Shells, features and interaction

[Doug Gwyn <gwyn>]

Oh boy!  Shell wars!

> The System V implementation of functions has the following deficiencies
> most of which exist in the 8th. edition Bourne shell:

Well, Dave, I always thought you were the one who added this feature
to the System V shell for Release 2.0; guess I was mistaken.  Whoever
did it, it would be interesting to hear why the particular design was
arrived at and whether it will be improved in future releases.

> For the sake of simplicity, the Bourne shell is riddled with little things
> that confuse the user.  Consider the following list of annoyances of the
> 'simple' Bourne shell:

> 2.	sh script doesn't perform path search for script.

Why should it?  I would be very upset if it did, since my cwd is last
in my $PATH for good and sufficient reasons, and I often am testing
new versions of scripts that live in public places.

> 8.	PATH=/bin:/usr/bin: will not search current directory last.

That's simply a bug.  I posted a fix for this some time ago.
(The fixed version is even simpler and smaller.)

> 14.	| and ^ are used as synonyms.

That was for compatibility, to avoid breaking old shell scripts.
I admit that at this point in time it is more just a nuisance.

The SVR2 shell is on the verge of becoming too big for 64Kb address
space machines such as the PDP-11.  Some of us think it would be a
shame for UNIX to be unimplementable on small systems due to the
shell being too big.  Perhaps a subset/superset approach (like sh/ksh)
would be best.