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From: richard@aiai.ed.ac.uk (Richard Tobin)
Newsgroups: comp.unix.questions
Subject: Re: Strangeness in shell
Message-ID: <673@skye.ed.ac.uk>
Date: 3 Aug 89 19:02:45 GMT
References: <432@mccc.UUCP> <9700009@osiris.cso.uiuc.edu> <2277@auspex.auspex.com> <10639@smoke.BRL.MIL> <5404@ficc.uu.net> <10650@smoke.BRL.MIL>
Reply-To: richard@aiai.UUCP (Richard Tobin)
Organization: AIAI, University of Edinburgh, Scotland
Lines: 27

]-] Some of us think the right place is in the terminal!

]-The one problem with this approach is that you really should only maintain
]-a command line history when you're in canonical mode (ICANON, or COOKED).

]The terminal shouldn't know what a "command line" is.  Therefore it
]shouldn't be making this distinction.  I snarf&barf text freely between
]editor displays, command lines, and other text sources/sinks all the time.

Sure, but there's more to command-line editing than "snarf&barf".  If
you want to always be able to get your previous shell command by
typing control-P, and would like that to work in Lisp and /bin/cat as
well, but you also want control-P to be passed direct to emacs, then
it's fairly difficult for a terminal on a serial line to keep track.

It should be possible (if you have ptys) to write a program that
provides you with line-based command editing only when the terminal is
in cooked mode.  (It would be rather like "script".)  At present that
requires checking the terminal mode for each character typed - it
would be nice if there were a pty mode that told you when ioctls are
done on the slave side.

-- Richard
-- 
Richard Tobin,                       JANET: R.Tobin@uk.ac.ed             
AI Applications Institute,           ARPA:  R.Tobin%uk.ac.ed@nsfnet-relay.ac.uk
Edinburgh University.                UUCP:  ...!ukc!ed.ac.uk!R.Tobin