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 | |
2ae52c40 |
88 | # Indicates if the XS portion has been loaded or not |
89 | my $Booted = 0; |
4633a7c4 |
90 | |
8b88ae92 |
91 | # The 'natural and safe form' for UNIX (pwd may be setuid root) |
96e4d5b1 |
92 | |
8b88ae92 |
93 | sub _backtick_pwd { |
7e03f963 |
94 | my $cwd = `pwd`; |
95 | # `pwd` may fail e.g. if the disk is full |
96 | chomp($cwd) if defined $cwd; |
4633a7c4 |
97 | $cwd; |
8b88ae92 |
98 | } |
4633a7c4 |
99 | |
100 | # Since some ports may predefine cwd internally (e.g., NT) |
101 | # we take care not to override an existing definition for cwd(). |
102 | |
ea54c8bd |
103 | unless(defined &cwd) { |
104 | # The pwd command is not available in some chroot(2)'ed environments |
4aecb5b5 |
105 | if($^O eq 'MacOS' || grep { -x "$_/pwd" } split(':', $ENV{PATH})) { |
ea54c8bd |
106 | *cwd = \&_backtick_pwd; |
107 | } |
108 | else { |
109 | *cwd = \&getcwd; |
110 | } |
111 | } |
a0d0e21e |
112 | |
1f4f94f5 |
113 | # set a reasonable (and very safe) default for fastgetcwd, in case it |
114 | # isn't redefined later (20001212 rspier) |
115 | *fastgetcwd = \&cwd; |
748a9306 |
116 | |
a0d0e21e |
117 | # By Brandon S. Allbery |
118 | # |
119 | # Usage: $cwd = getcwd(); |
120 | |
121 | sub getcwd |
122 | { |
07569ed3 |
123 | abs_path('.'); |
a0d0e21e |
124 | } |
125 | |
0d2079fa |
126 | # Now a callout to an XSUB. We have to delay booting of the XSUB |
127 | # until the first time fastcwd is called since Cwd::cwd is needed in the |
128 | # building of perl when dynamic loading may be unavailable |
a0d0e21e |
129 | sub fastcwd { |
2ae52c40 |
130 | unless ($Booted) { |
0d2079fa |
131 | require XSLoader; |
132 | XSLoader::load("Cwd"); |
2ae52c40 |
133 | ++$Booted; |
a0d0e21e |
134 | } |
0d2079fa |
135 | return &Cwd::_fastcwd; |
a0d0e21e |
136 | } |
137 | |
138 | |
4633a7c4 |
139 | # Keeps track of current working directory in PWD environment var |
a0d0e21e |
140 | # Usage: |
141 | # use Cwd 'chdir'; |
142 | # chdir $newdir; |
143 | |
4633a7c4 |
144 | my $chdir_init = 0; |
a0d0e21e |
145 | |
4633a7c4 |
146 | sub chdir_init { |
3b8e3443 |
147 | if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos' and $^O ne 'MSWin32') { |
a0d0e21e |
148 | my($dd,$di) = stat('.'); |
149 | my($pd,$pi) = stat($ENV{'PWD'}); |
150 | if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) { |
4633a7c4 |
151 | $ENV{'PWD'} = cwd(); |
a0d0e21e |
152 | } |
153 | } |
154 | else { |
3b8e3443 |
155 | my $wd = cwd(); |
156 | $wd = Win32::GetFullPathName($wd) if $^O eq 'MSWin32'; |
157 | $ENV{'PWD'} = $wd; |
a0d0e21e |
158 | } |
4633a7c4 |
159 | # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) |
3b8e3443 |
160 | if ($^O ne 'MSWin32' and $ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { |
a0d0e21e |
161 | my($pd,$pi) = stat($2); |
162 | my($dd,$di) = stat($1); |
163 | if (defined $pd and defined $dd and $di == $pi and $dd == $pd) { |
164 | $ENV{'PWD'}="$2$3"; |
165 | } |
166 | } |
167 | $chdir_init = 1; |
168 | } |
169 | |
170 | sub chdir { |
22978713 |
171 | my $newdir = @_ ? shift : ''; # allow for no arg (chdir to HOME dir) |
3b8e3443 |
172 | $newdir =~ s|///*|/|g unless $^O eq 'MSWin32'; |
a0d0e21e |
173 | chdir_init() unless $chdir_init; |
4ffa1610 |
174 | my $newpwd; |
175 | if ($^O eq 'MSWin32') { |
176 | # get the full path name *before* the chdir() |
177 | $newpwd = Win32::GetFullPathName($newdir); |
