libcurl example

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

// This function basically deals with the buffers of data returned when we make a HTTP GET request.
size_t writefunc(char* data, size_t charsize, const size_t buffsize, std::string *ret)
{
    const size_t realsize = charsize * buffsize;

    // Convert data into a C string
    char* cstr = new char[realsize+1];
    for(size_t i = 0; i < realsize; ++i)
        cstr[i] = data[i];
    cstr[realsize] = '\0';

    // Create the return value
    *ret += cstr;

    // We have to return this or else curl will throw an error.
    return realsize;
}

int main()
{
    std::string ret; // Our return value to the GET request, basically the HTTP page.

    CURL *curl; // This will be our curl request.

    // Initialise curl.
    curl = curl_easy_init();
    if(!curl)
    {
        std::cerr << "Error initialising curl!" << std::endl;
        return 1;
    }

    // Curl options.
    curl_easy_setopt(curl, CURLOPT_URL, "http://example.com");
    curl_easy_setopt(curl, CURLOPT_FOLLOWLOCATION, true);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, writefunc); // The function we use to deal with the stream of data.
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &ret); // Arguments passed onto the write function.

    // Execute it.
    curl_easy_perform(curl);

    // Show the web page in text.
    std::cout << ret << std::endl;

    // Clean up.
    curl_easy_cleanup(curl);
    return 0;
}