#!/bin/sh
 
APP="$(basename "$0")"
 
DB="~/.config/dnsdb.lst"
 
## Arguments ######
 
if [ $# -lt 1 ]; then
  echo
  echo "Usage: $APP <hostname1 [hostname2 [...]]> "
  echo
  echo "Script will test resolution of 'hostname' with DNS servers :"
  awk '{ printf("\n%-15s  %-15s",$1,$2) }' "$DB"
  echo
  echo
  exit 0
fi
 
## Check ######
 
c=0
for target in $* ; do
  c=$((c+1))
  echo "DNS resolution attempts on '$target'"
 
  printf "\n%-15s | %-20s | %-15s | Result" "DNS server" "DNS name" "IP found"
  printf "\n%-15s | %-20s | %-15s | ------" "----------" "--------" "--------"
 
  ## Check #-----
 
  cat "$DB"|while read line ; do
    dns_ip="$(echo "$line"|cut -d':' -f2|awk '{ print $1 }')"
    dns_server="$(echo "$line"|cut -d':' -f2|awk '{ print $2 }'|sed 's/_/ /g')"
    sleep .1
    result="$(dig -4 @$dns_ip $target A 2>/dev/null)"
    str_res=$(echo "$result"|grep -A1 ";; ANSWER"|tail -n1|grep -Fw IN|grep -Fwqs A 
                && echo "OK" 
                || echo "NOK")
    ip_found=$(echo "$result"|grep -A1 ";; ANSWER"|tail -n1|grep -Fw IN|grep -Fw A|awk '{ print $5 }')
    printf "\n%-15s | %-20s | %-15s | $str_res" "$dns_ip" "$dns_server" "$ip_found"
  done
 
  ## Output #-----
 
  printf "\n"
  [ $c -eq $# ] || for i in $(seq 3 -1 0) ; do
    printf "\r[CTRL+C] to abort, waiting ${i}s ..."
    sleep .5
  done
  printf "\r" ; for i in $(seq 1 54) ; do printf " " ; done
 
done
echo