code: func coreNameAdd(keysDir, name, addr string) error {
  	namesDir, err := returnNamesDir(keysDir)
  	if err != nil {
  		return err
  	}
  	dataDir, err := returnDataDir(keysDir)
  	if err != nil {
  		return err
  	}
  	if _, err := os.Stat(path.Join(dataDir, addr+".json")); err != nil {
  		return fmt.Errorf("Unknown key %s", addr)
  	}
  	return ioutil.WriteFile(path.Join(namesDir, name), []byte(addr), 0600)
  }
docs: //----------------------------------------------------------------
  // manage names for keys