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() 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.

Re-implements the getcwd(3) (or getwd(3)) functions in Perl.

Taint-safe.

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).

Taint-safe.

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().

abs_path and friends

These functions are exported only on request. They each take a single argument and return the absolute pathname for it.

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).

Taint-safe.

realpath

my $abs_path = realpath($file);

A synonym for abs_path().

Taint-safe.

fast_abs_path

my $abs_path = fast_abs_path($file);

A more dangerous, but potentially faster version of abs_path.

This function is Not taint-safe : you can't use it in programs that work under taint mode.

$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().