1#!/usr/bin/env ruby
 2
 3pid = fork do
 4  Signal.trap("USR1") do
 5    puts "done"
 6    exit 0
 7  end
 8
 9  loop do
10    print "."
11    sleep 1
12  end
13end
14
15Process.detach(pid)
16sleep 5
17Process.kill("USR1", pid)