check OpenBSD lid status and reconfigure display/WM accordingly, using autorandr and fvwm2

lid.sh

#!/bin/sh

# make sure the appropriate autorandr configurations exist
for a_status in docked docked_open; do
	autorandr | egrep -q "^$a_status( .*)?$" || \
		{ echo "Error: no autorandr for $a_status"; exit 1; }
done

lid_status=$(sysctl -n hw.sensors.acpibtn0.indicator0 | cut -f1 -d' ')
if [ $lid_status = "On" ]; then		# "On" = lid open
	autorandr -l docked_open 2>&1 | grep -q '^Config already loaded$' && exit
elif [ $lid_status = "Off" ]; then	# "Off" = lid closed
	autorandr -l docked 2>&1 | grep -q '^Config already loaded$' && exit
else
	echo "ERROR: invalid lid status"; exit 1
fi

# Restart fvwm2 (needs Module FvwmCommandS in fvwm2)
/usr/local/bin/FvwmCommand Restart