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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 | |
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13 | use Cwd 'abs_path'; |
14 | my $abs_path = abs_path($file); |
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15 | |
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16 | =head1 DESCRIPTION |
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17 | |
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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 | |
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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 | |
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26 | =head2 getcwd and friends |
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27 | |
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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 | |
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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(). |
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71 | |
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72 | =back |
73 | |
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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 | |
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114 | |
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115 | =head1 NOTES |
116 | |
117 | =over 4 |
118 | |
119 | =item * |
120 | |
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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 * |
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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; |
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141 | |
142 | use Carp; |
143 | |
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144 | our $VERSION = '2.06'; |
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145 | |
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146 | use base qw/ Exporter /; |
147 | our @EXPORT = qw(cwd getcwd fastcwd fastgetcwd); |
148 | our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); |
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149 | |
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150 | # sys_cwd may keep the builtin command |
151 | |
152 | # All the functionality of this module may provided by builtins, |
153 | # there is no sense to process the rest of the file. |
154 | # The best choice may be to have this in BEGIN, but how to return from BEGIN? |
155 | |
156 | if ($^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 | |
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169 | eval { |
170 | require XSLoader; |
171 | XSLoader::load('Cwd'); |
172 | }; |
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173 | |
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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 | } |
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207 | |
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208 | # set a reasonable (and very safe) default for fastgetcwd, in case it |
209 | # isn't redefined later (20001212 rspier) |
210 | *fastgetcwd = \&cwd; |
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211 | |
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212 | # By Brandon S. Allbery |
213 | # |
214 | # Usage: $cwd = getcwd(); |
215 | |
216 | sub getcwd |
217 | { |
07569ed3 |
218 | abs_path('.'); |
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219 | } |
220 | |
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221 | # Keeps track of current working directory in PWD environment var |
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222 | # Usage: |
223 | # use Cwd 'chdir'; |
224 | # chdir $newdir; |
225 | |
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226 | my $chdir_init = 0; |
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227 | |
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228 | sub chdir_init { |
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229 | if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos' and $^O ne 'MSWin32') { |
