Commit | Line | Data |
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a0d0e21e LW |
1 | package Cwd; |
2 | require 5.000; | |
a0d0e21e | 3 | |
f06db76b AD |
4 | =head1 NAME |
5 | ||
902bacac | 6 | Cwd - get pathname of current working directory |
f06db76b AD |
7 | |
8 | =head1 SYNOPSIS | |
9 | ||
4633a7c4 LW |
10 | use Cwd; |
11 | $dir = cwd; | |
12 | ||
13 | use Cwd; | |
14 | $dir = getcwd; | |
f06db76b AD |
15 | |
16 | use Cwd; | |
902bacac BS |
17 | $dir = fastcwd; |
18 | ||
19 | use Cwd; | |
4633a7c4 | 20 | $dir = fastgetcwd; |
f06db76b AD |
21 | |
22 | use Cwd 'chdir'; | |
23 | chdir "/tmp"; | |
24 | print $ENV{'PWD'}; | |
25 | ||
e4c51978 | 26 | use Cwd 'abs_path'; # aka realpath() |
20408e3c GS |
27 | print abs_path($ENV{'PWD'}); |
28 | ||
29 | use Cwd 'fast_abs_path'; | |
30 | print fast_abs_path($ENV{'PWD'}); | |
31 | ||
f06db76b AD |
32 | =head1 DESCRIPTION |
33 | ||
902bacac BS |
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 BS |
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 LW |
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 AD |
76 | =cut |
77 | ||
b060a406 | 78 | use strict; |
96e4d5b1 | 79 | |
80 | use Carp; | |
81 | ||
1f4f94f5 | 82 | our $VERSION = '2.04'; |
96e4d5b1 | 83 | |
b060a406 TJ |
84 | use base qw/ Exporter /; |
85 | our @EXPORT = qw(cwd getcwd fastcwd fastgetcwd); | |
86 | our @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); | |
a0d0e21e | 87 | |
f5f423e4 IZ |
88 | # sys_cwd may keep the builtin command |
89 | ||
90 | # All the functionality of this module may provided by builtins, | |
91 | # there is no sense to process the rest of the file. | |
92 | # The best choice may be to have this in BEGIN, but how to return from BEGIN? | |
93 | ||
94 | if ($^O eq 'os2' && defined &sys_cwd && defined &sys_abspath) { | |
95 | local $^W = 0; | |
96 | *cwd = \&sys_cwd; | |
97 | *getcwd = \&cwd; | |
98 | *fastgetcwd = \&cwd; | |
99 | *fastcwd = \&cwd; | |
100 | *abs_path = \&sys_abspath; | |
101 | *fast_abs_path = \&abs_path; | |
102 | *realpath = \&abs_path; | |
103 | *fast_realpath = \&abs_path; | |
104 | return 1; | |
105 | } | |
106 | ||
f22d8e4b DM |
107 | eval { |
108 | require XSLoader; | |
109 | XSLoader::load('Cwd'); | |
110 | }; | |
4633a7c4 | 111 | |
8b88ae92 | 112 | # The 'natural and safe form' for UNIX (pwd may be setuid root) |
96e4d5b1 | 113 | |
8b88ae92 | 114 | sub _backtick_pwd { |
7e03f963 TJ |
115 | my $cwd = `pwd`; |
116 | # `pwd` may fail e.g. if the disk is full | |
117 | chomp($cwd) if defined $cwd; | |
4633a7c4 | 118 | $cwd; |
8b88ae92 | 119 | } |
4633a7c4 LW |
120 | |
121 | # Since some ports may predefine cwd internally (e.g., NT) | |
122 | # we take care not to override an existing definition for cwd(). | |
123 | ||
ea54c8bd EC |
124 | unless(defined &cwd) { |
125 | # The pwd command is not available in some chroot(2)'ed environments | |
4aecb5b5 | 126 | if($^O eq 'MacOS' || grep { -x "$_/pwd" } split(':', $ENV{PATH})) { |
ea54c8bd EC |
