[TUHS] Shell control through external commands

[Doug McIlroy]

> 8th edition was essentially a re-port of 4.1c BSD, correct?

"Re-port" may be a bit strong. Internet stuff from Berkeley
was folded into the research code (for a huge increase in
kernel size). But I think it was done by pasting Berkeley
code into local source, rather than the other way around.
But, since much of the rest of the BSD kernel was Bell
Labs code, it's probably right that the result of the
merge had more code in common with BSD than with Research.
If you ask, though, what fraction of Research code
survived the merge, it was probably larger than the
surviving fraction of the total BSD code.

Doug