Commit | Line | Data |
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 | |
a0d0e21e |
124 | # By John Bazik |
125 | # |
126 | # Usage: $cwd = &fastcwd; |
127 | # |
128 | # This is a faster version of getcwd. It's also more dangerous because |
129 | # you might chdir out of a directory that you can't chdir back into. |
fb73857a |
130 | |
a0d0e21e |
131 | sub fastcwd { |
132 | my($odev, $oino, $cdev, $cino, $tdev, $tino); |
133 | my(@path, $path); |
134 | local(*DIR); |
135 | |
fb73857a |
136 | my($orig_cdev, $orig_cino) = stat('.'); |
137 | ($cdev, $cino) = ($orig_cdev, $orig_cino); |
a0d0e21e |
138 | for (;;) { |
40000a8c |
139 | my $direntry; |
a0d0e21e |
140 | ($odev, $oino) = ($cdev, $cino); |
e79e61e4 |
141 | CORE::chdir('..') || return undef; |
a0d0e21e |
142 | ($cdev, $cino) = stat('.'); |
143 | last if $odev == $cdev && $oino == $cino; |
fb73857a |
144 | opendir(DIR, '.') || return undef; |
a0d0e21e |
145 | for (;;) { |
40000a8c |
146 | $direntry = readdir(DIR); |
fb73857a |
147 | last unless defined $direntry; |
40000a8c |
148 | next if $direntry eq '.'; |
149 | next if $direntry eq '..'; |
a0d0e21e |
150 | |
40000a8c |
151 | ($tdev, $tino) = lstat($direntry); |
a0d0e21e |
152 | last unless $tdev != $odev || $tino != $oino; |
153 | } |
154 | closedir(DIR); |
fb73857a |
155 | return undef unless defined $direntry; # should never happen |
40000a8c |
156 | unshift(@path, $direntry); |
a0d0e21e |
157 | } |
fb73857a |
158 | $path = '/' . join('/', @path); |
21ac5ced |
159 | if ($^O eq 'apollo') { $path = "/".$path; } |
fb73857a |
160 | # At this point $path may be tainted (if tainting) and chdir would fail. |
161 | # To be more useful we untaint it then check that we landed where we started. |
392d8ab8 |
162 | $path = $1 if $path =~ /^(.*)\z/s; # untaint |
e79e61e4 |
163 | CORE::chdir($path) || return undef; |
fb73857a |
164 | ($cdev, $cino) = stat('.'); |
165 | die "Unstable directory path, current directory changed unexpectedly" |
166 | if $cdev != $orig_cdev || $cino != $orig_cino; |
a0d0e21e |
167 | $path; |
168 | } |
169 | |
170 | |
4633a7c4 |
171 | # Keeps track of current working directory in PWD environment var |
a0d0e21e |
172 | # Usage: |
173 | # use Cwd 'chdir'; |
174 | # chdir $newdir; |
175 | |
4633a7c4 |
176 | my $chdir_init = 0; |
a0d0e21e |
177 | |
4633a7c4 |
178 | sub chdir_init { |
3b8e3443 |
179 | if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos' and $^O ne 'MSWin32') { |
a0d0e21e |
180 | my($dd,$di) = stat('.'); |
181 | my($pd,$pi) = stat($ENV{'PWD'}); |
182 | if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) { |
4633a7c4 |
183 | $ENV{'PWD'} = cwd(); |
a0d0e21e |
184 | } |
185 | } |
186 | else { |
3b8e3443 |
187 | my $wd = cwd(); |
188 | $wd = Win32::GetFullPathName($wd) if $^O eq 'MSWin32'; |
189 | $ENV{'PWD'} = $wd; |
