Removes old entries of local hostname from the hosts file since the REH EC2 image inserts a new entry every reboot

ora-ec2hosts

#! /bin/sh  -x
#
# chkconfig: 2345 96 99
# description: removes old entries for this server name from the host file
# 	add then adds the correct hosts entry
#
hname=`hostname`
lev=`who -r`
echo "Called with ${1} hostname=${hname} ${lev}" | logger -t 'ora-ec2hosts'
	
case $1 in
'start')
	#get the real local ip
	ip="`/sbin/ifconfig eth0 | grep "inet addr" | awk '{print $2}' | awk -F: '{print $2}'`"

	#get the the ip of where the hostname (host file) resolves
	ping -c 1 -w 1 `hostname` | grep "PING" > /tmp/hostip.txt
	hostip=`sed "s/PING.* (\([^)]*\).*//" < /tmp/hostip.txt`

	echo "real=${ip} hostsetto=${hostip}" | logger -t 'ora-ec2hosts'

	# compare and replace if not the same
	if [ "${ip}" != "${hostip}" ]
	then
		# first delete the old entries
		cp -u /etc/hosts /etc/hosts.bak
		sed "/$hname/d" /etc/hosts > /tmp/sedr1.txt
		sed "/$ip/d" /tmp/sedr1.txt > /etc/hosts

		# replace
		echo "${ip}         ${hname}" >> /etc/hosts
		echo "now ${hname} set to =${ip}" | logger -t 'ora-ec2hosts'
	fi
	
	# so the backup is never overwritten again
	touch /etc/hosts.bak 
      	;;
*)
      	echo 'usage: $1 {start}'
      	exit
      	;;
esac
#
exit