History lessons

[Mike I'll be mellow when I'm dead Meyer]

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. The most glaring
example (to me, anyway) is the dbm library. I don't know (and can't
check) if the S3/5 find have -inum.

>It is true that the Unix *kernel* does not limit directories to a
>single pathname.  Neither does the kernel require the two filenames "."
>and ".." to be the first two names in a directory.  Nor does it require
>that file descriptors 0, 1, and 2 be used for standard input, output,
>and error, respectively.  Yet all three of these characteristics are
>considered to be part of the overall Unix system.  They are conventions
>that should be adhered to.  Are you claiming that "rmdir, mvdir, ln,
>and mkdir" are not part of Unix?

I have it from a reliable source (Ritchie) that in the original Unix file
system, the directory structure was an arbitrary graph. It was changed
to a tree because of the hair involved in consistency checking. As late
as v6, ln command allowed root to link directories, and across file
systems. This may have been a Purdue hack, though.

	<mike

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