从字符串中提取未知子字符串

Question

我有一个程序以下列格式返回数据:

<CFData 0x1001219c0 [0x7fff7027aee0]>{length = 20, capacity = 20, bytes = 0x8deead13b8ae7057f6a629fdaae5e1200bcb8cf5}

我需要提取8deead13b8ae7057f6a629fdaae5e1200bcb8cf5(是的,减去0x).我尝试使用sscanf并传递一些正则表达式,但我对此没有任何线索.

知道怎么做吗？代码片段表示赞赏.

Answer 1

您可以使用strstr()在输入字符串中定位"bytes = 0x"并复制字符串的其余部分(从"bytes = 0x"结尾),除了最后一个字符:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int main()
{
    char* s = "<CFData 0x1001219c0 [0x7fff7027aee0]>{length = 20, "
              "capacity = 20, "
              "bytes = 0x8deead13b8ae7057f6a629fdaae5e1200bcb8cf5}";
    char* value = 0;
    const char* begin = strstr(s, "bytes = 0x");

    if (begin)
    {
        begin += 10; /* Move past "bytes = 0x" */
        value = malloc(strlen(begin)); /* Don't need 1 extra for NULL as not
                                          copy last character from 'begin'. */
        if (value)
        {
            memcpy(value, begin, strlen(begin) - 1);
            *(value + strlen(begin) - 1) = 0;
            printf("%s\n", value);
            free(value);
        }
    }
    return 0;
}