Update /etc/hosts with IP address assigned through DHCP

My /etc/hosts file looks something like:

127.0.0.1       localhost
127.0.1.1       shihabpc

The host name shihabpc should be mapped to my network's IP address; not to a loop back IP address like 127.0.1.1. This is some how mandatory for RMI to work properly.
But the problem is that I have used DHCP to assign IP address and that is changed from one boot to another. So I have to change the /etc/hosts file every time my IP address changes.
So, I have written a script to update /etc/hosts:

#!/bin/sh
# /home/shihab/fixhosts.sh

file=/etc/hosts
interface=eth0

ip=`ip addr show $interface`
ip=`echo "$ip" | grep "inet "`
ip=`echo "$ip" | cut -d "i" -f 2`
ip=`echo "$ip" | cut -d " " -f 2`
ip=`echo "$ip" | cut -d / -f 1`

hostname=`hostname`

found=0
while read line
do
  if [ "`echo "$line" | grep $hostname`" != "" ]; then
    line="$ip $hostname"
    found=1
  fi
  if [ -z "$text" ]; then
    text="$line"
  else
    text="$text\n$line"
  fi
done < $file

if [ found = 0 ]; then
  text="$text\n$ip $hostname"
fi

echo -e "$text" > $file

And added it as an init.d script:

#!/bin/sh
# /etc/init.d/fixhosts

case "$1" in
start)
    /home/shihab/fixhosts.sh
    ;;
stop)
    # do nothing ;)
    ;;
restart)
    $0 stop
    $0 start
    ;;
*)
    echo "usage: $0 (start|stop|restart|help)"
esac

$sudo update-rc.d fixhosts defaults 99

That's it! :-)