C++ CharDev

void test_devchar()
{
    error_t er;
    OPtr<OPseudoFile> file; // do not garbage collect - such would delete the file

    if (ERROR(er = CreateTempKernFile(file)))
    {
        printf("couldn't create file %lli\n", er);
        return;
    }

    file->OnUserWrite([](OPtr<OPseudoFile> file, const void * buffer, size_t length, size_t off, size_t *bytesRead)
    {
        uint64_t len;
        const char * path;
        char msg[100];

        len = MIN(length, sizeof(msg) - 1);

        memset(msg, 0, 100);
        memcpy(msg, buffer, len);

        if (msg[len - 1] == '\n')
            msg[len - 1] = 0;

        if (ERROR(file->GetPath(&path)))
            path = "NULL";

        LogPrint(kLogInfo, "User said: %s to device %s\n", msg, path);

        *bytesRead = length;
        return true;
    });

    file->OnUserRead([](OPtr<OPseudoFile> file, void * buffer, size_t length, size_t off, size_t *bytesRead)
    {
        const char * msg;
        size_t mlen;

        msg = "Hello usermode component";
        mlen = MIN(length, 25 - 1 - off);

        memcpy(buffer, &msg[off], mlen);

        *bytesRead = mlen;
        return true;
    });
}