Hi All.
In 1983, while a grad student at Ga Tech, I did some contract programming
at Southern Bell. The system was a PDP 11/70 running USG Unix 4.0 (yes,
it existed! That's another story.)
Beside ed, the system had a screen editor named 'se' (not related to the
Ga Tech 'se' screen editor). It apparently was written within AT&T.
ISTR that it was written mainly for Vaxen but had been squeezed and made to
run on the PDP 11.
Did anyone else ever use this? Know anything about it? I never saw it
or heard it about it again; it didn't ship with System V.
Thanks,
Arnold
I am somewhat embarrassed to admit that this just occurred to me. Is the
reason that SIGKILL has the numeric value 9 because cats are reported to
have nine lives? Clearly the connection between 'cat' and 'kill -9' would
make for a irreverent but harmless inside joke if so....
- Dan C.
> I especially liked the bit in which Tom's virus infected a multi-level secured UNIX system that Doug McIlroy and Jim Reeds were developing which they didn't spot until they turned on all their protections ... and programs started crashing all over the place.
That's not quite right. The system was running nicely with a
lattice-based protection system (read from below, write to above)
working fine. Processes typocally begin at lattice bottom, but
move to hivel levels depending on what data they see (including,
of course any exec-ed file.) All the standard utilities, being
usable by anyone are at lattice bottom.
Cool, until you realize that highly trusted system programs
such as sudo are at lattice bottom and are protected only by
the old rwx bits, not by the read-write rules. So, following
an idea of Biba's, that integrity rules are the opposite of
secrecy rules. You don't want to forbid writing to high-integrity
places, nor read from low-integrity places.
This was done by setting the default security level away from
the lattice bottom. High-integrity stuff was below this floor;
high-secrecy above.
The Duff story is about the day we moved the floor off bottom.
An integrity violation during the boot sequence stopped the
system cold. Clearly we'd misconfigured something. But no, after
a couple of days of fruitless search, Jim Reeds lit up, "We
caught a virus!" We were unaware of Duff's experiment. He had
been chagrined when it escaped from one machine, but was able
to decontaminate all the machines in the center. Except ours,
which was not on the automatic software distrutioin list, since
it was running a different system.
> From: Andy Kosela
> That is why MIT and Bell Labs represented two very different cultures.
Oi! Not _everyone_ at MIT follows the "so complicated that there are no
obvious deficiencies" approach (to quote Hoare's wonderful aphorism from his
'Emperor's Old Clothes' Turing Award Lecture).
My personal design mantra (it's been at the top of my home page for decades)
is something I found as a footnote in Corbato and Saltzer, 'Multics: The First
Seven Years': "In anything at all, perfection has been attained, not when
there is nothing left to add, but when there is nothing left to take away..."
No doubt some people would be bemused that this should be in a Multics paper,
given the impression people have of Multics as incredibly - overly -
complicated. I'll avoid that discussion for the moment...
I've often tried to understand why some people create these incredibly
complicated systems. (Looking at the voluminous LISP Machine manual set from
Symbolics particularly caused this train of thought...) I think it's because
they are too smart - they can remember all that stuff.
Maybe my brain isn't like that (or perhaps I use large parts of it for other
stuff, like Japanese woodblock prints :-), but I much prefer simpler things.
Or maybe I'm just basically lazy, and like simpler things because they are
easier...
Noel
Hi,
ed(1) pre-dates pipes. When pipes came along, stderr was needed, and
lots of new idioms were found to make use of them. Why didn't ed gain a
`filter' command to accompany `r !foo' and `w !bar'?
To sort this paragraph, I
;/^$/w !sort >t
;/^$/d
-r t
I'd have thought that filtering was common enough to suggest a `^'
command with an implied `!'? (Not `|' since that was uncommon then.)
ex(1) has `!' that filters if applied to a range of lines, and this
carries through to vi's `!' that's often heavily used, especially when
the "file" is just a scratch buffer of commands, input, and output.
--
Cheers, Ralph.
https://plus.google.com/+RalphCorderoy
There's a story I heard once in supercomputing circles from the 80s, that
Ken visited CRI in Minneapolis, sat down at the console of a machine
running the then-new port of Unix to one of the Crays, typed a command, and
said something like "ah, that bug is still there."
Anybody know what the bug was?
It's time to assert my editorial control and say: no more 80 cols please!
Anybody who mentions 80 cols will be forced to use either a Hazeltine or
an ADM3 (not 3a) for a month.
Thanks, Warren
Jim "wkt" Moriarty:
> Anybody who mentions 80 cols will be forced to use either a Hazeltine or
> an ADM3 (not 3a) for a month.
=====
So who has a modern emulator for either of those terminals?
Norman Wilson
Toronto ON
(Still not really in Toronto, but no longer in Texas)
