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Koos van der Merwe · Guest

Hi

I'm debugging somebody else's code and want to add simple debug messages at certain points in the program to get a better idea of the program flow. I would like to know if it is possible to use <iostream.h>'s cout << (and cin >>) for debugging purposes on a console while the main (graphical) program is running in the forground. (This could be very usefull when using Kylix e.g.)

I would prefer to not have messageboxes popping up. Or a "debug" form that disappears when the application shuts down. Anybody with experience of a similar problem?

Thanks
Koos

Michel Leunen · Guest

Koos van der Merwe wrote:

Richard Ulrich · Guest

I had the same proble a while ago.
I found some code that should do exactly that. It showed a console
window, but cout was not redirected as the comments indicated.

Meanwhile I changed my code to use a function instead of cout to write
to the debug window.

Richard

Here's the code I'm using:

#ifndef DebugConsoleH
#define DebugConsoleH
//---------------------------------------------------------------------------
// Creates a debug console that lasts the duration of the DebugConsole
object
// lifetime, and syncs stdin/stdout/stderr and the C++ streams to print
there.
#include <windows.h>

class DebugConsole
{
public:
DebugConsole(unsigned short bufwid = 80, unsigned short bufheig
= 500);
~DebugConsole();
void LogMsg(char *msg);

private:
bool m_exists;
HANDLE stdouth;
};

#endif

#include "DebugConsole.h"
#include <iostream>
#include <fcntl.h>
#include <io.h>
#include <windows.h>
#include <assert.h>
//---------------------------------------------------------------------------
#pragma package(smart_init)
using namespace std;
typedef long intptr_t;
//---------------------------------------------------------------------------
DebugConsole::DebugConsole(unsigned short bufwid, unsigned short bufheig)
{
int ret, hConHandle;
intptr_t pStdHandle;
FILE* pFile;
char tmp[512];

m_exists = ::AllocConsole() != 0;
if(!m_exists)
{
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, GetLastError(),
0, tmp, sizeof(tmp)-1, NULL);
MessageBox(GetActiveWindow(), tmp, "Couldn't create debug
console!", MB_OK | MB_ICONERROR);
return;
}
stdouth = ::GetStdHandle(STD_OUTPUT_HANDLE);

//sync stdin, stdout, stderr fds up with the new console
//original source: http://www.halcyon.com/ast/dload/guicon.htm
//changes: removed all warnings by changing types and casting

// set the screen buffer to be big enough to let us scroll text

CONSOLE_SCREEN_BUFFER_INFO coninfo;
::GetConsoleScreenBufferInfo(stdouth, &coninfo);
coninfo.dwSize.X = bufwid;
coninfo.dwSize.Y = bufheig;
::SetConsoleScreenBufferSize(stdouth, coninfo.dwSize);

// redirect unbuffered STDOUT to the console
pStdHandle = reinterpret_cast<intptr_t>(stdouth);
SetConsoleMode(stdout,ENABLE_PROCESSED_OUTPUT |
ENABLE_WRAP_AT_EOL_OUTPUT);
hConHandle = _open_osfhandle(pStdHandle, O_TEXT);
pFile = _fdopen(hConHandle, "w");
*stdout = *pFile;
ret = setvbuf(stdout, NULL, _IONBF, 0);
if(ret)
{
FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM, NULL, GetLastError(),
0, tmp, sizeof(tmp)-1, NULL);
// MessageBox(GetActiveWindow(), tmp, "Could not set up debug
console window.", MB_OK | MB_ICONERROR);
}

/* not using stdin and stder for the time being
// redirect unbuffered STDIN to the console
pStdHandle = reinterpret_cast<intptr_t>(::GetStdHandle(STD_INPUT_HANDLE));
hConHandle = _open_osfhandle(pStdHandle, _O_TEXT);
pFile = _fdopen(hConHandle, "r");
*stdin = *pFile;
ret = setvbuf(stdin, NULL, _IONBF, 0);

// redirect unbuffered STDERR to the console
pStdHandle = reinterpret_cast<intptr_t>(::GetStdHandle(STD_ERROR_HANDLE));
hConHandle = _open_osfhandle(pStdHandle, _O_TEXT);
pFile = _fdopen(hConHandle, "w");
*stderr = *pFile;
ret = setvbuf(stderr, NULL, _IONBF, 0);
*/

// make cout, wcout, cin, wcin, wcerr, cerr, wclog and clog
// point to console as well
ios::sync_with_stdio(true);
ret = ret;
}
//---------------------------------------------------------------------------
DebugConsole::~DebugConsole()
{
if(m_exists)
{
::FreeConsole();
m_exists = false;
}
}
//---------------------------------------------------------------------------
void DebugConsole::LogMsg(char *msg)
{
DWORD byteswrritten;

WriteFile(stdouth, msg, strlen(msg), &byteswrritten, NULL);

if(strlen(msg) != byteswrritten)
MessageBeep(-1);
}
//---------------------------------------------------------------------------
//---------------------------------------------------------------------------

Sam S. Firouz · Guest

check out OutputDebugString and EventLog window of Builder IDE

Sam

"Koos van der Merwe" <kosie (AT) operamail (DOT) com> wrote

evil · Guest

On 7 Mar 2005 06:23:24 -0800, Koos van der Merwe <kosie (AT) operamail (DOT) com> revealed: