libcurl进行HTTP GET获取JSON数据(转载)

#include <stdio.h>
#include <iostream>
#include <sstream>
using namespacestd;
size_t write_data(void *ptr, size_t size, size_t nmemb, void *stream) 
{
    string data((const char*) ptr, (size_t) size *nmemb);
    *((stringstream*) stream) << data <<endl;
    return size *nmemb;
}
int main(int argc, char *argv[])
{
        //基于当前系统的当前日期/时间
        time_t now = time(0);
        char* dt = ctime(&now);
        cout << dt << "-------------------------------------" <<endl;
        /*HTTP GET json data*/
        std::stringstream out;
        void* curl =curl_easy_init();
        //设置URL
        curl_easy_setopt(curl, CURLOPT_URL, "http://if.qdocument.net:705/bic/download/initFiles?uid=weidong0925@126.com&pageNum=1");
        //设置接收数据的处理函数和存放变量
curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_data);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &out);
        //执行HTTP GET操作
        CURLcode res =curl_easy_perform(curl);
        if (res !=CURLE_OK) {
            fprintf(stderr, "curl_easy_perform() failed: %s
", curl_easy_strerror(res));
        }
        //接受数据存放在out中，输出之
        //cout << out.str() << endl;
        string str_json = out.str();
        printf("%s",str_json.c_str());
        curl_easy_cleanup(curl);
    return 0;
}