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1 | package Cwd; |
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2 | use 5.006; |
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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; |
4633a7c4 |
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 | |
4d6b4052 |
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 $VERSION = '2.06'; |
96e4d5b1 |
145 | |
b060a406 |
146 | use base qw/ Exporter /; |
147 | our @EXPORT = qw(cwd getcwd fastcwd fastgetcwd); |
148 | our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); |
a0d0e21e |
149 | |
f5f423e4 |
150 | # sys_cwd may keep the builtin command |
151 | |
152 | # All the functionality of this module may provided by builtins, |
153 | # there is no sense to process the rest of the file. |
154 | # The best choice may be to have this in BEGIN, but how to return from BEGIN? |
155 | |
156 | if ($^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; |
716e3b8c |
171 | undef *Cwd::fastcwd; # avoid redefinition warning |
f22d8e4b |
172 | XSLoader::load('Cwd'); |
173 | }; |
4633a7c4 |
174 | |
96e4d5b1 |
175 | |
3547aa9a |
176 | # Find the pwd command in the expected locations. We assume these |
177 | # are safe. This prevents _backtick_pwd() consulting $ENV{PATH} |
178 | # so everything works under taint mode. |
179 | my $pwd_cmd; |
180 | foreach my $try (qw(/bin/pwd /usr/bin/pwd)) { |
181 | if( -x $try ) { |
182 | $pwd_cmd = $try; |
183 | last; |
184 | } |
185 | } |
186 | $pwd_cmd ||= 'pwd'; |
187 | |
188 | # The 'natural and safe form' for UNIX (pwd may be setuid root) |
8b88ae92 |
189 | sub _backtick_pwd { |
3547aa9a |
190 | my $cwd = `$pwd_cmd`; |
ac3b20cb |
191 | # Belt-and-suspenders in case someone said "undef $/". |
5cf6da5f |
192 | local $/ = "\n"; |
ac3b20cb |
193 | # `pwd` may fail e.g. if the disk is full |
7e03f963 |
194 | chomp($cwd) if defined $cwd; |
4633a7c4 |
195 | $cwd; |
8b88ae92 |
196 | } |
4633a7c4 |
197 | |
198 | # Since some ports may predefine cwd internally (e.g., NT) |
199 | # we take care not to override an existing definition for cwd(). |
200 | |
ea54c8bd |
201 | unless(defined &cwd) { |
202 | # The pwd command is not available in some chroot(2)'ed environments |
4aecb5b5 |
203 | if($^O eq 'MacOS' || grep { -x "$_/pwd" } split(':', $ENV{PATH})) { |
ea54c8bd |
204 | *cwd = \&_backtick_pwd; |
205 | } |
206 | else { |
207 | *cwd = \&getcwd; |
208 | } |
209 | } |
a0d0e21e |
210 | |
1f4f94f5 |
211 | # set a reasonable (and very safe) default for fastgetcwd, in case it |
212 | # isn't redefined later (20001212 rspier) |
213 | *fastgetcwd = \&cwd; |
748a9306 |
214 | |
a0d0e21e |
215 | # By Brandon S. Allbery |
216 | # |
217 | # Usage: $cwd = getcwd(); |
218 | |
219 | sub getcwd |
220 | { |
07569ed3 |
221 | abs_path('.'); |
a0d0e21e |
222 | } |
223 | |
a0c9c202 |
224 | |
225 | # By John Bazik |
226 | # |
227 | # Usage: $cwd = &fastcwd; |
228 | # |
229 | # This is a faster version of getcwd. It's also more dangerous because |
230 | # you might chdir out of a directory that you can't chdir back into. |
231 | |
232 | sub fastcwd { |
233 | my($odev, $oino, $cdev, $cino, $tdev, $tino); |
234 | my(@path, $path); |
235 | local(*DIR); |
236 | |
237 | my($orig_cdev, $orig_cino) = stat('.'); |
238 | ($cdev, $cino) = ($orig_cdev, $orig_cino); |
239 | for (;;) { |
240 | my $direntry; |
241 | ($odev, $oino) = ($cdev, $cino); |
242 | CORE::chdir('..') || return undef; |
243 | ($cdev, $cino) = stat('.'); |
