15 Mar
2018
15 Mar
'18
4:29 p.m.
One of the things that's always fascinated me about Unix is the community
aspect; in particular, I imagine that in the early days when machines were
multiplexed among many simultaneous users, I wonder whether there was a
greater sense of knowing what others were up to, working on, or generally
doing.
I think of the /etc/motd file as being a part of this. It is, in some very
real sense, a way to announce things to the entire user community.
So what are its origins? Where did it first appear? I haven't dug into
this, but I imagine it was at Berkeley. What was it used for early on at
individual sites?
- Dan C.
15 Mar
15 Mar
4:35 p.m.
Ø So what are its origins? Where did it first appear? I haven't dug into this, but I
imagine it was at Berkeley. What was it used for early on at individual sites?
It was certainly present in Version 6 UNIX, so it predates Berkeley. While it being a
“file” is very UNIX-ish, the concept of a settable sign on message doesn’t originate with
UNIX. I had used other systems that ran a user defined program on user login (sort of a
compiled .profile) and it was common to put the system “news” in such.
One amusing thing to do with /etc/motd is to add the like “You might have mail.” I
thought it was a cute joke, but I never realized how much confusion it would cause. I
did it at BRL and had people sending me email asking why they didn’t have mail (it only
said you MIGHT).
I told one of my student programmers working for me at Rutgers that if he put that in the
motd on one of our systems I guaranteed within an hour someone will tell us they didn’t
have mail.
It took about 15 minutes for one of my SENIOR systems programmers to come into the office
and tell me that.
4:36 p.m.
On 3/15/18 11:35 AM, Ron Natalie wrote:
One amusing thing to do with /etc/motd is to add the
like “You might have
mail.” I thought it was a cute joke, but I never realized how much
confusion it would cause. I did it at BRL and had people sending me
email asking why they didn’t have mail (it only said you MIGHT).
Try adding "Segmentation Fault (core dumped)".
--
``The lyf so short, the craft so long to lerne.'' - Chaucer
``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, UTech, CWRU chet(a)case.edu http://tiswww.cwru.edu/~chet/
4:41 p.m.
Try adding "Segmentation Fault (core
dumped)".
About the time computers went from being a tool of the research geeks to operational use
at BRL (we went from senior management saying "don't send us email, we
don't read it" to management telling everybody "they must check their email
regularly for important messages from them:"), the security officers found out about
/etc/motd. They would periodically put the same kind of "security rah rah"
stuff we had posters all over the facility ("Strike up the band for safety.",
etc...). After a few months of this I started sneaking in slogans of my own. The
first few (things like "Security is good") escaped notice. But they caught on
the day I put up "Even the ears have walls."
9:20 p.m.
On Thu, 15 Mar 2018, Chet Ramey wrote:
I've done both of those, along with "System down for disk crashing at
...". It was sort of true, as it was scheduled maintenance which involved
removing the RK-05 disks, prising them open with something like a speculum
(in the open air!), and running some sort of a deflection gauge along the
platter to see how warped it was. I think the DEC Field Circus
Ginger-Beer also wiped the heads and replaced the NiCd battery...
--
Dave Horsfall DTM (VK2KFU) "Those who don't understand security will
suffer."
One amusing
thing to do with /etc/motd is to add the like “You might
have mail.” [...]
Try adding "Segmentation Fault (core dumped)". 
9:25 p.m.
On Thu, Mar 15, 2018 at 2:20 PM, Dave Horsfall <dave(a)horsfall.org> wrote:
On Thu, 15 Mar 2018, Chet Ramey wrote:
One amusing thing to do with /etc/motd is to add the like “You might have
I've done both of those, along with "System down for disk crashing at
...". It was sort of true, as it was scheduled maintenance which involved
removing the RK-05 disks, prising them open with something like a speculum
(in the open air!), and running some sort of a deflection gauge along the
platter to see how warped it was. I think the DEC Field Circus Ginger-Beer
also wiped the heads and replaced the NiCd battery...
At school, one of the admins had in place, for a day or three, a cron job
that randomly changed /etc/motd every few minutes to append one of several
variations of Segmentation Fault (core dumped), but it was deviously
different. "Segretation Fault (core dumped)" "Segmentation Fault (core
duped)" "Bussing Error (cops deployed)" etc
Warner
mail.”
[...]
Try adding "Segmentation Fault (core dumped)".
4:51 p.m.
On Thu, Mar 15, 2018 at 11:29 AM, Dan Cross <crossd(a)gmail.com> wrote:
One of the things that's always fascinated me
about Unix is the community
aspect; in particular, I imagine that in the early days when machines were
multiplexed among many simultaneous users, I wonder whether there was a
greater sense of knowing what others were up to, working on, or generally
doing.
I think of the /etc/motd file as being a part of this. It is, in some very
real sense, a way to announce things to the entire user community.
So what are its origins? Where did it first appear? I haven't dug into
this, but I imagine it was at Berkeley. What was it used for early on at
individual sites?
I'm pretty sure it predates the #1 editions, if check the sources for the
login program on TUHS you can be sure. Steve Johnson and others have
pointed out that systems people (such as Dennis) were often night owls and
often added/changed things in the UNIX group or their own systems. This
was no different than the way other systems (such as timesharing system
like TOPS or TSS worked). System time in the day was expensive and if you
wanted to make a change the affected a lot of people, you did it 'off
hours.'
Remember, most people in those days were 'dialing in' or going to a
terminal room. So you got a fresh log in session once or twice a day.
So, I believe that the idea of motd was to have a standard place where
everyone could get messages that might affect them and be pretty sure you
saw it before you started your work.
For instance, two messages I can think of I put the EE/Mellon systems years
ago were on the order of: *'New Pascal compiler installed, should fix the
core dump issue Tron was having - send me email if you are still having
issues. Clem'* Or *'Klone and I just updated our RK07 disk driver to
add bad disk block support -- we think its working as far as we have been
able to test. If you notice something strange, please check the console
log before you call either us.. Clem'*
You get the idea,
Clem
ᐧ
5:55 p.m.
One of the funniest I saw was logging into a Denelcor engineering machine. Their company
slogan was “Tomorrow’s computers…Today.”
I logged in to see the message “Tomorrow’s computers…some time next month.”
7:04 p.m.
(A similar question was asked a month ago here. From my response then
...)
v1 has the concept "message of the day"
http://minnie.tuhs.org/cgi-bin/utree.pl?file=V1/man/man7/login.7
but I don't find the code for it.
v2 login reads "/etc/motd"
http://minnie.tuhs.org/cgi-bin/utree.pl?file=V2/cmd/login.s
By the way, where is the code for the shell referenced in init.s for
the earlier Unix? http://minnie.tuhs.org/cgi-bin/utree.pl?file=PDP7-Unix
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9 comments
7 participants
participants (7)
-
Chet Ramey -
Clem Cole -
Dan Cross -
Dave Horsfall -
Jeremy C. Reed -
Ron Natalie -
Warner Losh