code: func parseDotConfFile(plugin string, conf *Config, target interface{}) error {
  	cfgPath := filepath.Join(conf.dotdDir(), fmt.Sprintf("%s.cfg", plugin))
  	if _, err := os.Stat(cfgPath); err == nil {
  		err = parseConfig(cfgPath, target, fmt.Sprintf("plugin.%s", plugin), conf.rawOpts)
  		if err != nil {
  			return err
  		}
  	}
  
  	return nil
  }
docs: // parseDotConfFile parses a file like /etc/..../plugin.d/package.cfg as if its full of
  // plugin.package.x = y lines and fill in a structure with the results if that structure
  // declares its options using the same tag structure as Config.
  //
  // If the supplied target structure is nil then the only side effect will be that the
  // supplied conf will be updated with the raw options so that HasOption() and Option()
  // can be used to extract the parsed settings