// Copyright (c) 2020 by Chrono

//

// sudo apt-get remove libcurl4

// sudo apt-get install libcurl4-openssl-dev

//

// curl-config --libs

// curl-config --version

// curl-config --features

// curl-config --protocols

//

// g++ curl.cpp -std=c++11 -lcurl -o a.out;./a.out

// g++ curl.cpp -std=c++14 -lcurl -o a.out;./a.out

#include <cassert>

#include <iostream>

#include <curl/curl.h>

using namespace std;

// in curl.h

size_t write_callback(char* ptr, size_t size, size_t nmemb, void* userdata);

void case1()

{

auto curl = curl_easy_init();

assert(curl);

curl_easy_setopt(curl, CURLOPT_URL, "http://nginx.org");

auto res = curl_easy_perform(curl);

if (res != CURLE_OK) {

cout << curl_easy_strerror(res) << endl;

}

curl_easy_cleanup(curl);

}

void case2()

{

//using curl_t = CURL;

auto curl = curl_easy_init();

if (!curl) {

cout << "curl init error" << endl;

return;

}

curl_easy_setopt(curl, CURLOPT_URL, "http://nginx.org");

//curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);

#if 0

decltype(&write_callback) f =

[](char *ptr, size_t size, size_t nmemb, void *userdata)

{

cout << "size = " << size * nmemb << endl;

return size * nmemb;

};

curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, f);

#endif

curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION,

(decltype(&write_callback))

[](char *ptr, size_t size, size_t nmemb, void *userdata)

{

cout << "size = " << size * nmemb << endl;

return size * nmemb;

}

);

auto res = curl_easy_perform(curl);

if (res != CURLE_OK) {

cout << curl_easy_strerror(res) << endl;

}

curl_easy_cleanup(curl);

}

int main()

{

curl_global_init(CURL_GLOBAL_SSL);

//case1();

case2();

cout << curl_version() << endl;

cout << "libcurl demo" << endl;

curl_global_cleanup();

}