178 | } |
179 | |
4633a7c4 |
180 | return 0 unless CORE::chdir $newdir; |
4ffa1610 |
181 | |
3b8e3443 |
182 | if ($^O eq 'VMS') { |
183 | return $ENV{'PWD'} = $ENV{'DEFAULT'} |
184 | } |
4aecb5b5 |
185 | elsif ($^O eq 'MacOS') { |
186 | return $ENV{'PWD'} = cwd(); |
187 | } |
3b8e3443 |
188 | elsif ($^O eq 'MSWin32') { |
4ffa1610 |
189 | $ENV{'PWD'} = $newpwd; |
3b8e3443 |
190 | return 1; |
191 | } |
748a9306 |
192 | |
392d8ab8 |
193 | if ($newdir =~ m#^/#s) { |
a0d0e21e |
194 | $ENV{'PWD'} = $newdir; |
4633a7c4 |
195 | } else { |
196 | my @curdir = split(m#/#,$ENV{'PWD'}); |
197 | @curdir = ('') unless @curdir; |
198 | my $component; |
a0d0e21e |
199 | foreach $component (split(m#/#, $newdir)) { |
200 | next if $component eq '.'; |
201 | pop(@curdir),next if $component eq '..'; |
202 | push(@curdir,$component); |
203 | } |
204 | $ENV{'PWD'} = join('/',@curdir) || '/'; |
205 | } |
4633a7c4 |
206 | 1; |
a0d0e21e |
207 | } |
208 | |
2ae52c40 |
209 | # Now a callout to an XSUB |
d57281c6 |
210 | sub abs_path |
211 | { |
2ae52c40 |
212 | unless ($Booted) { |
213 | require XSLoader; |
214 | XSLoader::load("Cwd"); |
215 | ++$Booted; |
8b88ae92 |
216 | } |
2ae52c40 |
217 | return &Cwd::_abs_path(@_); |
8b88ae92 |
218 | } |
219 | |
e4c51978 |
220 | # added function alias for those of us more |
221 | # used to the libc function. --tchrist 27-Jan-00 |
222 | *realpath = \&abs_path; |
223 | |
96e4d5b1 |
224 | sub fast_abs_path { |
225 | my $cwd = getcwd(); |
3c65c14b |
226 | my $path = @_ ? shift : '.'; |
e79e61e4 |
227 | CORE::chdir($path) || croak "Cannot chdir to $path:$!"; |
96e4d5b1 |
228 | my $realpath = getcwd(); |
e79e61e4 |
229 | CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; |
96e4d5b1 |
230 | $realpath; |
8b88ae92 |
231 | } |
232 | |
e4c51978 |
233 | # added function alias to follow principle of least surprise |
234 | # based on previous aliasing. --tchrist 27-Jan-00 |
235 | *fast_realpath = \&fast_abs_path; |
236 | |
4633a7c4 |
237 | |
238 | # --- PORTING SECTION --- |
239 | |
240 | # VMS: $ENV{'DEFAULT'} points to default directory at all times |
bd3fa61c |
241 | # 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu |
c6538b72 |
242 | # Note: Use of Cwd::chdir() causes the logical name PWD to be defined |
8b88ae92 |
243 | # in the process logical name table as the default device and directory |
244 | # seen by Perl. This may not be the same as the default device |
4633a7c4 |
245 | # and directory seen by DCL after Perl exits, since the effects |
246 | # the CRTL chdir() function persist only until Perl exits. |
4633a7c4 |
247 | |
248 | sub _vms_cwd { |
96e4d5b1 |
249 | return $ENV{'DEFAULT'}; |
250 | } |
251 | |
252 | sub _vms_abs_path { |
253 | return $ENV{'DEFAULT'} unless @_; |
254 | my $path = VMS::Filespec::pathify($_[0]); |
255 | croak("Invalid path name $_[0]") unless defined $path; |
256 | return VMS::Filespec::rmsexpand($path); |
4633a7c4 |
257 | } |
68dc0745 |
258 | |
4633a7c4 |
259 | sub _os2_cwd { |
260 | $ENV{'PWD'} = `cmd /c cd`; |
261 | chop $ENV{'PWD'}; |
262 | $ENV{'PWD'} =~ s:\\:/:g ; |
263 | return $ENV{'PWD'}; |
264 | } |
265 | |
96e4d5b1 |
266 | sub _win32_cwd { |
2d7a9237 |
267 | $ENV{'PWD'} = Win32::GetCwd(); |
96e4d5b1 |
268 | $ENV{'PWD'} =~ s:\\:/:g ; |
269 | return $ENV{'PWD'}; |
270 | } |
271 | |
272 | *_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && |
2d7a9237 |
