Following this line of thought, - and with the disclaimer that my own personal existence
begins roughly where what has been called “The Last True UNIX” [Seventh Edition] ends, I’d
say that, if ESR - who I know can be controversial - is correct, “BSD won in the
marketplace, but System V won the standards wars” or words to that effect.
With that in mind, and given that NetBSD was forked from 386BSD and in turn gave rise to
the other BSDs around today, it would be my candidate for “most direct descendant
available today,” particularly if we’re talking wide availability. (Whilst V1-6 and beyond
were of course only available to users of business and academic mainframes and
minicomputers, I’d argue that the other two contenders, Solaris and HP-UX, are
sufficiently rare in comparison to the availability even of the open source BSD’s that the
word “available” would be doing some rather heavy lifting if I were to include them.) The
BSDs (except macOS and whatever SCO’s cash cow is called this evening) are also open
source, of course, which is inline with the spirit of early Unix.
I’ve not done an audit - and am not qualified to - but I suspect the main objection to
this line of thinking is that despite the fact it still runs on VAX, it would not surprise
me in the least to find that (excluding comments, perhaps), not a single line of code
remains the same in NetBSD 10 (and indeed several versions prior) to the equivalent in V7
- and again, I’ve no idea how much of V1 remains in V7, nor (other than knowing it was
written in assembly) how closely early PDP-11 versions resembled PDP-7 versions. By then,
I suspect we really are getting into the Ship of Theseus problem - as the ancient Greeks
would have been familiar with the issue, by the time every single plank of Theseus’ Ship
has been replaced because the old ones have decayed, is it really the Ship of Theseus
anymore?
Plus of course, though it’s more a legal issue than a philosophical one, not only at least
one version of Mach-based macOS, but also one distribution of Linux - which is known not
to contain either Minix or UNIX code - have been certified as UNIX by The Open Group.
My 2c
Jeff
Sent from my iPhone
On 5 Jun 2024, at 18:51, Will Senn
<will.senn(a)gmail.com> wrote:
On 6/5/24 12:34 PM, segaloco via TUHS wrote:
On
Wednesday, June 5th, 2024 at 3:17 AM, Andrew Lynch via TUHS <tuhs(a)tuhs.org> wrote:
Hi
Out of curiosity, what would be considered the most direct descendent of Unix available
today?
...
Thanks, Andrew Lynch
snip
Given this, my humble opinion (which again this sort of thing I believe is largely a
philosophical matter of opinion...) is that the BSD line captures the spirit of Research
UNIX much more than System V does, while System V retains much more of the source code
lineage of what most folks would consider a "pure" UNIX. Of course all of this
too is predicated on treating V7 (really 32V...) as that central point of divergence.
When I saw this thread appear, I was of two minds about it, but this lines up with
where my thoughts were headed. I've done a lot of delving into the v6/v7 environments
over the last 10 years or so and it feels much closer in kinship to BSD derivatives than
to SysV... source code lineages aside. Also, I get more mileage out of my BSD books and
docs than those treating SysV. I'd vote for *BSD as sticking closest to the unix way,
if there is still such a thing... I say this as I just typed 'kldload linux64'
into freebsd's terminal so I could run sublime alongside nvi... sometimes I wish I
was a purist, but I'm way too fond of experimentation :).
Will