Re: Fix needed for communication with gpg-agent

[Werner Koch <wk@gnupg.org>]

On Thu, 22 Feb 2007 00:15, storm@cua.dk said:

> Since this was the main problem which we were concerned with, the
> problem is reduced to find a way to block Emacs from reading from the
> tty while pinentry needs it.

So the problem is that pinentry does not have exclusive access to the
tty.   What we do is:

  /* Open the desired terminal if necessary.  */
  if (tty_name)
    {
      ttyfi = fopen (tty_name, "r");
      if (!ttyfi)
	return -1;
      ttyfo = fopen (tty_name, "w");
      if (!ttyfo)
	{
	  int err = errno;
	  fclose (ttyfi);
	  errno = err;
	  return -1;
	}
      screen = newterm (tty_type, ttyfo, ttyfi);
      set_term (screen);
    }
  else
    {
      if (!init_screen)
	{
	  init_screen = 1;
	  initscr ();
	}
      else
	clear ();
    }
  
  keypad (stdscr, TRUE); /* Enable keyboard mapping.  */
  nonl ();		/* Tell curses not to do NL->CR/NL on output.  */
  cbreak ();		/* Take input chars one at a time, no wait for \n.  */
  noecho ();		/* Don't echo input - in color.  */

TTY_NAME is taken from the envvar GPG_TTY.  Just an idea:  What about
having emacs allocating a new pty pass that to gpg/gpg-agent.  Emacs
could then monitor the pty and thus notice if pinentry is going to use
it.




Salam-Shalom,

   Werner