Path: utzoo!utgpu!utstat!jarvis.csri.toronto.edu!mailrus!cornell!uw-beaver!rice!sun-spots-request
From: steinmetz!dawn!stpeters@uunet.uu.net
Newsgroups: comp.sys.sun
Subject: Re: Sun 3 console question
Keywords: SunOS
Message-ID: <13343@steinmetz.ge.com>
Date: 22 Mar 89 19:34:29 GMT
References: <8902230102.AA18999@nic.MR.NET>
Sender: usenet@rice.edu
Organization: GE Corporate R&D, Schenectady, NY
Lines: 24
Approved: Sun-Spots@rice.edu
Original-Date: 10 Mar 89 19:07:24 GMT
X-Sun-Spots-Digest: Volume 7, Issue 204, message 5 of 13
X-Issue-Reference: v7n182

slevy@nic.mr.net (Stuart Levy) writes:
>We've seen two problems which can cause Sun RS-232 consoles to hang up.
> ...
>Another, recently discovered by some people here, it's possible to "steal"
>the console device using the TIOCCONS ioctl.  It caught us when people
>were running xterm's on our server (to an X terminal) and happened to
>start a console one.  This is hard to prevent without a kernel mod but you
>can ask people not to do it.

This can be undone by opening "/dev/console" and doing a TIOCCONS ioctl on
the descriptor.

Being able to move the logical console is very handy.  A colleague here
(Bob Darrow) used it to help debug a device driver: printf's in a driver
show up on the console, wherever it may be.  We've also used it to watch
failing-disk error messages on a server in a noisy room down the hall from
the comfort of an office.

(BTW, aren't Sun serial ports RS-432 [or some such] instead of RS-232?)
--
Dick St.Peters                        
GE Corporate R&D, Schenectady, NY
stpeters@ge-crd.arpa              
uunet!steinmetz!stpeters