[TUHS] A few comments on porting the Bourne shell

[Larry McVoy]

On Mon, Jan 02, 2023 at 10:32:50AM -0700, Adam Thornton wrote:
> But of course the "after it had had a few years to settle" is doing
> a lot of lifting there.  During the Unix Wars, yeah, clearly using
> v7 sh as lowest-common-denominator was the right choice.  After the
> establishment of Linux Hegemony sometime in the early 2000s, I think I
> remember that you could pretty much count on everyone at least providing
> a POSIX shell, even if it wasn't the default.  (But of course by then,
> "everyone" that wasn't Linux or OS X was already down to more-or-less Sun,
> IBM, HP, and DEC/Compaq.)

I was supporting a commercial product in the early 2000's and there
were all sorts of systems then that had old shells.  Yes, you could make
everything a 2 level thing where the first level finds the correct shell,
but that's just fuss.  Just make things portable, it's not that hard
and it works everywhere.

When you get to the commercial world, you'd be stunned to see how long
old machines last.  If they are solving some problem, and they aren't
broken, nobody replaces them.  I'll bet you anything there are still
SCO registers out there, I'll bet there are still PDP-11s out there.

If it ain't broke, don't fix it.