timeout.rb

#/ Usage: ruby timeout.rb <seconds> -- command arg arg arg

timeout, separator, *command = ARGV
timeout = timeout.to_f
if timeout <= 0.0 || separator != '--' || command.empty?
  system "cat #$0 | grep ^#/ | cut -c4-"
  exit 1
end

trap(:CHLD) { exit 0 }
pid = spawn(*command)
trap(:INT) { kill :INT, pid }
sleep timeout
$stderr.puts "Time's up!"
Process.kill :INT, pid
sleep 1.0
$stderr.puts "... TERM"
Process.kill :TERM, pid
sleep 1.0
$stderr.puts "... QUIT"
Process.kill :QUIT, pid
sleep 1.0
$stderr.puts "... KILL"
Process.kill :KILL, pid