244 | last if $odev == $cdev && $oino == $cino; |
245 | opendir(DIR, '.') || return undef; |
246 | for (;;) { |
247 | $direntry = readdir(DIR); |
248 | last unless defined $direntry; |
249 | next if $direntry eq '.'; |
250 | next if $direntry eq '..'; |
251 | |
252 | ($tdev, $tino) = lstat($direntry); |
253 | last unless $tdev != $odev || $tino != $oino; |
254 | } |
255 | closedir(DIR); |
256 | return undef unless defined $direntry; # should never happen |
257 | unshift(@path, $direntry); |
258 | } |
259 | $path = '/' . join('/', @path); |
260 | if ($^O eq 'apollo') { $path = "/".$path; } |
261 | # At this point $path may be tainted (if tainting) and chdir would fail. |
262 | # To be more useful we untaint it then check that we landed where we started. |
263 | $path = $1 if $path =~ /^(.*)\z/s; # untaint |
264 | CORE::chdir($path) || return undef; |
265 | ($cdev, $cino) = stat('.'); |
266 | die "Unstable directory path, current directory changed unexpectedly" |
267 | if $cdev != $orig_cdev || $cino != $orig_cino; |
268 | $path; |
269 | } |
270 | |
271 | |
4633a7c4 |
272 | # Keeps track of current working directory in PWD environment var |
a0d0e21e |
273 | # Usage: |
274 | # use Cwd 'chdir'; |
275 | # chdir $newdir; |
276 | |
4633a7c4 |
277 | my $chdir_init = 0; |
a0d0e21e |
278 | |
4633a7c4 |
279 | sub chdir_init { |
3b8e3443 |
280 | if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos' and $^O ne 'MSWin32') { |
a0d0e21e |
281 | my($dd,$di) = stat('.'); |
282 | my($pd,$pi) = stat($ENV{'PWD'}); |
283 | if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) { |
4633a7c4 |
284 | $ENV{'PWD'} = cwd(); |
a0d0e21e |
285 | } |
286 | } |
287 | else { |
3b8e3443 |
288 | my $wd = cwd(); |
289 | $wd = Win32::GetFullPathName($wd) if $^O eq 'MSWin32'; |
290 | $ENV{'PWD'} = $wd; |
a0d0e21e |
291 | } |
4633a7c4 |
292 | # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) |
3b8e3443 |
293 | if ($^O ne 'MSWin32' and $ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { |
a0d0e21e |
294 | my($pd,$pi) = stat($2); |
295 | my($dd,$di) = stat($1); |
296 | if (defined $pd and defined $dd and $di == $pi and $dd == $pd) { |
297 | $ENV{'PWD'}="$2$3"; |
298 | } |
299 | } |
300 | $chdir_init = 1; |
301 | } |
302 | |
303 | sub chdir { |
22978713 |
304 | my $newdir = @_ ? shift : ''; # allow for no arg (chdir to HOME dir) |
3b8e3443 |
305 | $newdir =~ s|///*|/|g unless $^O eq 'MSWin32'; |
a0d0e21e |
306 | chdir_init() unless $chdir_init; |
4ffa1610 |
307 | my $newpwd; |
308 | if ($^O eq 'MSWin32') { |
309 | # get the full path name *before* the chdir() |
310 | $newpwd = Win32::GetFullPathName($newdir); |
311 | } |
312 | |
4633a7c4 |
313 | return 0 unless CORE::chdir $newdir; |
4ffa1610 |
314 | |
3b8e3443 |
315 | if ($^O eq 'VMS') { |
316 | return $ENV{'PWD'} = $ENV{'DEFAULT'} |
317 | } |
4aecb5b5 |
318 | elsif ($^O eq 'MacOS') { |
319 | return $ENV{'PWD'} = cwd(); |
320 | } |
3b8e3443 |
321 | elsif ($^O eq 'MSWin32') { |
4ffa1610 |
322 | $ENV{'PWD'} = $newpwd; |
3b8e3443 |
323 | return 1; |
324 | } |
748a9306 |
325 | |
392d8ab8 |
326 | if ($newdir =~ m#^/#s) { |
a0d0e21e |
327 | $ENV{'PWD'} = $newdir; |
4633a7c4 |
328 | } else { |
329 | my @curdir = split(m#/#,$ENV{'PWD'}); |
330 | @curdir = ('') unless @curdir; |
331 | my $component; |
a0d0e21e |
332 | foreach $component (split(m#/#, $newdir)) { |
333 | next if $component eq '.'; |
334 | pop(@curdir),next if $component eq '..'; |
335 | push(@curdir,$component); |
336 | } |
337 | $ENV{'PWD'} = join('/',@curdir) || '/'; |
338 | } |
4633a7c4 |
339 | 1; |
a0d0e21e |
340 | } |
341 | |
a0c9c202 |
342 | |
343 | # In case the XS version doesn't load. |
344 | *abs_path = \&_perl_abs_path unless defined &abs_path; |
345 | sub _perl_abs_path |
346 | { |
347 | my $start = @_ ? shift : '.'; |
348 | my($dotdots, $cwd, @pst, @cst, $dir, @tst); |
349 | |
350 | unless (@cst = stat( $start )) |
351 | { |
352 | carp "stat($start): $!"; |
353 | return ''; |
354 | } |
355 | $cwd = ''; |
356 | $dotdots = $start; |
357 | do |
358 | { |
359 | $dotdots .= '/..'; |
360 | @pst = @cst; |
361 | unless (opendir(PARENT, $dotdots)) |
362 | { |
363 | carp "opendir($dotdots): $!"; |
364 | return ''; |
365 | } |
366 | unless (@cst = stat($dotdots)) |
367 | { |
368 | carp "stat($dotdots): $!"; |
369 | closedir(PARENT); |
370 | return ''; |
371 | } |
372 | if ($pst[0] == $cst[0] && $pst[1] == $cst[1]) |
373 | { |
374 | $dir = undef; |
375 | } |
376 | else |
377 | { |
378 | do |
379 | { |
380 | unless (defined ($dir = readdir(PARENT))) |
381 | { |
382 | carp "readdir($dotdots): $!"; |
383 | closedir(PARENT); |
384 | return ''; |
385 | } |
386 | $tst[0] = $pst[0]+1 unless (@tst = lstat("$dotdots/$dir")) |
387 | } |
388 | while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] || |
389 | $tst[1] != $pst[1]); |
390 | } |
391 | $cwd = (defined $dir ? "$dir" : "" ) . "/$cwd" ; |
392 | closedir(PARENT); |
393 | } while (defined $dir); |
394 | chop($cwd) unless $cwd eq '/'; # drop the trailing / |
395 | $cwd; |
396 | } |
397 | |
398 | |
e4c51978 |
399 | # added function alias for those of us more |
400 | # used to the libc function. --tchrist 27-Jan-00 |
401 | *realpath = \&abs_path; |
402 | |
96e4d5b1 |
403 | sub fast_abs_path { |
404 | my $cwd = getcwd(); |
4d6b4052 |
405 | require File::Spec; |
406 | my $path = @_ ? shift : File::Spec->curdir; |
e79e61e4 |
407 | CORE::chdir($path) || croak "Cannot chdir to $path:$!"; |
96e4d5b1 |
408 | my $realpath = getcwd(); |
e79e61e4 |
409 | CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; |
96e4d5b1 |
410 | $realpath; |
8b88ae92 |
411 | } |
412 | |
e4c51978 |
413 | # added function alias to follow principle of least surprise |
414 | # based on previous aliasing. --tchrist 27-Jan-00 |
415 | *fast_realpath = \&fast_abs_path; |
416 | |
4633a7c4 |
417 | |
418 | # --- PORTING SECTION --- |
419 | |
420 | # VMS: $ENV{'DEFAULT'} points to default directory at all times |
bd3fa61c |
421 | # 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu |
c6538b72 |
422 | # Note: Use of Cwd::chdir() causes the logical name PWD to be defined |
8b88ae92 |
423 | # in the process logical name table as the default device and directory |
424 | # seen by Perl. This may not be the same as the default device |
4633a7c4 |
425 | # and directory seen by DCL after Perl exits, since the effects |
426 | # the CRTL chdir() function persist only until Perl exits. |
4633a7c4 |
427 | |
428 | sub _vms_cwd { |
96e4d5b1 |
429 | return $ENV{'DEFAULT'}; |
430 | } |
431 | |
432 | sub _vms_abs_path { |
433 | return $ENV{'DEFAULT'} unless @_; |
434 | my $path = VMS::Filespec::pathify($_[0]); |
435 | croak("Invalid path name $_[0]") unless defined $path; |
436 | return VMS::Filespec::rmsexpand($path); |
4633a7c4 |
437 | } |
68dc0745 |
438 | |
4633a7c4 |
439 | sub _os2_cwd { |
440 | $ENV{'PWD'} = `cmd /c cd`; |
441 | chop $ENV{'PWD'}; |
aa6b7957 |
442 | $ENV{'PWD'} =~ s:\\:/:g ; |
4633a7c4 |
