參考：http://blog.csdn.net/yannanxiu/article/details/56841726
1.libcurl的應用舉例：

#include <stdio.h>  
#include <curl.h>    

#pragma comment(lib,"libcurld.lib")  

int main(int argc, char* argv[])

{

    CURL *curl;
    CURLcode res;

    curl = curl_easy_init();

    if (curl) {
        curl_easy_setopt(curl, CURLOPT_URL, "http://www.baidu.com");
        /* example.com is redirected, so we tell libcurl to follow redirection */
        curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, 1L);

        /* Perform the request, res will get the return code */
        res = curl_easy_perform(curl);
        /* Check for errors */
        if (res != CURLE_OK)
            fprintf(stderr, "curl_easy_perform() failed: %s\n",
                curl_easy_strerror(res));
        system("pause");
        /* always cleanup */
        curl_easy_cleanup(curl);
    }
    return 0;
}