I'm not sure to really understand the actual meaning of your message "Anonymous Monk", nevertheless, I'll try to answer.

1. Am I wasting my time? I don't know who can actually judge of that here but indeed I am learning and gaining experience so I only see positive output.

2. Investing my knowledge into SAAS? I don't understand the relation with this post. Can you elaborate?

3. The app reads and transform large text files used as input for machining. I want this to run on Windows so the end users can all run this app, no matter their platform. The reason for the two independent scripts is that I don't own the one I called compute.pl in my initial post and his author and I would rather keep that independence. I am the owner of the gui.pl script and do my best to make it work with this constraint.

I hope this answers well your post, that I find a little bit offensive. I'm just learning and trying to achieve a certain goal, if I'm doing wrong or not explaining all what should be, then I appreciate being guided, not just getting told that I'm wasting my time.