C语言sscanf函数的总结

在处理字符串的程序当中，经常会分析字符串，从一大长串的字符串截取我们需要的数据，这如果通过自己手写函数来分析，虽然可以，但当你知道sscanf的功能，那就自己写函数分析就显得多此一举。

这些函数的使用都很简单，总结一下，等下次使用一目了然。俗话说：好记性不如烂笔头，记录下来就是效率。

以下源代码是本人测试的源文件，附带讲解注释。

/*****************************************************

** Name : sscanf.c

** Author : gzshun

** Version : 1.0

** Date : 2011-12

** Description : sscanf function

******************************************************/

#include <stdio.h>

#include <stdlib.h>

#include <string.h>


static void sscanf_test(void);


static void sscanf_test(void)

{
int ret;

char *string;

int digit;

char buf1[255];

char buf2[255];

char buf3[255];

char buf4[255];


/*1.最简单的用法*/

string = "china beijing 123";

ret = sscanf(string, "%s %s %d", buf1, buf2, &digit);

printf("1.string=%s\n", string);

printf("1.ret=%d, buf1=%s, buf2=%s, digit=%d\n\n", ret, buf1, buf2, digit);

/*

**执行结果:

**1.ret=2, buf1=china, buf2=beijing, digit=123

**可以看出,sscanf的返回值是读取的参数个数

*/


/*2.取指定长度的字符串*/

string = "123456789";

sscanf(string, "%5s", buf1);

printf("2.string=%s\n", string);

printf("2.buf1=%s\n\n", buf1);

/*

**执行结果:

**2.buf1=12345

*/


/*3.取到指定字符为止的字符串*/

string = "123/456";

sscanf(string, "%[^/]", buf1);

printf("3.string=%s\n", string);

printf("3.buf1=%s\n\n", buf1);

/*

**执行结果:

**3.buf1=123

*/


/*4.取到指定字符集为止的字符串*/

string = "123abcABC";

sscanf(string, "%[^A-Z]", buf1);

printf("4.string=%s\n", string);

printf("4.buf1=%s\n\n", buf1);

/*

**执行结果:

**4.buf1=123abc

*/


/*5.取仅包含指定字符集的字符串*/

string = "0123abcABC";

sscanf(string, "%[0-9]%[a-z]%[A-Z]", buf1, buf2, buf3);

printf("5.string=%s\n", string);

printf("5.buf1=%s, buf2=%s, buf3=%s\n\n", buf1, buf2, buf3);

/*

**执行结果:

**5.buf1=123

*/


/*6.获取指定字符中间的字符串*/

string = "ios<Android>wp7";

sscanf(string, "%*[^<]<%[^>]", buf1);

printf("6.string=%s\n", string);

printf("6.buf1=%s\n\n", buf1);

/*

**执行结果:

**6.buf1=android

*/


/*7.指定要跳过的字符串*/

string = "iosVSandroid";

sscanf(string, "%[a-z]VS%[a-z]", buf1, buf2);

printf("7.string=%s\n", string);

printf("7.buf1=%s, buf2=%s\n\n", buf1, buf2);

/*

**执行结果:

**7.buf1=ios, buf2=android

*/


/*8.分割以某字符隔开的字符串*/

string = "android-iphone-wp7";

/*

**字符串取道'-'为止,后面还需要跟着分隔符'-',

**起到过滤作用,有点类似于第7点

*/

sscanf(string, "%[^-]-%[^-]-%[^-]", buf1, buf2, buf3);

printf("8.string=%s\n", string);

printf("8.buf1=%s, buf2=%s, buf3=%s\n\n", buf1, buf2, buf3);

/*

**执行结果:

**8.buf1=android, buf2=iphone, buf3=wp7

*/


/*9.提取邮箱地址*/

string = "Email:beijing@sina.com.cn";

sscanf(string, "%[^:]:%[^@]@%[^.].%s", buf1, buf2, buf3, buf4);

printf("9.string=%s\n", string);

printf("9.buf1=%s, buf2=%s, buf3=%s, buf4=%s\n\n", buf1, buf2, buf3, buf4);

/*

**执行结果:

**9.buf1=Email, buf2=beijing, buf3=sina, buf4=com.cn

*/

}

int main(int argc, char **argv)

{
sscanf_test();

return 0;

}

/*

**测试程序

**环境:

**Linux Ubuntu 2.6.32-24-generic-pae #39-Ubuntu SMP Wed Jul 28 07:39:26 UTC 2010 i686 GNU/Linux

**gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5)

**

gzshun@ubuntu:~/c/sscanf$ gcc sscanf.c -o sscanf

gzshun@ubuntu:~/c/sscanf$ ./sscanf

1.string=china beijing 123

1.ret=3, buf1=china, buf2=beijing, digit=123


2.string=123456789

2.buf1=12345


3.string=123/456

3.buf1=123


4.string=123abcABC

4.buf1=123abc


5.string=0123abcABC

5.buf1=0123, buf2=abc, buf3=ABC


6.string=ios<android>wp7

6.buf1=android


7.string=iosVSandroid

7.buf1=ios, buf2=android


8.string=android-iphone-wp7

8.buf1=android, buf2=iphone, buf3=wp7


9.string=Email:beijing@sina.com.cn

9.buf1=Email, buf2=beijing, buf3=sina, buf4=com.cn

*/