Cwd::Ext - get abs path without symlink dereference and more


Let's imagine that '/home/myself/stuff/music' is a soft link to '/home/myself/documents/music', and our current working directory is '/home/myself'..

   use Cwd::Ext ':all';
   abs_path_nd('./stuff/music'); # returns /home/myself/stuff/music
   abs_path_is_in_nd( '/home/myself/stuff/music', '/home/myself/stuff' ); 
   # returns /home/myself/stuff/music
   abs_path_is_in( '/home/myself/thisdir', '/tmp' );
   # returns false, beacuse is not inside tmp

Is path in webshare?

   abs_path_in_nd( '/home/myself/public_html/resource', $ENV{DOCUMENT_ROOT} );


These are some things that feel missing from Cwd.

Questions like, Is path a inside the filesystem hierarchy of path b? What is the resolved absolute path of a file, without dereferencing symlinks?

Unlike with Cwd, this module is in baby stage. So it is NOT tweaked for OS2, NT, etc etc. This is developed under POSIX.

This module does not export by default. You must explicitely import what you want to use.



Argument is a path string. Returns abs path.

Works just like Cwd::abs_path , only it does (n)o symlink (d)ereference.


Arguments are path string for child path in question, parent string path to test against. Returns resolved abs path of child. If false, returns false.

Will confess if missing arguments. If either path can't be resolved, warns and returns undef.

Is /home/myself/file1.jpg inside the filesystem hierarchy of /home/myself ?

   my $child  = '/home/myself/file1.jpg';
   my $parent = '/home/myself';

   printf "Does [$child] reside in [$parent]? %s\n",
      ( Cwd::Ext::abs_path_is_in($child,$parent) ? 'yes' : 'no' );   

If both paths resolve to same place, returns abs path and warns. (Should this be different? Is /home/me inside /home/me? At present we deem yes.)


Same as abs_path_is_in() but does not resolve symlinks.


Arg is child abs path, and parent abs path. Does not use Cwd to resolve anything, this just performs a substring match. Returns boolean.

Does an eval to check if this machine supports symlinks. Returns boolean.


This module is in ALPHA state. Needs feedback.


I want this to inherit Cwd. So that cwd(), etc are exported. Currently, you have to use Cwd and Cwd::Ext to access both these subs and Cwd subs.




Leo Charre leocharre at cpan dot org


Copyright (c) 2009 Leo Charre. All rights reserved.


This package is free software; you can redistribute it and/or modify it under the same terms as Perl itself, i.e., under the terms of the "Artistic License" or the "GNU General Public License".


This package is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

See the "GNU General Public License" for more details.