Commit | Line | Data |
---|---|---|
a0d0e21e LW |
1 | package Cwd; |
2 | require 5.000; | |
a0d0e21e | 3 | |
f06db76b AD |
4 | =head1 NAME |
5 | ||
6 | getcwd - get pathname of current working directory | |
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; | |
4633a7c4 | 17 | $dir = fastgetcwd; |
f06db76b AD |
18 | |
19 | use Cwd 'chdir'; | |
20 | chdir "/tmp"; | |
21 | print $ENV{'PWD'}; | |
22 | ||
e4c51978 | 23 | use Cwd 'abs_path'; # aka realpath() |
20408e3c GS |
24 | print abs_path($ENV{'PWD'}); |
25 | ||
26 | use Cwd 'fast_abs_path'; | |
27 | print fast_abs_path($ENV{'PWD'}); | |
28 | ||
f06db76b AD |
29 | =head1 DESCRIPTION |
30 | ||
31 | The getcwd() function re-implements the getcwd(3) (or getwd(3)) functions | |
4633a7c4 | 32 | in Perl. |
f06db76b | 33 | |
20408e3c | 34 | The abs_path() function takes a single argument and returns the |
e4c51978 GS |
35 | absolute pathname for that argument. It uses the same algorithm |
36 | as getcwd(). (Actually, getcwd() is abs_path(".")) Symbolic links | |
37 | and relative-path components ("." and "..") are resolved to return | |
38 | the canonical pathname, just like realpath(3). Also callable as | |
39 | realpath(). | |
20408e3c | 40 | |
cb1a09d0 | 41 | The fastcwd() function looks the same as getcwd(), but runs faster. |
fb73857a | 42 | It's also more dangerous because it might conceivably chdir() you out |
43 | of a directory that it can't chdir() you back into. If fastcwd | |
44 | encounters a problem it will return undef but will probably leave you | |
45 | in a different directory. For a measure of extra security, if | |
46 | everything appears to have worked, the fastcwd() function will check | |
47 | that it leaves you in the same directory that it started in. If it has | |
48 | changed it will C<die> with the message "Unstable directory path, | |
49 | current directory changed unexpectedly". That should never happen. | |
f06db76b | 50 | |
20408e3c GS |
51 | The fast_abs_path() function looks the same as abs_path(), but runs faster. |
52 | And like fastcwd() is more dangerous. | |
53 | ||
4633a7c4 LW |
54 | The cwd() function looks the same as getcwd and fastgetcwd but is |
55 | implemented using the most natural and safe form for the current | |
56 | architecture. For most systems it is identical to `pwd` (but without | |
fb73857a | 57 | the trailing line terminator). |
58 | ||
59 | It is recommended that cwd (or another *cwd() function) is used in | |
60 | I<all> code to ensure portability. | |
4633a7c4 LW |
61 | |
62 | If you ask to override your chdir() built-in function, then your PWD | |
63 | environment variable will be kept up to date. (See | |
55497cff | 64 | L<perlsub/Overriding Builtin Functions>.) Note that it will only be |
1fef88e7 | 65 | kept up to date if all packages which use chdir import it from Cwd. |
4633a7c4 | 66 | |
f06db76b AD |
67 | =cut |
68 | ||
96e4d5b1 | 69 | ## use strict; |
70 | ||
71 | use Carp; | |
72 | ||
