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1 | package Cwd; |
2 | require 5.000; |
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3 | |
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4 | =head1 NAME |
5 | |
6 | getcwd - get pathname of current working directory |
7 | |
8 | =head1 SYNOPSIS |
9 | |
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10 | use Cwd; |
11 | $dir = cwd; |
12 | |
13 | use Cwd; |
14 | $dir = getcwd; |
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15 | |
16 | use Cwd; |
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17 | $dir = fastgetcwd; |
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18 | |
19 | use Cwd 'chdir'; |
20 | chdir "/tmp"; |
21 | print $ENV{'PWD'}; |
22 | |
e4c51978 |
23 | use Cwd 'abs_path'; # aka realpath() |
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24 | print abs_path($ENV{'PWD'}); |
25 | |
26 | use Cwd 'fast_abs_path'; |
27 | print fast_abs_path($ENV{'PWD'}); |
28 | |
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29 | =head1 DESCRIPTION |
30 | |
31 | The getcwd() function re-implements the getcwd(3) (or getwd(3)) functions |
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32 | in Perl. |
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33 | |
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34 | The abs_path() function takes a single argument and returns the |
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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(). |
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40 | |
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41 | The fastcwd() function looks the same as getcwd(), but runs faster. |
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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. |
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50 | |
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51 | The fast_abs_path() function looks the same as abs_path(), but runs faster. |
52 | And like fastcwd() is more dangerous. |
53 | |
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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 |
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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. |
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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 |
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64 | L<perlsub/Overriding Builtin Functions>.) Note that it will only be |
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65 | kept up to date if all packages which use chdir import it from Cwd. |
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66 | |
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67 | =cut |
68 | |
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69 | ## use strict; |
70 | |
71 | use Carp; |
72 | |
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73 | $VERSION = '2.03'; |
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74 | |
75 | require Exporter; |
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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); |
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79 | |
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80 | |
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81 | # The 'natural and safe form' for UNIX (pwd may be setuid root) |
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82 | |
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83 | sub _backtick_pwd { |
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84 | my $cwd; |
85 | chop($cwd = `pwd`); |
86 | $cwd; |
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87 | } |
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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; |
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93 | |
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94 | |
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95 | # By Brandon S. Allbery |
96 | # |
97 | # Usage: $cwd = getcwd(); |
98 | |
99 | sub getcwd |
100 | { |
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101 | abs_path('.'); |
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102 | } |
103 | |
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104 | # By John Bazik |
105 | # |
106 | # Usage: $cwd = &fastcwd; |
107 | # |
108 | # This is a faster version of getcwd. It's also more dangerous because |
109 | # you might chdir out of a directory that you can't chdir back into. |
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110 | |
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111 | sub fastcwd { |
112 | my($odev, $oino, $cdev, $cino, $tdev, $tino); |
113 | my(@path, $path); |
114 | local(*DIR); |
115 | |
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116 | my($orig_cdev, $orig_cino) = stat('.'); |
117 | ($cdev, $cino) = ($orig_cdev, $orig_cino); |
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118 | for (;;) { |
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119 | my $direntry; |
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120 | ($odev, $oino) = ($cdev, $cino); |
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121 | CORE::chdir('..') || return undef; |
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122 | ($cdev, $cino) = stat('.'); |
123 | last if $odev == $cdev && $oino == $cino; |
