I.S.:

As I mentioned, the input structure was not the issue at hand; however, perhaps I did not make it clear enough that the targetted input structure is, in fact, XML, and yes we will be using XML::Simple. I am currently using YAML for development because I am very familiar with it.

And in fact, I have encapsulated the configuration reading and writing, so you see, changing the input format really is of no consequence at all.