code: def RunValidationOutputToFilename(feed, options, output_filename):
    
    try:
      output_file = open(output_filename, 'w')
      exit_code = RunValidationOutputToFile(feed, options, output_file)
      output_file.close()
    except IOError as e:
      print('Error while writing %s: %s' % (output_filename, e))
      output_filename = None
      exit_code = 2
  
    if options.manual_entry and output_filename:
      webbrowser.open('file://%s' % os.path.abspath(output_filename))
  
    return exit_code
docs: Validate feed, save HTML at output_filename and return an exit code.