a0d0e21e |
230 | my($dd,$di) = stat('.'); |
231 | my($pd,$pi) = stat($ENV{'PWD'}); |
232 | if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) { |
4633a7c4 |
233 | $ENV{'PWD'} = cwd(); |
a0d0e21e |
234 | } |
235 | } |
236 | else { |
3b8e3443 |
237 | my $wd = cwd(); |
238 | $wd = Win32::GetFullPathName($wd) if $^O eq 'MSWin32'; |
239 | $ENV{'PWD'} = $wd; |
a0d0e21e |
240 | } |
4633a7c4 |
241 | # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) |
3b8e3443 |
242 | if ($^O ne 'MSWin32' and $ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { |
a0d0e21e |
243 | my($pd,$pi) = stat($2); |
244 | my($dd,$di) = stat($1); |
245 | if (defined $pd and defined $dd and $di == $pi and $dd == $pd) { |
246 | $ENV{'PWD'}="$2$3"; |
247 | } |
248 | } |
249 | $chdir_init = 1; |
250 | } |
251 | |
252 | sub chdir { |
22978713 |
253 | my $newdir = @_ ? shift : ''; # allow for no arg (chdir to HOME dir) |
3b8e3443 |
254 | $newdir =~ s|///*|/|g unless $^O eq 'MSWin32'; |
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255 | chdir_init() unless $chdir_init; |
4ffa1610 |
256 | my $newpwd; |
257 | if ($^O eq 'MSWin32') { |
258 | # get the full path name *before* the chdir() |
259 | $newpwd = Win32::GetFullPathName($newdir); |
260 | } |
261 | |
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262 | return 0 unless CORE::chdir $newdir; |
4ffa1610 |
263 | |
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264 | if ($^O eq 'VMS') { |
265 | return $ENV{'PWD'} = $ENV{'DEFAULT'} |
266 | } |
4aecb5b5 |
267 | elsif ($^O eq 'MacOS') { |
268 | return $ENV{'PWD'} = cwd(); |
269 | } |
3b8e3443 |
270 | elsif ($^O eq 'MSWin32') { |
4ffa1610 |
271 | $ENV{'PWD'} = $newpwd; |
3b8e3443 |
272 | return 1; |
273 | } |
748a9306 |
274 | |
392d8ab8 |
275 | if ($newdir =~ m#^/#s) { |
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276 | $ENV{'PWD'} = $newdir; |
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277 | } else { |
278 | my @curdir = split(m#/#,$ENV{'PWD'}); |
279 | @curdir = ('') unless @curdir; |
280 | my $component; |
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281 | foreach $component (split(m#/#, $newdir)) { |
282 | next if $component eq '.'; |
283 | pop(@curdir),next if $component eq '..'; |
284 | push(@curdir,$component); |
285 | } |
286 | $ENV{'PWD'} = join('/',@curdir) || '/'; |
287 | } |
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288 | 1; |
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289 | } |
290 | |
e4c51978 |
291 | # added function alias for those of us more |
292 | # used to the libc function. --tchrist 27-Jan-00 |
293 | *realpath = \&abs_path; |
294 | |
96e4d5b1 |
295 | sub fast_abs_path { |
296 | my $cwd = getcwd(); |
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297 | require File::Spec; |
298 | my $path = @_ ? shift : File::Spec->curdir; |
e79e61e4 |
299 | CORE::chdir($path) || croak "Cannot chdir to $path:$!"; |
96e4d5b1 |
300 | my $realpath = getcwd(); |
e79e61e4 |
301 | CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; |
96e4d5b1 |
302 | $realpath; |
8b88ae92 |
303 | } |
304 | |
e4c51978 |
305 | # added function alias to follow principle of least surprise |
306 | # based on previous aliasing. --tchrist 27-Jan-00 |
307 | *fast_realpath = \&fast_abs_path; |
308 | |
4633a7c4 |
309 | |
310 | # --- PORTING SECTION --- |
311 | |
312 | # VMS: $ENV{'DEFAULT'} points to default directory at all times |
bd3fa61c |
313 | # 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu |
c6538b72 |
314 | # Note: Use of Cwd::chdir() causes the logical name PWD to be defined |
8b88ae92 |
315 | # in the process logical name table as the default device and directory |
316 | # seen by Perl. This may not be the same as the default device |
4633a7c4 |
317 | # and directory seen by DCL after Perl exits, since the effects |
318 | # the CRTL chdir() function persist only until Perl exits. |
4633a7c4 |
319 | |
320 | sub _vms_cwd { |
96e4d5b1 |
321 | return $ENV{'DEFAULT'}; |
322 | } |
323 | |
324 | sub _vms_abs_path { |
