youtube-dl hang workaround

physics-dl.rb

require 'timeout'

loop do
  pid = fork

  if pid.nil?
    exec("youtube-dl https://www.youtube.com/playlist?list=PL47F408D36D4CF129")
  else
    begin
      Timeout::timeout(15 * 60) {
        Process.waitpid(pid, 0)
      }
    rescue Timeout::Error
      Process.kill("HUP", pid)
    end
  end
end