Linux下使用curl.h头文件报错解决方法

环境：ubuntu 1604

需要使用C++进行网络通信，选择使用curl库

编译的时候，报了链接错误。

这里记录一下Linux上安装curl的过程。

1. 去这个网站：https://curl.haxx.se/download.html 下载最新的curl压缩包，我这里是7.60

2. 解压：     tar -zxf curl-7.60.0.tar.gz 

3. 进入当前目录:    cd curl-7.60.0/

4. 依次输入如下命令：

   ./configure

make
sudo make install  

5. 等待完成即可

6. terminal输入 g++ main.cpp -lcurl，即可看到默认的a.out文件生成啦

一个例子代码：

#include <iostream>
#include <string>
#include <curl/curl.h>

size_t CurlWrite_CallbackFunc_StdString(void *contents, size_t size, size_t nmemb, std::string *s)
{
    size_t newLength = size*nmemb;
    size_t oldLength = s->size();
    try
    {
        s->resize(oldLength + newLength);
    }
    catch(std::bad_alloc &e)
    {
        //handle memory problem
        return 0;
    }

    std::copy((char*)contents,(char*)contents+newLength,s->begin()+oldLength);
    return size*nmemb;
}
int main()
{
    CURL *curl;
    CURLcode res;

    //curl_global_init(CURL_GLOBAL_DEFAULT);

    curl = curl_easy_init();
    std::string s;

//    while (){
//
//    }
    if(curl)
    {

        curl_easy_setopt(curl, CURLOPT_URL, "http://47.89.179.202:5000/turn/2");

//        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L); //only for https
//        curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L); //only for https
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, CurlWrite_CallbackFunc_StdString);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &s);



        /* 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));
        }

        /* always cleanup */
        curl_easy_cleanup(curl);
    }

    std::cout<<s<<std::endl;

    std::cout<< "Program finished!" << std::endl;
}

参考资料：

https://curl.haxx.se/docs/install.html