サブネット計算機

ipcalc.py

#!/usr/bin/python
# ip address util by Keiya Chinen

def binary_ip(dec_ip):
    ip_l = dec_ip.split('.')
    ip = (int(ip_l[0]) << 24) | (int(ip_l[1]) << 16) | (int(ip_l[2]) << 8) | int(ip_l[3])
    return ip

def decimal_ip(bin_ip):
    return (bin_ip >> 24, bin_ip >> 16 & 0xff, bin_ip >> 8 & 0xff, bin_ip & 0xff)

if __name__ == '__main__':
    ip = '192.168.129.1'
    mask = '255.255.255.0'

    # test code
    # print('{0[0]}.{0[1]}.{0[2]}.{0[3]}'.format(decimal_ip(binary_ip(ip))))

    # calculates subnet address by [ip AND subnet-mask]
    net = binary_ip(ip) & binary_ip(mask)
    print('subnet numeric: {0}'.format(net))

    # then, convert to human readable
    net_h = decimal_ip(net)
    print('subnet ip: {0[0]}.{0[1]}.{0[2]}.{0[3]}'.format(net_h))