using select.kqueue for monitoring a file

test_kqueue.py

#!/usr/bin/python
# -*- coding: utf-8 -*-
# Copyright : (c) SAEKI Yoshiyasu
# License   : MIT-style license
#             <http://www.opensource.org/licenses/mit-license.php>
# last updated: 2011/05/07

import select
# import os

f = open("foo")
# when monitoring a directory: f = os.open("foo", os.O_RDONLY)
kq = select.kqueue()
ke = select.kevent(f, filter=select.KQ_FILTER_VNODE,
                   flags=select.KQ_EV_ADD | select.KQ_EV_ENABLE | select.KQ_EV_CLEAR,
                   fflags=select.KQ_NOTE_DELETE | select.KQ_NOTE_WRITE)
events = kq.control([ke], 0, None)
while True:
    r_events = kq.control([ke], 1, None)
    for event in r_events:
        print event
        if event.fflags & select.KQ_NOTE_DELETE:
            print "file was deleted!"
        elif event.fflags & select.KQ_NOTE_WRITE:
            print "file was updated!"
f.close()