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124 | opendir(DIR, '.') || return undef; |
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125 | for (;;) { |
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126 | $direntry = readdir(DIR); |
fb73857a |
127 | last unless defined $direntry; |
40000a8c |
128 | next if $direntry eq '.'; |
129 | next if $direntry eq '..'; |
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130 | |
40000a8c |
131 | ($tdev, $tino) = lstat($direntry); |
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132 | last unless $tdev != $odev || $tino != $oino; |
133 | } |
134 | closedir(DIR); |
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135 | return undef unless defined $direntry; # should never happen |
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136 | unshift(@path, $direntry); |
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137 | } |
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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. |
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142 | $path = $1 if $path =~ /^(.*)\z/s; # untaint |
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143 | CORE::chdir($path) || return undef; |
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144 | ($cdev, $cino) = stat('.'); |
145 | die "Unstable directory path, current directory changed unexpectedly" |
146 | if $cdev != $orig_cdev || $cino != $orig_cino; |
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147 | $path; |
148 | } |
149 | |
150 | |
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151 | # Keeps track of current working directory in PWD environment var |
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152 | # Usage: |
153 | # use Cwd 'chdir'; |
154 | # chdir $newdir; |
155 | |
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156 | my $chdir_init = 0; |
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157 | |
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158 | sub chdir_init { |
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159 | if ($ENV{'PWD'} and $^O ne 'os2' and $^O ne 'dos') { |
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160 | my($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(); |
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164 | } |
165 | } |
166 | else { |
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167 | $ENV{'PWD'} = cwd(); |
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168 | } |
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169 | # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar) |
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170 | if ($ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|s) { |
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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 { |
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181 | my $newdir = shift || ''; # allow for no arg (chdir to HOME dir) |
182 | $newdir =~ s|///*|/|g; |
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183 | chdir_init() unless $chdir_init; |
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184 | return 0 unless CORE::chdir $newdir; |
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185 | if ($^O eq 'VMS') { return $ENV{'PWD'} = $ENV{'DEFAULT'} } |
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186 | |
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187 | if ($newdir =~ m#^/#s) { |
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188 | $ENV{'PWD'} = $newdir; |
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189 | } else { |
190 | my @curdir = split(m#/#,$ENV{'PWD'}); |
191 | @curdir = ('') unless @curdir; |
192 | my $component; |
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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 | } |
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200 | 1; |
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201 | } |
202 | |
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203 | |
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204 | # By Jeff "japhy" Pinyan (07/23/2000) |
205 | # usage: abs_path(PATHNAME) |
206 | # see the docs |
207 | |
208 | sub abs_path { |
209 | my $base = @_ ? $_[0] : "."; |
210 | my $path = ""; |
211 | my $file; |
212 | |
213 | do { |
214 | my @devino = (stat($base))[0,1] or |
215 | carp("stat($base): $!"), return; |
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216 | |
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217 | $base .= "/.."; |
218 | |
219 | opendir PREV, $base or carp("opendir($base): $!"), return; |
220 | while (defined($file = readdir PREV)) { |
221 | next if $file eq "." or $file eq ".."; |
222 | my @entry = (lstat("$base/$file"))[0,1] or |
223 | carp("lstat($base/$file): $!"), return; |
224 | last if $devino[0] == $entry[0] and $devino[1] == $entry[1]; |
8b88ae92 |
225 | } |
929327b2 |
226 | closedir PREV; |
227 | |
228 | $path = (defined $file and $file) . "/$path"; |
229 | } while defined $file; |
230 | |
231 | length($path) > 1 and chop $path; |
232 | return $path; |
8b88ae92 |
233 | } |
234 | |
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235 | |
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236 | # added function alias for those of us more |
237 | # used to the libc function. --tchrist 27-Jan-00 |
238 | *realpath = \&abs_path; |
239 | |
