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a0d0e21e |
1 | package Cwd; |
2 | require 5.000; |
a0d0e21e |
3 | |
f06db76b |
4 | =head1 NAME |
5 | |
902bacac |
6 | Cwd - get pathname of current working directory |
f06db76b |
7 | |
8 | =head1 SYNOPSIS |
9 | |
4633a7c4 |
10 | use Cwd; |
11 | $dir = cwd; |
12 | |
13 | use Cwd; |
14 | $dir = getcwd; |
f06db76b |
15 | |
16 | use Cwd; |
902bacac |
17 | $dir = fastcwd; |
18 | |
19 | use Cwd; |
4633a7c4 |
20 | $dir = fastgetcwd; |
f06db76b |
21 | |
22 | use Cwd 'chdir'; |
23 | chdir "/tmp"; |
24 | print $ENV{'PWD'}; |
25 | |
e4c51978 |
26 | use Cwd 'abs_path'; # aka realpath() |
20408e3c |
27 | print abs_path($ENV{'PWD'}); |
28 | |
29 | use Cwd 'fast_abs_path'; |
30 | print fast_abs_path($ENV{'PWD'}); |
31 | |
f06db76b |
32 | =head1 DESCRIPTION |
33 | |
902bacac |
34 | This module provides functions for determining the pathname of the |
35 | current working directory. By default, it exports the functions |
36 | cwd(), getcwd(), fastcwd(), and fastgetcwd() into the caller's |
37 | namespace. Each of these functions are called without arguments and |
38 | return the absolute path of the current working directory. It is |
39 | recommended that cwd (or another *cwd() function) be used in I<all> |
40 | code to ensure portability. |
41 | |
42 | The cwd() is the most natural and safe form for the current |
43 | architecture. For most systems it is identical to `pwd` (but without |
44 | the trailing line terminator). |
45 | |
f06db76b |
46 | The getcwd() function re-implements the getcwd(3) (or getwd(3)) functions |
4633a7c4 |
47 | in Perl. |
f06db76b |
48 | |
cb1a09d0 |
49 | The fastcwd() function looks the same as getcwd(), but runs faster. |
fb73857a |
50 | It's also more dangerous because it might conceivably chdir() you out |
51 | of a directory that it can't chdir() you back into. If fastcwd |
52 | encounters a problem it will return undef but will probably leave you |
53 | in a different directory. For a measure of extra security, if |
54 | everything appears to have worked, the fastcwd() function will check |
55 | that it leaves you in the same directory that it started in. If it has |
56 | changed it will C<die> with the message "Unstable directory path, |
57 | current directory changed unexpectedly". That should never happen. |
f06db76b |
58 | |
902bacac |
59 | The fastgetcwd() function is provided as a synonym for cwd(). |
fb73857a |
60 | |
902bacac |
61 | The abs_path() function takes a single argument and returns the |
62 | absolute pathname for that argument. It uses the same algorithm as |
63 | getcwd(). (Actually, getcwd() is abs_path(".")) Symbolic links and |
64 | relative-path components ("." and "..") are resolved to return the |
65 | canonical pathname, just like realpath(3). This function is also |
66 | callable as realpath(). |
67 | |
68 | The fast_abs_path() function looks the same as abs_path() but runs |
69 | faster and, like fastcwd(), is more dangerous. |
