def main():
    """Expected arguments:
    sys.argv[1] - The add/update/delete operation performed by the PD agent
    sys.argv[2] - The file where the new prefix should be written
    sys.argv[3] - The process ID of the L3 agent to be notified of this change
    """
    operation = sys.argv[1]
    prefix_fname = sys.argv[2]
    agent_pid = sys.argv[3]
    prefix = os.getenv('PREFIX1', "::")

    if operation == "add" or operation == "update":
        utils.replace_file(prefix_fname, "%s/64" % prefix)
    elif operation == "delete":
        utils.replace_file(prefix_fname, "::/64")
    os.kill(int(agent_pid), signal.SIGUSR1)
dataset/ETHPy150Open openstack/neutron/neutron/cmd/pd_notify.py/main/original