c++操作ip地址

    string ip = "192.168.0.1";
    int i = ip.find_last_of(".");
    string sub = ip.substr(i+1, sizeof(ip) - i);
    cout << sub<<endl;

    //string to int
    int tmp = strtol(sub.c_str(), NULL,10)+250;
    cout << tmp<< endl;

    //int to string
    sub = to_string(tmp);
    //cout << typeid(sub).name() << endl;
    cout << sub << endl;
    ip = ip.replace(i+1, sizeof(ip) - i, sub);
    cout << ip << endl;