摘要：本文详细介绍了diff命令的基本用法 作者：zieckey （zieckey＠yahoo.com.cn） All Rights Reserved！ 有这样两个文件： 程序清单1 ：hello.c #include int main(void) { char msg[] = "Hello world!"; puts(msg); printf("Welcome to use diff commond./n"); return 0; } 程序清单2：hello_diff.c #include #include int main(void) { char msg[] = "Hello world,fome hello_diff.c"; puts(msg); printf("hello_diff.c says,'Here you are,using diff.'/n"); return 0; } 我们使用diff命令来查看这两个文件的不同之处，有一下几种方便的方法： 1、普通格式输出： [root@localhost diff]# diff hello.c hello_diff.c 1a2 > #include 5c6 < char msg[] = "Hello world!"; --- > char msg[] = "Hello world,fome hello_diff.c"; 8c9 < printf("Welcome to use diff commond./n"); --- > printf("hello_diff.c says,'Here you are,using diff.'/n"); [root@localhost diff]# 上面的“1a2”表示后面的一个文件"hello_diff.c"比前面的一个文件"hello.c"多了一行 "5c6"表示第一个文件的第5行与第二个文件的第6行有区别 2、并排格式输出 [root@localhost diff]# diff hello.c hello_diff.c -y -W 130 #include #include > #include int main(void) int main(void) { { char msg[] = "Hello world!"; | char msg[] = "Hello world,fome hello_diff.c"; puts(msg); puts(msg); printf("Welcome to use diff commond./n"); | printf("hello_diff.c says,'Here you are,using diff.'/ return 0; return 0; } } [root@localhost diff]# 这种并排格式的对比一目了然，可以快速找到不同的地方。 -W选择可以指定输出列的宽度，这里指定输出列宽为130 3、上下文输出格式 [root@localhost diff]# diff hello.c hello_diff.c -c *** hello.c 2007-09-25 17:54:51.000000000 +0800 --- hello_diff.c 2007-09-25 17:56:00.000000000 +0800 *************** *** 1,11 **** #include int main(void) { ! char msg[] = "Hello world!"; puts(msg); ! printf("Welcome to use diff commond./n"); return 0; } --- 1,12 ---- #include + #include int main(void) { ! char msg[] = "Hello world,fome hello_diff.c"; puts(msg); ! printf("hello_diff.c says,'Here you are,using diff.'/n"); return 0; } [root@localhost diff]# 这种方式在开头两行作了比较文件的说明，这里有三中特殊字符： ＋ 比较的文件的后者比前着多一行 － 比较的文件的后者比前着少一行 ！ 比较的文件两者有差别的行 4、统一输出格式 [root@localhost diff]# diff hello.c hello_diff.c -u --- hello.c 2007-09-25 17:54:51.000000000 +0800 +++ hello_diff.c 2007-09-25 17:56:00.000000000 +0800 @@ -1,11 +1,12 @@ #include +#include int main(void) { - char msg[] = "Hello world!"; + char msg[] = "Hello world,fome hello_diff.c"; puts(msg); - printf("Welcome to use diff commond./n"); + printf("hello_diff.c says,'Here you are,using diff.'/n"); return 0; } [root@localhost diff]# 正如看到的那样，统一格式的输出更加紧凑，所以更易于理解，更易于修改。 5、其他 假如你想查看两个文件是否不同又不想显示差异之处的话，可以加上－q选项： [root@localhost diff]# diff hello.c hello_diff.c -q Files hello.c and hello_diff.c differ [root@localhost diff]# 另外你还可以提供一些匹配规则来忽略某中差别，可以用 -I regexp [root@localhost diff]# diff hello.c hello_diff.c -c -I include *** hello.c 2007-09-25 17:54:51.000000000 +0800 --- hello_diff.c 2007-09-25 17:56:00.000000000 +0800 *************** *** 2,11 **** int main(void) { ! char msg[] = "Hello world!"; puts(msg); ! printf("Welcome to use diff commond./n"); return 0; } --- 3,12 ---- int main(void) { ! char msg[] = "Hello world,fome hello_diff.c"; puts(msg); ! printf("hello_diff.c says,'Here you are,using diff.'/n"); return 0; } [root@localhost diff]# 这里通过“ -I include”选项来忽略带有“ include”字样的行
