#!/bin/sh

MENUS=/usr/src/usr.sbin/sysinstall/menus.c

NTP_LIST="$(cat $MENUS | grep ntpdate_flags= | sed -e s'/\"ntpdate_enable=YES,ntpdate_flags=//g' | sed -e 's/\".*//g')"

echo "Could not find following NTP servers in DNS:" 
echo "==========================================="
for NTP_SERVER in $NTP_LIST
do
   host $NTP_SERVER > /dev/null
   if [ $? -ne 0 ]
   then
      grep $NTP_SERVER $MENUS | grep -v ntpdate
   fi
done
echo "==========================================="