code: def do_shell(self, arg):
          "run a shell commad"
          print(">", arg)
          sub_cmd = subprocess.Popen(arg, shell=True, stdout=subprocess.PIPE)
          print(sub_cmd.communicate()[0]f do_shell(self, arg):
          "run a shell commad"
          print(">", arg)
          sub_cmd = subprocess.Popen(arg, shell=True, stdout=subprocess.PIPE)
          print(sub_cmd.communicate()[0])
docs: run a shell commad