e4c51978 | 73 | $VERSION = '2.02'; |
96e4d5b1 | 74 | |
75 | require Exporter; | |
a0d0e21e | 76 | @ISA = qw(Exporter); |
e7ae0116 | 77 | @EXPORT = qw(cwd getcwd fastcwd fastgetcwd); |
e4c51978 | 78 | @EXPORT_OK = qw(chdir abs_path fast_abs_path realpath fast_realpath); |
a0d0e21e | 79 | |
4633a7c4 | 80 | |
8b88ae92 | 81 | # The 'natural and safe form' for UNIX (pwd may be setuid root) |
96e4d5b1 | 82 | |
8b88ae92 | 83 | sub _backtick_pwd { |
4633a7c4 LW |
84 | my $cwd; |
85 | chop($cwd = `pwd`); | |
86 | $cwd; | |
8b88ae92 | 87 | } |
4633a7c4 LW |
88 | |
89 | # Since some ports may predefine cwd internally (e.g., NT) | |
90 | # we take care not to override an existing definition for cwd(). | |
91 | ||
92 | *cwd = \&_backtick_pwd unless defined &cwd; | |
a0d0e21e | 93 | |
748a9306 | 94 | |
a0d0e21e LW |
95 | # By Brandon S. Allbery |
96 | # | |
97 | # Usage: $cwd = getcwd(); | |
98 | ||
99 | sub getcwd | |
100 | { | |
07569ed3 | 101 | abs_path('.'); |
a0d0e21e LW |
102 | } |
103 | ||
a0d0e21e LW |
104 | # By John Bazik |
105 | # | |
106 | # Usage: $cwd = &fastcwd; | |
107 | # | |
108 | # This is a faster version of getcwd. It's also more dangerous because | |
109 | # you might chdir out of a directory that you can't chdir back into. | |
fb73857a | 110 | |
a0d0e21e LW |
111 | sub fastcwd { |
112 | my($odev, $oino, $cdev, $cino, $tdev, $tino); | |
113 | my(@path, $path); | |
114 | local(*DIR); | |
115 | ||
fb73857a | 116 | my($orig_cdev, $orig_cino) = stat('.'); |
117 | ($cdev, $cino) = ($orig_cdev, $orig_cino); | |
a0d0e21e | 118 | for (;;) { |
40000a8c | 119 | my $direntry; |
a0d0e21e | 120 | ($odev, $oino) = ($cdev, $cino); |
e79e61e4 | 121 | CORE::chdir('..') || return undef; |
a0d0e21e LW |
122 | ($cdev, $cino) = stat('.'); |
123 | last if $odev == $cdev && $oino == $cino; | |
fb73857a | 124 | opendir(DIR, '.') || return undef; |
a0d0e21e | 125 | for (;;) { |
40000a8c | 126 | $direntry = readdir(DIR); |
fb73857a | 127 | last unless defined $direntry; |
40000a8c AD |
128 | next if $direntry eq '.'; |
129 | next if $direntry eq '..'; | |
a0d0e21e | 130 | |
40000a8c | 131 | ($tdev, $tino) = lstat($direntry); |
a0d0e21e LW |
132 | last unless $tdev != $odev || $tino != $oino; |
133 | } | |
134 | closedir(DIR); | |
fb73857a | 135 | return undef unless defined $direntry; # should never happen |
40000a8c | 136 | unshift(@path, $direntry); |
a0d0e21e | 137 | } |
fb73857a | 138 | $path = '/' . join('/', @path); |
21ac5ced | 139 | if ($^O eq 'apollo') { $path = "/".$path; } |
fb73857a | 140 | # At this point $path may be tainted (if tainting) and chdir would fail. |
141 | # To be more useful we untaint it then check that we landed where we started. | |
392d8ab8 | 142 | $path = $1 if $path =~ /^(.*)\z/s; # untaint |
e79e61e4 | 143 | CORE::chdir($path) || return undef; |
fb73857a | 144 | ($cdev, $cino) = stat('.'); |
145 | die "Unstable directory path, current directory changed unexpectedly" | |
