Unsolicited messages (was Re: Slaying Gould dragon...)

[Roy Smith]

In article <22332 at rochester.ARPA> ken at rochester.UUCP (SKY) writes:
> I would like, for example, to designate one window for messages when
> I'm on a Sun.  We have the biff service, why not a mesg service?
> Has anybody worked on a general solution [...]

	On my Sun-3, running 3.0, all the usual write, biff, wall, etc
messages come up in my console window.  I havn't looked into it too
closely, but it seems like it works something like this:

	Programs all see that I'm logged in on /dev/console and write to me
there.  The console device driver is just an indirect driver (much like
/dev/tty) which hands off I/O to the apropriate pty.  Presumably when I
designate a window as a console, the shelltool issues some sort of ioctl to
indicate that the particular pty it is using is to be considered the
console from now on.  Works fine.  Seems pretty general.
-- 
Roy Smith, {allegra,cmcl2,philabs}!phri!roy
System Administrator, Public Health Research Institute
455 First Avenue, New York, NY 10016

"you can't spell deoxyribonucleic without unix!"