#!/usr/bin/perl -l $zipadidoda = 'le12 ogx'; print "In: $zipadidoda"; if( $zipadidoda =~ s/^([A-Z]{1,2}\d{1,2}[A-Z]?)\s?(O|\d)([A-Z]{2})$/uc("$1 ".(0+$2).$3)/ie ) { print "Out: $zipadidoda"; } else { print "Invalid zipcode"; }