Whois with lookup against registrar

whois.sh

#!/bin/bash

set -e
set -o pipefail

BIN="/usr/bin/whois"
DOMAIN=$1

echo "Fetching domain's whois server..."
RES=$($BIN $DOMAIN)
SERVER=$(echo "$RES" | grep -i whois\ server: | head -1 | awk '{print $NF'})
if [[ $SERVER ]]; then
        echo "Querying whois server '$SERVER'..."
        # Avoid rate-limiting
        sleep 1
        $BIN -h $SERVER $DOMAIN
else
        echo "$RES"
fi

exit 0