https://blog.gongquiz.com/2021/04/07/linux-%eb%aa%85%eb%a0%b9%ec%96%b4-%ec%a4%91-%ed%8a%b9%ec%a0%95%ed%95%9c-%ed%8c%8c%ec%9d%bc%ec%9d%84-%ec%b0%be%ea%b3%a0%ec%9e%90-%ed%95%a0-%eb%95%8c-%ec%82%ac%ec%9a%a9%ed%95%98%eb%8a%94-%eb%aa%85/