#!/usr/local/bin/bash

col1="\x1b[0;31;40m"
col2="\x1b[0;32;40m"
col3="\x1b[0;33;40m"
col4="\x1b[0;36;40m"
col5="\x1b[0;35;40m"

# edit this line
cachefile='/usr/local/share/cache'

printf "$col1 Hostnames for $HOSTNAME:\n"

while read ip host
do
   ((++i == 1))   && max="$ip" && continue
   [[ -z $host ]] && host="$col5 reverse lookup failed ._."
   printf "$col2%-*s $col3= $col4$host\n" "$max" "$ip"
done < "$cachefile"