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1 | package Cwd; |
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2 | require 5.6.0; |
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3 | |
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4 | =head1 NAME |
5 | |
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6 | Cwd - get pathname of current working directory |
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7 | |
8 | =head1 SYNOPSIS |
9 | |
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10 | use Cwd; |
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11 | my $dir = getcwd; |
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12 | |
04929354 |
13 | use Cwd 'abs_path'; |
14 | my $abs_path = abs_path($file); |
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15 | |
04929354 |
16 | =head1 DESCRIPTION |
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17 | |
04929354 |
18 | This module provides functions for determining the pathname of the |
19 | current working directory. It is recommended that getcwd (or another |
20 | *cwd() function) be used in I<all> code to ensure portability. |
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21 | |
04929354 |
22 | By default, it exports the functions cwd(), getcwd(), fastcwd(), and |
23 | fastgetcwd() into the caller's namespace. |
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24 | |
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25 | |
04929354 |
26 | =head2 getcwd and friends |
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27 | |
04929354 |
28 | Each of these functions are called without arguments and return the |
29 | absolute path of the current working directory. |
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30 | |
04929354 |
31 | =over 4 |
32 | |
33 | =item getcwd |
34 | |
35 | my $cwd = getcwd(); |
36 | |
37 | Returns the current working directory. |
38 | |
39 | Re-implements the getcwd(3) (or getwd(3)) functions in Perl. |
40 | |
41 | =item cwd |
42 | |
43 | my $cwd = cwd(); |
44 | |
45 | The cwd() is the most natural form for the current architecture. For |
46 | most systems it is identical to `pwd` (but without the trailing line |
47 | terminator). |
48 | |
49 | Unfortunately, cwd() tends to break if called under taint mode. |
50 | |
51 | =item fastcwd |
52 | |
53 | my $cwd = fastcwd(); |
54 | |
55 | A more dangerous version of getcwd(), but potentially faster. |
56 | |
57 | It might conceivably chdir() you out of a directory that it can't |
58 | chdir() you back into. If fastcwd encounters a problem it will return |
59 | undef but will probably leave you in a different directory. For a |
60 | measure of extra security, if everything appears to have worked, the |
61 | fastcwd() function will check that it leaves you in the same directory |
62 | that it started in. If it has changed it will C<die> with the message |
63 | "Unstable directory path, current directory changed |
64 | unexpectedly". That should never happen. |
65 | |
66 | =item fastgetcwd |
67 | |
68 | my $cwd = fastgetcwd(); |
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69 | |
