Считать результат с командной строки

function RunConsoleCmd(const Cmd: string;
  WorkDir: string = 'c:\'): string;
var
  SA: TSecurityAttributes;
  SI: TStartupInfo;
  PI: TProcessInformation;
  StdOutPipeRead, StdOutPipeWrite: THandle;
  WasOK: Boolean;
  Buffer: array [0 .. 255] of Char;
  BytesRead: Cardinal;
  Line: string;
  FCmd: WideString;
begin
  with SA do
  begin
    nLength := SizeOf(SA);
    bInheritHandle := True;
    lpSecurityDescriptor := nil;
  end;
  CreatePipe(StdOutPipeRead, StdOutPipeWrite, @SA, 0);
  try
    with SI do
    begin
      FillChar(SI, SizeOf(SI), 0);
      cb := SizeOf(SI);
      dwFlags := STARTF_USESHOWWINDOW or STARTF_USESTDHANDLES;
      wShowWindow := SW_HIDE;
      hStdInput := GetStdHandle(STD_INPUT_HANDLE);
      hStdOutput := StdOutPipeWrite;
      hStdError := StdOutPipeWrite;
    end;
    FCmd := Cmd;
    UniqueString(FCmd);
    WasOK := CreateProcess(nil, PChar(FCmd), nil, nil, True, 0, nil,
      PChar(WorkDir), SI, PI);
    CloseHandle(StdOutPipeWrite);
    Win32Check(WasOK);
    try
      Line := '';
      repeat
        WasOK := ReadFile(StdOutPipeRead, Buffer, 255, BytesRead, nil); //Здесь программа зависает
        if BytesRead > 0 then
        begin
          Buffer[BytesRead] := #0;
          Line := Line + Buffer;
        end;
      until not WasOK or (BytesRead = 0);
      WaitForSingleObject(PI.hProcess, INFINITE);
    finally
      CloseHandle(PI.hThread);
      CloseHandle(PI.hProcess);
    end;
  finally
    Result := Line;
    CloseHandle(StdOutPipeRead);
  end;
end;

RunConsoleCmd('"cmd.exe help"');