Re: rc 1.6 $version

[Tim Goodwin <tjg@star.le.ac.uk>]

Paul Haahr wrote:
> > Any objections to `rc_version'?
> 
> I'd prefer $rc-version, but either should be fine.

(As it turns out, this is all irrelevant, but I have would two
objections to this.  First, `-' turns on free careting, so you'd have
to say things like this.

    ; whatis $'rc-version'

Not so bad, but wrap it in another level of quotes, perhaps from a
less sane shell, and it starts to get *very* ugly.

    $ rc -c 'whatis $'"'rc-version'"

Secondly, rc is meant to be C-ish, not Lisp-ish.)

> However, making it such a magic variable feels silly.  As Eric noted,
> having assignments to a variable just be eaten without warning seems,
> er, surprising at best.

Mea culpa.  I failed to realise that there are two types of special
variable in rc: 1) those that merely have a default initial value, and
2) those that invoke special code when substituted.  Till now,
$version was in category 2.  I've just moved it to category 1.

Category 2 now contains just $apids and $status, which seems about
right; they are both, of necessity, magical.  Category 1 now contains
$ifs, $path, $pid, $prompt, and $version.  (I was surprised to
discover that assignments to pid are persistent!)

As a separate matter, several variables are not exportable.  These
are: $apid, $apids, $cdpath, $home, $ifs, $path, $pid, and $*.
(Remember that $cdpath, $home, and $path are all aliased to upper case
versions, which *are* exportable.  Also, the default assignment to
$path happens before $PATH is examined: so if $PATH is set, $path will
acquire its value instead of the default.)

I think $bqstatus and $status ought to be non-exportable too.  I've
just made them so; you can all see what this breaks in the next
release candidate :-).

Tim.