use strict; package my_temp_convert; my $cur_ctemp=0; sub set_ctemp {$cur_ctemp = shift;} sub c {return $cur_ctemp;} sub f {return 32 + (9 * $cur_ctemp) / 5;} package main; my_temp_convert::set_ctemp(32); printf "%d F is %d C\n", my_temp_convert::f(), my_temp_convert::c();