DNS ping test for selecting the fastest

testdns.sh

#!/usr/bin/env bash
# execute testdns.sh
command -v bc > /dev/null || { echo "bc was not found. Please install bc."; exit 1; }
{ command -v drill > /dev/null && dig=drill; } || { command -v dig > /dev/null && dig=dig; } || { echo "dig was not found. Please install dnsutils."; exit 1; }
NAMESERVERS=`cat /etc/resolv.conf | grep ^nameserver | cut -d " " -f 2 | sed 's/\(.*\)/&#&/'`
PROVIDERS="
1.1.1.1#cloudflare 
4.2.2.1#level3 
8.8.8.8#google 
9.9.9.9#quad9 
80.80.80.80#freenom 
208.67.222.123#opendns 
199.85.126.20#norton 
185.228.168.168#cleanbrowsing 
77.88.8.7#yandex 
176.103.130.132#adguard 
156.154.70.3#neustar 
8.26.56.26#comodo
192.168.1.1#192.168.1.1
192.168.0.1#192.168.0.1
185.3.119.14#vivancos.eu
193.142.146.117#vps2
140.238.168.70#vps3
"
# Dominios test.
DOMAINS2TEST="www.google.com amazon.com facebook.com www.youtube.com www.reddit.com  wikipedia.org twitter.com gmail.com www.google.es whatsapp.com forocoches.es"
totaldomains=0
printf "%-18s" ""
for d in $DOMAINS2TEST; do
    totaldomains=$((totaldomains + 1))
    printf "%-8s" "test$totaldomains"
done
printf "%-8s" "Average"
echo ""
for p in $NAMESERVERS $PROVIDERS; do
    pip=${p%%#*}
    pname=${p##*#}
    ftime=0
    printf "%-18s" "$pname"
    for d in $DOMAINS2TEST; do
        ttime=`$dig +tries=1 +time=2 +stats @$pip $d |grep "Query time:" | cut -d : -f 2- | cut -d " " -f 2`
        if [ -z "$ttime" ]; then
         #let's have time out be 1s = 1000ms
         ttime=1000
        elif [ "x$ttime" = "x0" ]; then
         ttime=1
     fi
        printf "%-8s" "$ttime ms"
        ftime=$((ftime + ttime))
    done
    avg=`bc -lq <<< "scale=2; $ftime/$totaldomains"`
    echo "  $avg"
done
exit 0;