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240 | sub fast_abs_path { |
241 | my $cwd = getcwd(); |
242 | my $path = shift || '.'; |
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243 | CORE::chdir($path) || croak "Cannot chdir to $path:$!"; |
96e4d5b1 |
244 | my $realpath = getcwd(); |
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245 | CORE::chdir($cwd) || croak "Cannot chdir back to $cwd:$!"; |
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246 | $realpath; |
8b88ae92 |
247 | } |
248 | |
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249 | # added function alias to follow principle of least surprise |
250 | # based on previous aliasing. --tchrist 27-Jan-00 |
251 | *fast_realpath = \&fast_abs_path; |
252 | |
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253 | |
254 | # --- PORTING SECTION --- |
255 | |
256 | # VMS: $ENV{'DEFAULT'} points to default directory at all times |
bd3fa61c |
257 | # 06-Mar-1996 Charles Bailey bailey@newman.upenn.edu |
c6538b72 |
258 | # Note: Use of Cwd::chdir() causes the logical name PWD to be defined |
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259 | # in the process logical name table as the default device and directory |
260 | # seen by Perl. This may not be the same as the default device |
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261 | # and directory seen by DCL after Perl exits, since the effects |
262 | # the CRTL chdir() function persist only until Perl exits. |
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263 | |
264 | sub _vms_cwd { |
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265 | return $ENV{'DEFAULT'}; |
266 | } |
267 | |
268 | sub _vms_abs_path { |
269 | return $ENV{'DEFAULT'} unless @_; |
270 | my $path = VMS::Filespec::pathify($_[0]); |
271 | croak("Invalid path name $_[0]") unless defined $path; |
272 | return VMS::Filespec::rmsexpand($path); |
4633a7c4 |
273 | } |
68dc0745 |
274 | |
4633a7c4 |
275 | sub _os2_cwd { |
276 | $ENV{'PWD'} = `cmd /c cd`; |
277 | chop $ENV{'PWD'}; |
278 | $ENV{'PWD'} =~ s:\\:/:g ; |
279 | return $ENV{'PWD'}; |
280 | } |
281 | |
96e4d5b1 |
282 | sub _win32_cwd { |
2d7a9237 |
283 | $ENV{'PWD'} = Win32::GetCwd(); |
96e4d5b1 |
284 | $ENV{'PWD'} =~ s:\\:/:g ; |
285 | return $ENV{'PWD'}; |
286 | } |
287 | |
288 | *_NT_cwd = \&_win32_cwd if (!defined &_NT_cwd && |
2d7a9237 |
289 | defined &Win32::GetCwd); |
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290 | |
291 | *_NT_cwd = \&_os2_cwd unless defined &_NT_cwd; |
68dc0745 |
292 | |
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293 | sub _dos_cwd { |
294 | if (!defined &Dos::GetCwd) { |
295 | $ENV{'PWD'} = `command /c cd`; |
296 | chop $ENV{'PWD'}; |
297 | $ENV{'PWD'} =~ s:\\:/:g ; |
298 | } else { |
299 | $ENV{'PWD'} = Dos::GetCwd(); |
300 | } |
55497cff |
301 | return $ENV{'PWD'}; |
302 | } |
303 | |
7fbf1995 |
304 | sub _qnx_cwd { |
305 | $ENV{'PWD'} = `/usr/bin/fullpath -t`; |
306 | chop $ENV{'PWD'}; |
307 | return $ENV{'PWD'}; |
308 | } |
309 | |
310 | sub _qnx_abs_path { |
311 | my $path = shift || '.'; |
312 | my $realpath=`/usr/bin/fullpath -t $path`; |
313 | chop $realpath; |
314 | return $realpath; |
315 | } |
316 | |
ac1ad7f0 |
317 | { |
db376a24 |
318 | no warnings; # assignments trigger 'subroutine redefined' warning |
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319 | |
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320 | if ($^O eq 'VMS') { |
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321 | *cwd = \&_vms_cwd; |
322 | *getcwd = \&_vms_cwd; |
323 | *fastcwd = \&_vms_cwd; |
324 | *fastgetcwd = \&_vms_cwd; |
325 | *abs_path = \&_vms_abs_path; |
326 | *fast_abs_path = \&_vms_abs_path; |
ac1ad7f0 |
327 | } |
328 | elsif ($^O eq 'NT' or $^O eq 'MSWin32') { |
329 | # We assume that &_NT_cwd is defined as an XSUB or in the core. |
96e4d5b1 |
330 | *cwd = \&_NT_cwd; |
331 | *getcwd = \&_NT_cwd; |
332 | *fastcwd = \&_NT_cwd; |
333 | *fastgetcwd = \&_NT_cwd; |
334 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
335 | } |
336 | elsif ($^O eq 'os2') { |
337 | # sys_cwd may keep the builtin command |
96e4d5b1 |
338 | *cwd = defined &sys_cwd ? \&sys_cwd : \&_os2_cwd; |
339 | *getcwd = \&cwd; |
340 | *fastgetcwd = \&cwd; |
341 | *fastcwd = \&cwd; |
342 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
343 | } |
39e571d4 |
344 | elsif ($^O eq 'dos') { |
345 | *cwd = \&_dos_cwd; |
346 | *getcwd = \&_dos_cwd; |
347 | *fastgetcwd = \&_dos_cwd; |
348 | *fastcwd = \&_dos_cwd; |
96e4d5b1 |
349 | *abs_path = \&fast_abs_path; |
ac1ad7f0 |
350 | } |
7fbf1995 |
351 | elsif ($^O eq 'qnx') { |
352 | *cwd = \&_qnx_cwd; |
353 | *getcwd = \&_qnx_cwd; |
354 | *fastgetcwd = \&_qnx_cwd; |
355 | *fastcwd = \&_qnx_cwd; |
356 | *abs_path = \&_qnx_abs_path; |
357 | *fast_abs_path = \&_qnx_abs_path; |
358 | } |
4fabb596 |
359 | elsif ($^O eq 'cygwin') { |
1cab015a |
360 | *getcwd = \&cwd; |
361 | *fastgetcwd = \&cwd; |
362 | *fastcwd = \&cwd; |
363 | *abs_path = \&fast_abs_path; |
364 | } |
55497cff |
365 | } |
4633a7c4 |
366 | |
367 | # package main; eval join('',<DATA>) || die $@; # quick test |
368 | |
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369 | 1; |
370 | |
4633a7c4 |
371 | __END__ |
372 | BEGIN { import Cwd qw(:DEFAULT chdir); } |
373 | print join("\n", cwd, getcwd, fastcwd, ""); |
374 | chdir('..'); |
375 | print join("\n", cwd, getcwd, fastcwd, ""); |
376 | print "$ENV{PWD}\n"; |