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1 | package Cwd; |
2 | require 5.000; |
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3 | |
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4 | =head1 NAME |
5 | |
6 | getcwd - get pathname of current working directory |
7 | |
8 | =head1 SYNOPSIS |
9 | |
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10 | use Cwd; |
11 | $dir = cwd; |
12 | |
13 | use Cwd; |
14 | $dir = getcwd; |
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15 | |
16 | use Cwd; |
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17 | $dir = fastgetcwd; |
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18 | |
19 | use Cwd 'chdir'; |
20 | chdir "/tmp"; |
21 | print $ENV{'PWD'}; |
22 | |
e4c51978 |
23 | use Cwd 'abs_path'; # aka realpath() |
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24 | print abs_path($ENV{'PWD'}); |
25 | |
26 | use Cwd 'fast_abs_path'; |
27 | print fast_abs_path($ENV{'PWD'}); |
28 | |
f06db76b |
29 | =head1 DESCRIPTION |
30 | |
31 | The getcwd() function re-implements the getcwd(3) (or getwd(3)) functions |
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32 | in Perl. |
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33 | |
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34 | The abs_path() function takes a single argument and returns the |
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35 | absolute pathname for that argument. It uses the same algorithm |
36 | as getcwd(). (Actually, getcwd() is abs_path(".")) Symbolic links |
37 | and relative-path components ("." and "..") are resolved to return |
38 | the canonical pathname, just like realpath(3). Also callable as |
39 | realpath(). |
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40 | |
cb1a09d0 |
41 | The fastcwd() function looks the same as getcwd(), but runs faster. |
fb73857a |
42 | It's also more dangerous because it might conceivably chdir() you out |
43 | of a directory that it can't chdir() you back into. If fastcwd |
44 | encounters a problem it will return undef but will probably leave you |
45 | in a different directory. For a measure of extra security, if |
46 | everything appears to have worked, the fastcwd() function will check |
47 | that it leaves you in the same directory that it started in. If it has |
48 | changed it will C<die> with the message "Unstable directory path, |
49 | current directory changed unexpectedly". That should never happen. |
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50 | |
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51 | The fast_abs_path() function looks the same as abs_path(), but runs faster. |
52 | And like fastcwd() is more dangerous. |
53 | |
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54 | The cwd() function looks the same as getcwd and fastgetcwd but is |
55 | implemented using the most natural and safe form for the current |
56 | architecture. For most systems it is identical to `pwd` (but without |
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57 | the trailing line terminator). |
58 | |
59 | It is recommended that cwd (or another *cwd() function) is used in |
60 | I<all> code to ensure portability. |
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61 | |
62 | If you ask to override your chdir() built-in function, then your PWD |
63 | environment variable will be kept up to date. (See |
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64 | L<perlsub/Overriding Builtin Functions>.) Note that it will only be |
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65 | kept up to date if all packages which use chdir import it from Cwd. |
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66 | |
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67 | =cut |
68 | |
96e4d5b1 |
69 | ## use strict; |
70 | |
71 | use Carp; |
72 | |
d57281c6 |
73 | $VERSION = '2.02'; |
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74 | |
75 | require Exporter; |
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76 | @ISA = qw(Exporter); |
e7ae0116 |
77 | @EXPORT = qw(cwd getcwd fastcwd fastgetcwd); |
e4c51978 |
78 | @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); |
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79 | |
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80 | |
8b88ae92 |
81 | # The 'natural and safe form' for UNIX (pwd may be setuid root) |
