Retrieving network mask in Python

Question

How would one go about retrieving a network device\'s netmask (In Linux preferably, but if it\'s cross-platform then cool)? I know how in C on Linux but I can\'t find a way

Answer 1

Did you look here?

http://docs.python.org/library/fcntl.html

This works for me in python 2.5.2 on Linux. Was finishing it when Ben got ahead, but still here it goes (sad to waste the effort :-) ):

vinko@parrot:~$ more get_netmask.py
# get_netmask.py by Vinko Vrsalovic 2009
# Inspired by http://code.activestate.com/recipes/439093/
# and http://code.activestate.com/recipes/439094/
# Code: 0x891b SIOCGIFNETMASK

import socket
import fcntl
import struct
import sys

def get_netmask(ifname):
        s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
        return socket.inet_ntoa(fcntl.ioctl(s.fileno(), 0x891b, struct.pack('256
s',ifname))[20:24])

if len(sys.argv) == 2:
        print get_netmask(sys.argv[1])
vinko@parrot:~$ python get_netmask.py lo
255.0.0.0
vinko@parrot:~$ python get_netmask.py eth0
255.255.255.0