Thank you for that! At least I was on the right track with it all. And I think I'm beginning to understand a bit more about references. Just haven't got to that chapter of your book yet. :)

One other thing though. I've changed the subroutine code as you suggested to:

sub print_tree{
   my ($sub, $tab) = @_;
       foreach (@{$found{$sub}}){
                print "$tab$_\n";
                $tab .= "\t";
                print_tree($_, $tab);
                }
       return;
       }
[download]

but the spacing is still one tab off after the first run through.

I get:

a
  c
    f
    e
b
etc...
[download]

instead of:

a
  c
    f
  e
b
etc...
[download]

Any idea on why the $tab variable isn't resetting itself when the recursion starts coming back up it's chain? The e should be in the same column position as c.

Thanks!

There is no emoticon for what I'm feeling now.