#!/usr/bin/python


import socket

import struct

import fcntl


def getip(ethname):

    s=socket.socket(socket.AF_INET, socket.SOCK_DGRAM)

    return socket.inet_ntoa(fcntl.ioctl(s.fileno(), 0X8915, struct.pack('256s', ethname[:15]))[20:24])


if __name__=='__main__':

    print getip('eth0')