#!/usr/bin/perl
# This is a very ugly way to get primes.  Warning, it runs forever, 
# until you 'kill -TERM' it because the second
# condition of $x is simply that it is larger than 0, which it will always be.
# Assumes you have 'factor' installed, which any Linux system should.
# Creates a file called log.txt with the list of primes, one per line.
# This program is hereby put into the Public Domain

for ($x=1;$x>0;$x=($x+2)){ # we only check odd numbers 
  if(`factor $x|grep '$x: $x'`){
    open(LOG,">>log.txt");
    print LOG "$x\n";
    close(LOG);
  }
}
1;