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70 | The fastgetcwd() function is provided as a synonym for cwd(). |
fb73857a |
71 | |
04929354 |
72 | =back |
73 | |
902bacac |
74 | |
04929354 |
75 | =head2 abs_path and friends |
76 | |
77 | These functions are exported only on request. They each take a single |
78 | argument and return the absolute pathname for it. |
79 | |
80 | =over 4 |
81 | |
82 | =item abs_path |
83 | |
84 | my $abs_path = abs_path($file); |
85 | |
86 | Uses the same algorithm as getcwd(). Symbolic links and relative-path |
87 | components ("." and "..") are resolved to return the canonical |
88 | pathname, just like realpath(3). |
89 | |
90 | =item realpath |
91 | |
92 | my $abs_path = realpath($file); |
93 | |
94 | A synonym for abs_path(). |
95 | |
96 | =item fast_abs_path |
97 | |
98 | my $abs_path = abs_path($file); |
99 | |
100 | A more dangerous, but potentially faster version of abs_path. |
101 | |
102 | =back |
103 | |
104 | =head2 $ENV{PWD} |
105 | |
106 | If you ask to override your chdir() built-in function, |
107 | |
108 | use Cwd qw(chdir); |
109 | |
110 | then your PWD environment variable will be kept up to date. Note that |
111 | it will only be kept up to date if all packages which use chdir import |
112 | it from Cwd. |
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113 | |
4633a7c4 |
114 | |
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115 | =head1 NOTES |
116 | |
117 | =over 4 |
118 | |
119 | =item * |
120 | |
04929354 |
121 | Since the path seperators are different on some operating systems ('/' |
122 | on Unix, ':' on MacPerl, etc...) we recommend you use the File::Spec |
123 | modules wherever portability is a concern. |
124 | |
04929354 |
125 | =item * |
4d6b4052 |
126 | |
127 | Actually, on Mac OS, the C<getcwd()>, C<fastgetcwd()> and C<fastcwd()> |
128 | functions are all aliases for the C<cwd()> function, which, on Mac OS, |
129 | calls `pwd`. Likewise, the C<abs_path()> function is an alias for |
130 | C<fast_abs_path()>. |
131 | |
132 | =back |
133 | |
04929354 |
134 | =head1 SEE ALSO |
135 | |
136 | L<File::chdir> |
137 | |
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138 | =cut |
139 | |
b060a406 |
140 | use strict; |
96e4d5b1 |
141 | |
142 | use Carp; |
143 | |
04929354 |
144 | our $VERSION = '2.06'; |
96e4d5b1 |
145 | |
b060a406 |
146 | use base qw/ Exporter /; |
147 | our @EXPORT = qw(cwd getcwd fastcwd fastgetcwd); |
148 | our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); |
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149 | |
f5f423e4 |
150 | # sys_cwd may keep the builtin command |
151 | |
152 | # All the functionality of this module may provided by builtins, |
153 | # there is no sense to process the rest of the file. |
154 | # The best choice may be to have this in BEGIN, but how to return from BEGIN? |
155 | |
156 | if ($^O eq 'os2' && defined &sys_cwd && defined &sys_abspath) { |
157 | local $^W = 0; |
158 | *cwd = \&sys_cwd; |
159 | *getcwd = \&cwd; |
160 | *fastgetcwd = \&cwd; |
161 | *fastcwd = \&cwd; |
162 | *abs_path = \&sys_abspath; |
163 | *fast_abs_path = \&abs_path; |
164 | *realpath = \&abs_path; |
165 | *fast_realpath = \&abs_path; |
