How do I write to StdOut from a GUI app started from the command line?

Question

I am writing a standard windows app in Delphi 7.

If I was writing a console app, I can call the following to output to the cmd line or output file.

write         


        

Answer 1

FWIW, I played around with this problem and happened upon AttachConsole which seems to do the trick. The only problem I ran into with my code is that the program won't give the console up without an extra ENTER key or two. It's not real polished since I was trying to fix that problem and (kind of) gave up. Perhaps someone here will see it?

program writecon; uses windows, dialogs;

  function AttachConsole(dwProcessID: DWord): BOOL; stdcall; external 'kernel32.dll';

  function load_attach_console: boolean;
    begin
      Result := AttachConsole(-1);
    end;

  begin
    // the function requires XP or greater, you might want to check for that here.
    if load_attach_console = true then
      begin
        writeln;
        writeln('This is running in the console.');
        write('Press ENTER to continue.');
        readln;
        // from the linked page, you have to detach yourself from the console
        // when you're done, this is probably where the problem is.
        Flush(Output);
        Flush(Input);
        FreeConsole;
      end
    else
      MessageDlg('This is not running in the console.', mtInformation, [mbOk], 0);
  end.