Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!csd4.milw.wisc.edu!bionet!agate!shelby!csli!gandalf
From: gandalf@csli.Stanford.EDU (Juergen Wagner)
Newsgroups: comp.unix.questions
Subject: Re: Unix deficiencies/problems
Message-ID: <8907@csli.Stanford.EDU>
Date: 10 May 89 07:36:21 GMT
References: <810038@hpsemc.HP.COM> <810046@hpsemc.HP.COM> <159@dg.dg.com> <424@algor2.UUCP> <676@dtscp1.UUCP> <1528@cmx.npac.syr.edu> <8892@csli.Stanford.EDU> <2914@cps3xx.UUCP>
Sender: gandalf@csli.Stanford.EDU (Juergen Wagner)
Reply-To: gandalf@csli.stanford.edu (Juergen Wagner)
Organization: Center for the Study of Language and Information, Stanford U.
Lines: 23

In article <2914@cps3xx.UUCP> rang@cpsin3.cps.msu.edu (Anton Rang) writes:
>...
>  Does anyone know the original reason for the immediate echoing?
>...

The question which has to be raised is who echoes the characters as they
are typed. Is it the driver which is in some echo mode, or is it the
application (shell, emacs, whatever)?

Sh/csh don't know about echoing. They happily process characters as they
come along. (Famous example: killing certain programs leaves the terminal
in a bad, non-echoing state)

The alternative would be to require the application to echo characters just
as it reads them (this would give you the desired behaviour). However, what
happens if you invoke a program from csh? Should the program be expected to
handle all echoing, or should the driver now take over? I guess, somebody
has made a decision towards simplicity, and has chosen to let the driver
echo input unless the application explicitly resets the terminal mode.

-- 
Juergen Wagner		   			gandalf@csli.stanford.edu
						 wagner@arisia.xerox.com