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1 | package Cwd; |
2 | require 5.000; |
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3 | |
f06db76b |
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; |
f06db76b |
15 | |
16 | use Cwd; |
4633a7c4 |
17 | $dir = fastgetcwd; |
f06db76b |
18 | |
19 | use Cwd 'chdir'; |
20 | chdir "/tmp"; |
21 | print $ENV{'PWD'}; |
22 | |
e4c51978 |
23 | use Cwd 'abs_path'; # aka realpath() |
20408e3c |
24 | print abs_path($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(). |
20408e3c |
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 | |
4633a7c4 |
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 |
fb73857a |
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 | |
f06db76b |
67 | =cut |
68 | |
b060a406 |
69 | use strict; |
96e4d5b1 |
70 | |
71 | use Carp; |
72 | |
b060a406 |
73 | our $VERSION = '2.03'; |
96e4d5b1 |
74 | |
b060a406 |
75 | use base qw/ Exporter /; |
76 | our @EXPORT = qw(cwd getcwd fastcwd fastgetcwd); |
77 | our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); |
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78 | |
4633a7c4 |
79 | |
8b88ae92 |
80 | # The 'natural and safe form' for UNIX (pwd may be setuid root) |
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81 | |
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82 | sub _backtick_pwd { |
7e03f963 |
83 | my $cwd = `pwd`; |
84 | # `pwd` may fail e.g. if the disk is full |
85 | chomp($cwd) if defined $cwd; |
4633a7c4 |
86 | $cwd; |
8b88ae92 |
87 | } |
4633a7c4 |
88 | |
89 | # Since some ports may predefine cwd internally (e.g., NT) |
90 | # we take care not to override an existing definition for cwd(). |
91 | |
ea54c8bd |
92 | unless(defined &cwd) { |
93 | # The pwd command is not available in some chroot(2)'ed environments |
94 | if(grep { -x "$_/pwd" } split(':', $ENV{PATH})) { |
95 | *cwd = \&_backtick_pwd; |
96 | } |
97 | else { |
98 | *cwd = \&getcwd; |
99 | } |
100 | } |
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101 | |
748a9306 |
102 | |
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103 | # By Brandon S. Allbery |
104 | # |
105 | # Usage: $cwd = getcwd(); |
106 | |
107 | sub getcwd |
108 | { |
07569ed3 |
109 | abs_path('.'); |
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110 | } |
111 | |
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112 | # By John Bazik |
113 | # |
114 | # Usage: $cwd = &fastcwd; |
115 | # |
116 | # This is a faster version of getcwd. It's also more dangerous because |
117 | # you might chdir out of a directory that you can't chdir back into. |
fb73857a |
118 | |
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119 | sub fastcwd { |
120 | my($odev, $oino, $cdev, $cino, $tdev, $tino); |
121 | my(@path, $path); |
122 | local(*DIR); |
123 | |
fb73857a |
124 | my($orig_cdev, $orig_cino) = stat('.'); |
125 | ($cdev, $cino) = ($orig_cdev, $orig_cino); |
a0d0e21e |
126 | for (;;) { |
40000a8c |
127 | my $direntry; |
a0d0e21e |
128 | ($odev, $oino) = ($cdev, $cino); |
e79e61e4 |
129 | CORE::chdir('..') || return undef; |
a0d0e21e |
130 | ($cdev, $cino) = stat('.'); |
131 | last if $odev == $cdev && $oino == $cino; |
fb73857a |
132 | opendir(DIR, '.') || return undef; |
a0d0e21e |
133 | for (;;) { |
40000a8c |
134 | $direntry = readdir(DIR); |
fb73857a |
135 | last unless defined $direntry; |
40000a8c |
136 | next if $direntry eq '.'; |
