Function _prefixlenToNetmask

vrtManager/IPy.py:1285–1296

Return a mask of n bits as a long integer. From 'IP address conversion functions with the builtin socket module' by Alex Martelli http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/66517

(prefixlen, version)

def _prefixlenToNetmask(prefixlen, version):
    """Return a mask of n bits as a long integer.

    From 'IP address conversion functions with the builtin socket module'
    by Alex Martelli
    http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/66517
    """
    if prefixlen == 0:
        return 0
    elif prefixlen < 0:
        raise ValueError, "Prefixlen must be > 0"
    return ((2L << prefixlen - 1) - 1) << (_ipVersionToLen(version) - prefixlen)


if __name__ == "__main__":