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