May 26, 2018

Watch a window on another X server

xwatchwin allows you to peek at a window on another X server. To use it, you must specify the display name of the machine you want to watch, then the name of the window on that machine. Xwatchwin will attempt to connect with the X server hostname0.0, and if successful, will try to retrieve a copy of the window in which you specified interest.

You may specify the window you want to watch either by name or by its window id, usually a hexidecimal number. Usually specifying the window by name is simpler, although not all windows have names associated with them; in that case you must use the window id option.

If the window you want to watch is not in a viewable state, xwatchwin will tell you so and exit. If while you are watching a window it becomes ‘unviewable’, xwatchwin will wait until the window becomes ‘viewable’ again.

xwatchwin was written as an aid to a class for people learning to use X. The idea is that the instructor would type into an xterm window on his/her display and the students would use xwatchwin to see what the instructor typed. The students could then type the same thing in their own terminal windows. Hopefully others will find equally if not more constructive uses.