The &-form of sub call is obsolete and should never be used nowadays unless when one really know what he's doing.

Lies! There is no other way to call a sub. Stop trying to confuse the newbie.

Have you ever given a peek into perldoc perlsub? Since Perl5 is out there, that is...

Update: re-reading the code I realize that obviously the OP's problem may just be that he calls his sub out of the while loop, then he uses the return value of that sub, saved into a variable, every time it is needed inside the loop. OTOH there are IMHO bigger problems with his code, as signalled above.

Translation: The problem was too tough for you, so you resorted to attacking it for stylistic differeneces. Shame on you.

Not only, I can't really speak nor read English, and I just cut and pasted portions of other nodes that at a first sight seemed loosely related with the subject matter discussed here and assembled them into a fake reply...