#!/bin/bash
#Simple script to use standard DNS if Unbound (behind Adguard) is unavailable for some reason
if [[ -z $1 ]]; then
	SECONDS=0
#	^ If nothing is specified, do not wait
else
	SECONDS=$1
#       ^ If specified, wait however many seconds user specifies
fi
sleep $SECONDS
if ! nc -vz localhost 53 >/dev/null 2>&1; then
#	    ^ If you cannot connect to DNS port on local host
	sed -i -e 's/192.168.0.66/1.1.1.1/g' /etc/resolv.conf
#	^ replace local address with 1.1.1.1 (Cloudflare DNS)
else
	sed -i -e 's/1.1.1.1/192.168.0.66/g' /etc/resolv.conf	
#	^ If connection is established, use local DNS
fi
#Force update of DNS resolution
/sbin/netconfig update -f