[TUHS] Origins of shell prompt suffixes % $ > #

[Bakul Shah]

On Tue, 07 Aug 2018 00:31:36 -0700 Kurt H Maier <khm at sciops.net> wrote:
> On Mon, Aug 06, 2018 at 09:53:33PM +0100, Brian Zick wrote:
> >
> > rc uses ;
>        
> Does it?  10th edition Unix and Plan 9 rc both have ('% ' ' ') as the   
> default value of $prompt.  At least that's how it's described in the
> manual.  None of the v8/9/10 tarballs in the archive contain rc code,
> but some contain manual source, and those describe % prompts.
>
> I've seen other references to ; (presumably  ('; ' ' ')) as the rc 
> prompt but I've never seen it in the wild.  Does anyone here know what 
> the story is?

The es shell (by Haar and Rakitzis) used ; - the reason (as
per the man page)is that a user can cut-n-paste a previous
line to rexecute it (for the same reason people use term% and
cpu% functions to execute their args).  Es syntax was derived
from rc, which may be why the confusion.