4633a7c4 |
70 | |
71 | If you ask to override your chdir() built-in function, then your PWD |
72 | environment variable will be kept up to date. (See |
55497cff |
73 | L<perlsub/Overriding Builtin Functions>.) Note that it will only be |
1fef88e7 |
74 | kept up to date if all packages which use chdir import it from Cwd. |
4633a7c4 |
75 | |
f06db76b |
76 | =cut |
77 | |
b060a406 |
78 | use strict; |
96e4d5b1 |
79 | |
80 | use Carp; |
81 | |
1f4f94f5 |
82 | our $VERSION = '2.04'; |
96e4d5b1 |
83 | |
b060a406 |
84 | use base qw/ Exporter /; |
85 | our @EXPORT = qw(cwd getcwd fastcwd fastgetcwd); |
86 | our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); |
a0d0e21e |
87 | |
4633a7c4 |
88 | |
8b88ae92 |
89 | # The 'natural and safe form' for UNIX (pwd may be setuid root) |
96e4d5b1 |
90 | |
8b88ae92 |
91 | sub _backtick_pwd { |
7e03f963 |
92 | my $cwd = `pwd`; |
93 | # `pwd` may fail e.g. if the disk is full |
94 | chomp($cwd) if defined $cwd; |
4633a7c4 |
95 | $cwd; |
8b88ae92 |
96 | } |
4633a7c4 |
97 | |
98 | # Since some ports may predefine cwd internally (e.g., NT) |
99 | # we take care not to override an existing definition for cwd(). |
100 | |
ea54c8bd |
101 | unless(defined &cwd) { |
102 | # The pwd command is not available in some chroot(2)'ed environments |
4aecb5b5 |
103 | if($^O eq 'MacOS' || grep { -x "$_/pwd" } split(':', $ENV{PATH})) { |
ea54c8bd |
104 | *cwd = \&_backtick_pwd; |
105 | } |
106 | else { |
107 | *cwd = \&getcwd; |
108 | } |
109 | } |
a0d0e21e |
110 | |
1f4f94f5 |
111 | # set a reasonable (and very safe) default for fastgetcwd, in case it |
112 | # isn't redefined later (20001212 rspier) |
113 | *fastgetcwd = \&cwd; |
748a9306 |
114 | |
a0d0e21e |
115 | # By Brandon S. Allbery |
116 | # |
117 | # Usage: $cwd = getcwd(); |
118 | |
119 | sub getcwd |
120 | { |
07569ed3 |
121 | abs_path('.'); |
a0d0e21e |
122 | } |
123 | |
0d2079fa |
124 | # Now a callout to an XSUB. We have to delay booting of the XSUB |
125 | # until the first time fastcwd is called since Cwd::cwd is needed in the |
126 | # building of perl when dynamic loading may be unavailable |
127 | my $booted = 0; |
a0d0e21e |
128 | sub fastcwd { |
0d2079fa |
129 | unless ($booted) { |
130 | require XSLoader; |
131 | XSLoader::load("Cwd"); |
132 | ++$booted; |
a0d0e21e |
133 | } |
0d2079fa |
134 | return &Cwd::_fastcwd; |
a0d0e21e |
135 | } |
136 | |
137 | |
4633a7c4 |
138 | # Keeps track of current working directory in PWD environment var |
a0d0e21e |
139 | # Usage: |
140 | # use Cwd 'chdir'; |
141 | # chdir $newdir; |
142 | |
4633a7c4 |
143 | my $chdir_init = 0; |
a0d0e21e |
144 | |
4633a7c4 |
145 | sub chdir_init { |
3b8e3443 |
146 | if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos' and $^O ne 'MSWin32') { |
a0d0e21e |
147 | my($dd,$di) = stat('.'); |
148 | my($pd,$pi) = stat($ENV{'PWD'}); |
149 | if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) { |
4633a7c4 |
150 | $ENV{'PWD'} = cwd(); |
a0d0e21e |
151 | } |
152 | } |
