gistfile1.txt

// Maybe https://stackoverflow.com/questions/67274905/c-c-resolving-docker-compose-services-to-same-ip can help
// https://man7.org/linux/man-pages/man3/getaddrinfo.3.html
template <class F>
bool getaddr(const char* host, const char* service, F&& f)
{
    addrinfo hints{};
    addrinfo* result;

    //hints.ai_family = AF_UNSPEC;    /* Allow IPv4 or IPv6 */
    hints.ai_family = PF_INET;    /* Allow IPv4 or IPv6 */
    hints.ai_socktype = SOCK_DGRAM; /* Datagram socket */
    hints.ai_flags = AI_PASSIVE;    /* For wildcard IP address */
    hints.ai_protocol = 0;          /* Any protocol */
    hints.ai_canonname = NULL;
    hints.ai_addr = NULL;
    hints.ai_next = NULL;

    int ret = getaddrinfo(host, service, &hints, &result);

    if(ret != 0)
    {
        std::cerr << gai_strerror(ret) << std::endl;
        return false;
        //exit(-1);
    }

    for(const addrinfo* i = result; i != nullptr; i = i->ai_next)
    {
        f(*i);
    }

    freeaddrinfo(result);

    return true;
}