[people/ms/dnsmasq.git] / contrib / reverse-dns / reverse_dns.sh

#!/bin/bash
# $Id: reverse_dns.sh 4 2015-02-17 20:14:59Z jo $
#
# Usage: reverse_dns.sh IP
# Uses the dnsmasq query log to lookup the name 
# that was last queried to return the given IP.
#

IP=$1
qmIP=`echo $IP | sed 's#\.#\\.#g'`
LOG=/var/log/dnsmasq.log

IP_regex='^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$'

if ! [[ $IP =~ $IP_regex ]]; then
  echo -n $IP
  exit
fi

NAME=`tac $LOG | \
  grep " is $IP" | head -1 | \
  sed "s#.* \([^ ]*\) is $qmIP.*#\1#" `

if [ -z "$NAME" ]; then
  echo -n $IP
else
  echo -n $NAME
fi
Commit	Line	Data
47b9ac59 JZ	1	#!/bin/bash
	2	# $Id: reverse_dns.sh 4 2015-02-17 20:14:59Z jo $
	3	#
	4	# Usage: reverse_dns.sh IP
	5	# Uses the dnsmasq query log to lookup the name
	6	# that was last queried to return the given IP.
	7	#
	8
	9	IP=$1
	10	qmIP=`echo $IP \| sed 's#\.#\\.#g'`
	11	LOG=/var/log/dnsmasq.log
	12
	13	IP_regex='^[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$'
	14
	15	if ! [[ $IP =~ $IP_regex ]]; then
	16	echo -n $IP
	17	exit
	18	fi
	19
	20	NAME=`tac $LOG \| \
	21	grep " is $IP" \| head -1 \| \
	22	sed "s#.* \([^ ]\) is $qmIP.#\1#" `
	23
	24	if [ -z "$NAME" ]; then
	25	echo -n $IP
	26	else
	27	echo -n $NAME
	28	fi
	29