code: def parse_config_file(parser, stdin_args):
      
      config_args = []
  
      # Temporary switch required args and save them to restore.
      required_args = []
      for action in parser._actions:
          if action.required:
              required_args.append(action)
              action.required = False
  
      parsed_args = parser.parse_args(stdin_args)
  
      # Restore required args.
      for action in required_args:
          action.required = True
  
      if not parsed_args.config_file:
          return config_args
  
      config = ConfigParser()
      if not config.read(parsed_args.config_file):
          sys.stderr.write('Config file "{0}" doesn\'t exists\n'.format(parsed_args.config_file))
          sys.exit(7)  # It isn't used anywhere.
  
      config_args = _convert_config_to_stdin(config, parser)
      return config_args
docs: Parse config file.
  
      Returns a list of additional args.