How to Open Console Window in a Win32 Application

When you create a basic main()-based application, you get the console window implicitly; but a typical WinMain()-based application does not open a console window – you have to allocate the console and to connect the I/O streams yourself.

Yet, this is not a thing you find described in manuals. Fortunately, it’s simple to do, and the code presented here can be used as-is in all your projects.

#include <stdio.h>
#include <io.h>
#include <fcntl.h>
#include <windows.h>

int APIENTRY WinMain(HINSTANCE hInstance,
                     HINSTANCE hPrevInstance,
                     LPSTR     lpCmdLine,
                     int       nCmdShow)
{
    AllocConsole();

    HANDLE handle_out = GetStdHandle(STD_OUTPUT_HANDLE);
    int hCrt = _open_osfhandle((long) handle_out, _O_TEXT);
    FILE* hf_out = _fdopen(hCrt, "w");
    setvbuf(hf_out, NULL, _IONBF, 1);
    *stdout = *hf_out;

    HANDLE handle_in = GetStdHandle(STD_INPUT_HANDLE);
    hCrt = _open_osfhandle((long) handle_in, _O_TEXT);
    FILE* hf_in = _fdopen(hCrt, "r");
    setvbuf(hf_in, NULL, _IONBF, 128);
    *stdin = *hf_in;

    // use the console just like a normal one - printf(), getchar(), ...
}

35 responses to “How to Open Console Window in a Win32 Application

  1. Oh I know this is a bit of a noob question. Is there anything I need to get rid of or delete from that code that may cause memory leaks?

  2. Thanks, it is great.
    But when I run the program in a console, I get an error. Can I avoid that ?
    cheers

  3. Great! That really helped me. I was searching for a way to make a Qt Application close the console on exit.

  4. I want to show some thanks to you just for rescuing me from this crisis. Just after checking throughout the world-wide-web and seeing basics that were not productive, I was thinking my entire life was well over. Living without the presence of answers to the problems you have resolved by way of your good site is a critical case, as well as those that might have in a negative way damaged my career if I hadn’t discovered your web page. Your own competence and kindness in playing with the whole thing was tremendous. I am not sure what I would’ve done if I had not come upon such a solution like this. It’s possible to at this moment look forward to my future. Thanks a lot very much for this high quality and amazing guide. I won’t be reluctant to suggest your web page to anyone who would like guide on this situation.

  5. Great post! Though, I see one problem: no code to free resources you aquired. File handles and console must be explicitly freed. Still, I’m googling how to do this properly)

  6. Hi, thanks for this. Would it be possible to cite some of the evidence based research you quoted as this would be really helpful and powerful 3 week diet.

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