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Cwd(3pm)                              Perl Programmers Reference Guide                              Cwd(3pm)



NAME
       Cwd - get pathname of current working directory

SYNOPSIS
           use Cwd;
           my $dir = getcwd;

           use Cwd 'abs_path';
           my $abs_path = abs_path($file);

DESCRIPTION
       This module provides functions for determining the pathname of the current working directory.  It is
       recommended that getcwd (or another *cwd() function) be used in all code to ensure portability.

       By default, it exports the functions cwd(), getcwd(), fastcwd(), and fastgetcwd() (and, on Win32,
       getdcwd()) into the caller's namespace.

   getcwd and friends
       Each of these functions are called without arguments and return the absolute path of the current
       working directory.

       getcwd
               my $cwd = getcwd();

           Returns the current working directory.

           Exposes the POSIX function getcwd(3) or re-implements it if it's not available.

       cwd
               my $cwd = cwd();

           The cwd() is the most natural form for the current architecture. For most systems it is identical
           to `pwd` (but without the trailing line terminator).

       fastcwd
               my $cwd = fastcwd();

           A more dangerous version of getcwd(), but potentially faster.

           It might conceivably chdir() you out of a directory that it can't chdir() you back into.  If
           fastcwd encounters a problem it will return undef but will probably leave you in a different
           directory.  For a measure of extra security, if everything appears to have worked, the fastcwd()
           function will check that it leaves you in the same directory that it started in. If it has
           changed it will "die" with the message "Unstable directory path, current directory changed
           unexpectedly". That should never happen.

       fastgetcwd
             my $cwd = fastgetcwd();

           The fastgetcwd() function is provided as a synonym for cwd().

       getdcwd
               my $cwd = getdcwd();
               my $cwd = getdcwd('C:');

           The getdcwd() function is also provided on Win32 to get the current working directory on the
           specified drive, since Windows maintains a separate current working directory for each drive.  If
           no drive is specified then the current drive is assumed.

           This function simply calls the Microsoft C library _getdcwd() function.

   abs_path and friends
       These functions are exported only on request.  They each take a single argument and return the
       absolute pathname for it.  If no argument is given they'll use the current working directory.

       abs_path
             my $abs_path = abs_path($file);

           Uses the same algorithm as getcwd().  Symbolic links and relative-path components ("." and "..")
           are resolved to return the canonical pathname, just like realpath(3).

       realpath
             my $abs_path = realpath($file);

           A synonym for abs_path().

       fast_abs_path
             my $abs_path = fast_abs_path($file);

           A more dangerous, but potentially faster version of abs_path.

   $ENV{PWD}
       If you ask to override your chdir() built-in function,

         use Cwd qw(chdir);

       then your PWD environment variable will be kept up to date.  Note that it will only be kept up to
       date if all packages which use chdir import it from Cwd.

NOTES
       •   Since the path seperators are different on some operating systems ('/' on Unix, ':' on MacPerl,
           etc...) we recommend you use the File::Spec modules wherever portability is a concern.

       •   Actually, on Mac OS, the "getcwd()", "fastgetcwd()" and "fastcwd()" functions  are all aliases
           for the "cwd()" function, which, on Mac OS, calls `pwd`. Likewise, the "abs_path()" function is
           an alias for "fast_abs_path()".

AUTHOR
       Originally by the perl5-porters.

       Maintained by Ken Williams <KWILLIAMS@cpan.org>

COPYRIGHT
       Copyright (c) 2004 by the Perl 5 Porters.  All rights reserved.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl
       itself.

       Portions of the C code in this library are copyright (c) 1994 by the Regents of the University of
       California.  All rights reserved.  The license on this code is compatible with the licensing of the
       rest of the distribution - please see the source code in Cwd.xs for the details.

SEE ALSO
       File::chdir



perl v5.12.5                                     2012-11-03                                         Cwd(3pm)