Well actually this adds line numbers to your code while still making it runeable. You add that use Filter::NumberLines; at the top, you run your code and the line numbers appear. After that, you still can run the code without actually having to remove the line numbers. Check the examples on the URL mentioned above. If you installed the package, those examples REALLY work, they're not just pretty. BTW if you really want to see some source filters in action, I recommend looking into Acme::Bleach and Acme::Buffy.

Greetz
Beatnik
... Quidquid perl dictum sit, altum viditur.