Hum, I see. I was expecting an equivalent to the "previously" condition in a common-lisp loop structure. A chunk of code that happens only once before the main body of the function starts iterating. I understand that if I need to do something within each subdirectory (check if something happens inside each subdir first), I would need then to traverse the tree two times using two different find functions. One for directories only, and a second for all files. Right? can't be done in one take?

I'm a bit unclear exactly what you're asking, but if you want to do something for files and something different for directories:

sub wanted {
    if (-d){
        print "directory\n";
    }
    if (-f){
        print "file\n";
    }
}
[download]

Mmmh. Could work, I'll try this and see what happens. Thanks