Clean-up script

#!/bin/sh
if ! grep -q 127.0.0.1 "/etc/resolv.conf"; then
  echo "nameserver 127.0.0.1" >> /etc/resolv.conf
fi
 
IP4="$( ip route get 8.8.8.8 | awk 'NR==1 {print $NF}' )"
IP6="$( ip -6 addr | grep inet6 | awk -F '[ \t]+|/' '{print $3}' | grep -v ^::1 )"
grep -rl 65.49.80.106 /etc | xargs sed -i "s/65.49.80.106/$IP4/g"
grep -rl fe80::216:3eff:fee5:feb /etc | xargs sed -i "s/fe80::216:3eff:fee5:feb/$IP6/g"