From the Canyon Edge -- :-Dustin

Thursday, October 13, 2011

The email I received from Dennis Ritchie (by way of maddog)

I learned earlier this morning that Dennis Ritchie, one of the fathers of the C programming and UNIX as we know it, passed away.  Thank you so much, Mr. Ritchie, for the immeasurable contributions you've made to the modern world of computing!  I think I'm gainfully employed and love computer technology in the way I do, and am in no small ways indebted to your innovation and open contributions to that world.

Sadly, I've never met "dmr", but I did have a very small conversation with him, via a mutual friend -- Jon "maddog" Hall (who wrote his own farewell in this heartfelt article).

A couple of years ago, I created the update-motd utility for Ubuntu systems, whereby the "message of the day", traditionally located at /etc/motd could be dynamically generated, rather than a static message composed by the system's administrator.  The initial driver for this was Canonical's Landscape project, but numerous others have found it useful, especially in Cloud environments.

A while back, a colleague of mine complemented the sheer simplicity of the idea of placing executable scripts in /etc/update-motd.d/ and collating the results at login into /etc/motd.  He asked if any Linux or UNIX distribution had ever provided a simple framework for dynamically generating the MOTD.  I've only been around Linux/UNIX for ~15 years, so I really had no idea.  This would take a bit of old school research into the origins of the MOTD!

I easily traced it back through every FHS release, back to the old fsstnd-1.0.  The earliest reference I could find in print that specifically referred to the path /etc/motd was Using the Unix System by Richard L. Gauthier (1981).

At this point, I reached out to colleagues Rusty Russell and Jon "maddog" Hall, and asked if they could help me a bit more with my search.  Rusty said that I would specifically need someone with a beard, and CC'd "maddog" (who I had also emailed :-)

Maddog did a bit of digging himself...if by "digging" you mean emailing the author of C and Unix!  I had a smile from ear to ear when this message appeared in my inbox:
Jon 'maddog' Hall to Dustin on Tue, Apr 20, 2010 at 10:08 PM: 

> A young friend of mine is investigating the origins of /etc/motd.  I
> think he is working on a mechanism to easily update that file.
>
> I think I can remember it in AT&T Unix of 1977, when I joined the labs,
> but we do not know how long it was in Unix before that, and if it was
> inspired by some other system.
>
> Can you help us out with this piece of trivia?


Ah, a softball!
MOTD is quite old.  The same thing was in CTSS and then
Multics, and doubtless in other systems.  I suspect
even the name is pretty old.  It came into Unix early on.


I haven't looked for the best  citation, but I bet it's easily
findable:  one of the startling things that happened
on CTSS was that someone was editing the password
file (at that time with no encryption) and managed
to save the password file as the MOTD.


Hope you're well,
 Regards,
 Dennis
Well sure enough, Dennis was (of course) right.  The "message of the day" does actually predate UNIX itself!  I would eventually find Time-sharing Computer Systems, by Maurice Wilkes (1968), which says:

"There is usually also a message of the day, a feature designed to keep users in touch with new facilities introduced and with other changes in the system"


As well as the Second National Symposium on Engineering Information, New York, October 27, 1965 proceedings:
"When a user sits down at his desk (console), he finds a "message of the day".  It is tailored to his specific interests, which are of course known by the system."

Brilliant!  So it wasn't so much that update-motd had introduced something that no one had ever thought of, but rather that it had re-introduced an old idea that had long since been forgotten in the annals of UNIX history.

I must express a belated "thank you" to Dennis (and maddog), for the nudges in the right direction.  Thank you for so many years of C and UNIX innovation.  Few complex technologies have stood the test of time as well as C, UNIX and the internal combustion engine.

RIP, Dennis.

-Dustin

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