127 | *cwd = \&_backtick_pwd; |
128 | } | |
129 | else { | |
130 | *cwd = \&getcwd; | |
131 | } | |
132 | } | |
a0d0e21e | 133 | |
1f4f94f5 RS |
134 | # set a reasonable (and very safe) default for fastgetcwd, in case it |
135 | # isn't redefined later (20001212 rspier) | |
136 | *fastgetcwd = \&cwd; | |
748a9306 | 137 | |
a0d0e21e LW |
138 | # By Brandon S. Allbery |
139 | # | |
140 | # Usage: $cwd = getcwd(); | |
141 | ||
142 | sub getcwd | |
143 | { | |
07569ed3 | 144 | abs_path('.'); |
a0d0e21e LW |
145 | } |
146 | ||
4633a7c4 | 147 | # Keeps track of current working directory in PWD environment var |
a0d0e21e LW |
148 | # Usage: |
149 | # use Cwd 'chdir'; | |
150 | # chdir $newdir; | |
151 | ||
4633a7c4 | 152 | my $chdir_init = 0; |
a0d0e21e | 153 | |
4633a7c4 | 154 | sub chdir_init { |
3b8e3443 | 155 | if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos' and $^O ne 'MSWin32') { |
a0d0e21e LW |
156 | my($dd,$di) = stat('.'); |
157 | my($pd,$pi) = stat($ENV{'PWD'}); | |
158 | if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) { | |
4633a7c4 | 159 | $ENV{'PWD'} = cwd(); |
a0d0e21e LW |
160 | } |
161 | } | |
162 | else { | |
3b8e3443 GS |
163 | my $wd = cwd(); |
164 | $wd = Win32::GetFullPathName($wd) if $^O eq 'MSWin32'; | |
165 | $ENV{'PWD'} = $wd; | |
a0d0e21e | 166 | } |
4633a7c4 | 167 | # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) |
3b8e3443 | 168 | if ($^O ne 'MSWin32' and $ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { |
a0d0e21e LW |
169 | my($pd,$pi) = stat($2); |
170 | my($dd,$di) = stat($1); | |
171 | if (defined $pd and defined $dd and $di == $pi and $dd == $pd) { | |
172 | $ENV{'PWD'}="$2$3"; | |
173 | } | |
174 | } | |
175 | $chdir_init = 1; | |
176 | } | |
177 | ||
178 | sub chdir { | |
22978713 | 179 | my $newdir = @_ ? shift : ''; # allow for no arg (chdir to HOME dir) |
3b8e3443 | 180 | $newdir =~ s|///*|/|g unless $^O eq 'MSWin32'; |
a0d0e21e | 181 | chdir_init() unless $chdir_init; |
4ffa1610 JH |
182 | my $newpwd; |
183 | if ($^O eq 'MSWin32') { | |
184 | # get the full path name *before* the chdir() | |
185 | $newpwd = Win32::GetFullPathName($newdir); | |
186 | } | |
187 | ||
4633a7c4 | 188 | return 0 unless CORE::chdir $newdir; |
4ffa1610 | 189 | |
3b8e3443 GS |
190 | if ($^O eq 'VMS') { |
191 | return $ENV{'PWD'} = $ENV{'DEFAULT'} | |
192 | } | |
4aecb5b5 JH |
193 | elsif ($^O eq 'MacOS') { |
194 | return $ENV{'PWD'} = cwd(); | |
195 | } | |
3b8e3443 | 196 | elsif ($^O eq 'MSWin32') { |
4ffa1610 | 197 | $ENV{'PWD'} = $newpwd; |
3b8e3443 GS |
198 | return 1; |
199 | } | |
748a9306 | 200 | |
392d8ab8 | 201 | if ($newdir =~ m#^/#s) { |
a0d0e21e | 202 | $ENV{'PWD'} = $newdir; |
4633a7c4 LW |
203 | } else { |
204 | my @curdir = split(m#/#,$ENV{'PWD'}); | |
205 | @curdir = ('') unless @curdir; | |
206 | my $component; | |
a0d0e21e LW |
207 | foreach $component (split(m#/#, $newdir)) { |
208 | next if $component eq '.'; | |
209 | pop(@curdir),next if $component eq '..'; | |