a0d0e21e |
190 | } |
4633a7c4 |
191 | # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) |
3b8e3443 |
192 | if ($^O ne 'MSWin32' and $ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { |
a0d0e21e |
193 | my($pd,$pi) = stat($2); |
194 | my($dd,$di) = stat($1); |
195 | if (defined $pd and defined $dd and $di == $pi and $dd == $pd) { |
196 | $ENV{'PWD'}="$2$3"; |
197 | } |
198 | } |
199 | $chdir_init = 1; |
200 | } |
201 | |
202 | sub chdir { |
22978713 |
203 | my $newdir = @_ ? shift : ''; # allow for no arg (chdir to HOME dir) |
3b8e3443 |
204 | $newdir =~ s|///*|/|g unless $^O eq 'MSWin32'; |
a0d0e21e |
205 | chdir_init() unless $chdir_init; |
4633a7c4 |
206 | return 0 unless CORE::chdir $newdir; |
3b8e3443 |
207 | if ($^O eq 'VMS') { |
208 | return $ENV{'PWD'} = $ENV{'DEFAULT'} |
209 | } |
4aecb5b5 |
210 | elsif ($^O eq 'MacOS') { |
211 | return $ENV{'PWD'} = cwd(); |
212 | } |
3b8e3443 |
213 | elsif ($^O eq 'MSWin32') { |
214 | $ENV{'PWD'} = Win32::GetFullPathName($newdir); |
215 | return 1; |
216 | } |
748a9306 |
217 | |
392d8ab8 |
218 | if ($newdir =~ m#^/#s) { |
a0d0e21e |
219 | $ENV{'PWD'} = $newdir; |
4633a7c4 |
220 | } else { |
221 | my @curdir = split(m#/#,$ENV{'PWD'}); |
222 | @curdir = ('') unless @curdir; |
223 | my $component; |
a0d0e21e |
224 | foreach $component (split(m#/#, $newdir)) { |
225 | next if $component eq '.'; |
226 | pop(@curdir),next if $component eq '..'; |
227 | push(@curdir,$component); |
228 | } |
229 | $ENV{'PWD'} = join('/',@curdir) || '/'; |
230 | } |
4633a7c4 |
231 | 1; |
a0d0e21e |
232 | } |
233 | |
d57281c6 |
234 | # Taken from Cwd.pm It is really getcwd with an optional |
235 | # parameter instead of '.' |
236 | # |
8b88ae92 |
237 | |
d57281c6 |
238 | sub abs_path |
239 | { |
240 | my $start = @_ ? shift : '.'; |
241 | my($dotdots, $cwd, @pst, @cst, $dir, @tst); |
929327b2 |
242 | |
d57281c6 |
243 | unless (@cst = stat( $start )) |
244 | { |
245 | carp "stat($start): $!"; |
246 | return ''; |
8b88ae92 |
247 | } |
d57281c6 |
248 | $cwd = ''; |
249 | $dotdots = $start; |
250 | do |
251 | { |
252 | $dotdots .= '/..'; |
253 | @pst = @cst; |
254 | unless (opendir(PARENT, $dotdots)) |
255 | { |
256 | carp "opendir($dotdots): $!"; |
257 | return ''; |
258 | } |
259 | unless (@cst = stat($dotdots)) |
260 | { |
261 | carp "stat($dotdots): $!"; |
262 | closedir(PARENT); |
263 | return ''; |
264 | } |
265 | if ($pst[0] == $cst[0] && $pst[1] == $cst[1]) |
266 | { |
267 | $dir = undef; |
268 | } |
269 | else |
270 | { |
271 | do |
272 | { |
273 | unless (defined ($dir = readdir(PARENT))) |
274 | { |
275 | carp "readdir($dotdots): $!"; |
276 | closedir(PARENT); |
277 | return ''; |
278 | } |
279 | $tst[0] = $pst[0]+1 unless (@tst = lstat("$dotdots/$dir")) |
280 | } |
281 | while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] || |
