Re: [9fans] what features would you like in a shell?

[erik quanstrom <quanstro@quanstro.net>]

On Tue Mar 31 11:37:06 EDT 2009, noagbodjivictor@gmail.com wrote:
> hello,
>
> I'm a undergrade CS student doing a project for my introductory
> operating systems class. my team wants to write a simple shell from
> scratch.
>
> one idea we have found so far is the following. the shell will record
> all the programs it has run. whenever a program goes awry and is
> killed by the kernel. the shell will reload it.

unfortunately, the most common reason for a program to go
arwy is that the program is broken and it will break again when
reloated.

it would be more interesting to explore how a shell in plan 9
could be used to build simple fs.

rc has a very interesting virtual machine.  it might be interesting
to build a shell with some hooks into its vm.  paul haahr and
byron built a shell with scheme-y internals and exposed them.
interesting, but complicated.

it would be interesting to use something closer to regular expressions
rather than standard shell globbing.  the challenge would be
to avoid gratuitous breakage and yet allow the match operator
to be much more powerful.

these are areas where rc might be improved upon.  however,
as per usual, it was hard to improve on bourne, and it's even
harder to improve on duff.

nevertheless, i learned quite a bit from failing to improve on
rc.

- erik