Ubuntu: How to send a “close” command to a window with a title matching a regex?

Question

I need to programatically close a window in some program, based on the window title.

Is there a tool or a built-in system command I can use for that?

Answer 1

wmctrl can close a window based on a substring or exact match of the window title (wmctrl -c 'substring' or wmctrl -F -c 'exact match').

If you need more control, you can parse wmctrl -l, extract the matching window IDs and pass them to wmctrl -i -c. You can use wmctrl -x -l and match the class as well; in fact, I recommend it, since applications you haven't thought about might have windows with the same title.