Focus on a window provided a given PID

activateWindowByPid.sh

#!/usr/bin/env bash

set -o nounset -o noclobber
export LC_ALL=C
export PATH="/bin:/sbin:/usr/bin:/usr/sbin:$PATH"
export PS4=' (${BASH_SOURCE##*/}:$LINENO ${FUNCNAME[0]:-main})  '

function getParent {
	typeset pid="$1"
	awk '$1 == "PPid:"{ print $2}' /proc/$pid/status
}

function windowActivate {
	typeset wid="$1"
	if type -p "wmctrl" >/dev/null; then
		wmctrl -ia "$wid"
		return $?
	elif type -p "xdotool" >/dev/null; then
		xdotool windowactivate "$wid"
		return $?
	else
		echo >&2 "Cannot find wmctrl nor xdotool. Stopping"
		exit 1
	fi
}

function windowList {
	if type -p "wmctrl" >/dev/null; then
		wmctrl -l | awk '{ print $1 }'
	elif type -p "xdotool" >/dev/null; then
		xdotool search --onlyvisible . 2>/dev/null
	else
		echo >&2 "Cannot find xdotool nor wmctrl. Stopping"
		exit 1
	fi
}

function windowGetPid {
	typeset wid="$1"

	if type -p "xprop" >/dev/null; then
		typeset wpid="$(xprop -id "$wid" _NET_WM_PID)"
		echo "${wpid##* }"
	elif type -p "xdotool" >/dev/null; then
		xdotool getwindowpid "$wid" 2>/dev/null
	else
		echo >&2 "Cannot find xprop nor xdotool. Stopping"
		exit 1
	fi
}

# List all window, and their associated PID
typeset -A pid2window
for wid in $(windowList); do
	typeset wpid="$(windowGetPid "$wid")"
	if [[ -n "$wpid" ]]; then
		pid2window[$wpid]+="$wid "
	fi
done

if [[ $# -ne 1 ]]; then
	cat <<-EOT
		Usage: $0 <pid>

		Will focus the window hosting the provided PID.
		Requires at least xdotool or wmctrl to work.
		EOT
	exit 0
fi


typeset pid="$1"
# Take our target pid and check it and its parents until we find a window
while [[ -n "$pid" ]] && [[ -e "/proc/$pid/" ]]; do

	if (set +u; [[ -n "${pid2window[$pid]}" ]] ); then
		for wid in ${pid2window[$pid]}; do
			echo "Trying to activate window $wid (pid $pid)"
			windowActivate $wid && exit 0
		done
		exit $?
	fi

	echo "No window matched pid $pid. Trying its parent"
	pid=$(getParent "$pid")
done

exit 1