Cwd - get pathname of current working directory
use Cwd;
$dir = cwd;
use Cwd;
$dir = getcwd;
use Cwd;
$dir = fastcwd;
use Cwd;
$dir = fastgetcwd;
use Cwd 'chdir';
chdir "/tmp";
print $ENV{'PWD'};
use Cwd 'abs_path'; # aka realpath()
print abs_path($ENV{'PWD'});
use Cwd 'fast_abs_path';
print fast_abs_path($ENV{'PWD'});
This module provides functions for determining the pathname of the
current working directory. By default, it exports the functions
cwd(), getcwd(), fastcwd(), and fastgetcwd() into the caller's
namespace. Each of these functions are called without arguments and
return the absolute path of the current working directory. It is
recommended that cwd (or another *cwd() function) be used in all
code to ensure portability.
The cwd() is the most natural and safe form for the current
architecture. For most systems it is identical to `pwd` (but without
the trailing line terminator).
The getcwd() function re-implements the getcwd(3) (or getwd(3)) functions
in Perl.
The fastcwd() function looks the same as getcwd(), but runs faster.
It's also more dangerous because 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.
The fastgetcwd() function is provided as a synonym for cwd().
The abs_path() function takes a single argument and returns the
absolute pathname for that argument. It uses the same algorithm as
getcwd(). (Actually, getcwd() is abs_path(``.'')) Symbolic links and
relative-path components (``.'' and ``..'') are resolved to return the
canonical pathname, just like realpath(3). This function is also
callable as realpath().
The fast_abs_path() function looks the same as abs_path() but runs
faster and, like fastcwd(), is more dangerous.
If you ask to override your chdir() built-in function, then your PWD
environment variable will be kept up to date. (See
perlsub/Overriding Builtin Functions.) Note that it will only be
kept up to date if all packages which use chdir import it from Cwd.
