1Cwd(3)                User Contributed Perl Documentation               Cwd(3)
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NAME

6       Cwd - get pathname of current working directory
7

SYNOPSIS

9           use Cwd;
10           my $dir = getcwd;
11
12           use Cwd 'abs_path';
13           my $abs_path = abs_path($file);
14

DESCRIPTION

16       This module provides functions for determining the pathname of the
17       current working directory.  It is recommended that getcwd (or another
18       *cwd() function) be used in all code to ensure portability.
19
20       By default, it exports the functions cwd(), getcwd(), fastcwd(), and
21       fastgetcwd() (and, on Win32, getdcwd()) into the caller's namespace.
22
23   getcwd and friends
24       Each of these functions are called without arguments and return the
25       absolute path of the current working directory.
26
27       getcwd
28               my $cwd = getcwd();
29
30           Returns the current working directory.  On error returns "undef",
31           with $! set to indicate the error.
32
33           Exposes the POSIX function getcwd(3) or re-implements it if it's
34           not available.
35
36       cwd
37               my $cwd = cwd();
38
39           The cwd() is the most natural form for the current architecture.
40           For most systems it is identical to `pwd` (but without the trailing
41           line terminator).
42
43       fastcwd
44               my $cwd = fastcwd();
45
46           A more dangerous version of getcwd(), but potentially faster.
47
48           It might conceivably chdir() you out of a directory that it can't
49           chdir() you back into.  If fastcwd encounters a problem it will
50           return undef but will probably leave you in a different directory.
51           For a measure of extra security, if everything appears to have
52           worked, the fastcwd() function will check that it leaves you in the
53           same directory that it started in.  If it has changed it will "die"
54           with the message "Unstable directory path, current directory
55           changed unexpectedly".  That should never happen.
56
57       fastgetcwd
58             my $cwd = fastgetcwd();
59
60           The fastgetcwd() function is provided as a synonym for cwd().
61
62       getdcwd
63               my $cwd = getdcwd();
64               my $cwd = getdcwd('C:');
65
66           The getdcwd() function is also provided on Win32 to get the current
67           working directory on the specified drive, since Windows maintains a
68           separate current working directory for each drive.  If no drive is
69           specified then the current drive is assumed.
70
71           This function simply calls the Microsoft C library _getdcwd()
72           function.
73
74   abs_path and friends
75       These functions are exported only on request.  They each take a single
76       argument and return the absolute pathname for it.  If no argument is
77       given they'll use the current working directory.
78
79       abs_path
80             my $abs_path = abs_path($file);
81
82           Uses the same algorithm as getcwd().  Symbolic links and relative-
83           path components ("." and "..") are resolved to return the canonical
84           pathname, just like realpath(3).  On error returns "undef", with $!
85           set to indicate the error.
86
87       realpath
88             my $abs_path = realpath($file);
89
90           A synonym for abs_path().
91
92       fast_abs_path
93             my $abs_path = fast_abs_path($file);
94
95           A more dangerous, but potentially faster version of abs_path.
96
97   $ENV{PWD}
98       If you ask to override your chdir() built-in function,
99
100         use Cwd qw(chdir);
101
102       then your PWD environment variable will be kept up to date.  Note that
103       it will only be kept up to date if all packages which use chdir import
104       it from Cwd.
105

NOTES

107       •   Since the path separators are different on some operating systems
108           ('/' on Unix, ':' on MacPerl, etc...) we recommend you use the
109           File::Spec modules wherever portability is a concern.
110
111       •   Actually, on Mac OS, the "getcwd()", "fastgetcwd()" and "fastcwd()"
112           functions are all aliases for the "cwd()" function, which, on Mac
113           OS, calls `pwd`.  Likewise, the "abs_path()" function is an alias
114           for "fast_abs_path()".
115

AUTHOR

117       Originally by the perl5-porters.
118
119       Maintained by Ken Williams <KWILLIAMS@cpan.org>
120

122       Copyright (c) 2004 by the Perl 5 Porters.  All rights reserved.
123
124       This program is free software; you can redistribute it and/or modify it
125       under the same terms as Perl itself.
126
127       Portions of the C code in this library are copyright (c) 1994 by the
128       Regents of the University of California.  All rights reserved.  The
129       license on this code is compatible with the licensing of the rest of
130       the distribution - please see the source code in Cwd.xs for the
131       details.
132

SEE ALSO

134       File::chdir
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137
138perl v5.34.0                      2022-01-21                            Cwd(3)
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