Cwd

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



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 cur-
       rent 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() func-
           tion.

       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
       o   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.

       o   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 v5.8.6                       2007-05-21                            Cwd(3)