" is simple: just read the program specification. Wot? Not got one? Then maybe you should sit down with your users/sponsors and write one
. Methinks someone decided on the solution before understanding the problem.
If you have never written a GUI then you might consider a web-based approach instead - in other words let the browser be your GUI and use HTML. Since you are running on Linux then you probably already have all the components, like Apache, installed. This also has the advantange of allowing the users to access the interface remotely.