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From: hansm@cs.kun.nl (Hans Mulder)
Newsgroups: comp.unix.shell
Subject: Re: separate the command language and interactive she
Message-ID: <3496@wn1.sci.kun.nl>
Date: 1 May 91 17:17:28 GMT
References: <2509@optima.cs.arizona.edu>
Sender: root@sci.kun.nl
Organization: University of Nijmegen, The Netherlands
Lines: 34

In <2509@optima.cs.arizona.edu> gudeman@cs.arizona.edu (David Gudeman) writes:

>Just to clarify my terms: I would call sh a command language and csh a
>combination of command language and interactive shell.  I wasn't
>suggesting a completely different type of command language like those
>mentioned above (although I think it is a good idea).  My suggestion
>was just to separate the interactive part of the unix shell from the
>command part.  You would run the interactive shell of your choice with
>the interactive command language of your choice; for example you could
>run an interactive shell that implements the csh history mechanism
>with sh as your command language.

>(In the following, an interactive shell is an ish and a command
>language is a clang.)

Sorry for injection some facts into an otherwise useful theoretical
discussion, but in 1987 (according to the copyright notice) Kazumasa
Utashiro of Software Research Associates, Inc. wrote a nice "ish"
called "fep" (for Front End Processor).  It's invocation is

fep [-emacs|-vi] clang

The option indicates which flavor of key bindings you want to use for
editing the history.  As you would expect, "fep sh" gives you a Korn
shell emulation, of sorts.

Conclusions:
1. It Can Be Done.
2. The clang doesn't have to know about the ish.

--
Have a nice day,

Hans Mulder	hansm@cs.kun.nl