double_ctrl_c_trapper.rb

module DoubleCtrlCTrapper
  TOLERANCE = 3
  def self.tolerance?(sec)
    sec < TOLERANCE
  end

  def self.freq?(current)
    b = @last_trapped && tolerance?(current - @last_trapped)
    @last_trapped = current
    b
  end

  def self.included(mod)
    trap(:INT) {
      exit if freq?(Time.now)
      STDERR.puts 'To exit, press Ctrl-C twice'
    }
  end
end

if $0 == __FILE__
  include DoubleCtrlCTrapper

  while(true)
    sleep(1)
  end
end