X-messages to terminals

* by user
chmod g+r `echo $XAUTHORITY`
So, sender as root:
* Get user's XAUTHORITY file:
/etc/X11/gdm/gdm.conf:
[daemon]
XAuthDir=
UserAuthFile=.Xauthority
* Get user's DISPLAY:
xauth -f <.xauth-file&rt; list | gawk '{print $1}' | grep -v “0.0.0.0”
XAUTHORITY=<user's XAUTHORITY file&rt; DISPLAY=<user's DISPLAY&rt; xmessage “something”