diff -ruN old/ new/ > your_patch_file 生成new和old的patch
patch -p2 < your_patch_file #跳过patch的filename的前2级,然后apply到当前目录
patch -RE -p2 your_patch_file # revert刚才apply的patch,然后删除空文件
patch old_file your_patch_file # 给old_patch 打补丁
patch -R cur_file patch # 从当前文件revert掉patch