166 | return 1; |
167 | } |
168 | |
f22d8e4b |
169 | eval { |
170 | require XSLoader; |
171 | XSLoader::load('Cwd'); |
172 | }; |
4633a7c4 |
173 | |
96e4d5b1 |
174 | |
3547aa9a |
175 | # Find the pwd command in the expected locations. We assume these |
176 | # are safe. This prevents _backtick_pwd() consulting $ENV{PATH} |
177 | # so everything works under taint mode. |
178 | my $pwd_cmd; |
179 | foreach my $try (qw(/bin/pwd /usr/bin/pwd)) { |
180 | if( -x $try ) { |
181 | $pwd_cmd = $try; |
182 | last; |
183 | } |
184 | } |
185 | $pwd_cmd ||= 'pwd'; |
186 | |
187 | # The 'natural and safe form' for UNIX (pwd may be setuid root) |
8b88ae92 |
188 | sub _backtick_pwd { |
3547aa9a |
189 | my $cwd = `$pwd_cmd`; |
7e03f963 |
190 | # `pwd` may fail e.g. if the disk is full |
191 | chomp($cwd) if defined $cwd; |
4633a7c4 |
192 | $cwd; |
8b88ae92 |
193 | } |
4633a7c4 |
194 | |
195 | # Since some ports may predefine cwd internally (e.g., NT) |
196 | # we take care not to override an existing definition for cwd(). |
197 | |
ea54c8bd |
198 | unless(defined &cwd) { |
199 | # The pwd command is not available in some chroot(2)'ed environments |
4aecb5b5 |
200 | if($^O eq 'MacOS' || grep { -x "$_/pwd" } split(':', $ENV{PATH})) { |
ea54c8bd |
201 | *cwd = \&_backtick_pwd; |
202 | } |
203 | else { |
204 | *cwd = \&getcwd; |
205 | } |
206 | } |
a0d0e21e |
207 | |
1f4f94f5 |
208 | # set a reasonable (and very safe) default for fastgetcwd, in case it |
209 | # isn't redefined later (20001212 rspier) |
210 | *fastgetcwd = \&cwd; |
748a9306 |
211 | |
a0d0e21e |
212 | # By Brandon S. Allbery |
213 | # |
214 | # Usage: $cwd = getcwd(); |
215 | |
216 | sub getcwd |
217 | { |
07569ed3 |
218 | abs_path('.'); |
a0d0e21e |
219 | } |
220 | |
a0c9c202 |
221 | |
222 | # By John Bazik |
223 | # |
224 | # Usage: $cwd = &fastcwd; |
225 | # |
226 | # This is a faster version of getcwd. It's also more dangerous because |
227 | # you might chdir out of a directory that you can't chdir back into. |
228 | |
229 | sub fastcwd { |
230 | my($odev, $oino, $cdev, $cino, $tdev, $tino); |
231 | my(@path, $path); |
232 | local(*DIR); |
233 | |
234 | my($orig_cdev, $orig_cino) = stat('.'); |
235 | ($cdev, $cino) = ($orig_cdev, $orig_cino); |
236 | for (;;) { |
237 | my $direntry; |
238 | ($odev, $oino) = ($cdev, $cino); |
239 | CORE::chdir('..') || return undef; |
240 | ($cdev, $cino) = stat('.'); |
241 | last if $odev == $cdev && $oino == $cino; |
242 | opendir(DIR, '.') || return undef; |
243 | for (;;) { |
244 | $direntry = readdir(DIR); |
245 | last unless defined $direntry; |
246 | next if $direntry eq '.'; |
247 | next if $direntry eq '..'; |
248 | |
249 | ($tdev, $tino) = lstat($direntry); |
250 | last unless $tdev != $odev || $tino != $oino; |
251 | } |
252 | closedir(DIR); |
253 | return undef unless defined $direntry; # should never happen |
254 | unshift(@path, $direntry); |
255 | } |
256 | $path = '/' . join('/', @path); |
257 | if ($^O eq 'apollo') { $path = "/".$path; } |
258 | # At this point $path may be tainted (if tainting) and chdir would fail. |
259 | # To be more useful we untaint it then check that we landed where we started. |
