The current display settings File

[Parameshwara Bhat]

Hello List,

Where is the current display selection stored?(Which file?)or how can 
you find out the present X display settings (resolution,depth,
frequency etc.,)

xorg.cong / XFree86.Config files list all possible display "mode"s. 
How to know which one of them is curently selected ? Is there a 
command to show current settings and change that other than the 
graphical UI?

Thanking in advance,

Parameshwara Bhat