terminal command-completion notifications from inside tmux

command-completion.sh

# Like gnome-terminal's command-completion notifications, but usually run
# everything within a tmux window? No problem: add this to your .bashrc, and
# make sure `xdotool` is installed. Adjust the `notify-send` command line to
# taste.
#
# THIS DOESN'T WORK WITH WAYLAND. If you're on Wayland, let me know if you
# come up with a reliable way to identify the currently-focused window.
function notify_finished() {
    # If we're not in tmux, fall back to gnome-terminal's notification.
    [[ -z $TMUX_PANE ]] && __vte_prompt_command && return

    # On Xorg, gnome-terminal and others make WINDOWID available to shells,
    # which we can compare to the active window to see if focus is elsewhere.
    if [[ $WINDOWID != $(xdotool getactivewindow) ]]
    then
        local hist
        hist="$(history 1)"
        notify-send -a 'bash' -i utilities-terminal \
          'Command completed' "${hist:7}"
    fi
}
PROMPT_COMMAND="notify_finished"