Sorry for the double post, but I just realized this is not a Debian specific issue, and I won't get many reads in Debian.

This error message appears when I try to use synaptic now.

debian:/home/servant# synaptic
Xlib: connection to ":0.0" refused by server
Xlib: Client is not authorized to connect to Server
synaptic:could not open display

Somewhere I read that you must login as root to use synaptic for some reason after something, but I can't find it by searching Google/linux and here. I know the answer is out there, but apparently I'm not entering the right information in my search.

Could someone tell me what it is that I need to change, to run synaptic as root in a terminal but logged in as a user? I'm still Googling and searching as I post.



TIA

Here's what's happening.

When you have an Xserver running, you have a display referenced by the DISPLAY variable.

The user who logged into the Xsession makes connections to $DISPLAY and the Xserver allows the client program to connect using MIT-MAGIC-COOKIES which are to be found in the originating user's $HOME/.Xauthority file.

So if you su to another user and want to start an X program, like synaptic, you have to make sure that the DISPLAY variable is set in order to reference the correct Xserver DISPLAY (could be the local one, or one on the other side of the Internet) and also that you are authorized to do so.

The way that this is easily achieved is by the user who started the Xsession to issue the command

xhost + $HOST

to allow any user on the host reference by $HOST (which should be set to the name of the localhost) to access the resources of his display.

But note that this does have security implications, since it means that any user on the authorized machine can run a program to connect to your
DISPLAY and change any of your X properties and even run a program to capture what is on your screen.

Also, if HOST is not set, the above command become

xhost +

which allows any machine whatsoever to connect.

So please exercise caution.

Thanks.

I'm using debian sarge, and was able to get this to work by issuing:

"xhost + local:localhost"

I can now run synaptic from the kde konsole, where I do most of my root-stuff.

I'm still trying to figure out where I should put this so that it initializes this way every time. Somewhere in the KDE initialization would be nice.

I thinks it's worth quoting something I found at http://www.phy.bnl.gov/cybersecurity/xhost_plus.html

QUOTE> Using "xhost +" allows anyone the ability to watch your keystrokes, capture windows and insert command strings into your windows. This situation is particularly bad when you have root access to a machine. There is no legitimate reason to run "xhost +". <QUOTE

Of course, that's from their perspective. Some might argue that the inability to figure out the intricacies of using "xhost + What-Exactly-Do-I-Type-Here-To-Make-It-Work???" might be a very legitimate reason to just use "xhost +". So if "xhost + local:localhost" doesn't work for you... good luck!!!

~David.