#! /bin/sh

FILE='/etc/resolv.conf'
CONTENT=\
'nameserver 167.206.13.180
nameserver 167.206.13.181
nameserver 192.168.1.1'

uncommented() {
	echo "$CONTENT"
}

commented() {
	for line in "$CONTENT"
	do
		echo "$line" | sed 's/^/#/'
	done
}

switch_on() {
	chattr -i "$FILE"  # Make mutable
	rm -f "$FILE"
	uncommented > "$FILE"
	chmod a+r "$FILE"
}

switch_off() {
	rm -f "$FILE"
	commented > "$FILE"
	chmod a-rw "$FILE"
	chattr +i "$FILE"  # Make immutable
}

case "$1" in
	'on' ) switch_on;;
	'off') switch_off;;
	'')
		echo "usage: $0 SWITCH\n\nSWITCH = on | off"
		exit 1;;
esac