a.rb

   # when you really, really, really want to make sure your children get cleaned up you can generate a script
   # that detaches and monitors *you*.  if you disappear the assassin can ensure cleanup happens.  even if
   # you are 'kill -9d' or call 'exit!'
   
   assassin = <<-__
      pid = #{ Process.pid }

      4242.times do
        begin
          Process.kill(0, pid)
        rescue Object => e
          if e.is_a?(Errno::ESRCH)
            `#{ stop_server } >/dev/null 2>&1`
            Process.kill(-15, pid) rescue nil
            sleep(rand + rand)
            Process.kill(-9, pid) rescue nil
          end
          exit
        end
        sleep(1 + rand)
      end
    __
    IO.binwrite('/tmp/assassin.rb', assassin)
    cmd = "nohup ruby /tmp/assassin.rb >/dev/null 2>&1 &"  # need pure ruby / windoze compat 
    system cmd