137 | next if $direntry eq '..'; |
a0d0e21e |
138 | |
40000a8c |
139 | ($tdev, $tino) = lstat($direntry); |
a0d0e21e |
140 | last unless $tdev != $odev || $tino != $oino; |
141 | } |
142 | closedir(DIR); |
fb73857a |
143 | return undef unless defined $direntry; # should never happen |
40000a8c |
144 | unshift(@path, $direntry); |
a0d0e21e |
145 | } |
fb73857a |
146 | $path = '/' . join('/', @path); |
21ac5ced |
147 | if ($^O eq 'apollo') { $path = "/".$path; } |
fb73857a |
148 | # At this point $path may be tainted (if tainting) and chdir would fail. |
149 | # To be more useful we untaint it then check that we landed where we started. |
392d8ab8 |
150 | $path = $1 if $path =~ /^(.*)\z/s; # untaint |
e79e61e4 |
151 | CORE::chdir($path) || return undef; |
fb73857a |
152 | ($cdev, $cino) = stat('.'); |
153 | die "Unstable directory path, current directory changed unexpectedly" |
154 | if $cdev != $orig_cdev || $cino != $orig_cino; |
a0d0e21e |
155 | $path; |
156 | } |
157 | |
158 | |
4633a7c4 |
159 | # Keeps track of current working directory in PWD environment var |
a0d0e21e |
160 | # Usage: |
161 | # use Cwd 'chdir'; |
162 | # chdir $newdir; |
163 | |
4633a7c4 |
164 | my $chdir_init = 0; |
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165 | |
4633a7c4 |
166 | sub chdir_init { |
3b8e3443 |
167 | if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos' and $^O ne 'MSWin32') { |
a0d0e21e |
168 | my($dd,$di) = stat('.'); |
169 | my($pd,$pi) = stat($ENV{'PWD'}); |
170 | if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) { |
4633a7c4 |
171 | $ENV{'PWD'} = cwd(); |
a0d0e21e |
172 | } |
173 | } |
174 | else { |
3b8e3443 |
175 | my $wd = cwd(); |
176 | $wd = Win32::GetFullPathName($wd) if $^O eq 'MSWin32'; |
177 | $ENV{'PWD'} = $wd; |
a0d0e21e |
178 | } |
4633a7c4 |
179 | # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) |
3b8e3443 |
180 | if ($^O ne 'MSWin32' and $ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { |
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181 | my($pd,$pi) = stat($2); |
182 | my($dd,$di) = stat($1); |
183 | if (defined $pd and defined $dd and $di == $pi and $dd == $pd) { |
184 | $ENV{'PWD'}="$2$3"; |
185 | } |
186 | } |
187 | $chdir_init = 1; |
188 | } |
189 | |
190 | sub chdir { |
22978713 |
191 | my $newdir = @_ ? shift : ''; # allow for no arg (chdir to HOME dir) |
3b8e3443 |
192 | $newdir =~ s|///*|/|g unless $^O eq 'MSWin32'; |
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193 | chdir_init() unless $chdir_init; |
4633a7c4 |
194 | return 0 unless CORE::chdir $newdir; |
3b8e3443 |
195 | if ($^O eq 'VMS') { |
196 | return $ENV{'PWD'} = $ENV{'DEFAULT'} |
197 | } |
198 | elsif ($^O eq 'MSWin32') { |
199 | $ENV{'PWD'} = Win32::GetFullPathName($newdir); |
200 | return 1; |
201 | } |
748a9306 |
202 | |
392d8ab8 |
203 | if ($newdir =~ m#^/#s) { |
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204 | $ENV{'PWD'} = $newdir; |
4633a7c4 |
205 | } else { |
206 | my @curdir = split(m#/#,$ENV{'PWD'}); |
207 | @curdir = ('') unless @curdir; |
208 | my $component; |
a0d0e21e |
209 | foreach $component (split(m#/#, $newdir)) { |
210 | next if $component eq '.'; |
211 | pop(@curdir),next if $component eq '..'; |
212 | push(@curdir,$component); |
213 | } |
214 | $ENV{'PWD'} = join('/',@curdir) || '/'; |
215 | } |
4633a7c4 |
216 | 1; |
a0d0e21e |
217 | } |
218 | |
d57281c6 |
