Thanks again LanX, you are becoming my teacher in elenctic method.. ;=)

My attempt is only to show something i discovered and that fascinate me, as everytime with Perl. In a 'reinvent the wheel' style as a way to learn. As you can guess from my signature i would use Devel::TraceUse in a real project. Your comment are correct.

I do not think to release something, may be usefull for me to investigate what a source filter is.

When i was on my motorbike, 20 minutes after last post, i thought to the __DATA__ and __END__ side effect.

See you at next question, i hope.

L*