Hi purna, and welcome to the monastery.

It sounds as though dedupe.pl is a particular program written in Perl. Although people here can answer your questions about Perl in general, dedupe.pl isn't a standard thing that comes as part of Perl - it's something that someone has written specially.

So, at the moment we don't know what it is - you're going to need to tell us. Is it this?

Best wishes, andye