146 | if $cdev != $orig_cdev || $cino != $orig_cino; | |
a0d0e21e LW |
147 | $path; |
148 | } | |
149 | ||
150 | ||
4633a7c4 | 151 | # Keeps track of current working directory in PWD environment var |
a0d0e21e LW |
152 | # Usage: |
153 | # use Cwd 'chdir'; | |
154 | # chdir $newdir; | |
155 | ||
4633a7c4 | 156 | my $chdir_init = 0; |
a0d0e21e | 157 | |
4633a7c4 | 158 | sub chdir_init { |
39e571d4 | 159 | if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos') { |
a0d0e21e LW |
160 | my($dd,$di) = stat('.'); |
161 | my($pd,$pi) = stat($ENV{'PWD'}); | |
162 | if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) { | |
4633a7c4 | 163 | $ENV{'PWD'} = cwd(); |
a0d0e21e LW |
164 | } |
165 | } | |
166 | else { | |
4633a7c4 | 167 | $ENV{'PWD'} = cwd(); |
a0d0e21e | 168 | } |
4633a7c4 | 169 | # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) |
392d8ab8 | 170 | if ($ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { |
a0d0e21e LW |
171 | my($pd,$pi) = stat($2); |
172 | my($dd,$di) = stat($1); | |
173 | if (defined $pd and defined $dd and $di == $pi and $dd == $pd) { | |
174 | $ENV{'PWD'}="$2$3"; | |
175 | } | |
176 | } | |
177 | $chdir_init = 1; | |
178 | } | |
179 | ||
180 | sub chdir { | |
4633a7c4 LW |
181 | my $newdir = shift || ''; # allow for no arg (chdir to HOME dir) |
182 | $newdir =~ s|///*|/|g; | |
a0d0e21e | 183 | chdir_init() unless $chdir_init; |
4633a7c4 | 184 | return 0 unless CORE::chdir $newdir; |
c6538b72 | 185 | if ($^O eq 'VMS') { return $ENV{'PWD'} = $ENV{'DEFAULT'} } |
748a9306 | 186 | |
392d8ab8 | 187 | if ($newdir =~ m#^/#s) { |
a0d0e21e | 188 | $ENV{'PWD'} = $newdir; |
4633a7c4 LW |
189 | } else { |
190 | my @curdir = split(m#/#,$ENV{'PWD'}); | |
191 | @curdir = ('') unless @curdir; | |
192 | my $component; | |
a0d0e21e LW |
193 | foreach $component (split(m#/#, $newdir)) { |
194 | next if $component eq '.'; | |
195 | pop(@curdir),next if $component eq '..'; | |
196 | push(@curdir,$component); | |
197 | } | |
198 | $ENV{'PWD'} = join('/',@curdir) || '/'; | |
199 | } | |
4633a7c4 | 200 | 1; |
a0d0e21e LW |
201 | } |
202 | ||
8b88ae92 NIS |
203 | # Taken from Cwd.pm It is really getcwd with an optional |
204 | # parameter instead of '.' | |
205 | # | |
206 | ||
207 | sub abs_path | |
208 | { | |
07569ed3 | 209 | my $start = @_ ? shift : '.'; |
8b88ae92 NIS |
210 | my($dotdots, $cwd, @pst, @cst, $dir, @tst); |
211 | ||
212 | unless (@cst = stat( $start )) | |
213 | { | |
214 | carp "stat($start): $!"; | |
215 | return ''; | |
216 | } | |
217 | $cwd = ''; | |
218 | $dotdots = $start; | |
219 | do | |
220 | { | |
221 | $dotdots .= '/..'; | |
222 | @pst = @cst; | |
223 | unless (opendir(PARENT, $dotdots)) | |
224 | { | |
225 | carp "opendir($dotdots): $!"; | |
226 | return ''; | |
227 | } | |
228 | unless (@cst = stat($dotdots)) | |
229 | { | |
230 | carp "stat($dotdots): $!"; | |
231 | closedir(PARENT); | |
232 | return ''; | |
233 | } | |
234 | if ($pst[0] == $cst[0] && $pst[1] == $cst[1]) | |
