#include <curl/curl.h>
#include <iostream>
#include <string>
 
// Callback function to capture the response.
static size_t WriteCallback(void* contents, size_t size, size_t nmemb, void* userp)
{
    ((std::string*)userp)->append((char*)contents, size * nmemb);
    return size * nmemb;
}
 
int main() {
    CURL *curl;
    CURLcode res;
    std::string readBuffer;
 
    curl = curl_easy_init();
    if(curl) {
        const char* postData = "{\"text\": \"Hello, world!\"}";
 
        // Set URL for the POST request.
        curl_easy_setopt(curl, CURLOPT_URL, "http://localhost:5000/echo");
        curl_easy_setopt(curl, CURLOPT_POSTFIELDS, postData);
 
        struct curl_slist *headers = NULL;
        headers = curl_slist_append(headers, "Content-Type: application/json");
        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);
 
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &readBuffer);
 
        res = curl_easy_perform(curl);
        if(res != CURLE_OK) {
            std::cerr << "curl_easy_perform() failed: " << curl_easy_strerror(res) << "\n";
        } else {
            std::cout << "Response: " << readBuffer << "\n";
        }
        curl_easy_cleanup(curl);
        curl_slist_free_all(headers);
    }
    return 0;
}
 

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