C语言从字符串中提取数字

利用正则表达式：

参考：http://blog.youkuaiyun.com/yangbingzhou/article/details/51352648

 

#include <regex.h>

	char tmpbuf[128] = {0};
	char buffer[128] = {0};
	char sizebuf[30] = {0};
	int ret = 0, res = 0;
	int size = 0;
	regex_t re;
	regmatch_t match[1];

	memset(&re, 0, sizeof(re));
	res = regcomp(&re, "[0-9]+", REG_EXTENDED);
	if (res) {
		sprintf(ddr_size, "Unknown");
		goto out;
	}
	ret = regexec(&re, tmpbuf, 1, match, 0);
	if (ret == 0 && match[0].rm_so >= 0)
		memcpy(sizebuf, &tmpbuf[match[0].rm_so],
			(match[0].rm_eo-match[0].rm_so));
	size = atoi(sizebuf);

如果是格式已知的字符串, 如 "profile3", 从中提取数字3, 则可以使用函数sscanf, 如下:

char profile[20] = "profile3";
int err, profile_id;
err = sscanf(profile, "profile%d", &profile_id);

参考: https://www.cnblogs.com/lanjianhappy/p/6861728.html

 

例子: 从文件中提取数字<