History lessons

[Guy Harris]

> Some misinformation about the history of Unix has been floating around
> the net. In the interests of truth, justice, and the Unix way, I'm going
> to post what I believe to be correct information.
> 
> >P.S. 4.xBSD is the only UNIX that documents "-inum" but I think it's been
> >in there since V7 and is thus in S3 and S5 as well.
> 
> Contrary to popular believe, S3 and S5 are *not* descended from v7. They
> spun off the research Unix line somewhere between v6 and v7, and some of
> the things in v7 were added after that happened.

I'm *quite* aware of that, thank you.  However, the point of spin-off was
*FAR* closer to V7 than to V6 (UNIX/TS 1.0 had the V7 file system, the new
V7 system calls, and the Bourne shell).  The chances are *extremely* good
that if something was in V7 it was in S3 as well.

> The most glaring example (to me, anyway) is the dbm library.

Which may have come out after UNIX/TS 1.0 was done, or may have come out
before but wasn't picked up by the people doing UNIX/TS.  Could anybody with
real knowledge say which was the case?

> I don't know (and can't check) if the S3/5 find have -inum.

It has it; I looked.

> As late as v6, ln command allowed root to link directories, and across file
> systems. This may have been a Purdue hack, though.

It certainly was.  "ln" *across file systems*?  V6 sure as hell didn't
support that (remember, the V6 directory format and the V7 directory format
are the same; there's room in a link for an inumber but not for a file
system).

> "4.2 isn't to big. v7 was to big; 4.2 is efing HUGE."

V6 was too small (no supported "long" or "short" data types, a weak shell,
no Standard I/O library, no "make", no environment, etc., etc.).

	Guy Harris