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
- */