Lock
dbus-send --type=method_call --dest=org.gnome.ScreenSaver /org/gnome/ScreenSaver org.gnome.ScreenSaver.Lock
Unlock
sleep 5; xdotool type <your pass>; xdotool key Return
Lock
dbus-send --type=method_call --dest=org.gnome.ScreenSaver /org/gnome/ScreenSaver org.gnome.ScreenSaver.Lock
Unlock
sleep 5; xdotool type <your pass>; xdotool key Return