On a terminal (local terminal or ssh with X11 forwarding), a user can open X application however, another user is not able after suing.
Please see the output below.
u1@cluster:~$ xclock
u1@cluster:~$ su
Password:
root@cluster:# su - u2
[u2@cluster ~]$ xclock
No protocol specified
Error: Can't open display: localhost:11.0
[u2@cluster ~]$
So, what is the solution?
I usually create the following script in either /usr/local/bin or $HOME/bin.
#!/bin/bash
HOSTNAME=`uname -n`
ARG=`echo $DISPLAY | sed -e "s/localhost/$HOSTNAME\/unix/"`
XAUTH=`/usr/bin/xauth -i -f ~/.Xauthority list ${ARG}`
echo "The following is used for graphical displays through ssh."
echo "Copy and paste the following commands AFTER you have \"su - [user]\""
echo "---------------- Copy below ------------------------------------"
echo "DISPLAY=$DISPLAY;export DISPLAY"
echo "/usr/bin/xauth -bi add \\"
echo "${XAUTH}"
echo "---------------- Copy above ------------------------------------"
You would execute this script before using su or sudo. After becoming the other user, cut and paste the output as noted. Your X programs should run.
[bschuck@dhcp-10-100-11-138 ~]$ bin/xtunnel
The following is used for graphical displays through ssh.
Copy and paste the following commands AFTER you have "su - [user]"
---------------- Copy below ------------------------------------
DISPLAY=localhost:10.0;export DISPLAY
/usr/bin/xauth -bi add \
dhcp-10-100-11-138/unix:10 MIT-MAGIC-COOKIE-1 \
b64ace6b49bb1b49c59679a2db6411eb
---------------- Copy above ------------------------------------
[bschuck@dhcp-10-100-11-138 ~]$ su - zippy
Password:
[zippy@dhcp-10-100-11-138 ~]$ DISPLAY=localhost:10.0;export DISPLAY
[zippy@dhcp-10-100-11-138 ~]$ /usr/bin/xauth -bi add \
> dhcp-10-100-11-138/unix:10 MIT-MAGIC-COOKIE-1
b64ace6b49bb1b49c59679a2db6411eb
[zippy@dhcp-10-100-11-138 ~]$ xclock &
[1] 6076
[zippy@dhcp-10-100-11-138 ~]$
