I have seen many scripts that recurse over directories listing files, but what I am trying to do, with no success, is list the directories only.

It doesn't help that the directory I am trying to list all directories of is quite large, but it's what I need to do :(

Can anyone help me figure out how to do this? I figured using DirectoryIterator would probably be the best option, but documentation explaining it is incredibly scarce, and not many user submitted examples.

I have tried doing this the old fashion way reading a directory and recursively listing only those that are directories, but it times out.