diff和patch命令在制作补丁时的使用方法

1) diff/patch这对工具在数学上来说，diff是对2个集合求差，patch是求和

    diff A B > C 生成A和B的diff文件C

    patch A C 给A打上diff文件得到B

    patch -R B C B还原为A

2) 内核补丁

    生成

    diff -uNr linux-2.6.xxx linux-2.6.xxx.1 > diff.patch

    升级

    cp diff.patch linux-2.6.xxx/.

    cd linux-2.6.xxx

    patch -p1 < diff.patch