code: func ValidateOutputPathFileMode(fileMode os.FileMode) error {
  	switch {
  	case fileMode&os.ModeDevice != 0:
  		return errors.New("got a device")
  	case fileMode&os.ModeIrregular != 0:
  		return errors.New("got an irregular file")
  	}
  	return nil
  }
docs: // ValidateOutputPathFileMode validates the output paths of the `cp` command and serves as a
  // helper to `ValidateOutputPath`