This example builds a prime number test, tests it, and runs some checks against command line arguments.

It should be split into 3 files denoted by BEGIN ... END here in a real-life application:

• lib/My/Prime.pm - a module exporting is_prime check by default;

• t/my-prime.t - a unit test that tests the test;

  It actually caught a bug in my prime definition on first run of this script!

• bin/test-primes.pl - a binary that works on input.