cat.rb

lifes = 9

puts "Try to kill me, I got #{lifes} lifes!\n"

loop do
  begin
    sleep 1
  rescue Exception => e
    lifes = lifes - 1

    if lifes == 0
      puts "Bye bye, I'm dead"
      exit
    else
      puts "You hit me, still got #{lifes} life#{lifes > 1 ? 's' : ''} :)\n"
    end
  end
end

Why you should never catch Exception in ruby

Execute this program and try to kill it with ctrl-c. You'll be surprised how sustainable a cat is.