Code snippet

One note to my self, this is piece of code which I was using for starting application from command prompt and getting an information, was that succesfull or not.

function CaptureConsoleOutput(DosApp : string; var strLog : String): Boolean;
const
  ReadBuffer = 1048576;  // 1 MB Buffer
var
  Security: TSecurityAttributes;
  ReadPipe,WritePipe: THandle;
  start: TStartUpInfo;
  ProcessInfo: TProcessInformation;
  Buffer: Pchar;
  TotalBytesRead,
  BytesRead: DWORD;
  Apprunning,n,
  BytesLeftThisMessage,
  TotalBytesAvail : integer;
  xCode: Cardinal;
  bolOk: Boolean;
begin
  bolOk := False;

  with Security do
  begin
    nlength := SizeOf(TSecurityAttributes);
    binherithandle := true;
    lpsecuritydescriptor := nil;
  end;

  if CreatePipe (ReadPipe, WritePipe, @Security, 0) then
  begin
  // Redirect In- and Output through STARTUPINFO structure

  Buffer := AllocMem(ReadBuffer + 1);
  FillChar(Start,Sizeof(Start),#0);
  start.cb := SizeOf(start);
  start.hStdOutput := WritePipe;
  start.hStdInput := ReadPipe;
  start.dwFlags := STARTF_USESTDHANDLES + STARTF_USESHOWWINDOW;
  start.wShowWindow := SW_HIDE;
  start.hStdError := WritePipe;

  // Create a Console Child Process with redirected input and output

  if CreateProcess(nil, PChar(DosApp),
  @Security,@Security,
true, CREATE_NO_WINDOW or NORMAL_PRIORITY_CLASS,
nil, nil,
  start, ProcessInfo) then
  begin
  n:=0;
  TotalBytesRead:=0;
  repeat
  // Increase counter to prevent an endless loop if the process is dead
  Inc(n,1);

  // wait for end of child process
  Apprunning := WaitForSingleObject(ProcessInfo.hProcess,100);
  Application.ProcessMessages;

  // it is important to read from time to time the output information
  // so that the pipe is not blocked by an overflow. New information
  // can be written from the console app to the pipe only if there is
  // enough buffer space.

  if not PeekNamedPipe(ReadPipe  ,@Buffer[TotalBytesRead],
  ReadBuffer, @BytesRead,
 @TotalBytesAvail,@BytesLeftThisMessage) then break
  else if BytesRead > 0 then
  ReadFile(ReadPipe,Buffer[TotalBytesRead],BytesRead,BytesRead,nil);
  TotalBytesRead:=TotalBytesRead+BytesRead;
  until (Apprunning <> WAIT_TIMEOUT) or (n > 150);
  GetExitCodeProcess(ProcessInfo.hProcess,xCode);
  if xCode=0 then
  bolOk := True
  else
  bolOk := False;

  Buffer[TotalBytesRead]:= #0;
  OemToChar(Buffer,Buffer);
  strLog := strLog + StrPas(Buffer);
  end;
  FreeMem(Buffer);

  CloseHandle(ProcessInfo.hProcess);
  CloseHandle(ProcessInfo.hThread);
  CloseHandle(ReadPipe);
  CloseHandle(WritePipe);
  Result := bolOk;
  end;
end;