260 | $path = $1 if $path =~ /^(.*)\z/s; # untaint |
261 | CORE::chdir($path) || return undef; |
262 | ($cdev, $cino) = stat('.'); |
263 | die "Unstable directory path, current directory changed unexpectedly" |
264 | if $cdev != $orig_cdev || $cino != $orig_cino; |
265 | $path; |
266 | } |
267 | |
268 | |
4633a7c4 |
269 | # Keeps track of current working directory in PWD environment var |
a0d0e21e |
270 | # Usage: |
271 | # use Cwd 'chdir'; |
272 | # chdir $newdir; |
273 | |
4633a7c4 |
274 | my $chdir_init = 0; |
a0d0e21e |
275 | |
4633a7c4 |
276 | sub chdir_init { |
3b8e3443 |
277 | if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos' and $^O ne 'MSWin32') { |
a0d0e21e |
278 | my($dd,$di) = stat('.'); |
279 | my($pd,$pi) = stat($ENV{'PWD'}); |
280 | if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) { |
4633a7c4 |
281 | $ENV{'PWD'} = cwd(); |
a0d0e21e |
282 | } |
283 | } |
284 | else { |
3b8e3443 |
285 | my $wd = cwd(); |
286 | $wd = Win32::GetFullPathName($wd) if $^O eq 'MSWin32'; |
287 | $ENV{'PWD'} = $wd; |
a0d0e21e |
288 | } |
4633a7c4 |
289 | # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) |
3b8e3443 |
290 | if ($^O ne 'MSWin32' and $ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { |
a0d0e21e |
291 | my($pd,$pi) = stat($2); |
292 | my($dd,$di) = stat($1); |
293 | if (defined $pd and defined $dd and $di == $pi and $dd == $pd) { |
294 | $ENV{'PWD'}="$2$3"; |
295 | } |
296 | } |
297 | $chdir_init = 1; |
298 | } |
299 | |
300 | sub chdir { |
22978713 |
301 | my $newdir = @_ ? shift : ''; # allow for no arg (chdir to HOME dir) |
3b8e3443 |
302 | $newdir =~ s|///*|/|g unless $^O eq 'MSWin32'; |
a0d0e21e |
303 | chdir_init() unless $chdir_init; |
4ffa1610 |
304 | my $newpwd; |
305 | if ($^O eq 'MSWin32') { |
306 | # get the full path name *before* the chdir() |
307 | $newpwd = Win32::GetFullPathName($newdir); |
308 | } |
309 | |
4633a7c4 |
310 | return 0 unless CORE::chdir $newdir; |
4ffa1610 |
311 | |
3b8e3443 |
312 | if ($^O eq 'VMS') { |
313 | return $ENV{'PWD'} = $ENV{'DEFAULT'} |
314 | } |
4aecb5b5 |
315 | elsif ($^O eq 'MacOS') { |
316 | return $ENV{'PWD'} = cwd(); |
317 | } |
3b8e3443 |
318 | elsif ($^O eq 'MSWin32') { |
4ffa1610 |
319 | $ENV{'PWD'} = $newpwd; |
3b8e3443 |
320 | return 1; |
321 | } |
748a9306 |
322 | |
392d8ab8 |
323 | if ($newdir =~ m#^/#s) { |
a0d0e21e |
324 | $ENV{'PWD'} = $newdir; |
4633a7c4 |
325 | } else { |
326 | my @curdir = split(m#/#,$ENV{'PWD'}); |
327 | @curdir = ('') unless @curdir; |
328 | my $component; |
a0d0e21e |
329 | foreach $component (split(m#/#, $newdir)) { |
330 | next if $component eq '.'; |
331 | pop(@curdir),next if $component eq '..'; |
332 | push(@curdir,$component); |
333 | } |
334 | $ENV{'PWD'} = join('/',@curdir) || '/'; |
335 | } |
4633a7c4 |
336 | 1; |
a0d0e21e |
337 | } |
338 | |
a0c9c202 |
339 | |
340 | # In case the XS version doesn't load. |
341 | *abs_path = \&_perl_abs_path unless defined &abs_path; |
342 | sub _perl_abs_path |
343 | { |
344 | my $start = @_ ? shift : '.'; |
345 | my($dotdots, $cwd, @pst, @cst, $dir, @tst); |
346 | |
347 | unless (@cst = stat( $start )) |
348 | { |
349 | carp "stat($start): $!"; |
350 | return ''; |
351 | } |
