Example a work with inotify in Python

inotify_example.py

import os
import sys
import struct
from collections import namedtuple

from ctypes import\
    CDLL,\
    CFUNCTYPE,\
    c_int,\
    c_char_p,\
    c_uint32

from ctypes.util import find_library


libc_name = None
try:
    libc_name = find_library("c")
except (OSError, IOError):
    libc_name = 'libc.so.6'


libc = CDLL(libc_name, use_errno=True)

if(not hasattr(libc, 'inotify_init') or
   not hasattr(libc, 'inotify_add_watch') or
   not hasattr(libc, 'inotify_rm_watch')):
    print "libs not supported inotify_init, inotify_add_watch, inotify_rm_watch"

inotify_init = CFUNCTYPE(c_int, use_errno=True)(("inotify_init", libc))

inotify_add_watch = CFUNCTYPE(
    c_int, c_int, c_char_p, c_uint32, use_errno=True)(("inotify_add_watch", libc))

inotify_rm_watch = CFUNCTYPE(c_int, c_int, c_uint32, use_errno=True)(
    ("inotify_rm_watch", libc))


InotifyEvent = namedtuple("InotifyEvent", ["wd", "mask", "cookie", "len", "name"])


def parse_event_buffer(event_buffer, events_list):
    """
        struct inotify_event {
            __s32 wd;            /* watch descriptor */
            __u32 mask;          /* watch mask */
            __u32 cookie;        /* cookie to synchronize two events */
            __u32 len;           /* length (including nulls) of name */
            char  name[0];       /* stub for possible name */
        };
    """
    while len(event_buffer) > 16:
        data = struct.unpack_from('iIII', event_buffer)

        name = event_buffer[16:16 + data[3]].rstrip('\0')
        inotify_event = InotifyEvent(*data, name=name)
        event_buffer = event_buffer[16 + inotify_event.len:]
        events_list.append(inotify_event)

    return event_buffer

IN_ACCESS = 0x00000001     # File was accessed.
IN_MODIFY = 0x00000002     # File was modified.
IN_ATTRIB = 0x00000004     # Meta-data changed.
IN_CLOSE_WRITE = 0x00000008     # Writable file was closed.
IN_CLOSE_NOWRITE = 0x00000010     # Unwritable file closed.
IN_OPEN = 0x00000020     # File was opened.
IN_MOVED_FROM = 0x00000040     # File was moved from X.
IN_MOVED_TO = 0x00000080     # File was moved to Y.
IN_CREATE = 0x00000100     # Subfile was created.
IN_DELETE = 0x00000200     # Subfile was deleted.
IN_DELETE_SELF = 0x00000400     # Self was deleted.
IN_MOVE_SELF = 0x00000800     # Self was moved.

EVENT_BUFFER_SIZE = 1024

inotify_fd = inotify_init()
if(inotify_fd == -1):
    sys.exit(-1)

wd = inotify_add_watch(inotify_fd, "example.txt", IN_ACCESS | IN_ATTRIB | IN_MODIFY)


events_list = []

event_buffer = ""
while True:
    event_buffer += os.read(inotify_fd, EVENT_BUFFER_SIZE)
    event_buffer = parse_event_buffer(event_buffer, events_list)
    if events_list:
        event = events_list.pop()
        print event

inotify_rm_watch(inotify_fd, wd)
os.close(inotify_fd)