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82 | |
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83 | sub _backtick_pwd { |
7e03f963 |
84 | my $cwd = `pwd`; |
85 | # `pwd` may fail e.g. if the disk is full |
86 | chomp($cwd) if defined $cwd; |
4633a7c4 |
87 | $cwd; |
8b88ae92 |
88 | } |
4633a7c4 |
89 | |
90 | # Since some ports may predefine cwd internally (e.g., NT) |
91 | # we take care not to override an existing definition for cwd(). |
92 | |
93 | *cwd = \&_backtick_pwd unless defined &cwd; |
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94 | |
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95 | |
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96 | # By Brandon S. Allbery |
97 | # |
98 | # Usage: $cwd = getcwd(); |
99 | |
100 | sub getcwd |
101 | { |
07569ed3 |
102 | abs_path('.'); |
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103 | } |
104 | |
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105 | # By John Bazik |
106 | # |
107 | # Usage: $cwd = &fastcwd; |
108 | # |
109 | # This is a faster version of getcwd. It's also more dangerous because |
110 | # you might chdir out of a directory that you can't chdir back into. |
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111 | |
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112 | sub fastcwd { |
113 | my($odev, $oino, $cdev, $cino, $tdev, $tino); |
114 | my(@path, $path); |
115 | local(*DIR); |
116 | |
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117 | my($orig_cdev, $orig_cino) = stat('.'); |
118 | ($cdev, $cino) = ($orig_cdev, $orig_cino); |
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119 | for (;;) { |
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120 | my $direntry; |
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121 | ($odev, $oino) = ($cdev, $cino); |
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122 | CORE::chdir('..') || return undef; |
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123 | ($cdev, $cino) = stat('.'); |
124 | last if $odev == $cdev && $oino == $cino; |
fb73857a |
125 | opendir(DIR, '.') || return undef; |
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126 | for (;;) { |
40000a8c |
127 | $direntry = readdir(DIR); |
fb73857a |
128 | last unless defined $direntry; |
40000a8c |
129 | next if $direntry eq '.'; |
130 | next if $direntry eq '..'; |
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131 | |
40000a8c |
132 | ($tdev, $tino) = lstat($direntry); |
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133 | last unless $tdev != $odev || $tino != $oino; |
134 | } |
135 | closedir(DIR); |
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136 | return undef unless defined $direntry; # should never happen |
40000a8c |
137 | unshift(@path, $direntry); |
a0d0e21e |
138 | } |
fb73857a |
139 | $path = '/' . join('/', @path); |
21ac5ced |
140 | if ($^O eq 'apollo') { $path = "/".$path; } |
fb73857a |
141 | # At this point $path may be tainted (if tainting) and chdir would fail. |
142 | # To be more useful we untaint it then check that we landed where we started. |
392d8ab8 |
143 | $path = $1 if $path =~ /^(.*)\z/s; # untaint |
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144 | CORE::chdir($path) || return undef; |
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145 | ($cdev, $cino) = stat('.'); |
146 | die "Unstable directory path, current directory changed unexpectedly" |
147 | if $cdev != $orig_cdev || $cino != $orig_cino; |
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148 | $path; |
149 | } |
150 | |
151 | |
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152 | # Keeps track of current working directory in PWD environment var |
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153 | # Usage: |
154 | # use Cwd 'chdir'; |
155 | # chdir $newdir; |
156 | |
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157 | my $chdir_init = 0; |
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158 | |
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159 | sub chdir_init { |
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160 | if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos') { |
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161 | my($dd,$di) = stat('.'); |
162 | my($pd,$pi) = stat($ENV{'PWD'}); |
