C语言调用curl库抓取网页图片-白红宇

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。

#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 = 0;

char *tmp = NULL;

int flag = 0;

char key[1024] = {0};

char str1[128] = {0};

char str2[128] = {0};

if ((fp = fopen("test.txt", "w")) == NULL)

{

return 1;

}

curl = curl_easy_init();

if (curl)

{

flag = 1;

curl_easy_setopt(curl, CURLOPT_URL, argv[1]); //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, 0, 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, 0, 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 0;

}

//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 + 1, "%s", p + strlen(str1));

key[len + 1] = '\0';

}

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

./test url

即可