Mailinglist Archive: opensuse-kde (310 mails)

[Robb Romans <robb@xxxxxxxxxxxx>]

On Wed, 8 May 2002, AnonymousCoward wrote:

> > Yes, and you will have to "export DISPLAY=:0.0" from the root login, as
> > well.
> >
> > Another way in your root console is:
> > # xauth merge /home/username/.Xauthority
> > # export DISPLAY=:0.0
> >
> > This will not require opening up xsessions to everyone via xhost +.
> >
> > 		Regards,
> > 		Robb
> 
> Dude you might have lost me here.
> 
> I understand these need to be entered in a root console, but I can't fathom 
> what they do.  And presumably the 'export DISPLAY' command would have to be 
> done on every reboot?

The first xwindows session started, whether via the startx command or on
boot via xdm, kdm, etc., is almost always named 0.0  When you execute a
graphical program as another user than whom started the windowmanager, you
need to tell the program what display to run on - hence the "export
DISPLAY=:0.0" And no, environment variables like DISPLAY do not survive a
reboot unless they are picked up on login from a file like .profile.

Each xsession, or more simply when you start a windowmanager, has a
security token associated with it that is unique to the user who started
it. The "xauth merge" command tells the xserver to combine the tokens and
let the new user (root in this case) have access to the display.

The reason I don't like the "xhost +localhost" command is that it lets ANY
user access your screen if they know how and consequently see anything
that you type. If you simply type "xhost +" as some suggest, you let ANY
user on ANY machine whether local to that machine or any machine on the
network (think Internet) access your display data.

Better to use ssh -X (hint: rtfm)  or the xauth command.

> The terms "opening up xsessions" and "via xhost +" are unfamiliar.  Any 
> enlightenment appreciated.

I've tried to help and may have missed some details, so see the man pages
if you want more.

		Regards,
		Robb

-- 
Robb Romans
Linux Commando
k i l l s o f t .com

"so then let us not sleep as others do, but let us be alert and sober."
	1 Thessalonians 5:6