#!/bin/sh

#Some variables
SERVER=$1
QUERY=$2
OPTIONS="+short +timeout=3"

# Usage info
usage() {
  echo "$0 <SERVER> <QUERY>"
}

# Display usage if not all information is supplied
if [ ! $2 ]; then
  usage
  exit 2
fi

# Execute command
OUTPUT=`/usr/local/bin/dig ${OPTIONS} @${SERVER} ${QUERY} 2>&1`
EXIT=$?

# Debug info, only show when debugging (enable manually)
#echo "$EXIT $OUTPUT $SERVER $QUERY"

# Evaluate and display
if [ ${EXIT} = 9 ]; then
  echo "DNS Query Timeout"
  exit 3
elif [ ${EXIT} != 0 -o ! "$OUTPUT" ]; then
  echo "DNS Failed: Error in resolving $QUERY"
  exit 2
else
  echo "DNS OK"
  exit 0
fi