lib:Cwd
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
use Cwd; $dir = cwd;
use Cwd; $dir = getcwd;
use Cwd; $dir = fastgetcwd;
use Cwd 'chdir'; chdir "/tmp"; print $ENV{'PWD'};
use Cwd
The
getcwd()
function re-implements thegetcwd(3)
(orgetwd(3))
functions in Perl.The
abs_path()
function takes a single argument and returns the absolute pathname for that argument. It uses the same algoritm asgetcwd().
(actuallygetcwd()
isabs_path(``.''))
The
fastcwd()
function looks the same asgetcwd(),
but runs faster. It's also more dangerous because it might conceivablychdir()
you out of a directory that it can'tchdir()
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, thefastcwd()
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
fast_abs_path()
function looks the same asabs_path(),
but runs faster. And likefastcwd()
is more dangerous.The
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.