Priorty messages in Unix

[Mike Spitzer]

In article <1857 at wpi.wpi.edu> ojr at wpi.wpi.edu (Walden H. Leverich III) writes:
>Does anyone know if there is a way to tell 4.xBSD Unix to let certain
>priorty messages through? And how to encode the messages as being priorty.
>
>Perhaps even better, is there a way to allow only mesages from certain
>users to come through? The binary choice offered by mesg y/n just does
>not cut it.

Using distributed Berkeley software, there really isn't an easy
way to accomplish this.  We (the Purdue University Computer Center)
have come up with some local modifications to 4.3BSD that allow more
complicated talk(1) message filtering.  Here's a summary:

1.  We have a local mesg(1) command that allows you to, among other
	things, turn on "group" messages.  Before 4.3BSD and the "tty"
	group, this used to just turn on the group write permissions
	on `tty`.  Since this doesn't get along with the 4.3BSD, it
	now just turns on the group read bit on `tty`.

2.  Talkd recognizes the group message bit in the tty modes (the group
	read bit), which lets users in the same login group , talk to
	a given user (as long as the user is coming in from a
	"friendly" host).

3.  In addition to the "group" message facility in talk, we also
	support ".talkrc" file.  This file, in a user's home
	directory, contains regular expressions of users and groups
	that are allowed to talk to a user.  It looks something like:

		!annoying_user
		.*
		%%
		!annoying group
		.*
	
	which would allow everyone except annoying_user and people in
	annoying_group to talk to you.  %% is the separator between
	the list of users and the list of groups.  Since these are
	regular expressions you can set up just about anything you
	want...

If you have an interest in getting this software, send me mail... I
can probably gather this together into a distributable state.

--
Michael J. Spitzer		Purdue University Computing Center
mjs at mentor.cc.purdue.edu	pur-ee!mentor.cc.purdue.edu!mjs