GetIP.cpp

// Find the IP address we're on, given a configured interface
const string interface = "enx847beb51d7b4";

ifaddrs* adresses { };
getifaddrs(&adresses);

while (adresses->ifa_name != interface)
{
    if (adresses->ifa_next == nullptr)
    {
        return -3;
    }

    adresses = adresses->ifa_next;
}

string address;
// Grab the address
if (adresses->ifa_addr->sa_family == AF_INET)
{
    auto addressPtr = &((sockaddr_in*)adresses->ifa_addr)->sin_addr;
    auto nameBuffer = make_unique<char[]>(INET_ADDRSTRLEN);
    inet_ntop(AF_INET, addressPtr, nameBuffer.get(), INET_ADDRSTRLEN);

    address = string(nameBuffer.get());
}
else if (adresses->ifa_addr->sa_family == AF_INET6)
{
    auto addressPtr = &((sockaddr_in6*)adresses->ifa_addr)->sin6_addr;
    auto nameBuffer = make_unique<char[]>(INET6_ADDRSTRLEN);
    inet_ntop(AF_INET6, addressPtr, nameBuffer.get(), INET6_ADDRSTRLEN);

    address = string(nameBuffer.get());
}