gistfile1.txt

primez.rb

#!/usr/bin/env ruby

Infinity = 1.0/0
@start = Time.now
@primes = []

print "PRIMEZ! "

trap("INT") do
  duration = (Time.now - @start).round
  puts
  puts "=" * 80
  puts "Calculated #{@primes.size} primes in #{duration} secs"

  throw :exit
end

catch(:exit) do
  (2..Infinity).each do |number|
    catch(:composite) do
      2.upto(Math.sqrt(number)).each { |divisor| throw :composite if number % divisor == 0 }
      @primes << number
      print "#{number} "
    end
  end
end