1Cwd(3pm)               Perl Programmers Reference Guide               Cwd(3pm)
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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.
31
32           Exposes the POSIX function getcwd(3) or re-implements it if it's
33           not available.
34
35       cwd
36               my $cwd = cwd();
37
38           The cwd() is the most natural form for the current architecture.
39           For most systems it is identical to `pwd` (but without the trailing
40           line terminator).
41
42       fastcwd
43               my $cwd = fastcwd();
44
45           A more dangerous version of getcwd(), but potentially faster.
46
47           It might conceivably chdir() you out of a directory that it can't
48           chdir() you back into.  If fastcwd encounters a problem it will
49           return undef but will probably leave you in a different directory.
50           For a measure of extra security, if everything appears to have
51           worked, the fastcwd() function will check that it leaves you in the
52           same directory that it started in. If it has changed it will "die"
53           with the message "Unstable directory path, current directory
54           changed unexpectedly". That should never happen.
55
56       fastgetcwd
57             my $cwd = fastgetcwd();
58
59           The fastgetcwd() function is provided as a synonym for cwd().
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61       getdcwd
62               my $cwd = getdcwd();
63               my $cwd = getdcwd('C:');
64
65           The getdcwd() function is also provided on Win32 to get the current
66           working directory on the specified drive, since Windows maintains a
67           separate current working directory for each drive.  If no drive is
68           specified then the current drive is assumed.
69
70           This function simply calls the Microsoft C library _getdcwd()
71           function.
72
73   abs_path and friends
74       These functions are exported only on request.  They each take a single
75       argument and return the absolute pathname for it.  If no argument is
76       given they'll use the current working directory.
77
78       abs_path
79             my $abs_path = abs_path($file);
80
81           Uses the same algorithm as getcwd().  Symbolic links and relative-
82           path components ("." and "..") are resolved to return the canonical
83           pathname, just like realpath(3).
84
85       realpath
86             my $abs_path = realpath($file);
87
88           A synonym for abs_path().
89
90       fast_abs_path
91             my $abs_path = fast_abs_path($file);
92
93           A more dangerous, but potentially faster version of abs_path.
94
95   $ENV{PWD}
96       If you ask to override your chdir() built-in function,
97
98         use Cwd qw(chdir);
99
100       then your PWD environment variable will be kept up to date.  Note that
101       it will only be kept up to date if all packages which use chdir import
102       it from Cwd.
103

NOTES

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

AUTHOR

115       Originally by the perl5-porters.
116
117       Maintained by Ken Williams <KWILLIAMS@cpan.org>
118

120       Copyright (c) 2004 by the Perl 5 Porters.  All rights reserved.
121
122       This program is free software; you can redistribute it and/or modify it
123       under the same terms as Perl itself.
124
125       Portions of the C code in this library are copyright (c) 1994 by the
126       Regents of the University of California.  All rights reserved.  The
127       license on this code is compatible with the licensing of the rest of
128       the distribution - please see the source code in Cwd.xs for the
129       details.
130

SEE ALSO

132       File::chdir
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136perl v5.10.1                      2009-07-06                          Cwd(3pm)
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