219 | # Taken from Cwd.pm It is really getcwd with an optional |
220 | # parameter instead of '.' |
221 | # |
8b88ae92 |
222 | |
d57281c6 |
223 | sub abs_path |
224 | { |
225 | my $start = @_ ? shift : '.'; |
226 | my($dotdots, $cwd, @pst, @cst, $dir, @tst); |
929327b2 |
227 | |
d57281c6 |
228 | unless (@cst = stat( $start )) |
229 | { |
230 | carp "stat($start): $!"; |
231 | return ''; |
8b88ae92 |
232 | } |
d57281c6 |
233 | $cwd = ''; |
234 | $dotdots = $start; |
235 | do |
236 | { |
237 | $dotdots .= '/..'; |
238 | @pst = @cst; |
239 | unless (opendir(PARENT, $dotdots)) |
240 | { |
241 | carp "opendir($dotdots): $!"; |
242 | return ''; |
243 | } |
244 | unless (@cst = stat($dotdots)) |
245 | { |
246 | carp "stat($dotdots): $!"; |
247 | closedir(PARENT); |
248 | return ''; |
249 | } |
250 | if ($pst[0] == $cst[0] && $pst[1] == $cst[1]) |
251 | { |
252 | $dir = undef; |
253 | } |
254 | else |
255 | { |
256 | do |
257 | { |
258 | unless (defined ($dir = readdir(PARENT))) |
259 | { |
260 | carp "readdir($dotdots): $!"; |
261 | closedir(PARENT); |
262 | return ''; |
263 | } |
264 | $tst[0] = $pst[0]+1 unless (@tst = lstat("$dotdots/$dir")) |
265 | } |
266 | while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] || |
267 | $tst[1] != $pst[1]); |
268 | } |
269 | $cwd = (defined $dir ? "$dir" : "" ) . "/$cwd" ; |
270 | closedir(PARENT); |
271 | } while (defined $dir); |
272 | chop($cwd) unless $cwd eq '/'; # drop the trailing / |
273 | $cwd; |
8b88ae92 |
274 | } |
275 | |
e4c51978 |
276 | # added function alias for those of us more |
277 | # used to the libc function. --tchrist 27-Jan-00 |
278 | *realpath = \&abs_path; |
279 | |
96e4d5b1 |
280 | sub fast_abs_path { |
281 | my $cwd = getcwd(); |
3c65c14b |
282 | my $path = @_ ? shift : '.'; |
e79e61e4 |
283 | CORE::chdir($path) || croak "Cannot chdir to $path:$!"; |
96e4d5b1 |
284 | my $realpath = getcwd(); |
e79e61e4 |
285 | CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; |
96e4d5b1 |
286 | $realpath; |
8b88ae92 |
287 | } |
288 | |
e4c51978 |
289 | # added function alias to follow principle of least surprise |
290 | # based on previous aliasing. --tchrist 27-Jan-00 |
291 | *fast_realpath = \&fast_abs_path; |
292 | |
4633a7c4 |
293 | |
294 | # --- PORTING SECTION --- |
295 | |
296 | # VMS: $ENV{'DEFAULT'} points to default directory at all times |
bd3fa61c |
297 | # 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu |
c6538b72 |
298 | # Note: Use of Cwd::chdir() causes the logical name PWD to be defined |
8b88ae92 |
299 | # in the process logical name table as the default device and directory |
300 | # seen by Perl. This may not be the same as the default device |
4633a7c4 |
301 | # and directory seen by DCL after Perl exits, since the effects |
302 | # the CRTL chdir() function persist only until Perl exits. |
4633a7c4 |
303 | |
304 | sub _vms_cwd { |
96e4d5b1 |
305 | return $ENV{'DEFAULT'}; |
306 | } |
307 | |
308 | sub _vms_abs_path { |
309 | return $ENV{'DEFAULT'} unless @_; |
310 | my $path = VMS::Filespec::pathify($_[0]); |
311 | croak("Invalid path name $_[0]") unless defined $path; |
312 | return VMS::Filespec::rmsexpand($path); |
4633a7c4 |
313 | } |
68dc0745 |
314 | |
4633a7c4 |
315 | sub _os2_cwd { |
316 | $ENV{'PWD'} = `cmd /c cd`; |
317 | chop $ENV{'PWD'}; |
318 | $ENV{'PWD'} =~ s:\\:/:g ; |
319 | return $ENV{'PWD'}; |
320 | } |
321 | |
96e4d5b1 |
322 | sub _win32_cwd { |
2d7a9237 |
