To know if domain has dns active.

altDomainTaken.sh

#!/usr/bin/env bash
v=`whois $1 | grep match | wc | awk '{print $1}'`
 
if [ $v = 0 ];
then
	echo "$1 is taken"
else
	echo "I don't know if $1 is taken"
fi

domainTaken.sh

#!/usr/bin/env bash

n=`nslookup $1 1.1.1.1 | grep 'Name' | wc | awk '{print $1}'`

if [ $n = 0 ];
then
	echo "I don't know if $1 is taken"
else
	echo "$1 is taken"
fi