netmask

#!/usr/bin/env python
#@auteur : Omar AKHAM
##Masque sous reseau

import sys

def mask_calc(i):
    """function for calculating mask of a given i"""
    netmask = '00000000000000000000000000000000'
    for j in range(i):
        netmask = netmask[:j]+'1'+netmask[j+1:]
    SEG1 =  netmask[:8]
    SEG2 = netmask[8:16]
    SEG3 = netmask[16:24]
    SEG4 = netmask[24:]
    bin_mask = SEG1+'.'+SEG2+'.'+SEG3+'.'+SEG4
    dec_mask = str(int(SEG1,2))+'.'+str(int(SEG2,2))+'.'+str(int(SEG3,2))+'.'+str(int(SEG4,2))
    return dict(_bin=bin_mask, _dec=dec_mask)
    
if len(sys.argv) == 1:
    for i in range(0,33):
        mask = mask_calc(i)
        print '/%d \t %s \t %s'%(i, mask['_dec'],mask['_bin'])
        if i in [8,16,24,32]:
            print '\n'
elif len(sys.argv) == 2:
    i = int(sys.argv[1])
    mask = mask_calc(i)
    print '/%d \t %s \t %s'%(i, mask['_dec'],mask['_bin'])