#!/bin/bash

arp-scan -l | grep '^[0-9]*\.' | while read line
 do
   set $line
   ip="$1"
   mac="$2"
   rest="$3 $4 $5 $6 $7 $8 $9"
   name=$(dig -x ${ip} +short)
   if [[ "X${name}" == "X" ]]
    then
      name='unknown'
    else
      name=$(echo ${name} | sed 's/\.$//')
    fi
   printf "%30s %15s %18s " ${name} ${ip} ${mac} 
   echo ${rest}
 done