Subject: Re: X display tectonics
To: T. Sean <tschulze@compuserve.com>
From: Colin Wood <cwood@ichips.intel.com>
List: port-mac68k
Date: 02/17/1998 11:24:00
T. Sean wrote:
[Charset ISO-8859-1 unsupported, filtering to ASCII...]
> Thanks David, Colin and Paul.
> 
> On 2/16/98 23:14, Colin Wood at cwood@ichips.intel.com wrote:
> 
> >
> >David Brownlee wrote:
> >> 	The system is outputting a line to the console indicating
> >> 	an 'su' has taken place. You should really run xconsole or
> >> 	one 'xterm -C' to capture this console output.
> >
> >I think that this requires "options UCONSOLE" in the kernel config file,
> >but the GENERIC kernels do include this option.
> > 
> 
> I checked the xterm man page, and the flag "-C" is supposed to send 
> console output to the xterm window so blessed.  'Course the man page also 
> says this option is not supported on all systems.  I normally run with 
> one window set up with the "-C" flag, and that window runs in the 
> foreground so that when I exit that xterm, I exit X Window.  I've just 
> run some tests using the "-C" flag on some other windows to see if I 
> could use the "-C" flag in a window called specifically to do a su, but 
> in each case I still got the shift I described.  I can report, however, 
> that xrefresh works well. :-)

It's conceivable that our version of xterm doesn't do the proper suid
calls (or maybe it's not installed suid).  I know that the 1.3 version of
xconsole _does_ work when installed properly (I tried it the other night).
 
> Note also that I am running GENERICSBC#56, so if this option needs to be 
> compiled into the kernel, it would appear it was not compiled into 
> GENERICSBC#56.

The option is definitely there.  It has been in the GENERIC config files
since 1.2C, I think.

> >> On Mon, 16 Feb 1998, T. Sean (Theo) Schulze wrote:
> >> 
> >> > Whenever I am running X under my own account and I su to root in one of 
> >> > the xterms, the left hand side of the screen shifts up one line.  The 
> >> > shifted section is about as wide as my system prompt, and there is a 
> >> > small one-line high bit of black and white at the bottom left-hand corner 
> >> > of the screen.  All the icons and windows lying on the "fault line" get 
> >> > shifted also, and I usually make the windows into icons or vice versa to 
> >> > get most everything back to looking like it should.  Generally, I have to 
> >> > do something to cause a screen redraw to make it go away completely.
> >> > 
> >> > I suspect what is happening is that somehow after I su, the new system 
> >> > prompt is getting partially printed to the display.  Does anyone else 
> >> > have this problem?  I don't see anything about this in the (April '97) 
> >> > FAQ.  Can I do something to make this stop, or should I just live with 
> >> > it?  I just noticed that even though xset has blanked the screen, when I 
> >> > telneted in and su'd, the blanked screen shifted.
> >
> >Just wondering, what FAQ was this that you were looking at?
> >
> 
> The FAQ I was looking at was the NetBSD/mac68k FAQ with Answers v1.2.1, 
> 21 April, 1997.  I apologize if this is covered in a newer version of the 
> FAQ.  I'll pull down a newer one tonight and go over it.  (Good to be 
> current anyway!)

Ah, there have been at least 2 versions since then.  The latest version
(v1.3.1?) covers through the 1.3 release (no -current yet; I'm not running
it myself, so I don't have much experience with it at this time).  I don't
know if the latest version covers this particular phenomenon.  I'll put it
on the todo list, tho.

> BTW, going back over some messages I had missed over the last couple of 
> weeks, I noticed a reference to trying to solve this problem by editing 
> syslog.conf.  I haven't really look too deaply into that, but I wonder if 
> it would work.  Essentially, I would be trying to get the system to not 
> put up a command prompt in a window.  That could work too well, and when 
> I su'd, I wouldn't have a system prompt at all. :-\

Well, this "solution" is basically to redirect all syslog messages that
would normally go to /dev/console to go somewhere else instead.  It
doesn't have anything to do with the prompt coming up in any window.  The
only real loss for doing this is that you might get a lot of rather
important error messages that only show up in /var/log/messages and not on
the console.  Since most people don't watch /var/log/messages, you could
miss something rather important.

Later.

-- 
Colin Wood                                 cwood@ichips.intel.com
Component Design Engineer - MD6                 Intel Corporation
-----------------------------------------------------------------
I speak only on my own behalf, not for my employer.