163 | if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) { |
4633a7c4 |
164 | $ENV{'PWD'} = cwd(); |
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165 | } |
166 | } |
167 | else { |
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168 | $ENV{'PWD'} = cwd(); |
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169 | } |
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170 | # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) |
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171 | if ($ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { |
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172 | my($pd,$pi) = stat($2); |
173 | my($dd,$di) = stat($1); |
174 | if (defined $pd and defined $dd and $di == $pi and $dd == $pd) { |
175 | $ENV{'PWD'}="$2$3"; |
176 | } |
177 | } |
178 | $chdir_init = 1; |
179 | } |
180 | |
181 | sub chdir { |
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182 | my $newdir = shift || ''; # allow for no arg (chdir to HOME dir) |
183 | $newdir =~ s|///*|/|g; |
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184 | chdir_init() unless $chdir_init; |
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185 | return 0 unless CORE::chdir $newdir; |
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186 | if ($^O eq 'VMS') { return $ENV{'PWD'} = $ENV{'DEFAULT'} } |
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187 | |
392d8ab8 |
188 | if ($newdir =~ m#^/#s) { |
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189 | $ENV{'PWD'} = $newdir; |
4633a7c4 |
190 | } else { |
191 | my @curdir = split(m#/#,$ENV{'PWD'}); |
192 | @curdir = ('') unless @curdir; |
193 | my $component; |
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194 | foreach $component (split(m#/#, $newdir)) { |
195 | next if $component eq '.'; |
196 | pop(@curdir),next if $component eq '..'; |
197 | push(@curdir,$component); |
198 | } |
199 | $ENV{'PWD'} = join('/',@curdir) || '/'; |
200 | } |
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201 | 1; |
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202 | } |
203 | |
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204 | # Taken from Cwd.pm It is really getcwd with an optional |
205 | # parameter instead of '.' |
206 | # |
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207 | |
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208 | sub abs_path |
209 | { |
210 | my $start = @_ ? shift : '.'; |
211 | my($dotdots, $cwd, @pst, @cst, $dir, @tst); |
929327b2 |
212 | |
d57281c6 |
213 | unless (@cst = stat( $start )) |
214 | { |
215 | carp "stat($start): $!"; |
216 | return ''; |
8b88ae92 |
217 | } |
d57281c6 |
218 | $cwd = ''; |
219 | $dotdots = $start; |
220 | do |
221 | { |
222 | $dotdots .= '/..'; |
223 | @pst = @cst; |
224 | unless (opendir(PARENT, $dotdots)) |
225 | { |
226 | carp "opendir($dotdots): $!"; |
227 | return ''; |
228 | } |
229 | unless (@cst = stat($dotdots)) |
230 | { |
231 | carp "stat($dotdots): $!"; |
232 | closedir(PARENT); |
233 | return ''; |
234 | } |
235 | if ($pst[0] == $cst[0] && $pst[1] == $cst[1]) |
236 | { |
237 | $dir = undef; |
238 | } |
239 | else |
240 | { |
241 | do |
242 | { |
243 | unless (defined ($dir = readdir(PARENT))) |
244 | { |
245 | carp "readdir($dotdots): $!"; |
246 | closedir(PARENT); |
247 | return ''; |
248 | } |
249 | $tst[0] = $pst[0]+1 unless (@tst = lstat("$dotdots/$dir")) |
250 | } |
251 | while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] || |
252 | $tst[1] != $pst[1]); |
253 | } |
254 | $cwd = (defined $dir ? "$dir" : "" ) . "/$cwd" ; |
255 | closedir(PARENT); |
256 | } while (defined $dir); |
257 | chop($cwd) unless $cwd eq '/'; # drop the trailing / |
258 | $cwd; |
8b88ae92 |
259 | } |
260 | |
e4c51978 |
261 | # added function alias for those of us more |
262 | # used to the libc function. --tchrist 27-Jan-00 |
263 | *realpath = \&abs_path; |
264 | |
96e4d5b1 |
265 | sub fast_abs_path { |
266 | my $cwd = getcwd(); |
267 | my $path = shift || '.'; |
e79e61e4 |
268 | CORE::chdir($path) || croak "Cannot chdir to $path:$!"; |
96e4d5b1 |
269 | my $realpath = getcwd(); |
e79e61e4 |
270 | CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; |
96e4d5b1 |
271 | $realpath; |
8b88ae92 |
272 | } |
273 | |
e4c51978 |
274 | # added function alias to follow principle of least surprise |
275 | # based on previous aliasing. --tchrist 27-Jan-00 |
