6 # Use osname for portability switches (doubled to cheaply avoid -w warning)
7 my $osname = $Config::Config{'osname'} || $Config::Config{'osname'};
12 getcwd - get pathname of current working directory
31 The getcwd() function re-implements the getcwd(3) (or getwd(3)) functions
34 The fastgetcwd() function looks the same as getcwd(), but runs faster.
35 It's also more dangerous because you might conceivably chdir() out of a
36 directory that you can't chdir() back into.
38 The cwd() function looks the same as getcwd and fastgetcwd but is
39 implemented using the most natural and safe form for the current
40 architecture. For most systems it is identical to `pwd` (but without
41 the trailing line terminator). It is recommended that cwd (or another
42 *cwd() function) is used in I<all> code to ensure portability.
44 If you ask to override your chdir() built-in function, then your PWD
45 environment variable will be kept up to date. (See
46 L<perlsub/Overriding builtin functions>.) Note that it will only be
47 kept up to date it all packages which use chdir import it from Cwd.
52 @EXPORT = qw(cwd getcwd fastcwd);
53 @EXPORT_OK = qw(chdir);
57 sub _backtick_pwd { # The 'natural and safe form' for UNIX (pwd may be setuid root)
63 # Since some ports may predefine cwd internally (e.g., NT)
64 # we take care not to override an existing definition for cwd().
66 *cwd = \&_backtick_pwd unless defined &cwd;
69 # By Brandon S. Allbery
71 # Usage: $cwd = getcwd();
75 my($dotdots, $cwd, @pst, @cst, $dir, @tst);
77 unless (@cst = stat('.'))
86 $dotdots .= '/' if $dotdots;
89 unless (opendir(PARENT, $dotdots))
91 warn "opendir($dotdots): $!";
94 unless (@cst = stat($dotdots))
96 warn "stat($dotdots): $!";
100 if ($pst[0] == $cst[0] && $pst[1] == $cst[1])
108 unless (defined ($dir = readdir(PARENT)))
110 warn "readdir($dotdots): $!";
114 unless (@tst = lstat("$dotdots/$dir"))
116 warn "lstat($dotdots/$dir): $!";
121 while ($dir eq '.' || $dir eq '..' || $tst[0] != $pst[0] ||
127 chop($cwd); # drop the trailing /
135 # Usage: $cwd = &fastcwd;
137 # This is a faster version of getcwd. It's also more dangerous because
138 # you might chdir out of a directory that you can't chdir back into.
141 my($odev, $oino, $cdev, $cino, $tdev, $tino);
145 ($cdev, $cino) = stat('.');
148 ($odev, $oino) = ($cdev, $cino);
150 ($cdev, $cino) = stat('.');
151 last if $odev == $cdev && $oino == $cino;
154 $direntry = readdir(DIR);
155 next if $direntry eq '.';
156 next if $direntry eq '..';
158 last unless defined $direntry;
159 ($tdev, $tino) = lstat($direntry);
160 last unless $tdev != $odev || $tino != $oino;
163 unshift(@path, $direntry);
165 chdir($path = '/' . join('/', @path));
170 # Keeps track of current working directory in PWD environment var
178 if ($ENV{'PWD'} and $osname ne 'os2') {
179 my($dd,$di) = stat('.');
180 my($pd,$pi) = stat($ENV{'PWD'});
181 if (!defined $dd or !defined $pd or $di != $pi or $dd != $pd) {
188 # Strip an automounter prefix (where /tmp_mnt/foo/bar == /foo/bar)
189 if ($ENV{'PWD'} =~ m|(/[^/]+(/[^/]+/[^/]+))(.*)|) {
190 my($pd,$pi) = stat($2);
191 my($dd,$di) = stat($1);
192 if (defined $pd and defined $dd and $di == $pi and $dd == $pd) {
200 my $newdir = shift || ''; # allow for no arg (chdir to HOME dir)
201 $newdir =~ s|///*|/|g;
202 chdir_init() unless $chdir_init;
203 return 0 unless CORE::chdir $newdir;
204 if ($osname eq 'VMS') { return $ENV{'PWD'} = $ENV{'DEFAULT'} }
206 if ($newdir =~ m#^/#) {
207 $ENV{'PWD'} = $newdir;
209 my @curdir = split(m#/#,$ENV{'PWD'});
210 @curdir = ('') unless @curdir;
212 foreach $component (split(m#/#, $newdir)) {
213 next if $component eq '.';
214 pop(@curdir),next if $component eq '..';
215 push(@curdir,$component);
217 $ENV{'PWD'} = join('/',@curdir) || '/';
223 # --- PORTING SECTION ---
225 # VMS: $ENV{'DEFAULT'} points to default directory at all times
226 # 08-Dec-1994 Charles Bailey bailey@genetics.upenn.edu
227 # Note: Use of Cwd::getcwd() or Cwd::chdir() (but not Cwd::fastcwd())
228 # causes the logical name PWD to be defined in the process
229 # logical name table as the default device and directory
230 # seen by Perl. This may not be the same as the default device
231 # and directory seen by DCL after Perl exits, since the effects
232 # the CRTL chdir() function persist only until Perl exits.
233 # This does not apply to other systems (where only chdir() sets PWD).
236 return $ENV{'DEFAULT'}
239 return $ENV{'PWD'} = $ENV{'DEFAULT'}
242 $ENV{'PWD'} = `cmd /c cd`;
244 $ENV{'PWD'} =~ s:\\:/:g ;
248 if ($osname eq 'VMS') {
251 *getcwd = \&_vms_pwd;
252 *fastgetcwd = \&_vms_cwd;
254 elsif ($osname eq 'NT') {
259 elsif ($osname eq 'os2') {
261 *getcwd = \&_os2_cwd;
262 *fastgetcwd = \&_os2_cwd;
263 *fastcwd = \&_os2_cwd;
266 # package main; eval join('',<DATA>) || die $@; # quick test
271 BEGIN { import Cwd qw(:DEFAULT chdir); }
272 print join("\n", cwd, getcwd, fastcwd, "");
274 print join("\n", cwd, getcwd, fastcwd, "");