job control

[Moderator, John Quarterman]

From: guy at sun.com (Guy Harris)
Date: Sat, 11 Oct 86 02:29:27 PDT

> > Something like the `pseudo-tty' concept would be very useful:   an  entity
> > which  looks like  a  terminal from one side, but whose behavior is under
> > user-process control from the other side.  Some existing systems do
> > implement such things, but the lack of standardization largely prevents
> > use of them in portable programs.

> One idea would be to put Ritchie's streams in the standard or an extension
> of the standard so that there is a "clean" way of writing user level window
> managers.  Given this there would probably be many window managers
> implemented and likes shells you wouldn't need a single standard one, but
> could provide several and allow users to write their own.

Streams don't in and of themselves provide a "clean" way of writing
user-level window managers.  As Henry pointed out, a pseudo-tty is what you
want here; you have a window manager that simulates a terminal (using a real
terminal or some other sort of display) and provides a tty-like interface to
clients using a pseudo-tty.

Streams might permit a fairly clean implementation of a pseudo-tty, but they
don't provide the only clean way of writing user-level window managers; any
sufficiently powerful pseudo-tty mechanism will do that.  Streams might
provide the cleanest way of providing a sufficiently powerful pseudo-tty
mechanism.

Volume-Number: Volume 7, Number 49