153 | else { |
3b8e3443 |
154 | my $wd = cwd(); |
155 | $wd = Win32::GetFullPathName($wd) if $^O eq 'MSWin32'; |
156 | $ENV{'PWD'} = $wd; |
a0d0e21e |
157 | } |
4633a7c4 |
158 | # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) |
3b8e3443 |
159 | if ($^O ne 'MSWin32' and $ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { |
a0d0e21e |
160 | my($pd,$pi) = stat($2); |
161 | my($dd,$di) = stat($1); |
162 | if (defined $pd and defined $dd and $di == $pi and $dd == $pd) { |
163 | $ENV{'PWD'}="$2$3"; |
164 | } |
165 | } |
166 | $chdir_init = 1; |
167 | } |
168 | |
169 | sub chdir { |
22978713 |
170 | my $newdir = @_ ? shift : ''; # allow for no arg (chdir to HOME dir) |
3b8e3443 |
171 | $newdir =~ s|///*|/|g unless $^O eq 'MSWin32'; |
a0d0e21e |
172 | chdir_init() unless $chdir_init; |
4ffa1610 |
173 | my $newpwd; |
174 | if ($^O eq 'MSWin32') { |
175 | # get the full path name *before* the chdir() |
176 | $newpwd = Win32::GetFullPathName($newdir); |
177 | } |
178 | |
4633a7c4 |
179 | return 0 unless CORE::chdir $newdir; |
4ffa1610 |
180 | |
3b8e3443 |
181 | if ($^O eq 'VMS') { |
182 | return $ENV{'PWD'} = $ENV{'DEFAULT'} |
183 | } |
4aecb5b5 |
184 | elsif ($^O eq 'MacOS') { |
185 | return $ENV{'PWD'} = cwd(); |
186 | } |
3b8e3443 |
187 | elsif ($^O eq 'MSWin32') { |
4ffa1610 |
188 | $ENV{'PWD'} = $newpwd; |
3b8e3443 |
189 | return 1; |
190 | } |
748a9306 |
191 | |
392d8ab8 |
192 | if ($newdir =~ m#^/#s) { |
a0d0e21e |
193 | $ENV{'PWD'} = $newdir; |
4633a7c4 |
194 | } else { |
195 | my @curdir = split(m#/#,$ENV{'PWD'}); |
196 | @curdir = ('') unless @curdir; |
197 | my $component; |
a0d0e21e |
198 | foreach $component (split(m#/#, $newdir)) { |
199 | next if $component eq '.'; |
200 | pop(@curdir),next if $component eq '..'; |
201 | push(@curdir,$component); |
202 | } |
203 | $ENV{'PWD'} = join('/',@curdir) || '/'; |
204 | } |
4633a7c4 |
205 | 1; |
a0d0e21e |
206 | } |
207 | |
d57281c6 |
208 | # Taken from Cwd.pm It is really getcwd with an optional |
209 | # parameter instead of '.' |
210 | # |
8b88ae92 |
211 | |
d57281c6 |
212 | sub abs_path |
213 | { |
214 | my $start = @_ ? shift : '.'; |
215 | my($dotdots, $cwd, @pst, @cst, $dir, @tst); |
929327b2 |
216 | |
d57281c6 |
217 | unless (@cst = stat( $start )) |
218 | { |
219 | carp "stat($start): $!"; |
220 | return ''; |
8b88ae92 |
221 | } |
d57281c6 |
222 | $cwd = ''; |
223 | $dotdots = $start; |
224 | do |
225 | { |
226 | $dotdots .= '/..'; |
227 | @pst = @cst; |
228 | unless (opendir(PARENT, $dotdots)) |
229 | { |
230 | carp "opendir($dotdots): $!"; |
231 | return ''; |
232 | } |
233 | unless (@cst = stat($dotdots)) |
234 | { |
235 | carp "stat($dotdots): $!"; |
236 | closedir(PARENT); |
237 | return ''; |
238 | } |
239 | if ($pst[0] == $cst[0] && $pst[1] == $cst[1]) |
240 | { |
241 | $dir = undef; |
242 | } |
243 | else |
244 | { |
245 | do |
246 | { |
247 | unless (defined ($dir = readdir(PARENT))) |
248 | { |
249 | carp "readdir($dotdots): $!"; |
250 | closedir(PARENT); |
