code: def main():
      
      # Monkey patch warnings.showwarning:
      warnings.showwarning = customized_warning
  
      # Read command line args, if any:
      args = read_cmdline()
  
      # Configuration file, if given on the command line:
      config_file = args['config_file']
  
      try:
          ellis = Ellis(config_file)
      except NoRuleError:
          msg = ("There are no valid rules in the config file. "
                 "Ellis can not run without rules.")
          print_err(msg)
      else:
          ellis.start()
docs: Entry point for Ellis.