An existing console printing *something* for windowed applications

win32_console_out.cpp

// To output stderr/stdout to an existing console for windowed applications. It works.
// Sometimes. Even with UTF-8 and terminal colors, if you are lucky.

void conout_initialize()
{
    if (!IsDebuggerPresent()) {

        // Win32 console output is awful! This tries to rewire stdout so that we
        // get to see *something* in the CMD prompt.

        if (AttachConsole(ATTACH_PARENT_PROCESS) != 0) {

            FILE * stdout_redirect;
            freopen_s(&stdout_redirect, "CONOUT$", "w", stdout);

            FILE * stderr_redirect;
            freopen_s(&stderr_redirect, "CONOUT$", "w", stderr);

            HANDLE con_out = CreateFile(
                TEXT("CONOUT$"),
                GENERIC_READ | GENERIC_WRITE,
                FILE_SHARE_READ | FILE_SHARE_WRITE,
                nullptr,
                OPEN_EXISTING,
                FILE_ATTRIBUTE_NORMAL,
                nullptr
            );

            SetStdHandle(STD_OUTPUT_HANDLE, con_out);

            SetConsoleOutputCP(CP_UTF8);

            // clears current line, moves cursor to the left

            fprintf(stdout, "\x1b[2K\r");
        }
    }
}

void conout_shutdown()
{
    fprintf(stdout, "\x1b[2K\r\x1b[32m[Bye!]\x1b[0m\r\n");
    fflush(stdout);

    if (HWND console = GetConsoleWindow()) {
        // sends a final return key event to close the console window
        SendMessage(console, WM_CHAR, VK_RETURN, 0);
        FreeConsole();
    }
}