c++ http post

To perform an HTTP POST request in C++, you can use the cURL library. Here's an example of how you can make an HTTP POST request using cURL in C++:

#include <iostream>
#include <string>
#include <curl/curl.h>
// Callback function to write response data into a string
size_t WriteCallback(void* contents, size_t size, size_t nmemb, std::string* response) {
    size_t totalSize = size * nmemb;
    response->append((char*)contents, totalSize);
    return totalSize;
}
int main() {
    CURL* curl;
    CURLcode res;
    std::string url = "https://example.com/api/endpoint";
    std::string postData = "param1=value1¶m2=value2"; // POST data
    
    curl_global_init(CURL_GLOBAL_DEFAULT);
    curl = curl_easy_init();
    
    if (curl) {
        // Set the URL
        curl_easy_setopt(curl, CURLOPT_URL, url.c_str());
        
        // Set the POST data
        curl_easy_setopt(curl, CURLOPT_POSTFIELDS, postData.c_str());
        
        // Set the callback function to write the response data into a string
        std::string response;
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response);
        
        // Perform the request
        res = curl_easy_perform(curl);
        
        // Check for errors
        if (res != CURLE_OK) {
            std::cerr << "curl_easy_perform() failed: " << curl_easy_strerror(res) << std::endl;
        }
        else {
            // Print the response
            std::cout << "Response: " << response << std::endl;
        }
        
        // Clean up
        curl_easy_cleanup(curl);
    }
    
    curl_global_cleanup();
    
    return 0;
}

In this example, we use the curl_easy_setopt() function to set various options for the cURL request. We set the URL with CURLOPT_URL, the POST data with CURLOPT_POSTFIELDS, and the callback function to handle the response with CURLOPT_WRITEFUNCTION and CURLOPT_WRITEDATA. Finally, we perform the request with curl_easy_perform() and handle any errors that occur.

Make sure to link against the cURL library by adding -lcurl to your compiler flags when compiling the code.