[Guy Harris <gharris@xxxxxxxxx>]

Scott Lowrey wrote:

> If you're logged into your Linux box as a non-root user running KDE, an 
> Ethereal window running as root (via sudo, su, whatever) will not appear 
> on the local display unless you make the change I described  -- on SuSE 
> 9.1 :).
> Maybe it's a root thing - the connection is apparently being made via 
> TCP on the loopback.  Or they're blocking the domain sockets, too, 
> although I doubt that.

That's bizarre.  If DISPLAY is set to :0.0, it shouldn't be connecting 
over TCP.  What does "sudo env" report the value of DISPLAY as?

Access over UNIX-domain sockets is, I think, authenticated based on the 
user ID of the connecting process on at least some platforms where 
credentials can be sent over the socket; this includes Linux.  It 
*might* be that if the connection fails over the UNIX-domain socket, 
XLib tries doing a TCP connection to localhost:6000, in which case doing 
an xhost to allow root to open windows locally should work as well 
(without exposing your X server to other hosts on the network).