251 | return ''; |
252 | } |
253 | $tst[0] = $pst[0]+1 unless (@tst = lstat("$dotdots/$dir")) |
254 | } |
255 | while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] || |
256 | $tst[1] != $pst[1]); |
257 | } |
258 | $cwd = (defined $dir ? "$dir" : "" ) . "/$cwd" ; |
259 | closedir(PARENT); |
260 | } while (defined $dir); |
261 | chop($cwd) unless $cwd eq '/'; # drop the trailing / |
262 | $cwd; |
8b88ae92 |
263 | } |
264 | |
e4c51978 |
265 | # added function alias for those of us more |
266 | # used to the libc function. --tchrist 27-Jan-00 |
267 | *realpath = \&abs_path; |
268 | |
96e4d5b1 |
269 | sub fast_abs_path { |
270 | my $cwd = getcwd(); |
3c65c14b |
271 | my $path = @_ ? shift : '.'; |
e79e61e4 |
272 | CORE::chdir($path) || croak "Cannot chdir to $path:$!"; |
96e4d5b1 |
273 | my $realpath = getcwd(); |
e79e61e4 |
274 | CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; |
96e4d5b1 |
275 | $realpath; |
8b88ae92 |
276 | } |
277 | |
e4c51978 |
278 | # added function alias to follow principle of least surprise |
279 | # based on previous aliasing. --tchrist 27-Jan-00 |
280 | *fast_realpath = \&fast_abs_path; |
281 | |
4633a7c4 |
282 | |
283 | # --- PORTING SECTION --- |
284 | |
285 | # VMS: $ENV{'DEFAULT'} points to default directory at all times |
bd3fa61c |
286 | # 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu |
c6538b72 |
287 | # Note: Use of Cwd::chdir() causes the logical name PWD to be defined |
8b88ae92 |
288 | # in the process logical name table as the default device and directory |
289 | # seen by Perl. This may not be the same as the default device |
4633a7c4 |
290 | # and directory seen by DCL after Perl exits, since the effects |
291 | # the CRTL chdir() function persist only until Perl exits. |
4633a7c4 |
292 | |
293 | sub _vms_cwd { |
96e4d5b1 |
294 | return $ENV{'DEFAULT'}; |
295 | } |
296 | |
297 | sub _vms_abs_path { |
298 | return $ENV{'DEFAULT'} unless @_; |
299 | my $path = VMS::Filespec::pathify($_[0]); |
300 | croak("Invalid path name $_[0]") unless defined $path; |
301 | return VMS::Filespec::rmsexpand($path); |
4633a7c4 |
302 | } |
68dc0745 |
303 | |
4633a7c4 |
304 | sub _os2_cwd { |
305 | $ENV{'PWD'} = `cmd /c cd`; |
306 | chop $ENV{'PWD'}; |
307 | $ENV{'PWD'} =~ s:\\:/:g ; |
308 | return $ENV{'PWD'}; |
309 | } |
310 | |
96e4d5b1 |
311 | sub _win32_cwd { |
2d7a9237 |
312 | $ENV{'PWD'} = Win32::GetCwd(); |
96e4d5b1 |
313 | $ENV{'PWD'} =~ s:\\:/:g ; |
314 | return $ENV{'PWD'}; |
315 | } |
316 | |
317 | *_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && |
2d7a9237 |
318 | defined &Win32::GetCwd); |
96e4d5b1 |
319 | |
320 | *_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; |
68dc0745 |
321 | |
39e571d4 |
322 | sub _dos_cwd { |
323 | if (!defined &Dos::GetCwd) { |
324 | $ENV{'PWD'} = `command /c cd`; |
325 | chop $ENV{'PWD'}; |
326 | $ENV{'PWD'} =~ s:\\:/:g ; |
327 | } else { |
328 | $ENV{'PWD'} = Dos::GetCwd(); |
329 | } |
55497cff |
330 | return $ENV{'PWD'}; |
