Send SMS with ⚙️ C++

// 1 — PRIMARY — use this
https://www.isms.com.my/isms_send_all_id.php
// 2 — Mirror — backup only
https://smtpapi2.vocotext.com/isms_send_all_id.php
// 3 — Mirror — backup only
https://smtpapi.vocotext.com/isms_send_all_id.php
// 4 — Mirror — backup only
https://ww3.isms.com.my/isms_send_all_id.php

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

// Callback to capture response body
static size_t WriteCallback(void* ptr, size_t size, size_t nmemb, std::string* data) {
    data->append((char*)ptr, size * nmemb);
    return size * nmemb;
}

int main() {
    curl_global_init(CURL_GLOBAL_DEFAULT);
    CURL* curl = curl_easy_init();

    if (!curl) {
        std::cerr << "Failed to initialize libcurl" << std::endl;
        return 1;
    }

    std::string postFields =
        "un=your_username"
        "&pwd=your_password"
        "&dstno=601X-XXXXXXX"    // Full international format
        "&msg=Hello+from+iSMS%21" // URL-encode spaces and special chars
        "&type=1"               // 1 = ASCII, 2 = Unicode
        "&agreedterm=YES"
        "&sendid=MyBrand";      // Optional, max 11 chars

    std::string response;

    curl_easy_setopt(curl, CURLOPT_URL, "https://www.isms.com.my/isms_send_all_id.php");
    curl_easy_setopt(curl, CURLOPT_POST, 1L);
    curl_easy_setopt(curl, CURLOPT_POSTFIELDS, postFields.c_str());
    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 1L);   // Always verify SSL
    curl_easy_setopt(curl, CURLOPT_TIMEOUT, 30L);
    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteCallback);
    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &response);

    CURLcode res = curl_easy_perform(curl);

    if (res != CURLE_OK) {
        std::cerr << "curl error: " << curl_easy_strerror(res) << std::endl;
    } else if (response.rfind("2000", 0) == 0) {
        std::string trxId = response.substr(response.find(':') + 1);
        std::cout << "SMS sent! Transaction ID: " << trxId << std::endl;
    } else {
        std::cerr << "Failed: " << response << std::endl;
    }

    curl_easy_cleanup(curl);
    curl_global_cleanup();
    return 0;
}

// Compile: g++ send_sms.cpp -lcurl -o send_sms