352 | $cwd = ''; |
353 | $dotdots = $start; |
354 | do |
355 | { |
356 | $dotdots .= '/..'; |
357 | @pst = @cst; |
358 | unless (opendir(PARENT, $dotdots)) |
359 | { |
360 | carp "opendir($dotdots): $!"; |
361 | return ''; |
362 | } |
363 | unless (@cst = stat($dotdots)) |
364 | { |
365 | carp "stat($dotdots): $!"; |
366 | closedir(PARENT); |
367 | return ''; |
368 | } |
369 | if ($pst[0] == $cst[0] && $pst[1] == $cst[1]) |
370 | { |
371 | $dir = undef; |
372 | } |
373 | else |
374 | { |
375 | do |
376 | { |
377 | unless (defined ($dir = readdir(PARENT))) |
378 | { |
379 | carp "readdir($dotdots): $!"; |
380 | closedir(PARENT); |
381 | return ''; |
382 | } |
383 | $tst[0] = $pst[0]+1 unless (@tst = lstat("$dotdots/$dir")) |
384 | } |
385 | while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] || |
386 | $tst[1] != $pst[1]); |
387 | } |
388 | $cwd = (defined $dir ? "$dir" : "" ) . "/$cwd" ; |
389 | closedir(PARENT); |
390 | } while (defined $dir); |
391 | chop($cwd) unless $cwd eq '/'; # drop the trailing / |
392 | $cwd; |
393 | } |
394 | |
395 | |
e4c51978 |
396 | # added function alias for those of us more |
397 | # used to the libc function. --tchrist 27-Jan-00 |
398 | *realpath = \&abs_path; |
399 | |
96e4d5b1 |
400 | sub fast_abs_path { |
401 | my $cwd = getcwd(); |
4d6b4052 |
402 | require File::Spec; |
403 | my $path = @_ ? shift : File::Spec->curdir; |
e79e61e4 |
404 | CORE::chdir($path) || croak "Cannot chdir to $path:$!"; |
96e4d5b1 |
405 | my $realpath = getcwd(); |
e79e61e4 |
406 | CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; |
96e4d5b1 |
407 | $realpath; |
8b88ae92 |
408 | } |
409 | |
e4c51978 |
410 | # added function alias to follow principle of least surprise |
411 | # based on previous aliasing. --tchrist 27-Jan-00 |
412 | *fast_realpath = \&fast_abs_path; |
413 | |
4633a7c4 |
414 | |
415 | # --- PORTING SECTION --- |
416 | |
417 | # VMS: $ENV{'DEFAULT'} points to default directory at all times |
bd3fa61c |
418 | # 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu |
c6538b72 |
419 | # Note: Use of Cwd::chdir() causes the logical name PWD to be defined |
8b88ae92 |
420 | # in the process logical name table as the default device and directory |
421 | # seen by Perl. This may not be the same as the default device |
4633a7c4 |
422 | # and directory seen by DCL after Perl exits, since the effects |
423 | # the CRTL chdir() function persist only until Perl exits. |
4633a7c4 |
424 | |
425 | sub _vms_cwd { |
96e4d5b1 |
426 | return $ENV{'DEFAULT'}; |
427 | } |
428 | |
429 | sub _vms_abs_path { |
430 | return $ENV{'DEFAULT'} unless @_; |
431 | my $path = VMS::Filespec::pathify($_[0]); |
432 | croak("Invalid path name $_[0]") unless defined $path; |
433 | return VMS::Filespec::rmsexpand($path); |
4633a7c4 |
434 | } |
68dc0745 |
435 | |
4633a7c4 |
436 | sub _os2_cwd { |
437 | $ENV{'PWD'} = `cmd /c cd`; |
438 | chop $ENV{'PWD'}; |
439 | $ENV{'PWD'} =~ s:\\:/:g ; |
440 | return $ENV{'PWD'}; |
441 | } |
442 | |
96e4d5b1 |
443 | sub _win32_cwd { |
2d7a9237 |
444 | $ENV{'PWD'} = Win32::GetCwd(); |
96e4d5b1 |
445 | $ENV{'PWD'} =~ s:\\:/:g ; |
446 | return $ENV{'PWD'}; |
447 | } |
448 | |
