dnscheck

#!/bin/bash

MAXRTT=0
MINRTT=999
SUM=0

die () {
    printf "Error, exiting: " 1>&2
    echo "$@" 1>&2
    exit 255
}

for X in time bc dig; do
    which "${X}" >/dev/null 2>&1 || die "required application ${X} not found"
done

[ -z ${1} ] && exit 1

BCFUNK="define max(a,b){if(a>b){return(a)}else{return(b)}} define min(a,b){if(a>b){return(b)}else{return(a)}}"

round() {
   echo $(printf %.$2f $(echo "scale=$2;(((10^$2)*$1)+0.5)/(10^$2)" | bc))
};

CT="$(date +%Y%m%d\ %H:%M:%S)"

for ((X=0;X<15;X++)) ; do
    RTT[$X]=$(/usr/bin/time -f %e dig @${1} google.com +short 2>&1 >/dev/null)
done

#get sum & other stuff
for ((X=0;X<15;X++)); do
    SUM=$(echo "${SUM} + ${RTT[$X]}"| bc -l)
    MINRTT=$(echo "${BCFUNK} min(${MINRTT},${RTT[$X]})" |bc -l)
    MAXRTT=$(echo "${BCFUNK} max(${MAXRTT},${RTT[$X]})" |bc -l)
done
#AVG=$(echo ${SUM}/15 |bc -l)
#AVG=$(round $AVG 2)
#printf "Sum of real time for 15 queries: $SUM\n"
#printf "Average query time:              $AVG\n"
#printf "Min RTT:                         $MINRTT\n"
#printf "Max RTT:                         $MAXRTT\n"

printf "$CT $SUM $MINRTT $MAXRTT\n"