I am really sorry to see that you don't seem to make a lot of progress with your project (you've posted quite a bit about it previously) - at least that's what it looks to me...

While what you are trying to achieve is absolutely doable (and Perl is an excellent choice for it) I think you should admit to yourself that you lack a bit of background to really get going...

Please don't take it personally but you seem to just randomly fiddle with pieces of code that you get from man-pages or god-knows-where without really understanding what you are doing...

While this can work sometimes it is just not a very clever strategy for the long run.

So I would advise you to work through a good introduction (Learning Perl maybe?) before you start hacking. That won't take you long and should improve your productivity significantly.

I really hope you teach your pupils better learning techniques than the ones you exhibit...