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 the 
getcwd(3) (or 
getwd(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 as 
getcwd(). (actually 
getcwd() is 
abs_path(``.''))


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 
fast_abs_path() function looks the same as 
abs_path(), but runs faster. And like 
fastcwd() 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.