libcurl 学习（0）

libcurl first sample

#include <iostream>
#include <typeinfo>
#include <stdio.h>
#include <windows.h>
#include <string>
#include <curl/curl.h>

using namespace std;

/*
*  size_t write_data(void *buffer, size_t size, size_t nmemb, void *userp)
*  curl_global_init(CURL_GLOBAL_WIN32);
*  CURL *easy_handle = curl_easy_init();
*  curl_easy_setopt(easy_handle, CURLOPT_URL, "http://www.baidu.com/img/baidu.gif");
*  curl_easy_setopt(easy_handle, CURLOPT_WRITEFUNCTION, write_data);
*  curl_easy_setopt(easy_handle, CURLOPT_WRITEDATA, &data);
*  curl_easy_perform(easy_handle);
*  curl_easy_cleanup(easy_handle);
*  curl_global_cleanup();
*/

size_t /* CALLBACK */
write_data(void *buffer, size_t size, size_t nmemb, void *userp)
{
    string &data = *((string*)userp);

    data.append((char*)buffer, size * nmemb);
    
    return size * nmemb;    
}

int main()
{
    CURLcode retCode;
    retCode = curl_global_init(CURL_GLOBAL_WIN32);

    if (retCode != CURLE_OK) {
        cout << "curl_global_init error" << endl;
        return retCode;
    }

    /* curl_version_info_data *infodata = curl_version_info(CURLVERSION_NOW); */

    CURL *easy_handle = curl_easy_init();

    curl_easy_setopt(easy_handle, CURLOPT_URL, "http://www.baidu.com/img/baidu.gif");

    string data;

    curl_easy_setopt(easy_handle, CURLOPT_WRITEFUNCTION, write_data);
    curl_easy_setopt(easy_handle, CURLOPT_WRITEDATA, &data);

    curl_easy_perform(easy_handle);

    FILE * file = fopen("baidu.gif","wb");
    fseek(file, 0, SEEK_SET);
    fwrite(data.c_str(), 1, data.length(), file);
    fclose(file);

    curl_easy_cleanup(easy_handle);
    curl_global_cleanup(); return0;
}