#!/bin/bash# Simple Zone Transfer Bash Script# $1 is first argument, if not given after bash script# Check if argument was given, if not, print usageif [ -z"$1" ]; thenecho"[*] Simple Zone Transfer script"echo"[*] Usage : $0 <domain name>"exit0fi# If argument was given, identify the DNS servers for the domain# For each of these servers, attempt a zone transferfor server in$(host-tns $1 |cut-d" " -f4); dohost-l $1 $server |grep"has address"done