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=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 */