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POhow to get access console buffer from another process? AttachConsole ERROR_INVALID_PARAMETER
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  1. POhow to get access console buffer from another process? AttachConsole ERROR_INVALID_PARAMETER
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    copied!<p>I want to get access to the buffer of another process console (via AttachConsole), for calling ReadConsoleOutput, etc.</p> <p>Is a DOS 16bit application. I can't use pipes because it doesn't writes output secuentially (it emulates "windows".. like FAR commander if you know what I mean).</p> <p>So I should:</p> <p>1) launch the app 2) get the process id 3) call AttachConsole(ProcId) 4) call GetConsoleScreenBufferInfo to get the size 5) call ReadConsoleOutput</p> <p>The problem is at 3: when I call AttachConsole ir returns 0, and after a call to GetLastError it reports ERROR_INVALID_PARAMETER 87 (0x57).</p> <p>The only parameter of AttachConsole is the ProcessId and I've checked it with ProcessExplorer that is right (it's actually the PID of ntvdm.exe that emulates the app).</p> <p>Delphi code:</p> <pre><code>function AttachConsole(dwProcessId: DWORD): Cardinal; external kernel32 name 'AttachConsole'; var Handle: HWND; function EnumWindowsProc(hwnd: HWND; lParam: LPARAM): BOOL; stdcall; var s: string; IsVisible, IsOwned, IsAppWindow: Boolean; begin Result := True;//carry on enumerating IsVisible := IsWindowVisible(hwnd); if not IsVisible then exit; IsOwned := GetWindow(hwnd, GW_OWNER)&lt;&gt;0; if IsOwned then exit; IsAppWindow := GetWindowLongPtr(hwnd, GWL_STYLE) and WS_EX_APPWINDOW&lt;&gt;0; if not IsAppWindow then exit; SetLength(s, GetWindowTextLength(hwnd)); GetWindowText(hwnd, PChar(s), Length(s)+1); if AnsiContainsText(s, '????.EXE') then // set windows name to search Handle := hwnd; end; procedure Test(Strings: TStrings); var ProcessID: Cardinal; begin Handle := 0; EnumWindows(@EnumWindowsProc, 0); Strings.Add('Handle: ' + IntToStr(Handle)); if Handle &lt;&gt; 0 then SetForegroundWindow(Handle); Sleep(100); GetWindowThreadProcessId(Handle, @ProcessID); Strings.Add('ProcessId: ' + IntToStr(ProcessID)); if AttachConsole(ProcessId) &lt;&gt; 0 then Strings.Add('Ok Attached') else Strings.Add('Error: ' + IntToStr(GetLastError)); end; </code></pre> <p>Drop memo and button in form. At OnClick call Test(Memo1.Lines).</p> <p>===== EDIT complete solution =====</p> <pre><code>function AttachAndGetConsoleHandle(ProcessId: Cardinal): Cardinal; begin if not AttachConsole(ProcessId) then raise Exception.Create('AttachConsole error: ' + IntToStr(GetLastError)); Result := GetStdHandle(STD_OUTPUT_HANDLE); if Result = INVALID_HANDLE_VALUE then raise Exception.Create('GetStdHandle(STD_OUTPUT_HANDLE) error: ' + IntToStr(GetLastError)); end; procedure DettachConsole; begin if not FreeConsole then raise Exception.Create('FreeConsole error: ' + IntToStr(GetLastError)); end; function ReadConsole(ConsoleHandle: Cardinal): TStringList; var BufferInfo: _CONSOLE_SCREEN_BUFFER_INFO; BufferSize, BufferCoord: _COORD; ReadRegion: _SMALL_RECT; Buffer: Array of _CHAR_INFO; I, J: Integer; Line: AnsiString; begin Result := TStringList.Create; ZeroMemory(@BufferInfo, SizeOf(BufferInfo)); if not GetConsoleScreenBufferInfo(ConsoleHandle, BufferInfo) then raise Exception.Create('GetConsoleScreenBufferInfo error: ' + IntToStr(GetLastError)); SetLength(Buffer, BufferInfo.dwSize.X * BufferInfo.dwSize.Y); BufferSize.X := BufferInfo.dwSize.X; BufferSize.Y := BufferInfo.dwSize.Y; BufferCoord.X := 0; BufferCoord.Y := 0; ReadRegion.Left := 0; ReadRegion.Top := 0; ReadRegion.Right := BufferInfo.dwSize.X; ReadRegion.Bottom := BufferInfo.dwSize.Y; if ReadConsoleOutput(ConsoleHandle, Pointer(Buffer), BufferSize, BufferCoord, ReadRegion) then begin for I := 0 to BufferInfo.dwSize.Y - 1 do begin Line := ''; for J := 0 to BufferInfo.dwSize.X - 1 do Line := Line + Buffer[I * BufferInfo.dwSize.X + J].AsciiChar; Result.Add(Line) end end else raise Exception.Create('ReadConsoleOutput error: ' + IntToStr(GetLastError)); end; </code></pre>
 

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