static int
IsJoystick(int fd, char *namebuf, const size_t namebuflen, SDL_JoystickGUID *guid)
{
    struct input_id inpid;
    Uint16 *guid16 = (Uint16 *) ((char *) &guid->data);

#if !SDL_USE_LIBUDEV
    /* When udev is enabled we only get joystick devices here, so there's no need to test them */
    unsigned long evbit[NBITS(EV_MAX)] = { 0 };
    unsigned long keybit[NBITS(KEY_MAX)] = { 0 };
    unsigned long absbit[NBITS(ABS_MAX)] = { 0 };

    if ((ioctl(fd, EVIOCGBIT(0, sizeof(evbit)), evbit) < 0) ||
        (ioctl(fd, EVIOCGBIT(EV_KEY, sizeof(keybit)), keybit) < 0) ||
        (ioctl(fd, EVIOCGBIT(EV_ABS, sizeof(absbit)), absbit) < 0)) {
        return (0);
    }

    if (!(test_bit(EV_KEY, evbit) && test_bit(EV_ABS, evbit) &&
          test_bit(ABS_X, absbit) && test_bit(ABS_Y, absbit))) {
        return 0;
    }
#endif

    if (ioctl(fd, EVIOCGNAME(namebuflen), namebuf) < 0) {
        return 0;
    }

    if (ioctl(fd, EVIOCGID, &inpid) < 0) {
        return 0;
    }

#ifdef DEBUG_JOYSTICK
    printf("Joystick: %s, bustype = %d, vendor = 0x%x, product = 0x%x, version = %d\n", namebuf, inpid.bustype, inpid.vendor, inpid.product, inpid.version);
#endif

    SDL_memset(guid->data, 0, sizeof(guid->data));

    /* We only need 16 bits for each of these; space them out to fill 128. */
    /* Byteswap so devices get same GUID on little/big endian platforms. */
    *(guid16++) = SDL_SwapLE16(inpid.bustype);
    *(guid16++) = 0;

    if (inpid.vendor && inpid.product && inpid.version) {
        *(guid16++) = SDL_SwapLE16(inpid.vendor);
        *(guid16++) = 0;
        *(guid16++) = SDL_SwapLE16(inpid.product);
        *(guid16++) = 0;
        *(guid16++) = SDL_SwapLE16(inpid.version);
        *(guid16++) = 0;
    } else {
        SDL_strlcpy((char*)guid16, namebuf, sizeof(guid->data) - 4);
    }

    return 1;
}