浅析C语言中sscanf 的用法

函数原型:
Int  sscanf( string str, string fmt, mixed var1, mixed var2 ... );
int scanf( const char *format [,argument]... );

/*****************************************************
** 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=3, 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, buf2=abc, buf3=ABC
 */
 /*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
 */
 /*10.过滤掉不想截取或不需要的字符串--补充,
 **在%号后面加一*号,代表过滤这个字符串,不读取
 */
 string = "android iphone wp7";
 sscanf(string, "%s %*s %s", buf1, buf2);
 printf("10.string=%s\n", string);
 printf("10.buf1=%s, buf2=%s\n\n", buf1, buf2);
 /*
 **执行结果:
 **10.android wp7
 */
}
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
10.string=android iphone wp7
10.buf1=android, buf2=wp7
*/