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How do I keep SDL from outputting stdout to a file?

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Hmm, right now I dont have access to a compiler or I would test this:

in the SDL source code:


So maybe you can:


Then again, this may be something you have to do when you compile SDL.

I hope this helps.

p.s. in linux it is pretty easy if I remember correctly using close(stdout); and then opening it with 0 I think.

On windows I am not sure.

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Does this have anything to do with input/ and output?because in allegro you can't really do use allegro functions in a console window so thats probable the same thing with SDL not sure so don't flame if I'am wrong.

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Well I installed dev-cpp on this computer and the define didnt work :(

So I was thinking I would be clever..

FILE* oldStdout;
*oldStdout = *stdout; //causes the application to crash :(



*stdout = *oldStdout;

I thought for sure this would work... alas, I was wrong.

If you are using windows, microsoft claims:
STDOUT 1 Output to the Command Prompt window source

If you find an answer let me know :)

If I think of anything else I will give it a try.

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Guest Anonymous Poster
Look into your project option.

Try playing with the option in either General tab's or the Compiler\Linker.


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Original post by Drakkcon
Could someone tell me how to allow stdio to use the console window?

It's platform specific, so the following is Windows only.

  1. Create a new console window if your app is a "Win32 Application." AllocConsole is the API you want.

  2. Once you have your console, retrieve its standard input (or, possibly in the future, standard output) stream handle. You want GetStdHandle.

  3. You then want to get a C file descriptor corresponding to said handle. Windows provides the _open_osfhandle API for exactly this purpose.

  4. Now retrieve a FILE * for that file descriptor: call _fdopen.

  5. Finally, redirect the standard I/O stream pointer with code like the following:
    *stdin = *conin;
    *stdout = *conout;
    where conin and conout are the FILE *s that correspond to the input and output handles of your console, respectively.

  6. One extra step is to eliminate I/O buffering, so any data printed to stdout shows up immediately (if you want). Call setvbuf with the appropriate parameters.

You can save a lot of time by analyzing and copying the relevant bits of code from this excellent article.

Alternatively, if you're up to rebuilding SDL entirely, pass --disable-stdio-redirect as a compilation parameter.

Happy hacking.

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void ActivateConsole()

HANDLE newConsoleInput = GetStdHandle(STD_INPUT_HANDLE);
HANDLE newConsoleOutput = GetStdHandle(STD_OUTPUT_HANDLE);

int inFd = _open_osfhandle((long)newConsoleInput, _O_TEXT);
int outFd = _open_osfhandle((long)newConsoleOutput, _O_TEXT);

FILE* consoleIn = _fdopen(inFd, "r");
FILE* consoleOut = _fdopen(outFd, "w");

setvbuf(consoleIn, NULL, _IONBF, 0);
setvbuf(consoleOut, NULL, _IONBF, 0);

*stdin = *consoleIn;
*stdout = *consoleOut;

Here's my console activation function. The only problem is, I still don't get a console [sad]. What I'm probably doing wrong involves HANDLEs probably, since I don't know what a handle is a typedef of. when I use _open_osfhandle(newConsoleInput, _0_TEXT); I get an error: invalid conversion from `void*' to `long int'. I have tried casting it to many things.

Any ideas?

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