code: func SetLogOut(log *logrus.Logger, outString string) error {
  	switch outString {
  	case "stdout":
  		log.Out = os.Stdout
  	case "stderr":
  		log.Out = os.Stderr
  	default:
  		f, err := os.OpenFile(outString, os.O_RDWR|os.O_CREATE|os.O_APPEND, 0644)
  
  		if err != nil {
  			return err
  		}
  
  		log.Out = f
  	}
  
  	return nil
  }
docs: // SetLogOut provide log stdout and stderr output