Get the IP address the DHCP server assigns and make it a static one for Ubuntu

ipaddr_ubuntu.sh

#!/bin/bash

# Set the LANG to C
LANG=C

# Acquiring the IP address
echo "[`date '+%Y/%m/%d %H:%M:%S'`] Acquiring the IP address." >> /tmp/static_ip.log

IP=`/sbin/ifconfig eth0 | grep 'inet addr' | awk '{print $2;}' | cut -f2 -d':'`

echo "[`date '+%Y/%m/%d %H:%M:%S'`] IP address is: $IP" >> /tmp/static_ip.log

# Back up the /etc/network/interfaces
echo "[`date '+%Y/%m/%d %H:%M:%S'`] Back up the /etc/network/interfaces." >> /tmp/static_ip.log

/bin/mv /etc/network/interfaces /etc/network/interfaces.`date '+%Y%m%d%H%M%S'`

# Generating the interfaces file:
echo "[`date '+%Y/%m/%d %H:%M:%S'`] Generating the /etc/network/interfaces file." >> /tmp/static_ip.log

echo "# Generating the interfaces file" >> /etc/network/interfaces
echo "# This file describes the network interfaces available on your system" >> /etc/network/interfaces
echo "# and how to activate them. For more information, see interfaces(5)." >> /etc/network/interfaces
echo "" >> /etc/network/interfaces
echo "# The loopback network interface" >> /etc/network/interfaces
echo "auto lo" >> /etc/network/interfaces
echo "iface lo inet loopback" >> /etc/network/interfaces
echo "" >> /etc/network/interfaces
echo "# The primary network interface" >> /etc/network/interfaces
echo "auto eth0" >> /etc/network/interfaces
echo "iface eth0 inet static" >> /etc/network/interfaces
echo "        address $IP" >> /etc/network/interfaces
echo "        netmask 255.255.255.0" >> /etc/network/interfaces
echo "        network 192.168.11.0" >> /etc/network/interfaces
echo "        broadcast 192.168.11.255" >> /etc/network/interfaces
echo "        gateway 192.168.11.1" >> /etc/network/interfaces

echo "[`date '+%Y/%m/%d %H:%M:%S'`] Finished generating the /etc/network/interfaces file." >> /tmp/static_ip.log