See the current Perl documentation for lib:Cwd.
Here is our local, out-dated (pre-5.6) version:
getcwd - get pathname of current working directory
$dir = cwd;
$dir = getcwd;
$dir = fastgetcwd;
use Cwd 'chdir';
getcwd() function re-implements the
getwd(3)) functions in Perl.
abs_path() function takes a single argument and returns the absolute pathname for that argument. It uses the same algoritm as
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.
fast_abs_path() function looks the same as
abs_path(), but runs faster. And like
fastcwd() is more dangerous.
cwd() function looks the same as
getcwd and fastgetcwd but is implemented using the most natural and safe
form for the current architecture. For most systems it is identical to
`pwd` (but without the trailing line terminator).
It is recommended that cwd (or another *cwd() function) is used in
all code to ensure portability.
If you ask to override your
chdir() built-in function, then your
PWD environment variable will be kept up to date. (See
perlsub.) Note that it will only be kept up to date if all packages which use
chdir import it from Cwd.