Console within GUI

[Gerome]

Hello,

The following mentionned code within the PellesC CHM help seems to work but getchar() seems not to work if i compile this code into a Windows project...
Does anyone has an idea please ?

Code Select Expand


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

void RedirectStdOut(void);

int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpszCmdLine, int nCmdShow )
{
RedirectStdOut();
  printf( "zz" );
  getchar(); // WHY this does not work ?
  return 0;
}

void RedirectStdOut(void)
{
   CONSOLE_SCREEN_BUFFER_INFO csbi;

   // Try creating a new console window.
   if (!AllocConsole()) return;

   // Set the screen buffer to be larger than normal.
   if (GetConsoleScreenBufferInfo(GetStdHandle(STD_OUTPUT_HANDLE), &csbi))
   {
       csbi.dwSize.Y = 1000; // any useful number...
       SetConsoleScreenBufferSize(GetStdHandle(STD_OUTPUT_HANDLE), csbi.dwSize);
   }

   // Redirect "stdout" to the console window.
   fclose(stdout);
   setbuf(stdout, NULL);

  FILE *fp = fdopen(_open_osfhandle((long)GetStdHandle(STD_OUTPUT_HANDLE), 0), "w");
   *stdout = *fp;
}


Thanks for anyhelp

[Greg]

I believe it's because stdout has been redirected to the new console, but stdin hasn't. getchar is returning EOF and, if you call it, ferror(stdin) is returning true.

INFO: Calling CRT Output Routines from a GUI Application

Later:

 For some reason, _getch works OK. So I'm not sure about it now.

 The same thing happens in Visual C/C++ 2003.

[frankie]

Gerome,
you can find an example of redirection for stdin, stdout and stderr in my code at http://smorgasbordet.com/phpBB2/viewtopic.php?t=726 in the cgi redirection handling. It works well becouse is directly derived from M$ example code (I included full M$ comments).

[Gerome]

Hi,

Thanks for your help
Here is my functional code this time with getchar() working

Code Select Expand


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

void RedirectStd(void);

int WINAPI WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpszCmdLine, int nCmdShow )
{
RedirectStd();
printf( "\nType any key to continue...\n" );
getchar();
return 0;
}

void RedirectStd(void)
{
int hCrt = -1;
FILE *hf = NULL;
int i    = -1;

AllocConsole();

hCrt = _open_osfhandle((long)GetStdHandle(STD_OUTPUT_HANDLE), _O_TEXT);
hf = _fdopen(hCrt, "w");
*stdout = *hf;
i = setvbuf(stdout, NULL, _IONBF, 0);
printf( "stdout//" );

hCrt = _open_osfhandle((long)GetStdHandle(STD_INPUT_HANDLE), _O_TEXT);
hf = _fdopen(hCrt, "r");
*stdin = *hf;
i = setvbuf(stdin, NULL, _IONBF, 0);
printf( "stdin//" );

hCrt = _open_osfhandle((long)GetStdHandle(STD_ERROR_HANDLE), _O_TEXT);
hf = _fdopen(hCrt, "w");
*stderr = *hf;
i = setvbuf(stderr, NULL, _IONBF, 0);
printf( "stderr//" );
}


[Greg]

Thanks for posting the working example. I tried to do the same thing but I couldn't get stdin to work. I was opening stdin for write intead of read. :roll: