Co je dns dotazy

dotazu dns

read -p 'enter a domain ' c;for i in $(seq 1 8);do for a in $(echo ns`echo $i`.dynamichosting.cloud);do dig  $c +short @$a;echo $a;done;done | grep -A1 '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}'  | tail -n 4 ;d=$(for i in $(seq 1 8);do for a in $(echo ns`echo $i`.dynamichosting.cloud);do dig  $c +short @$a;echo $a;done;done | grep -o '[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}\.[0-9]\{1,3\}'); e=$(echo $d | awk '{print $1}');host $e