Even though Perl is a language where you can do a lot of different useful things without ever reading a manual, that doesn't mean you should. A good book would have taught you about printf, sprintf and pack.

But you do use strict, so you must have read some introduction to Perl. What book or tutorial did you read?

Juerd # { site => 'juerd.nl', plp_site => 'plp.juerd.nl', do_not_use => 'spamtrap' }