When under kubuntu enter command xhost + I got answer:
access control disabled, clients can connect from any host
But when try running X application under different user (su - username) I got answer:
Error: Can't open display:
Connected link:"Can't open display" even after access with xhost
EDIT
Yes, $DISPLAY was empty. I obviously get used that it is always set correctly. Thanks Arjen.
1 Answer
X-applications try to connect to the X-server that is referred to in the environment variable DISPLAY. Enter echo $DISPLAY to show its current value. It should look like :0 or localhost:0.
When starting the su-shell with su - username, all environment variables will be cleared. This is a security measure.
You can start the X application in su-mode with DISPLAY=:0 xapplication (substitute :0 with the value that was shown with the echo command).
