Mega Code Archive
How do I know if my program is running in a debugger
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Title: How do I know if my program is running in a debugger
Question: If your program is being run in a debugger, and you want to see ShowMessage etc messages or you don't want it debugged, use this code.
Answer:
I came across this on a non Delphi site where it was written by a Mr Tim Chew and I give him full credit for it. It was too good not to copy into Delphi.
The original C/C++ code and article can be found on CodeProject at http://www.rntsoft.com/useritems/debugger.asp#xx72109xx
I have converted it to Delphi and tested it under Win 2000 Pro and it appears to work. Running in the Delphi IDE it reveals it is being debugged.
Just add a button to a form, create the event handler for the button and add this code below.
function IsDebuggerAttached: boolean;
var dw: integer;
begin
asm
push eax // Preserve the registers
push ecx
mov eax, fs:[$18] // Get the TIB's linear address
mov eax, dword ptr [eax + $30]
mov ecx, dword ptr [eax] // Get the whole DWORD
mov [dw], ecx // Save it
pop ecx // Restore the registers
pop eax
end;
// The 3rd byte is the byte we really need to check for the
// presence of a debugger. // Check the 3rd byte
result := (dw and $00010000 ) 0;
end;
procedure TForm1.Button1Click(Sender: TObject);
begin
if IsDebuggerAttached then
ShowMessage('Debugger')
else
ShowMessage('No Debugger');
end;
I haven't tested it on Windows 95/98. Anyone care to try it.
If you run it by double clicking you shoudl see 'No Debugger'. Inside the IDE or another debugger and you should see 'Debugger'.
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