235 | { | |
07569ed3 | 236 | $dir = undef; |
8b88ae92 NIS |
237 | } |
238 | else | |
239 | { | |
240 | do | |
241 | { | |
242 | unless (defined ($dir = readdir(PARENT))) | |
243 | { | |
244 | carp "readdir($dotdots): $!"; | |
245 | closedir(PARENT); | |
246 | return ''; | |
247 | } | |
248 | $tst[0] = $pst[0]+1 unless (@tst = lstat("$dotdots/$dir")) | |
249 | } | |
250 | while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] || | |
251 | $tst[1] != $pst[1]); | |
252 | } | |
07569ed3 | 253 | $cwd = (defined $dir ? "$dir" : "" ) . "/$cwd" ; |
8b88ae92 | 254 | closedir(PARENT); |
07569ed3 GB |
255 | } while (defined $dir); |
256 | chop($cwd) unless $cwd eq '/'; # drop the trailing / | |
8b88ae92 NIS |
257 | $cwd; |
258 | } | |
259 | ||
e4c51978 GS |
260 | # added function alias for those of us more |
261 | # used to the libc function. --tchrist 27-Jan-00 | |
262 | *realpath = \&abs_path; | |
263 | ||
96e4d5b1 | 264 | sub fast_abs_path { |
265 | my $cwd = getcwd(); | |
266 | my $path = shift || '.'; | |
e79e61e4 | 267 | CORE::chdir($path) || croak "Cannot chdir to $path:$!"; |
96e4d5b1 | 268 | my $realpath = getcwd(); |
e79e61e4 | 269 | CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; |
96e4d5b1 | 270 | $realpath; |
8b88ae92 NIS |
271 | } |
272 | ||
e4c51978 GS |
273 | # added function alias to follow principle of least surprise |
274 | # based on previous aliasing. --tchrist 27-Jan-00 | |
275 | *fast_realpath = \&fast_abs_path; | |
276 | ||
4633a7c4 LW |
277 | |
278 | # --- PORTING SECTION --- | |
279 | ||
280 | # VMS: $ENV{'DEFAULT'} points to default directory at all times | |
bd3fa61c | 281 | # 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu |
c6538b72 | 282 | # Note: Use of Cwd::chdir() causes the logical name PWD to be defined |
8b88ae92 NIS |
283 | # in the process logical name table as the default device and directory |
284 | # seen by Perl. This may not be the same as the default device | |
4633a7c4 LW |
285 | # and directory seen by DCL after Perl exits, since the effects |
286 | # the CRTL chdir() function persist only until Perl exits. | |
4633a7c4 LW |
287 | |
288 | sub _vms_cwd { | |
96e4d5b1 | 289 | return $ENV{'DEFAULT'}; |
290 | } | |
291 | ||
292 | sub _vms_abs_path { | |
293 | return $ENV{'DEFAULT'} unless @_; | |
294 | my $path = VMS::Filespec::pathify($_[0]); | |
295 | croak("Invalid path name $_[0]") unless defined $path; | |
296 | return VMS::Filespec::rmsexpand($path); | |
4633a7c4 | 297 | } |
68dc0745 | 298 | |
4633a7c4 LW |
299 | sub _os2_cwd { |
300 | $ENV{'PWD'} = `cmd /c cd`; | |
301 | chop $ENV{'PWD'}; | |
302 | $ENV{'PWD'} =~ s:\\:/:g ; | |
303 | return $ENV{'PWD'}; | |
304 | } | |
305 | ||
96e4d5b1 | 306 | sub _win32_cwd { |
2d7a9237 | 307 | $ENV{'PWD'} = Win32::GetCwd(); |
96e4d5b1 | 308 | $ENV{'PWD'} =~ s:\\:/:g ; |
309 | return $ENV{'PWD'}; | |
310 | } | |
311 | ||
312 | *_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && | |
