|xs;
256			$directory = $1;
257			$file = $2;
258			}
259
260			return ($volume,$directory,$file);
261			}
262
263
264			=item splitdir
265
266			The opposite of L</catdir()>.
267
268			@dirs = File::Spec->splitdir( $directories );
269
270			$directories must be only the directory portion of the path on systems
271			that have the concept of a volume or that have path syntax that differentiates
272			files from directories.
273
274			Unlike just splitting the directories on the separator, empty
275			directory names (C<''>) can be returned, because these are significant
276			on some OSs.
277
278			On Unix,
279
280			File::Spec->splitdir( "/a/b//c/" );
281
282			Yields:
283
284			( '', 'a', 'b', '', 'c', '' )
285
286			=cut
287
288			sub splitdir {
289			return split m\|/\|, $_[1], -1; # Preserve trailing fields
290			}
291
292
293			=item catpath()
294
295			Takes volume, directory and file portions and returns an entire path. Under
296			Unix, $volume is ignored, and directory and file are concatenated. A '/' is
297			inserted if needed (though if the directory portion doesn't start with
298			'/' it is not added). On other OSs, $volume is significant.
299
300			=cut
301
302			sub catpath {
303			my ($self,$volume,$directory,$file) = @_;
304
305			if ( $directory ne '' &&
306			$file ne '' &&
307			substr( $directory, -1 ) ne '/' &&
308			substr( $file, 0, 1 ) ne '/'
309			) {
310			$directory .= "/$file" ;
311			}
312			else {
313			$directory .= $file ;
314			}
315
316			return $directory ;
317			}
318
319			=item abs2rel
320
321			Takes a destination path and an optional base path returns a relative path
322			from the base path to the destination path:
323
324			$rel_path = File::Spec->abs2rel( $path ) ;
325			$rel_path = File::Spec->abs2rel( $path, $base ) ;
326
327			If $base is not present or '', then L<cwd()\|Cwd> is used. If $base is
328			relative, then it is converted to absolute form using
329			L</rel2abs()>. This means that it is taken to be relative to
330			L<cwd()\|Cwd>.
331
332			On systems that have a grammar that indicates filenames, this ignores the
333			$base filename. Otherwise all path components are assumed to be
334			directories.
335
336			If $path is relative, it is converted to absolute form using L</rel2abs()>.
337			This means that it is taken to be relative to L<cwd()\|Cwd>.
338
339			No checks against the filesystem are made. On VMS, there is
340			interaction with the working environment, as logicals and
341			macros are expanded.
342
343			Based on code written by Shigio Yamaguchi.
344
345			=cut
346
347			sub abs2rel {
348			my($self,$path,$base) = @_;
349
350			# Clean up $path
351			if ( ! $self->file_name_is_absolute( $path ) ) {
352			$path = $self->rel2abs( $path ) ;
353			}
354			else {
355			$path = $self->canonpath( $path ) ;
356			}
357
358			# Figure out the effective $base and clean it up.
359			if ( !defined( $base ) \|\| $base eq '' ) {
360			$base = $self->_cwd();
361			}
362			elsif ( ! $self->file_name_is_absolute( $base ) ) {
363			$base = $self->rel2abs( $base ) ;
364			}
365			else {
366			$base = $self->canonpath( $base ) ;
367			}
368
369			# Now, remove all leading components that are the same
370			my @pathchunks = $self->splitdir( $path);
371			my @basechunks = $self->splitdir( $base);
372
373			while (@pathchunks && @basechunks && $pathchunks[0] eq $basechunks[0]) {
374			shift @pathchunks ;
375			shift @basechunks ;
376			}
377
378			$path = CORE::join( '/', @pathchunks );
379			$base = CORE::join( '/', @basechunks );
380
381			# $base now contains the directories the resulting relative path
382			# must ascend out of before it can descend to $path_directory. So,
383			# replace all names with $parentDir
384			$base =~ s\|[^/]+\|..\|g ;
385
386			# Glue the two together, using a separator if necessary, and preventing an
387			# empty result.
388			if ( $path ne '' && $base ne '' ) {
389			$path = "$base/$path" ;
390			} else {
391			$path = "$base$path" ;
392			}
393
394			return $self->canonpath( $path ) ;
395			}
396
397			=item rel2abs()
398
399			Converts a relative path to an absolute path.
400
401			$abs_path = File::Spec->rel2abs( $path ) ;
402			$abs_path = File::Spec->rel2abs( $path, $base ) ;
403
404			If $base is not present or '', then L<cwd()\|Cwd> is used. If $base is
405			relative, then it is converted to absolute form using
406			L</rel2abs()>. This means that it is taken to be relative to
407			L<cwd()\|Cwd>.
408
409			On systems that have a grammar that indicates filenames, this ignores
410			the $base filename. Otherwise all path components are assumed to be
411			directories.
412
413			If $path is absolute, it is cleaned up and returned using L</canonpath()>.
414
415			No checks against the filesystem are made. On VMS, there is
416			interaction with the working environment, as logicals and
417			macros are expanded.
418
419			Based on code written by Shigio Yamaguchi.
420
421			=cut
422
423			sub rel2abs {
424			my ($self,$path,$base ) = @_;
425
426			# Clean up $path
427			if ( ! $self->file_name_is_absolute( $path ) ) {
428			# Figure out the effective $base and clean it up.
429			if ( !defined( $base ) \|\| $base eq '' ) {
430			$base = $self->_cwd();
431			}
432			elsif ( ! $self->file_name_is_absolute( $base ) ) {
433			$base = $self->rel2abs( $base ) ;
434			}
435			else {
436			$base = $self->canonpath( $base ) ;
437			}
438
439			# Glom them together
440			$path = $self->catdir( $base, $path ) ;
441			}
442
443			return $self->canonpath( $path ) ;
444			}
445
446			=back
447
448			=head1 COPYRIGHT
449
450			Copyright (c) 2004 by the Perl 5 Porters. All rights reserved.
451
452			This program is free software; you can redistribute it and/or modify
453			it under the same terms as Perl itself.
454
455			=head1 SEE ALSO
456
457			L<File::Spec>
458
459			=cut
460
461			# Internal routine to File::Spec, no point in making this public since
462			# it is the standard Cwd interface. Most of the platform-specific
463			# File::Spec subclasses use this.
464			sub _cwd {
465			require Cwd;
466			Cwd::cwd();
467			}
468
469			1;