323 | $ENV{'PWD'} = Win32::GetCwd(); |
96e4d5b1 |
324 | $ENV{'PWD'} =~ s:\\:/:g ; |
325 | return $ENV{'PWD'}; |
326 | } |
327 | |
328 | *_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && |
2d7a9237 |
329 | defined &Win32::GetCwd); |
96e4d5b1 |
330 | |
331 | *_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; |
68dc0745 |
332 | |
39e571d4 |
333 | sub _dos_cwd { |
334 | if (!defined &Dos::GetCwd) { |
335 | $ENV{'PWD'} = `command /c cd`; |
336 | chop $ENV{'PWD'}; |
337 | $ENV{'PWD'} =~ s:\\:/:g ; |
338 | } else { |
339 | $ENV{'PWD'} = Dos::GetCwd(); |
340 | } |
55497cff |
341 | return $ENV{'PWD'}; |
342 | } |
343 | |
7fbf1995 |
344 | sub _qnx_cwd { |
345 | $ENV{'PWD'} = `/usr/bin/fullpath -t`; |
346 | chop $ENV{'PWD'}; |
347 | return $ENV{'PWD'}; |
348 | } |
349 | |
350 | sub _qnx_abs_path { |
fa921dc6 |
351 | my $path = @_ ? shift : '.'; |
7fbf1995 |
352 | my $realpath=`/usr/bin/fullpath -t $path`; |
353 | chop $realpath; |
354 | return $realpath; |
355 | } |
356 | |
ed79a026 |
357 | sub _epoc_cwd { |
358 | $ENV{'PWD'} = EPOC::getcwd(); |
359 | return $ENV{'PWD'}; |
360 | } |
361 | |
ac1ad7f0 |
362 | { |
db376a24 |
363 | no warnings; # assignments trigger 'subroutine redefined' warning |
4633a7c4 |
364 | |
ac1ad7f0 |
365 | if ($^O eq 'VMS') { |
96e4d5b1 |
366 | *cwd = \&_vms_cwd; |
367 | *getcwd = \&_vms_cwd; |
368 | *fastcwd = \&_vms_cwd; |
369 | *fastgetcwd = \&_vms_cwd; |
370 | *abs_path = \&_vms_abs_path; |
371 | *fast_abs_path = \&_vms_abs_path; |
ac1ad7f0 |
372 | } |
373 | elsif ($^O eq 'NT' or $^O eq 'MSWin32') { |
374 | # We assume that &_NT_cwd is defined as an XSUB or in the core. |
96e4d5b1 |
375 | *cwd = \&_NT_cwd; |
376 | *getcwd = \&_NT_cwd; |
377 | *fastcwd = \&_NT_cwd; |
378 | *fastgetcwd = \&_NT_cwd; |
379 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
380 | } |
381 | elsif ($^O eq 'os2') { |
382 | # sys_cwd may keep the builtin command |
96e4d5b1 |
383 | *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; |
384 | *getcwd = \&cwd; |
385 | *fastgetcwd = \&cwd; |
386 | *fastcwd = \&cwd; |
387 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
388 | } |
39e571d4 |
389 | elsif ($^O eq 'dos') { |
390 | *cwd = \&_dos_cwd; |
391 | *getcwd = \&_dos_cwd; |
392 | *fastgetcwd = \&_dos_cwd; |
393 | *fastcwd = \&_dos_cwd; |
96e4d5b1 |
394 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
395 | } |
7fbf1995 |
396 | elsif ($^O eq 'qnx') { |
397 | *cwd = \&_qnx_cwd; |
398 | *getcwd = \&_qnx_cwd; |
399 | *fastgetcwd = \&_qnx_cwd; |
400 | *fastcwd = \&_qnx_cwd; |
401 | *abs_path = \&_qnx_abs_path; |
402 | *fast_abs_path = \&_qnx_abs_path; |
403 | } |
4fabb596 |
404 | elsif ($^O eq 'cygwin') { |
1cab015a |
405 | *getcwd = \&cwd; |
406 | *fastgetcwd = \&cwd; |
407 | *fastcwd = \&cwd; |
408 | *abs_path = \&fast_abs_path; |
409 | } |
ed79a026 |
410 | elsif ($^O eq 'epoc') { |
fa6a1c44 |
411 | *cwd = \&_epoc_cwd; |
412 | *getcwd = \&_epoc_cwd; |
ed79a026 |
413 | *fastgetcwd = \&_epoc_cwd; |
414 | *fastcwd = \&_epoc_cwd; |
415 | *abs_path = \&fast_abs_path; |
416 | } |
55497cff |
417 | } |
4633a7c4 |
418 | |
419 | # package main; eval join('',<DATA>) || die $@; # quick test |
420 | |
a0d0e21e |
421 | 1; |
422 | |
4633a7c4 |
423 | __END__ |
424 | BEGIN { import Cwd qw(:DEFAULT chdir); } |
425 | print join("\n", cwd, getcwd, fastcwd, ""); |
426 | chdir('..'); |
427 | print join("\n", cwd, getcwd, fastcwd, ""); |
428 | print "$ENV{PWD}\n"; |