Which window has current focus?

Question

I'd like to know (programmatically) which window has current focus. Is there a window-manager independent way of discovering that?

Otherwise, how does one determine which window has focus in Compiz or Metacity?

Answer 1

What you want is libwnck (if you're just interested in windows) or libbamf (if you're interested in windows and the applications that own them).

Answer 2

If you're happy doing a little X11 programming, then the EWMH spec is what you're after - specifically _NET_ACTIVE_WINDOW.

Answer 3

Well if you can ping something back to the shell:

xdpyinfo | grep focus

Should work.

Edit: For slightly cleaner output, try this:

xdpyinfo | grep -Eo 'window 0x[^,]+' | cut -d" " -f2

Answer 4

Another thing you can use is xdotool:

xdotool getwindowfocus

would return the Window ID of the focussed window, and:

xdotool getwindowfocus getwindowname

would tell you its name.

Answer 5

From info xtool:

getactivewindow
   Output the current active window. This command is often more
   reliable than getwindowfocus. The result is saved to the window
   stack. See "WINDOW STACK" for more details.

This is what I use for getting the title. (I an on 10.04)

xwininfo -id "$(xdotool getactivewindow)" |sed -n \
  "2s/^xwininfo: Window id: \(0x[[:xdigit:]]\+\) \x22\(.*\)\x22$/\2/p"