Write debug output to console window

Environment: any MSVC

It's very common that we have to test our program on another machine where the Visual C++ IDE is not installed. So there will be no debug window for output. Logging into a file or keep popping up MessageBoxs are not very practical ways. An easy solution is to show the output strings in a console window.

Put the following code at the beginning of your app file or in a separate file.


#ifdef _DEBUG
    FILE* __fStdOut = NULL;
    HANDLE __hStdOut = NULL;
#endif

// width and height is the size of console window, if you specify fname, 
// the output will also be writton to this file. The file pointer is automatically closed 
// when you close the app
void startConsoleWin(int width=80, int height=25, char* fname = NULL);

void startConsoleWin(int width, int height, char* fname)
{
#ifdef _DEBUG
	AllocConsole();
	SetConsoleTitle("Debug Window");
	__hStdOut = GetStdHandle(STD_OUTPUT_HANDLE);

	COORD co = {width,height};
	SetConsoleScreenBufferSize(__hStdOut, co);

	if(fname)
		__fStdOut = fopen(fname, "w");
#endif
}

// Use wprintf like TRACE0, TRACE1, ... (The arguments are the same as printf)
int wprintf(char *fmt, ...)
{
#ifdef _DEBUG
	char s[300];
	va_list argptr;
	int cnt;

	va_start(argptr, fmt);
	cnt = vsprintf(s, fmt, argptr);
	va_end(argptr);

	DWORD cCharsWritten;

	if(__hStdOut)
		WriteConsole(__hStdOut, s, strlen(s), &cCharsWritten, NULL);

	if(__fStdOut)
		fprintf(__fStdOut, s);

	return(cnt);
#else
	return 0;
#endif
}

In CWinApp::InitInstance() call startConsoleWin() and a console window will popup. Then use wprintf at places where you used to use TRACE. The output strings will then appear in the console window.



Comments

  • There are no comments yet. Be the first to comment!

Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • Live Event Date: May 11, 2015 @ 1:00 p.m. ET / 10:00 a.m. PT One of the languages that have always been supported with the Intel® RealSense™ SDK (Software Developer Kit) is JavaScript, specifically so that web-enabled apps could be created. Come hear from Intel Expert Bob Duffy as he reviews his own little "space shooting" game where the orientation of your face controls the aiming reticle to help teach developers how to write apps and games in JavaScript that can use facial and gesture …

  • Live Event Date: May 6, 2015 @ 1:00 p.m. ET / 10:00 a.m. PT Where are you in your plans to adopt Disaster Recovery-as-a-Service? Are you just getting started? Fighting an uphill battle with management? At Cisco, Zerto and iland, we've seen it all – from the early adopters who excitedly rushed to implement DRaaS with us nine years ago to the IT folks dragging their business leaders into the future. With our years of experience, we've learned there are six types of DRaaS leaders – but which type …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date