443 | return $ENV{'PWD'}; |
444 | } |
445 | |
96e4d5b1 |
446 | sub _win32_cwd { |
2d7a9237 |
447 | $ENV{'PWD'} = Win32::GetCwd(); |
aa6b7957 |
448 | $ENV{'PWD'} =~ s:\\:/:g ; |
96e4d5b1 |
449 | return $ENV{'PWD'}; |
450 | } |
451 | |
452 | *_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && |
2d7a9237 |
453 | defined &Win32::GetCwd); |
96e4d5b1 |
454 | |
455 | *_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; |
68dc0745 |
456 | |
39e571d4 |
457 | sub _dos_cwd { |
458 | if (!defined &Dos::GetCwd) { |
459 | $ENV{'PWD'} = `command /c cd`; |
460 | chop $ENV{'PWD'}; |
aa6b7957 |
461 | $ENV{'PWD'} =~ s:\\:/:g ; |
39e571d4 |
462 | } else { |
463 | $ENV{'PWD'} = Dos::GetCwd(); |
464 | } |
55497cff |
465 | return $ENV{'PWD'}; |
466 | } |
467 | |
7fbf1995 |
468 | sub _qnx_cwd { |
469 | $ENV{'PWD'} = `/usr/bin/fullpath -t`; |
470 | chop $ENV{'PWD'}; |
471 | return $ENV{'PWD'}; |
472 | } |
473 | |
474 | sub _qnx_abs_path { |
fa921dc6 |
475 | my $path = @_ ? shift : '.'; |
7fbf1995 |
476 | my $realpath=`/usr/bin/fullpath -t $path`; |
477 | chop $realpath; |
478 | return $realpath; |
479 | } |
480 | |
ed79a026 |
481 | sub _epoc_cwd { |
482 | $ENV{'PWD'} = EPOC::getcwd(); |
483 | return $ENV{'PWD'}; |
484 | } |
485 | |
ac1ad7f0 |
486 | { |
db376a24 |
487 | no warnings; # assignments trigger 'subroutine redefined' warning |
4633a7c4 |
488 | |
ac1ad7f0 |
489 | if ($^O eq 'VMS') { |
96e4d5b1 |
490 | *cwd = \&_vms_cwd; |
491 | *getcwd = \&_vms_cwd; |
492 | *fastcwd = \&_vms_cwd; |
493 | *fastgetcwd = \&_vms_cwd; |
494 | *abs_path = \&_vms_abs_path; |
495 | *fast_abs_path = \&_vms_abs_path; |
ac1ad7f0 |
496 | } |
497 | elsif ($^O eq 'NT' or $^O eq 'MSWin32') { |
498 | # We assume that &_NT_cwd is defined as an XSUB or in the core. |
96e4d5b1 |
499 | *cwd = \&_NT_cwd; |
500 | *getcwd = \&_NT_cwd; |
501 | *fastcwd = \&_NT_cwd; |
502 | *fastgetcwd = \&_NT_cwd; |
503 | *abs_path = \&fast_abs_path; |
cade0c02 |
504 | *realpath = \&fast_abs_path; |
ac1ad7f0 |
505 | } |
506 | elsif ($^O eq 'os2') { |
507 | # sys_cwd may keep the builtin command |
96e4d5b1 |
508 | *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; |
509 | *getcwd = \&cwd; |
510 | *fastgetcwd = \&cwd; |
511 | *fastcwd = \&cwd; |
512 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
513 | } |
39e571d4 |
514 | elsif ($^O eq 'dos') { |
515 | *cwd = \&_dos_cwd; |
516 | *getcwd = \&_dos_cwd; |
517 | *fastgetcwd = \&_dos_cwd; |
518 | *fastcwd = \&_dos_cwd; |
96e4d5b1 |
519 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
520 | } |
7438b6ad |
521 | elsif ($^O =~ m/^(?:qnx|nto)$/ ) { |
7fbf1995 |
522 | *cwd = \&_qnx_cwd; |
523 | *getcwd = \&_qnx_cwd; |
524 | *fastgetcwd = \&_qnx_cwd; |
525 | *fastcwd = \&_qnx_cwd; |
526 | *abs_path = \&_qnx_abs_path; |
527 | *fast_abs_path = \&_qnx_abs_path; |
528 | } |
4fabb596 |
529 | elsif ($^O eq 'cygwin') { |
1cab015a |
530 | *getcwd = \&cwd; |
531 | *fastgetcwd = \&cwd; |
532 | *fastcwd = \&cwd; |
533 | *abs_path = \&fast_abs_path; |
534 | } |
ed79a026 |
535 | elsif ($^O eq 'epoc') { |
fa6a1c44 |
536 | *cwd = \&_epoc_cwd; |
537 | *getcwd = \&_epoc_cwd; |
ed79a026 |
538 | *fastgetcwd = \&_epoc_cwd; |
539 | *fastcwd = \&_epoc_cwd; |
540 | *abs_path = \&fast_abs_path; |
541 | } |
4aecb5b5 |
542 | elsif ($^O eq 'MacOS') { |
543 | *getcwd = \&cwd; |
544 | *fastgetcwd = \&cwd; |
545 | *fastcwd = \&cwd; |
546 | *abs_path = \&fast_abs_path; |
547 | } |
55497cff |
548 | } |
4633a7c4 |
549 | |
4633a7c4 |
550 | |
a0d0e21e |
551 | 1; |