325 | return $ENV{'DEFAULT'} unless @_; |
326 | my $path = VMS::Filespec::pathify($_[0]); |
327 | croak("Invalid path name $_[0]") unless defined $path; |
328 | return VMS::Filespec::rmsexpand($path); |
4633a7c4 |
329 | } |
68dc0745 |
330 | |
4633a7c4 |
331 | sub _os2_cwd { |
332 | $ENV{'PWD'} = `cmd /c cd`; |
333 | chop $ENV{'PWD'}; |
334 | $ENV{'PWD'} =~ s:\\:/:g ; |
335 | return $ENV{'PWD'}; |
336 | } |
337 | |
96e4d5b1 |
338 | sub _win32_cwd { |
2d7a9237 |
339 | $ENV{'PWD'} = Win32::GetCwd(); |
96e4d5b1 |
340 | $ENV{'PWD'} =~ s:\\:/:g ; |
341 | return $ENV{'PWD'}; |
342 | } |
343 | |
344 | *_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && |
2d7a9237 |
345 | defined &Win32::GetCwd); |
96e4d5b1 |
346 | |
347 | *_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; |
68dc0745 |
348 | |
39e571d4 |
349 | sub _dos_cwd { |
350 | if (!defined &Dos::GetCwd) { |
351 | $ENV{'PWD'} = `command /c cd`; |
352 | chop $ENV{'PWD'}; |
353 | $ENV{'PWD'} =~ s:\\:/:g ; |
354 | } else { |
355 | $ENV{'PWD'} = Dos::GetCwd(); |
356 | } |
55497cff |
357 | return $ENV{'PWD'}; |
358 | } |
359 | |
7fbf1995 |
360 | sub _qnx_cwd { |
361 | $ENV{'PWD'} = `/usr/bin/fullpath -t`; |
362 | chop $ENV{'PWD'}; |
363 | return $ENV{'PWD'}; |
364 | } |
365 | |
366 | sub _qnx_abs_path { |
fa921dc6 |
367 | my $path = @_ ? shift : '.'; |
7fbf1995 |
368 | my $realpath=`/usr/bin/fullpath -t $path`; |
369 | chop $realpath; |
370 | return $realpath; |
371 | } |
372 | |
ed79a026 |
373 | sub _epoc_cwd { |
374 | $ENV{'PWD'} = EPOC::getcwd(); |
375 | return $ENV{'PWD'}; |
376 | } |
377 | |
ac1ad7f0 |
378 | { |
db376a24 |
379 | no warnings; # assignments trigger 'subroutine redefined' warning |
4633a7c4 |
380 | |
ac1ad7f0 |
381 | if ($^O eq 'VMS') { |
96e4d5b1 |
382 | *cwd = \&_vms_cwd; |
383 | *getcwd = \&_vms_cwd; |
384 | *fastcwd = \&_vms_cwd; |
385 | *fastgetcwd = \&_vms_cwd; |
386 | *abs_path = \&_vms_abs_path; |
387 | *fast_abs_path = \&_vms_abs_path; |
ac1ad7f0 |
388 | } |
389 | elsif ($^O eq 'NT' or $^O eq 'MSWin32') { |
390 | # We assume that &_NT_cwd is defined as an XSUB or in the core. |
96e4d5b1 |
391 | *cwd = \&_NT_cwd; |
392 | *getcwd = \&_NT_cwd; |
393 | *fastcwd = \&_NT_cwd; |
394 | *fastgetcwd = \&_NT_cwd; |
395 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
396 | } |
397 | elsif ($^O eq 'os2') { |
398 | # sys_cwd may keep the builtin command |
96e4d5b1 |
399 | *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; |
400 | *getcwd = \&cwd; |
401 | *fastgetcwd = \&cwd; |
402 | *fastcwd = \&cwd; |
403 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
404 | } |
39e571d4 |
405 | elsif ($^O eq 'dos') { |
406 | *cwd = \&_dos_cwd; |
407 | *getcwd = \&_dos_cwd; |
408 | *fastgetcwd = \&_dos_cwd; |
409 | *fastcwd = \&_dos_cwd; |
96e4d5b1 |
410 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
411 | } |
7438b6ad |
412 | elsif ($^O =~ m/^(?:qnx|nto)$/ ) { |
7fbf1995 |
413 | *cwd = \&_qnx_cwd; |
414 | *getcwd = \&_qnx_cwd; |
415 | *fastgetcwd = \&_qnx_cwd; |
416 | *fastcwd = \&_qnx_cwd; |
417 | *abs_path = \&_qnx_abs_path; |
418 | *fast_abs_path = \&_qnx_abs_path; |
419 | } |
4fabb596 |
420 | elsif ($^O eq 'cygwin') { |
1cab015a |
421 | *getcwd = \&cwd; |
422 | *fastgetcwd = \&cwd; |
423 | *fastcwd = \&cwd; |
424 | *abs_path = \&fast_abs_path; |
425 | } |
ed79a026 |
426 | elsif ($^O eq 'epoc') { |
fa6a1c44 |
427 | *cwd = \&_epoc_cwd; |
428 | *getcwd = \&_epoc_cwd; |
ed79a026 |
429 | *fastgetcwd = \&_epoc_cwd; |
430 | *fastcwd = \&_epoc_cwd; |
431 | *abs_path = \&fast_abs_path; |
432 | } |
4aecb5b5 |
433 | elsif ($^O eq 'MacOS') { |
434 | *getcwd = \&cwd; |
435 | *fastgetcwd = \&cwd; |
436 | *fastcwd = \&cwd; |
437 | *abs_path = \&fast_abs_path; |
438 | } |
55497cff |
439 | } |
4633a7c4 |
440 | |
441 | # package main; eval join('',<DATA>) || die $@; # quick test |
442 | |
a0d0e21e |
443 | 1; |
444 | |
4633a7c4 |
445 | __END__ |
446 | BEGIN { import Cwd qw(:DEFAULT chdir); } |
447 | print join("\n", cwd, getcwd, fastcwd, ""); |
448 | chdir('..'); |
449 | print join("\n", cwd, getcwd, fastcwd, ""); |
450 | print "$ENV{PWD}\n"; |