https://purengom.com/2010/08/17/%ec%9e%90%eb%a7%89%ec%9d%84-%ec%a7%80%ec%9b%90%ed%95%98%ec%a7%80-%ec%95%8a%eb%8a%94-osx-%ec%9d%b8%ec%bd%94%eb%8d%94%ec%97%90%ec%84%9c-%ec%9e%90%eb%a7%89-%eb%84%a3%ec%96%b4-%ec%9d%b8%ec%bd%94%eb%94%a9/