273 | defined &Win32::GetCwd); |
96e4d5b1 |
274 | |
275 | *_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; |
68dc0745 |
276 | |
39e571d4 |
277 | sub _dos_cwd { |
278 | if (!defined &Dos::GetCwd) { |
279 | $ENV{'PWD'} = `command /c cd`; |
280 | chop $ENV{'PWD'}; |
281 | $ENV{'PWD'} =~ s:\\:/:g ; |
282 | } else { |
283 | $ENV{'PWD'} = Dos::GetCwd(); |
284 | } |
55497cff |
285 | return $ENV{'PWD'}; |
286 | } |
287 | |
7fbf1995 |
288 | sub _qnx_cwd { |
289 | $ENV{'PWD'} = `/usr/bin/fullpath -t`; |
290 | chop $ENV{'PWD'}; |
291 | return $ENV{'PWD'}; |
292 | } |
293 | |
294 | sub _qnx_abs_path { |
fa921dc6 |
295 | my $path = @_ ? shift : '.'; |
7fbf1995 |
296 | my $realpath=`/usr/bin/fullpath -t $path`; |
297 | chop $realpath; |
298 | return $realpath; |
299 | } |
300 | |
ed79a026 |
301 | sub _epoc_cwd { |
302 | $ENV{'PWD'} = EPOC::getcwd(); |
303 | return $ENV{'PWD'}; |
304 | } |
305 | |
ac1ad7f0 |
306 | { |
db376a24 |
307 | no warnings; # assignments trigger 'subroutine redefined' warning |
4633a7c4 |
308 | |
ac1ad7f0 |
309 | if ($^O eq 'VMS') { |
96e4d5b1 |
310 | *cwd = \&_vms_cwd; |
311 | *getcwd = \&_vms_cwd; |
312 | *fastcwd = \&_vms_cwd; |
313 | *fastgetcwd = \&_vms_cwd; |
314 | *abs_path = \&_vms_abs_path; |
315 | *fast_abs_path = \&_vms_abs_path; |
ac1ad7f0 |
316 | } |
317 | elsif ($^O eq 'NT' or $^O eq 'MSWin32') { |
318 | # We assume that &_NT_cwd is defined as an XSUB or in the core. |
96e4d5b1 |
319 | *cwd = \&_NT_cwd; |
320 | *getcwd = \&_NT_cwd; |
321 | *fastcwd = \&_NT_cwd; |
322 | *fastgetcwd = \&_NT_cwd; |
323 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
324 | } |
325 | elsif ($^O eq 'os2') { |
326 | # sys_cwd may keep the builtin command |
96e4d5b1 |
327 | *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; |
328 | *getcwd = \&cwd; |
329 | *fastgetcwd = \&cwd; |
330 | *fastcwd = \&cwd; |
331 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
332 | } |
39e571d4 |
333 | elsif ($^O eq 'dos') { |
334 | *cwd = \&_dos_cwd; |
335 | *getcwd = \&_dos_cwd; |
336 | *fastgetcwd = \&_dos_cwd; |
337 | *fastcwd = \&_dos_cwd; |
96e4d5b1 |
338 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
339 | } |
7fbf1995 |
340 | elsif ($^O eq 'qnx') { |
341 | *cwd = \&_qnx_cwd; |
342 | *getcwd = \&_qnx_cwd; |
343 | *fastgetcwd = \&_qnx_cwd; |
344 | *fastcwd = \&_qnx_cwd; |
345 | *abs_path = \&_qnx_abs_path; |
346 | *fast_abs_path = \&_qnx_abs_path; |
347 | } |
4fabb596 |
348 | elsif ($^O eq 'cygwin') { |
1cab015a |
349 | *getcwd = \&cwd; |
350 | *fastgetcwd = \&cwd; |
351 | *fastcwd = \&cwd; |
352 | *abs_path = \&fast_abs_path; |
353 | } |
ed79a026 |
354 | elsif ($^O eq 'epoc') { |
fa6a1c44 |
355 | *cwd = \&_epoc_cwd; |
356 | *getcwd = \&_epoc_cwd; |
ed79a026 |
357 | *fastgetcwd = \&_epoc_cwd; |
358 | *fastcwd = \&_epoc_cwd; |
359 | *abs_path = \&fast_abs_path; |
360 | } |
4aecb5b5 |
361 | elsif ($^O eq 'MacOS') { |
362 | *getcwd = \&cwd; |
363 | *fastgetcwd = \&cwd; |
364 | *fastcwd = \&cwd; |
365 | *abs_path = \&fast_abs_path; |
366 | } |
55497cff |
367 | } |
4633a7c4 |
368 | |
369 | # package main; eval join('',<DATA>) || die $@; # quick test |
370 | |
a0d0e21e |
371 | 1; |
372 | |
4633a7c4 |
373 | __END__ |
374 | BEGIN { import Cwd qw(:DEFAULT chdir); } |
375 | print join("\n", cwd, getcwd, fastcwd, ""); |
376 | chdir('..'); |
377 | print join("\n", cwd, getcwd, fastcwd, ""); |
378 | print "$ENV{PWD}\n"; |