A simple script to verify that the DNS update has propagated (Bash/Unix)

Same premise as the Windows/powershell one, but this is for Bash / Unix.

while(true); do

for domain in `cat domains.txt`; do

echo -en $domain ":" ;

for i in dnsserver1 dnsserver2 dnsserver3 ; do echo -en $i $(dig +short NS @$i $domain | grep dns.ap | wc -l) "\t";

done;

echo "" ;
done ;
sleep 10;
clear;

done