210 | push(@curdir,$component); | |
211 | } | |
212 | $ENV{'PWD'} = join('/',@curdir) || '/'; | |
213 | } | |
4633a7c4 | 214 | 1; |
a0d0e21e LW |
215 | } |
216 | ||
e4c51978 GS |
217 | # added function alias for those of us more |
218 | # used to the libc function. --tchrist 27-Jan-00 | |
219 | *realpath = \&abs_path; | |
220 | ||
96e4d5b1 | 221 | sub fast_abs_path { |
222 | my $cwd = getcwd(); | |
3c65c14b | 223 | my $path = @_ ? shift : '.'; |
e79e61e4 | 224 | CORE::chdir($path) || croak "Cannot chdir to $path:$!"; |
96e4d5b1 | 225 | my $realpath = getcwd(); |
e79e61e4 | 226 | CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; |
96e4d5b1 | 227 | $realpath; |
8b88ae92 NIS |
228 | } |
229 | ||
e4c51978 GS |
230 | # added function alias to follow principle of least surprise |
231 | # based on previous aliasing. --tchrist 27-Jan-00 | |
232 | *fast_realpath = \&fast_abs_path; | |
233 | ||
4633a7c4 LW |
234 | |
235 | # --- PORTING SECTION --- | |
236 | ||
237 | # VMS: $ENV{'DEFAULT'} points to default directory at all times | |
bd3fa61c | 238 | # 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu |
c6538b72 | 239 | # Note: Use of Cwd::chdir() causes the logical name PWD to be defined |
8b88ae92 NIS |
240 | # in the process logical name table as the default device and directory |
241 | # seen by Perl. This may not be the same as the default device | |
4633a7c4 LW |
242 | # and directory seen by DCL after Perl exits, since the effects |
243 | # the CRTL chdir() function persist only until Perl exits. | |
4633a7c4 LW |
244 | |
245 | sub _vms_cwd { | |
96e4d5b1 | 246 | return $ENV{'DEFAULT'}; |
247 | } | |
248 | ||
249 | sub _vms_abs_path { | |
250 | return $ENV{'DEFAULT'} unless @_; | |
251 | my $path = VMS::Filespec::pathify($_[0]); | |
252 | croak("Invalid path name $_[0]") unless defined $path; | |
253 | return VMS::Filespec::rmsexpand($path); | |
4633a7c4 | 254 | } |
68dc0745 | 255 | |
4633a7c4 LW |
256 | sub _os2_cwd { |
257 | $ENV{'PWD'} = `cmd /c cd`; | |
258 | chop $ENV{'PWD'}; | |
259 | $ENV{'PWD'} =~ s:\\:/:g ; | |
260 | return $ENV{'PWD'}; | |
261 | } | |
262 | ||
96e4d5b1 | 263 | sub _win32_cwd { |
2d7a9237 | 264 | $ENV{'PWD'} = Win32::GetCwd(); |
96e4d5b1 | 265 | $ENV{'PWD'} =~ s:\\:/:g ; |
266 | return $ENV{'PWD'}; | |
267 | } | |
268 | ||
269 | *_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && | |
2d7a9237 | 270 | defined &Win32::GetCwd); |
96e4d5b1 | 271 | |
272 | *_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; | |
68dc0745 | 273 | |
39e571d4 LM |
274 | sub _dos_cwd { |
275 | if (!defined &Dos::GetCwd) { | |
276 | $ENV{'PWD'} = `command /c cd`; | |
277 | chop $ENV{'PWD'}; | |
278 | $ENV{'PWD'} =~ s:\\:/:g ; | |
279 | } else { | |
280 | $ENV{'PWD'} = Dos::GetCwd(); | |
281 | } | |
55497cff | 282 | return $ENV{'PWD'}; |
283 | } | |
284 | ||
7fbf1995 NA |
285 | sub _qnx_cwd { |
286 | $ENV{'PWD'} = `/usr/bin/fullpath -t`; | |
287 | chop $ENV{'PWD'}; | |
288 | return $ENV{'PWD'}; | |
