NAME
       diff - compare files line by line
SYNOPSIS
       diff [OPTION]... FILES

   
NAME
       patch - apply a diff file to an original
SYNOPSIS
       patch [options] [originalfile [patchfile]]
       but usually just
       patch -pnum <patchfile

   
./file1.c
#include <stdio.h>
int main()
{
        printf("This is version 1!\n");
        return 0;
}

   
./file2.c
#include <stdio.h>
int main()
{
        printf("This is version 2!\n");
        return 0;
}

   
$ diff -uN file1.c file2.c >> file.patch

   
$ patch -p0 < file.patch 

   
$ diff -uN Remote/file1.c Local/file2.c >> file.patch
//在file.patch目录下
$ patch -p0 < file.patch