331 | } |
332 | |
7fbf1995 |
333 | sub _qnx_cwd { |
334 | $ENV{'PWD'} = `/usr/bin/fullpath -t`; |
335 | chop $ENV{'PWD'}; |
336 | return $ENV{'PWD'}; |
337 | } |
338 | |
339 | sub _qnx_abs_path { |
fa921dc6 |
340 | my $path = @_ ? shift : '.'; |
7fbf1995 |
341 | my $realpath=`/usr/bin/fullpath -t $path`; |
342 | chop $realpath; |
343 | return $realpath; |
344 | } |
345 | |
ed79a026 |
346 | sub _epoc_cwd { |
347 | $ENV{'PWD'} = EPOC::getcwd(); |
348 | return $ENV{'PWD'}; |
349 | } |
350 | |
ac1ad7f0 |
351 | { |
db376a24 |
352 | no warnings; # assignments trigger 'subroutine redefined' warning |
4633a7c4 |
353 | |
ac1ad7f0 |
354 | if ($^O eq 'VMS') { |
96e4d5b1 |
355 | *cwd = \&_vms_cwd; |
356 | *getcwd = \&_vms_cwd; |
357 | *fastcwd = \&_vms_cwd; |
358 | *fastgetcwd = \&_vms_cwd; |
359 | *abs_path = \&_vms_abs_path; |
360 | *fast_abs_path = \&_vms_abs_path; |
ac1ad7f0 |
361 | } |
362 | elsif ($^O eq 'NT' or $^O eq 'MSWin32') { |
363 | # We assume that &_NT_cwd is defined as an XSUB or in the core. |
96e4d5b1 |
364 | *cwd = \&_NT_cwd; |
365 | *getcwd = \&_NT_cwd; |
366 | *fastcwd = \&_NT_cwd; |
367 | *fastgetcwd = \&_NT_cwd; |
368 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
369 | } |
370 | elsif ($^O eq 'os2') { |
371 | # sys_cwd may keep the builtin command |
96e4d5b1 |
372 | *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; |
373 | *getcwd = \&cwd; |
374 | *fastgetcwd = \&cwd; |
375 | *fastcwd = \&cwd; |
376 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
377 | } |
39e571d4 |
378 | elsif ($^O eq 'dos') { |
379 | *cwd = \&_dos_cwd; |
380 | *getcwd = \&_dos_cwd; |
381 | *fastgetcwd = \&_dos_cwd; |
382 | *fastcwd = \&_dos_cwd; |
96e4d5b1 |
383 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
384 | } |
7fbf1995 |
385 | elsif ($^O eq 'qnx') { |
386 | *cwd = \&_qnx_cwd; |
387 | *getcwd = \&_qnx_cwd; |
388 | *fastgetcwd = \&_qnx_cwd; |
389 | *fastcwd = \&_qnx_cwd; |
390 | *abs_path = \&_qnx_abs_path; |
391 | *fast_abs_path = \&_qnx_abs_path; |
392 | } |
4fabb596 |
393 | elsif ($^O eq 'cygwin') { |
1cab015a |
394 | *getcwd = \&cwd; |
395 | *fastgetcwd = \&cwd; |
396 | *fastcwd = \&cwd; |
397 | *abs_path = \&fast_abs_path; |
398 | } |
ed79a026 |
399 | elsif ($^O eq 'epoc') { |
fa6a1c44 |
400 | *cwd = \&_epoc_cwd; |
401 | *getcwd = \&_epoc_cwd; |
ed79a026 |
402 | *fastgetcwd = \&_epoc_cwd; |
403 | *fastcwd = \&_epoc_cwd; |
404 | *abs_path = \&fast_abs_path; |
405 | } |
4aecb5b5 |
406 | elsif ($^O eq 'MacOS') { |
407 | *getcwd = \&cwd; |
408 | *fastgetcwd = \&cwd; |
409 | *fastcwd = \&cwd; |
410 | *abs_path = \&fast_abs_path; |
411 | } |
55497cff |
412 | } |
4633a7c4 |
413 | |
414 | # package main; eval join('',<DATA>) || die $@; # quick test |
415 | |
a0d0e21e |
416 | 1; |
417 | |
4633a7c4 |
418 | __END__ |
419 | BEGIN { import Cwd qw(:DEFAULT chdir); } |
420 | print join("\n", cwd, getcwd, fastcwd, ""); |
421 | chdir('..'); |
422 | print join("\n", cwd, getcwd, fastcwd, ""); |
423 | print "$ENV{PWD}\n"; |