449 | *_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && |
2d7a9237 |
450 | defined &Win32::GetCwd); |
96e4d5b1 |
451 | |
452 | *_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; |
68dc0745 |
453 | |
39e571d4 |
454 | sub _dos_cwd { |
455 | if (!defined &Dos::GetCwd) { |
456 | $ENV{'PWD'} = `command /c cd`; |
457 | chop $ENV{'PWD'}; |
458 | $ENV{'PWD'} =~ s:\\:/:g ; |
459 | } else { |
460 | $ENV{'PWD'} = Dos::GetCwd(); |
461 | } |
55497cff |
462 | return $ENV{'PWD'}; |
463 | } |
464 | |
7fbf1995 |
465 | sub _qnx_cwd { |
466 | $ENV{'PWD'} = `/usr/bin/fullpath -t`; |
467 | chop $ENV{'PWD'}; |
468 | return $ENV{'PWD'}; |
469 | } |
470 | |
471 | sub _qnx_abs_path { |
fa921dc6 |
472 | my $path = @_ ? shift : '.'; |
7fbf1995 |
473 | my $realpath=`/usr/bin/fullpath -t $path`; |
474 | chop $realpath; |
475 | return $realpath; |
476 | } |
477 | |
ed79a026 |
478 | sub _epoc_cwd { |
479 | $ENV{'PWD'} = EPOC::getcwd(); |
480 | return $ENV{'PWD'}; |
481 | } |
482 | |
ac1ad7f0 |
483 | { |
db376a24 |
484 | no warnings; # assignments trigger 'subroutine redefined' warning |
4633a7c4 |
485 | |
ac1ad7f0 |
486 | if ($^O eq 'VMS') { |
96e4d5b1 |
487 | *cwd = \&_vms_cwd; |
488 | *getcwd = \&_vms_cwd; |
489 | *fastcwd = \&_vms_cwd; |
490 | *fastgetcwd = \&_vms_cwd; |
491 | *abs_path = \&_vms_abs_path; |
492 | *fast_abs_path = \&_vms_abs_path; |
ac1ad7f0 |
493 | } |
494 | elsif ($^O eq 'NT' or $^O eq 'MSWin32') { |
495 | # We assume that &_NT_cwd is defined as an XSUB or in the core. |
96e4d5b1 |
496 | *cwd = \&_NT_cwd; |
497 | *getcwd = \&_NT_cwd; |
498 | *fastcwd = \&_NT_cwd; |
499 | *fastgetcwd = \&_NT_cwd; |
500 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
501 | } |
502 | elsif ($^O eq 'os2') { |
503 | # sys_cwd may keep the builtin command |
96e4d5b1 |
504 | *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; |
505 | *getcwd = \&cwd; |
506 | *fastgetcwd = \&cwd; |
507 | *fastcwd = \&cwd; |
508 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
509 | } |
39e571d4 |
510 | elsif ($^O eq 'dos') { |
511 | *cwd = \&_dos_cwd; |
512 | *getcwd = \&_dos_cwd; |
513 | *fastgetcwd = \&_dos_cwd; |
514 | *fastcwd = \&_dos_cwd; |
96e4d5b1 |
515 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
516 | } |
7438b6ad |
517 | elsif ($^O =~ m/^(?:qnx|nto)$/ ) { |
7fbf1995 |
518 | *cwd = \&_qnx_cwd; |
519 | *getcwd = \&_qnx_cwd; |
520 | *fastgetcwd = \&_qnx_cwd; |
521 | *fastcwd = \&_qnx_cwd; |
522 | *abs_path = \&_qnx_abs_path; |
523 | *fast_abs_path = \&_qnx_abs_path; |
524 | } |
4fabb596 |
525 | elsif ($^O eq 'cygwin') { |
1cab015a |
526 | *getcwd = \&cwd; |
527 | *fastgetcwd = \&cwd; |
528 | *fastcwd = \&cwd; |
529 | *abs_path = \&fast_abs_path; |
530 | } |
ed79a026 |
531 | elsif ($^O eq 'epoc') { |
fa6a1c44 |
532 | *cwd = \&_epoc_cwd; |
533 | *getcwd = \&_epoc_cwd; |
ed79a026 |
534 | *fastgetcwd = \&_epoc_cwd; |
535 | *fastcwd = \&_epoc_cwd; |
536 | *abs_path = \&fast_abs_path; |
537 | } |
4aecb5b5 |
538 | elsif ($^O eq 'MacOS') { |
539 | *getcwd = \&cwd; |
540 | *fastgetcwd = \&cwd; |
541 | *fastcwd = \&cwd; |
542 | *abs_path = \&fast_abs_path; |
543 | } |
55497cff |
544 | } |
4633a7c4 |
545 | |
4633a7c4 |
546 | |
a0d0e21e |
547 | 1; |