282 | $tst[1] != $pst[1]); |
283 | } |
284 | $cwd = (defined $dir ? "$dir" : "" ) . "/$cwd" ; |
285 | closedir(PARENT); |
286 | } while (defined $dir); |
287 | chop($cwd) unless $cwd eq '/'; # drop the trailing / |
288 | $cwd; |
8b88ae92 |
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(); |
3c65c14b |
297 | my $path = @_ ? shift : '.'; |
e79e61e4 |
298 | CORE::chdir($path) || croak "Cannot chdir to $path:$!"; |
96e4d5b1 |
299 | my $realpath = getcwd(); |
e79e61e4 |
300 | CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; |
96e4d5b1 |
301 | $realpath; |
8b88ae92 |
302 | } |
303 | |
e4c51978 |
304 | # added function alias to follow principle of least surprise |
305 | # based on previous aliasing. --tchrist 27-Jan-00 |
306 | *fast_realpath = \&fast_abs_path; |
307 | |
4633a7c4 |
308 | |
309 | # --- PORTING SECTION --- |
310 | |
311 | # VMS: $ENV{'DEFAULT'} points to default directory at all times |
bd3fa61c |
312 | # 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu |
c6538b72 |
313 | # Note: Use of Cwd::chdir() causes the logical name PWD to be defined |
8b88ae92 |
314 | # in the process logical name table as the default device and directory |
315 | # seen by Perl. This may not be the same as the default device |
4633a7c4 |
316 | # and directory seen by DCL after Perl exits, since the effects |
317 | # the CRTL chdir() function persist only until Perl exits. |
4633a7c4 |
318 | |
319 | sub _vms_cwd { |
96e4d5b1 |
320 | return $ENV{'DEFAULT'}; |
321 | } |
322 | |
323 | sub _vms_abs_path { |
324 | return $ENV{'DEFAULT'} unless @_; |
325 | my $path = VMS::Filespec::pathify($_[0]); |
326 | croak("Invalid path name $_[0]") unless defined $path; |
327 | return VMS::Filespec::rmsexpand($path); |
4633a7c4 |
328 | } |
68dc0745 |
329 | |
4633a7c4 |
330 | sub _os2_cwd { |
331 | $ENV{'PWD'} = `cmd /c cd`; |
332 | chop $ENV{'PWD'}; |
333 | $ENV{'PWD'} =~ s:\\:/:g ; |
334 | return $ENV{'PWD'}; |
335 | } |
336 | |
96e4d5b1 |
337 | sub _win32_cwd { |
2d7a9237 |
338 | $ENV{'PWD'} = Win32::GetCwd(); |
96e4d5b1 |
339 | $ENV{'PWD'} =~ s:\\:/:g ; |
340 | return $ENV{'PWD'}; |
341 | } |
342 | |
343 | *_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && |
2d7a9237 |
344 | defined &Win32::GetCwd); |
96e4d5b1 |
345 | |
346 | *_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; |
68dc0745 |
347 | |
39e571d4 |
348 | sub _dos_cwd { |
349 | if (!defined &Dos::GetCwd) { |
350 | $ENV{'PWD'} = `command /c cd`; |
351 | chop $ENV{'PWD'}; |
352 | $ENV{'PWD'} =~ s:\\:/:g ; |
353 | } else { |
354 | $ENV{'PWD'} = Dos::GetCwd(); |
355 | } |
55497cff |
356 | return $ENV{'PWD'}; |
357 | } |
358 | |
7fbf1995 |
359 | sub _qnx_cwd { |
360 | $ENV{'PWD'} = `/usr/bin/fullpath -t`; |
361 | chop $ENV{'PWD'}; |
362 | return $ENV{'PWD'}; |
363 | } |
364 | |
