Cwd - get pathname of current working directory
use Cwd;
my $dir = getcwd;
use Cwd 'abs_path';
my $abs_path = abs_path($file);
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.
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. On error returns "undef",
with $! set to indicate the error.
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.
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). On error returns
"undef", with $! set to indicate the error.
- 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.
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.
- •
- Since the path separators 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()".
Maintained by perl5-porters <
[email protected]>.
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.
File::chdir