C++要实现http网络连接，需要借助第三方库，libcurl使用起来还是很方便的
环境：win32 + vs2015
如果要在linux下使用，用cmake编译，使用基本同理
1，下载编译libcurl
下载curl源码，找到vs工程，按照x86 x64 并对应debug和release编译出静态库lib
2，构建工程
1）curl头文件和lib拷贝到工程目录
2）配置附加包含目录libcurl中的include和附加库目录libcurl中的lib目录
3）添加预编译宏USE_OPENSSL和CURL_STATICLIB
4）添加附加依赖库
ws2_32.lib wldap32.lib crypt32.lib advapi32.lib libcurl.lib注意版本对应
3，代码示例
#include <iostream> #include <string> #include "curl/curl.h" using namespace std; #pragma comment(lib, "ws2_32.lib") #pragma comment(lib, "wldap32.lib") #pragma comment(lib, "crypt32.lib") #pragma comment(lib, "advapi32.lib") #pragma comment(lib, "libcurl.lib") // reply of the requery size_t req_reply(void *ptr, size_t size, size_t nmemb, void *stream) { cout << "----->reply" << endl; string *str = (string*)stream; cout << *str << endl; (*str).append((char*)ptr, size*nmemb); return size * nmemb; } // http GET CURLcode curl_get_req(const std::string &url, std::string &response) { // init curl CURL *curl = curl_easy_init(); // res code CURLcode res; if (curl) { // set params curl_easy_setopt(curl, CURLOPT_URL, url.c_str()); // url curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false); // if want to use https curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, false); // set peer and host verify false curl_easy_setopt(curl, CURLOPT_VERBOSE, 1); curl_easy_setopt(curl, CURLOPT_READFUNCTION, NULL); curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, req_reply); curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&response); curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1); curl_easy_setopt(curl, CURLOPT_HEADER, 1); curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 3); // set transport and time out time curl_easy_setopt(curl, CURLOPT_TIMEOUT, 3); // start req res = curl_easy_perform(curl); } // release curl curl_easy_cleanup(curl); return res; } // http POST CURLcode curl_post_req(const string &url, const string &postParams, string &response) { // init curl CURL *curl = curl_easy_init(); // res code CURLcode res; if (curl) { // set params curl_easy_setopt(curl, CURLOPT_POST, 1); // post req curl_easy_setopt(curl, CURLOPT_URL, url.c_str()); // url curl_easy_setopt(curl, CURLOPT_POSTFIELDS, postParams.c_str()); // params curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, false); // if want to use https curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, false); // set peer and host verify false curl_easy_setopt(curl, CURLOPT_VERBOSE, 1); curl_easy_setopt(curl, CURLOPT_READFUNCTION, NULL); curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, req_reply); curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&response); curl_easy_setopt(curl, CURLOPT_NOSIGNAL, 1); curl_easy_setopt(curl, CURLOPT_HEADER, 1); curl_easy_setopt(curl, CURLOPT_CONNECTTIMEOUT, 3); curl_easy_setopt(curl, CURLOPT_TIMEOUT, 3); // start req res = curl_easy_perform(curl); } // release curl curl_easy_cleanup(curl); return res; } int main() { // global init curl_global_init(CURL_GLOBAL_ALL); // test get requery string getUrlStr = "http://cn.bing.com/images/trending?form=Z9LH"; string getResponseStr; auto res = curl_get_req(getUrlStr, getResponseStr); if (res != CURLE_OK) cerr << "curl_easy_perform() failed: " + string(curl_easy_strerror(res)) << endl; else cout << getResponseStr << endl; // test post requery string postUrlStr = "https://www.baidu.com/s"; string postParams = "f=8&rsv_bp=1&rsv_idx=1&word=picture&tn=98633779_hao_pg"; string postResponseStr; auto res = curl_post_req(postUrlStr, postParams, postResponseStr); if (res != CURLE_OK) cerr << "curl_easy_perform() failed: " + string(curl_easy_strerror(res)) << endl; else cout << postResponseStr << endl; // global release curl_global_cleanup(); system("pause"); return 0; }
get和post可以用于请求html信息，也可以请求xml和json等串可以添加自定义的header 域和cookies这是libcurl的简单接口，基本等同于阻塞试请求，libcurl有高阶的异步并发接口，运用更复杂