365 | sub _qnx_abs_path { |
fa921dc6 |
366 | my $path = @_ ? shift : '.'; |
7fbf1995 |
367 | my $realpath=`/usr/bin/fullpath -t $path`; |
368 | chop $realpath; |
369 | return $realpath; |
370 | } |
371 | |
ed79a026 |
372 | sub _epoc_cwd { |
373 | $ENV{'PWD'} = EPOC::getcwd(); |
374 | return $ENV{'PWD'}; |
375 | } |
376 | |
ac1ad7f0 |
377 | { |
db376a24 |
378 | no warnings; # assignments trigger 'subroutine redefined' warning |
4633a7c4 |
379 | |
ac1ad7f0 |
380 | if ($^O eq 'VMS') { |
96e4d5b1 |
381 | *cwd = \&_vms_cwd; |
382 | *getcwd = \&_vms_cwd; |
383 | *fastcwd = \&_vms_cwd; |
384 | *fastgetcwd = \&_vms_cwd; |
385 | *abs_path = \&_vms_abs_path; |
386 | *fast_abs_path = \&_vms_abs_path; |
ac1ad7f0 |
387 | } |
388 | elsif ($^O eq 'NT' or $^O eq 'MSWin32') { |
389 | # We assume that &_NT_cwd is defined as an XSUB or in the core. |
96e4d5b1 |
390 | *cwd = \&_NT_cwd; |
391 | *getcwd = \&_NT_cwd; |
392 | *fastcwd = \&_NT_cwd; |
393 | *fastgetcwd = \&_NT_cwd; |
394 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
395 | } |
396 | elsif ($^O eq 'os2') { |
397 | # sys_cwd may keep the builtin command |
96e4d5b1 |
398 | *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; |
399 | *getcwd = \&cwd; |
400 | *fastgetcwd = \&cwd; |
401 | *fastcwd = \&cwd; |
402 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
403 | } |
39e571d4 |
404 | elsif ($^O eq 'dos') { |
405 | *cwd = \&_dos_cwd; |
406 | *getcwd = \&_dos_cwd; |
407 | *fastgetcwd = \&_dos_cwd; |
408 | *fastcwd = \&_dos_cwd; |
96e4d5b1 |
409 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
410 | } |
7fbf1995 |
411 | elsif ($^O eq 'qnx') { |
412 | *cwd = \&_qnx_cwd; |
413 | *getcwd = \&_qnx_cwd; |
414 | *fastgetcwd = \&_qnx_cwd; |
415 | *fastcwd = \&_qnx_cwd; |
416 | *abs_path = \&_qnx_abs_path; |
417 | *fast_abs_path = \&_qnx_abs_path; |
418 | } |
4fabb596 |
419 | elsif ($^O eq 'cygwin') { |
1cab015a |
420 | *getcwd = \&cwd; |
421 | *fastgetcwd = \&cwd; |
422 | *fastcwd = \&cwd; |
423 | *abs_path = \&fast_abs_path; |
424 | } |
ed79a026 |
425 | elsif ($^O eq 'epoc') { |
fa6a1c44 |
426 | *cwd = \&_epoc_cwd; |
427 | *getcwd = \&_epoc_cwd; |
ed79a026 |
428 | *fastgetcwd = \&_epoc_cwd; |
429 | *fastcwd = \&_epoc_cwd; |
430 | *abs_path = \&fast_abs_path; |
431 | } |
4aecb5b5 |
432 | elsif ($^O eq 'MacOS') { |
433 | *getcwd = \&cwd; |
434 | *fastgetcwd = \&cwd; |
435 | *fastcwd = \&cwd; |
436 | *abs_path = \&fast_abs_path; |
437 | } |
55497cff |
438 | } |
4633a7c4 |
439 | |
440 | # package main; eval join('',<DATA>) || die $@; # quick test |
441 | |
a0d0e21e |
442 | 1; |
443 | |
4633a7c4 |
444 | __END__ |
445 | BEGIN { import Cwd qw(:DEFAULT chdir); } |
446 | print join("\n", cwd, getcwd, fastcwd, ""); |
447 | chdir('..'); |
448 | print join("\n", cwd, getcwd, fastcwd, ""); |
449 | print "$ENV{PWD}\n"; |