C语言调用curl库抓取网页图片(转)

思路是先用curl抓取网页源码，然后以关键字寻找出图片网址。

 范例：

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

 void get_key_from_str(char *origin, char *str1, char *str2, char *key);

 int main(int argc, char **argv)
 {
     CURL *curl;
     FILE *fp = NULL, *fp_read = NULL;
     int file_size = ;
     char *tmp = NULL;
     int flag = ;
     char key[] = {};
     char str1[] = {};
     char str2[] = {};

     if ((fp = fopen("test.txt", "w")) == NULL)
     {
         return ;
     }
     curl = curl_easy_init();
     if (curl)
     {
         flag = ;
         curl_easy_setopt(curl, CURLOPT_URL, argv[]);     //curl设置网址
         curl_easy_setopt(curl, CURLOPT_WRITEDATA, fp);     //将网页源码存在文件中，好像只能存文件，不能存字符串
         curl_easy_perform(curl);//开始抓取
         curl_easy_cleanup(curl);
         fclose(fp);
         fp_read = fopen("test.txt", "rb");
         fseek(fp_read, , SEEK_END);      //把指针移到文本最后
         file_size = ftell(fp_read)     ;//算出文本大小
         fseek(fp_read, , SEEK_SET);     //再把指针移到最前面
         tmp = (char *)malloc(file_size * sizeof(char));     //malloc一段内存
         printf("file_size:%d\n", file_size);
         fread(tmp, file_size, sizeof(char), fp_read);     //读取文件
         fclose(fp_read);
         snprintf(str1, sizeof(str1), "img src=\"");
         snprintf(str2, sizeof(str2), "\"");
         get_key_from_str(tmp, str1, str2, key);     //取得网址

         printf("key:%s\n", key);
         free(tmp);
     }

     if (!flag)
     {
         fclose(fp);
     }

     return ;
 }
 //抓取str1和str2之间的关键字
 void get_key_from_str(char *origin, char *str1, char *str2, char *key)
 {
     char *p = strstr(origin, str1);
     char *q = strstr(p + strlen(str1), str2);
     int len = q - p - strlen(str1);
     snprintf(key, len + , "%s", p + strlen(str1));
     key[len + ] = '\0';
 }

gcc -g -Wall main.c -o test -lcurl

./test url