VS2010 调用libcurl

以下内容有参考：http://dewei.iteye.com/blog/1572016 

另推荐vc助手，vs编程必备：

项目中需要调用http接口，采用该库较为简单，先记录调用方法。

下载libcurl，http://curl.haxx.se/download/libcurl-7.18.0-win32-msvc.zip，将dll放到system32目录下，将lib和include文件放到对应的vs2010的安装目录中。

下载zlib，将dll文件放入C:\WINDOWS\system32,下载：

// curl.cpp : 定义控制台应用程序的入口点。

//

#include "stdafx.h"
#include 
#include 
#include 
#include  

#include 
#include 
#include 

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

using  std::string;
using  std::cout;
using  std::endl;

static const char * const global_useragent = "libcurl-agent/1.0";

size_t call_wirte_func(const char *ptr, size_t size, size_t nmemb, string *stream)
{
    assert(stream != NULL);
    size_t len  = size * nmemb;
    stream->append(ptr, len);
    return len;
}

string open_url(const string& url)
{
    CURL *curl;
    CURLcode code;
    string szbuffer;
	
    curl_global_init(CURL_GLOBAL_ALL);
    curl = curl_easy_init();
    if (curl) 
    {

         //设置超时时间
        curl_easy_setopt(curl, CURLOPT_TIMEOUT, 5);
	  
        //设置url地址
        curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
        curl_easy_setopt(curl, CURLOPT_USERAGENT, global_useragent);
		
         //设置post值
        //curl_easy_setopt(curl, CURLOPT_POSTFIELDS, "username=jordan&secret=test");  
   
        //抓取内容后，回调函数
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, call_wirte_func);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &szbuffer);

        code = curl_easy_perform(curl);
        if  (CURLE_OK == code) 
	{
	   //执行成功
	   double val;  
            /* check for bytes downloaded */  
            code = curl_easy_getinfo(curl, CURLINFO_SIZE_DOWNLOAD, &val);  
            if ((CURLE_OK == code) && (val>0))  
                printf("Data downloaded: %0.0f bytes.\n", val);  
	}
        /* 释放内存 */
        curl_easy_cleanup(curl); }
        curl_global_cleanup();

	return szbuffer;
}

int _tmain(int argc, _TCHAR* argv[])
{
	
	string url = "";
  
	 string res = open_url(url);
	 string::size_type pos;

	 if (!res.empty())
	 {
		pos = res.find("404 Not Found");

		if ( pos != string::npos )
		{
		      cout << "The url is not valid" << endl;
		}
		else
		{
			 cout << "the url " << url.c_str() << "---return value is---->" << res.c_str() << endl;
		}
		
	 }
	 else
	 {
		 cout << "sorry， can not get any contents" << endl;
	 }

        system("pause");
	return 0;
}