write replacements (Was Re: BSD tty security, part 3: How to Fix It)

[Bill Stewart 908-949-0705 erebus.att.com!wcs]

In article <kre.673801266 at mundamutti.cs.mu.OZ.AU> kre at cs.mu.oz.au (Robert Elz) writes:
> wcs at cbnewsh.att.com (Bill Stewart 908-949-0705 erebus.att.com!wcs) writes:
> >* "mail" is for sending people messgaes with potentially structured
> (and is irrelevant here)
	Not really - if somebody want's to reach me, they send mail,
	and an icon pops up on my screen at work, and a bell rings
	on my terminal at home.  If I'm nearby, and don't mind
	being interrupted, I can reply.
> >* "talk" is for coordinated real-time conversations between people,
> >* "write" is for rudely interrupting people who haven't pre-arranged

> I disagree with this .. both initiate conversations, both rudely
> interrupt, the sole difference there is that with talk I cannot
> see any hint of the other person's message until I respond, and
> both have a very fixed interface style, that I can't alter.

	There are LOTS of talk programs out there.
	Admittedly, in the BSD world you've had sockets for 10 years,
	and probably all use the standard one, but here in the System V
	world we've used a variety of different talk programs.
	Some use sockets, some use files, some use FIFOs.
	Even in the BSD world, if you've got a workstation, you can
	use your own talk program instead of the standard one.

> The interface we have does not require any pre-arrangement in order
	By pre-arrangement, I meant pre-arrangement between you and the system,
	like putting "biff y" or "message-widget -foo &" in your .profile.
	You do need to find out what flavor of talk-program somebody uses,
	but that can be resolved by directories or finger,
	or by mentioning it in your "Please call me" mail.

> Unless you have operated in an academic environment with lots of
> moronic undergrad students you may not appreciate the usefulness of
> selective message control - I don't want to prevent messages from
	I used to always use "mesg y", but now that I'm in a window
	environment (and to some extent even when I'm using a screen editor)
	write and wall messages tend to get lost in the shuffle -
	maybe the bell gets through.  People can always send me mail,
	and mail makes it easy to pick out useful stuff.
	One option with vanilla write, by the way, is to
	make your terminal group-writable, with a group that your
	friends are in and the annoying undergrads aren't :-)

> in any case, the point is that its up to the user to decide just how,
> and when, if at all, he wants to be interrupted.
	Agree with you there.
-- 
				Pray for peace;		  Bill
# Bill Stewart 908-949-0705 erebus.att.com!wcs AT&T Bell Labs 4M-312 Holmdel NJ
# I never wanted to be a hacker!  I wanted to be --- a lumberjack!