2d7a9237 | 313 | defined &Win32::GetCwd); |
96e4d5b1 | 314 | |
315 | *_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; | |
68dc0745 | 316 | |
39e571d4 LM |
317 | sub _dos_cwd { |
318 | if (!defined &Dos::GetCwd) { | |
319 | $ENV{'PWD'} = `command /c cd`; | |
320 | chop $ENV{'PWD'}; | |
321 | $ENV{'PWD'} =~ s:\\:/:g ; | |
322 | } else { | |
323 | $ENV{'PWD'} = Dos::GetCwd(); | |
324 | } | |
55497cff | 325 | return $ENV{'PWD'}; |
326 | } | |
327 | ||
7fbf1995 NA |
328 | sub _qnx_cwd { |
329 | $ENV{'PWD'} = `/usr/bin/fullpath -t`; | |
330 | chop $ENV{'PWD'}; | |
331 | return $ENV{'PWD'}; | |
332 | } | |
333 | ||
334 | sub _qnx_abs_path { | |
335 | my $path = shift || '.'; | |
336 | my $realpath=`/usr/bin/fullpath -t $path`; | |
337 | chop $realpath; | |
338 | return $realpath; | |
339 | } | |
340 | ||
ac1ad7f0 | 341 | { |
db376a24 | 342 | no warnings; # assignments trigger 'subroutine redefined' warning |
4633a7c4 | 343 | |
ac1ad7f0 | 344 | if ($^O eq 'VMS') { |
96e4d5b1 | 345 | *cwd = \&_vms_cwd; |
346 | *getcwd = \&_vms_cwd; | |
347 | *fastcwd = \&_vms_cwd; | |
348 | *fastgetcwd = \&_vms_cwd; | |
349 | *abs_path = \&_vms_abs_path; | |
350 | *fast_abs_path = \&_vms_abs_path; | |
ac1ad7f0 PM |
351 | } |
352 | elsif ($^O eq 'NT' or $^O eq 'MSWin32') { | |
353 | # We assume that &_NT_cwd is defined as an XSUB or in the core. | |
96e4d5b1 | 354 | *cwd = \&_NT_cwd; |
355 | *getcwd = \&_NT_cwd; | |
356 | *fastcwd = \&_NT_cwd; | |
357 | *fastgetcwd = \&_NT_cwd; | |
358 | *abs_path = \&fast_abs_path; | |
ac1ad7f0 PM |
359 | } |
360 | elsif ($^O eq 'os2') { | |
361 | # sys_cwd may keep the builtin command | |
96e4d5b1 | 362 | *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; |
363 | *getcwd = \&cwd; | |
364 | *fastgetcwd = \&cwd; | |
365 | *fastcwd = \&cwd; | |
366 | *abs_path = \&fast_abs_path; | |
ac1ad7f0 | 367 | } |
39e571d4 LM |
368 | elsif ($^O eq 'dos') { |
369 | *cwd = \&_dos_cwd; | |
370 | *getcwd = \&_dos_cwd; | |
371 | *fastgetcwd = \&_dos_cwd; | |
372 | *fastcwd = \&_dos_cwd; | |
96e4d5b1 | 373 | *abs_path = \&fast_abs_path; |
ac1ad7f0 | 374 | } |
7fbf1995 NA |
375 | elsif ($^O eq 'qnx') { |
376 | *cwd = \&_qnx_cwd; | |
377 | *getcwd = \&_qnx_cwd; | |
378 | *fastgetcwd = \&_qnx_cwd; | |
379 | *fastcwd = \&_qnx_cwd; | |
380 | *abs_path = \&_qnx_abs_path; | |
381 | *fast_abs_path = \&_qnx_abs_path; | |
382 | } | |
4fabb596 | 383 | elsif ($^O eq 'cygwin') { |
1cab015a EF |
384 | *getcwd = \&cwd; |
385 | *fastgetcwd = \&cwd; | |
386 | *fastcwd = \&cwd; | |
387 | *abs_path = \&fast_abs_path; | |
388 | } | |
55497cff | 389 | } |
4633a7c4 LW |
390 | |
391 | # package main; eval join('',<DATA>) || die $@; # quick test | |
392 | ||
a0d0e21e LW |
393 | 1; |
394 | ||
4633a7c4 LW |
395 | __END__ |
396 | BEGIN { import Cwd qw(:DEFAULT chdir); } | |
397 | print join("\n", cwd, getcwd, fastcwd, ""); | |
398 | chdir('..'); | |
399 | print join("\n", cwd, getcwd, fastcwd, ""); | |
400 | print "$ENV{PWD}\n"; |