Function is_ip_address

dlib/sockets/sockets_extensions.cpp:261–288

// ----------------------------------------------------------------------------------------

    bool is_ip_address (
        std::string ip
    )
    {
        for (std::string::size_type i = 0; i < ip.size(); ++i)
        {
            if (ip[i] == '.')
                ip[i] = ' ';
        }
        std::istringstream sin(ip);
        
        bool bad = false;
        int num;
        for (int i = 0; i < 4; ++i)
        {
            sin >> num;
            if (!sin || num < 0 || num > 255)
            {
                bad = true;
                break;
            }
        }

        if (sin.get() != EOF)
            bad = true;
        
        return !bad;
    }

// ----------------------------------------------------------------------------------------