syck | swift yaml for ruby python perl

You need to use strict; (and use warnings; while you are at it, maybe use diagnostics; too, when you are really stuck). As a general rule, ALWAYS use strict; and use warnings; because they prevent problematic code from running and give you some much more helpful output.

You should also read perldoc perlreftut, which helps explain what you are dealing with.

Your variable $running_scripts is not a hash, but a "hash reference", which is an important distinction. When you call ref on a real hash, it returns a false value, since it is not a reference.

What you need to do is "dereference" using the arrow operator to get the value.

To get the keys call to work, there's a separate syntax for dereferencing.