Using STDIN with an AllocConsole()

Question

I have a third-party dll that I load into software that isn't mine, and I'm using AllocConsole() to create the standard windows CLI window so I have an easy means of outputting debug messages.

My problem is though, is that it ignores any kind of input. I just want to be able to use the console I allocated and enable the ability for me to give it some input.

Answer 1

Thanks to Ben Voigt, I was able to cause the console to take input after I allocated it by doing:

freopen("CONIN$", "r", stdin); 
freopen("CONOUT$", "w", stdout); 
freopen("CONOUT$", "w", stderr); 

This also directs the stdout and strerr to the same console window, in case they are directed someplace else for some reason.

Answer 2

Do you also redirect the stdoutand stderrto your console?

I used this code to get access to the JavaVM output from a Windows app.

if(::AllocConsole())
    {
        int hCrt = ::_open_osfhandle((intptr_t) ::GetStdHandle(STD_OUTPUT_HANDLE), _O_TEXT);
        FILE *hf = ::_fdopen( hCrt, "w" );
        *stdout = *hf;
        ::setvbuf(stdout, NULL, _IONBF, 0 );

        hCrt = ::_open_osfhandle((intptr_t) ::GetStdHandle(STD_ERROR_HANDLE), _O_TEXT);
        hf = ::_fdopen( hCrt, "w" );
        *stderr = *hf;
        ::setvbuf(stderr, NULL, _IONBF, 0 );
    }

After this I can see all stdoutand stderr outputs from the VM.

Answer 3

This is the code that works for me:

freopen("CONOUT$", "w", stdout);

You can probably do something similar with CONIN$ and stdin (Open for read, of course).

Answer 4

This is what I use.

    FILE *file = nullptr;
freopen_s(&file,"CONIN$", "r", stdin);
freopen_s(&file, "CONOUT$", "w", stdout);

Just hopes this helps someone.