how to check linux X11 version?

Question

I need to read X11 source code, since there are a number of X11 versions, like: X11R1 X11R2 ... X11R7.7

how can I find out which version of X11 my ubuntu 10.04 has installed?

thank you.

Answer 1

Filter the output of the xdpyinfo command

xdpyinfo | grep version

will output something like

version number:    11.0
X.Org version: 1.20.4

Answer 2

To not confuse you too much, just type in the following:

root@your-computer:/# x11 -version

This should provide you the information you were looking for.