debian:~# su - adam
adam@debian:~$ export DISPLAY=":0"
adam@debian:~$ xrandr
 SZ:    Pixels          Physical       Refresh
*0   1280 x 1024   ( 339mm x 271mm )  *60
 1   1024 x 768    ( 339mm x 271mm )   85
 2    800 x 600    ( 339mm x 271mm )   85
 3    640 x 480    ( 339mm x 271mm )   85
Current rotation - normal
Current reflection - none
Rotations possible - normal left inverted right
Reflections possible - none
adam@debian:~$