276 | *fast_realpath = \&fast_abs_path; |
277 | |
4633a7c4 |
278 | |
279 | # --- PORTING SECTION --- |
280 | |
281 | # VMS: $ENV{'DEFAULT'} points to default directory at all times |
bd3fa61c |
282 | # 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu |
c6538b72 |
283 | # Note: Use of Cwd::chdir() causes the logical name PWD to be defined |
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284 | # in the process logical name table as the default device and directory |
285 | # seen by Perl. This may not be the same as the default device |
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286 | # and directory seen by DCL after Perl exits, since the effects |
287 | # the CRTL chdir() function persist only until Perl exits. |
4633a7c4 |
288 | |
289 | sub _vms_cwd { |
96e4d5b1 |
290 | return $ENV{'DEFAULT'}; |
291 | } |
292 | |
293 | sub _vms_abs_path { |
294 | return $ENV{'DEFAULT'} unless @_; |
295 | my $path = VMS::Filespec::pathify($_[0]); |
296 | croak("Invalid path name $_[0]") unless defined $path; |
297 | return VMS::Filespec::rmsexpand($path); |
4633a7c4 |
298 | } |
68dc0745 |
299 | |
4633a7c4 |
300 | sub _os2_cwd { |
301 | $ENV{'PWD'} = `cmd /c cd`; |
302 | chop $ENV{'PWD'}; |
303 | $ENV{'PWD'} =~ s:\\:/:g ; |
304 | return $ENV{'PWD'}; |
305 | } |
306 | |
96e4d5b1 |
307 | sub _win32_cwd { |
2d7a9237 |
308 | $ENV{'PWD'} = Win32::GetCwd(); |
96e4d5b1 |
309 | $ENV{'PWD'} =~ s:\\:/:g ; |
310 | return $ENV{'PWD'}; |
311 | } |
312 | |
313 | *_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && |
2d7a9237 |
314 | defined &Win32::GetCwd); |
96e4d5b1 |
315 | |
316 | *_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; |
68dc0745 |
317 | |
39e571d4 |
318 | sub _dos_cwd { |
319 | if (!defined &Dos::GetCwd) { |
320 | $ENV{'PWD'} = `command /c cd`; |
321 | chop $ENV{'PWD'}; |
322 | $ENV{'PWD'} =~ s:\\:/:g ; |
323 | } else { |
324 | $ENV{'PWD'} = Dos::GetCwd(); |
325 | } |
55497cff |
326 | return $ENV{'PWD'}; |
327 | } |
328 | |
7fbf1995 |
329 | sub _qnx_cwd { |
330 | $ENV{'PWD'} = `/usr/bin/fullpath -t`; |
331 | chop $ENV{'PWD'}; |
332 | return $ENV{'PWD'}; |
333 | } |
334 | |
335 | sub _qnx_abs_path { |
336 | my $path = shift || '.'; |
337 | my $realpath=`/usr/bin/fullpath -t $path`; |
338 | chop $realpath; |
339 | return $realpath; |
340 | } |
341 | |
ac1ad7f0 |
342 | { |
db376a24 |
343 | no warnings; # assignments trigger 'subroutine redefined' warning |
4633a7c4 |
344 | |
ac1ad7f0 |
345 | if ($^O eq 'VMS') { |
96e4d5b1 |
346 | *cwd = \&_vms_cwd; |
347 | *getcwd = \&_vms_cwd; |
348 | *fastcwd = \&_vms_cwd; |
349 | *fastgetcwd = \&_vms_cwd; |
350 | *abs_path = \&_vms_abs_path; |
351 | *fast_abs_path = \&_vms_abs_path; |
ac1ad7f0 |
352 | } |
353 | elsif ($^O eq 'NT' or $^O eq 'MSWin32') { |
354 | # We assume that &_NT_cwd is defined as an XSUB or in the core. |
96e4d5b1 |
355 | *cwd = \&_NT_cwd; |
356 | *getcwd = \&_NT_cwd; |
357 | *fastcwd = \&_NT_cwd; |
358 | *fastgetcwd = \&_NT_cwd; |
359 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
360 | } |
361 | elsif ($^O eq 'os2') { |
362 | # sys_cwd may keep the builtin command |
96e4d5b1 |
363 | *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; |
364 | *getcwd = \&cwd; |
365 | *fastgetcwd = \&cwd; |
366 | *fastcwd = \&cwd; |
367 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
368 | } |
39e571d4 |
369 | elsif ($^O eq 'dos') { |
370 | *cwd = \&_dos_cwd; |
371 | *getcwd = \&_dos_cwd; |
372 | *fastgetcwd = \&_dos_cwd; |
373 | *fastcwd = \&_dos_cwd; |
96e4d5b1 |
374 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
375 | } |
7fbf1995 |
376 | elsif ($^O eq 'qnx') { |
377 | *cwd = \&_qnx_cwd; |
378 | *getcwd = \&_qnx_cwd; |
379 | *fastgetcwd = \&_qnx_cwd; |
380 | *fastcwd = \&_qnx_cwd; |
381 | *abs_path = \&_qnx_abs_path; |
382 | *fast_abs_path = \&_qnx_abs_path; |
383 | } |
4fabb596 |
384 | elsif ($^O eq 'cygwin') { |
1cab015a |
385 | *getcwd = \&cwd; |
386 | *fastgetcwd = \&cwd; |
387 | *fastcwd = \&cwd; |
388 | *abs_path = \&fast_abs_path; |
389 | } |
55497cff |
390 | } |
4633a7c4 |
391 | |
392 | # package main; eval join('',<DATA>) || die $@; # quick test |
393 | |
a0d0e21e |
394 | 1; |
395 | |
4633a7c4 |
396 | __END__ |
397 | BEGIN { import Cwd qw(:DEFAULT chdir); } |
398 | print join("\n", cwd, getcwd, fastcwd, ""); |
399 | chdir('..'); |
400 | print join("\n", cwd, getcwd, fastcwd, ""); |
401 | print "$ENV{PWD}\n"; |