289 | } | |
290 | ||
291 | sub _qnx_abs_path { | |
fa921dc6 | 292 | my $path = @_ ? shift : '.'; |
7fbf1995 NA |
293 | my $realpath=`/usr/bin/fullpath -t $path`; |
294 | chop $realpath; | |
295 | return $realpath; | |
296 | } | |
297 | ||
ed79a026 OF |
298 | sub _epoc_cwd { |
299 | $ENV{'PWD'} = EPOC::getcwd(); | |
300 | return $ENV{'PWD'}; | |
301 | } | |
302 | ||
ac1ad7f0 | 303 | { |
db376a24 | 304 | no warnings; # assignments trigger 'subroutine redefined' warning |
4633a7c4 | 305 | |
ac1ad7f0 | 306 | if ($^O eq 'VMS') { |
96e4d5b1 | 307 | *cwd = \&_vms_cwd; |
308 | *getcwd = \&_vms_cwd; | |
309 | *fastcwd = \&_vms_cwd; | |
310 | *fastgetcwd = \&_vms_cwd; | |
311 | *abs_path = \&_vms_abs_path; | |
312 | *fast_abs_path = \&_vms_abs_path; | |
ac1ad7f0 PM |
313 | } |
314 | elsif ($^O eq 'NT' or $^O eq 'MSWin32') { | |
315 | # We assume that &_NT_cwd is defined as an XSUB or in the core. | |
96e4d5b1 | 316 | *cwd = \&_NT_cwd; |
317 | *getcwd = \&_NT_cwd; | |
318 | *fastcwd = \&_NT_cwd; | |
319 | *fastgetcwd = \&_NT_cwd; | |
320 | *abs_path = \&fast_abs_path; | |
ac1ad7f0 PM |
321 | } |
322 | elsif ($^O eq 'os2') { | |
323 | # sys_cwd may keep the builtin command | |
96e4d5b1 | 324 | *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; |
325 | *getcwd = \&cwd; | |
326 | *fastgetcwd = \&cwd; | |
327 | *fastcwd = \&cwd; | |
328 | *abs_path = \&fast_abs_path; | |
ac1ad7f0 | 329 | } |
39e571d4 LM |
330 | elsif ($^O eq 'dos') { |
331 | *cwd = \&_dos_cwd; | |
332 | *getcwd = \&_dos_cwd; | |
333 | *fastgetcwd = \&_dos_cwd; | |
334 | *fastcwd = \&_dos_cwd; | |
96e4d5b1 | 335 | *abs_path = \&fast_abs_path; |
ac1ad7f0 | 336 | } |
7438b6ad | 337 | elsif ($^O =~ m/^(?:qnx|nto)$/ ) { |
7fbf1995 NA |
338 | *cwd = \&_qnx_cwd; |
339 | *getcwd = \&_qnx_cwd; | |
340 | *fastgetcwd = \&_qnx_cwd; | |
341 | *fastcwd = \&_qnx_cwd; | |
342 | *abs_path = \&_qnx_abs_path; | |
343 | *fast_abs_path = \&_qnx_abs_path; | |
344 | } | |
4fabb596 | 345 | elsif ($^O eq 'cygwin') { |
1cab015a EF |
346 | *getcwd = \&cwd; |
347 | *fastgetcwd = \&cwd; | |
348 | *fastcwd = \&cwd; | |
349 | *abs_path = \&fast_abs_path; | |
350 | } | |
ed79a026 | 351 | elsif ($^O eq 'epoc') { |
fa6a1c44 OF |
352 | *cwd = \&_epoc_cwd; |
353 | *getcwd = \&_epoc_cwd; | |
ed79a026 OF |
354 | *fastgetcwd = \&_epoc_cwd; |
355 | *fastcwd = \&_epoc_cwd; | |
356 | *abs_path = \&fast_abs_path; | |
357 | } | |
4aecb5b5 JH |
358 | elsif ($^O eq 'MacOS') { |
359 | *getcwd = \&cwd; | |
360 | *fastgetcwd = \&cwd; | |
361 | *fastcwd = \&cwd; | |
362 | *abs_path = \&fast_abs_path; | |
363 | } | |
55497cff | 364 | } |
4633a7c4 LW |
365 | |
366 | # package main; eval join('',<DATA>) || die $@; # quick test | |
367 | ||
a0d0e21e LW |
368 | 1; |
369 | ||
4633a7c4 LW |
370 | __END__ |
371 | BEGIN { import Cwd qw(:DEFAULT chdir); } | |
372 | print join("\n", cwd, getcwd, fastcwd, ""); | |
373 | chdir('..'); | |
374 | print join("\n", cwd, getcwd, fastcwd, ""); | |
375 | print "$ENV{PWD}\n"; |