Esther: considering the amount of runtimes you have, I think I'd better make the script somewhat smarter. Here's what I'm going to do: the script will first search in a list of "preferred" runtimes, and if it cannot resolve the reference using that list, it'll use the full list. As soon as it finds the reference, it'll add that runtime to the "preferred" list.
I think that checking for file existence is one of the more time consuming parts of the script, and this way I can reduce the amount of existence checks.

The pen is mightier than the sword. But if you literally want to have some impact, use a typewriter

My gallery   My freestuff