[fpc-pascal]No wait execution and redirection of stdin and stdout

[Full_Name]

Quoting "Peter H.M. Brooks" <peter at new.co.za>:

> - Firstly I'd like to launch a program with no wait and then check for
> its completion later.

Calling: 

winexec('c:\Listener.exe', sw_normal);

will execute the listener app, and leave it running independently. WinExec is 
depreciated in the windows api, but is way easier to use than createprocess. 
However, I think you would need to use createprocess to do your stdin/stdout 
redirection. A 1 minute search on google groups found the following (untested):

procedure RunAProgram(Directory: PChar; File2Run: PChar;
                      CmmdRun: PChar; How2Show: Word);
var
  pi  : TProcessInformation;
  si  : TStartupInfo;
begin
  with si do begin
    cb := SizeOf(si);
    lpReserved := nil;
    lpDesktop := nil;
    lpTitle := nil;
    dwFlags := 0;
    wShowWindow := How2Show;
    cbReserved2 := 0;
    lpReserved2 := nil;
  end;
  Chdir(Directory);
  CreateProcess(File2Run, cmmdRun, nil, nil, FALSE, 0, nil, nil, si, pi);
end;

Here's another part of the puzzle (it's delphi though, but afain it's pretty 
generic, bar the @windproc line that you have to cast to wndproc iirc in FPC, 
as noted.)

/////////////////////////////////////////////////////////////////////////
program Listener;
uses
  windows,
  sysutils,
  messages;

var
  HookMessage: longword = 0;
  Handle: HWND;
  wC : TWndClass;
  msg: tmsg;

const
  AppName: array[0..50] of char = 'application/x-vnd.MyApp'#0;

function WindowProc(Window: HWnd; Message, WParam: Word;
  LParam: Longint): Longint; stdcall;
begin
  if Message = HookMessage then begin
    //Do your action...
    writeln('I got a message...');

    Result := 1;
    Exit;
  end;

  case message of
    WM_CLOSE,
    WM_QUIT: PostQuitMessage(0);
  end;

  Result := DefWindowProc(Window, Message, WParam, LParam);
end;

var
  w: hwnd;
begin
  HookMessage := RegisterWindowMessage('Application/x-vnd.CustomHookMessage');
  with wC do begin
    style := CS_VREDRAW or CS_HREDRAW;
    lpfnWndProc := @WindowProc; //in fpc this should be 'wndproc(@WindowProc)'
    cbClsExtra := 0;
    cbWndExtra := 0;
    wC.hInstance := HInstance;
    hIcon := LoadIcon(HInstance,IDI_APPLICATION);
    hCursor := LoadCursor(HInstance,IDC_ARROW);
    hbrBackground := GetStockObject(LTGRAY_BRUSH);
    lpszMenuName := nil;
    lpszClassName:= @AppName;
  end;

  RegisterClass(WC);


  //create off screen window....
  handle := CreateWindow(wc.lpszClassName,
                         'Nothing',
                         WS_OVERLAPPEDWINDOW or WS_TABSTOP,
                         -100,
                         -100,
                         1,
                         1,
                         0,
                         0,
                         HInstance,
                         nil);

  
  ShowWindow(Handle, SW_HIDE); //completely hide the dummy window
  UpdateWindow(Handle);

  while Windows.GetMessage(msg, 0, 0, 0) do
  begin
    TranslateMessage(msg);
    DispatchMessage(msg);
  end;
end.
/////////////////////////////////////////////////////////////////////////////

/////////////////////////////////////////////////////////////////////////////
program Messenger;
uses
  SysUtils, windows, messages;

var
  HookMessage: longword = 0;

begin
  HookMessage := RegisterWindowMessage('Application/x-vnd.CustomHookMessage');
  
  postmessage(HWND_BROADCAST, HookMessage, 0, 0);
end.
/////////////////////////////////////////////////////////////////////////////


Hope that helps,

Matt
--

"Computer games don't affect kids; I mean if Pac-Man affected us as kids, 
we'd all be running around in darkened rooms, munching magic pills and 
listening to repetitive electronic music." 
Kristian Wilson, 
Nintendo, Inc, 1989

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