Re: [9fans] 'wall' messages

[Jim Choate <ravage@einstein.ssz.com>]

On Tue, 7 Oct 2003 a@9srv.net wrote:

> another problem with the 'echo 'rebooting now' > /dev/screen/*' or
> whatever is the fact that it requires more specific resources to
> exist. my primary interaction with plan 9 these days is (sadly) via
> ssh (ether on Virtual PC, anyone?), so most of the common /dev
> entries present on a terminal, via drawterm, or via vnc won't show
> up for me.

I don't see that as a serious problem. After all rio runs from a rc
prompt. Looks to me like all connections start with a rc shell that then
invokes other programs in some manner. So track the initial connection and
then as other things get cranked up (eg rio) you simply follow the chain.
The OS has to have a means (probably vector tables of one sort or another)
to keep track of it.

And as to there not being a /dev, that's a simple issue of creating a
logical alias on that initial rc connection into /dev/display/*. As that
gets updated (ie I execute the 'rio' command) another logical device could
be added or even replace the rc connection. In the case of a serial device
the logical link would work the same way once the handshaking was
completed.

It's not like there is any magic there, it's bits, it -all- breaks down
to read/write/and/or/not/shift/jump on bits in ram or a register in the
final analysis. The bottom line is that my view is that the complexity
should be in the OS hidden from the users (including bootes/eve) and the
users shouldn't have to jump through hoops to do things as simple as
sending a note to all logged in users. The exact scope of that permission
(ie should it be bootes/eve or all users or just particular groups)
should be left up to the system operators and a config script of some
sort.

The ability to share resources -is just as important- as being able to
prevent access. Perhaps more so if you're speaking of individuals working
on groups.

 -- --

God exists because mathematics is consistent, and the Devil exist because we
can't prove it.
                          Andre Weil, in H. Eves, Mathematical Circles Adieu

      ravage@ssz.com                            jchoate@open-forge.com
      www.ssz.com                               www.open-forge.com