def strip_server(path):
    """ Removes the server part from xrdfs output.

    Example input:
        root://polgrid4.in2p3.fr:1094//dpm/in2p3.fr/home/cms/trivcat/store/user/rembserj

    Output:
        /dpm/in2p3.fr/home/cms/trivcat/store/user/rembserj

    Note:
        Returns None if the input does not match the right pattern.
    """
    if not path.startswith("root://"):
        return None
    path = path[7:]
    hit = path.find("//")
    if hit < 0:
        return None
    return path[hit + 1 :]