Pyinotify

classes

WatchManager

• wm = pyinotify.WatchManager()
• The watch manager stores the watches and provides operations on watches.
• dict_of_watch_descriptors = wm.add_watch( '/dir', event_flags)
  • sym links not followed
  • can also call with rec=True for recursive
  • dict_of_watch_descriptors = { keys: path; values: corresponding watch descriptors }
  • to look for new directories created, use arg auto_add=True and make sure to search with flag pyinotify.IN_CREATE

ProcessEvent

• class myEventHandler( pyinotify.ProcessEvent ): ...
• Fires off methods whose name follows convention def process_EVENT_TYPE( self, event ):
  • use "process_default" method as a catchall with the lowest precedence

Notifier

• notifier = pyinotify.Notifier( wm, instanceOfMyventHandler )
  • can also call with arg timeout=10 seconds if you don't want to block
• notifier.loop() to start polling, will block until SIGINT is sent
  • can add as optional argument to loop( callback=somefunction )
• Don't forget to call notifier.stop() when finished (e.g., in a finally block of a try-catch-finally block)
• Coalesce multiple open-write-close events into one using notifier.coalesce_events() while using a notifier with a timeout

Example

#!/usr/bin/env python

import pyinotify
import os
import stat

def ProcessFile( path ):
	print "Processing " + path

class onImageSavedToDisk( pyinotify.ProcessEvent ):
	def process_IN_CLOSE_WRITE( self, event ):
		print "close-write: {0} raised a {1} event.".format( event.pathname, event.maskname )
		if os.stat( event.pathname )[ stat.ST_SIZE ] > 1:
			ProcessFile( event.pathname )


wm = pyinotify.WatchManager()

# create a notifier that checks the target directory every 5 seconds
handler = onImageSavedToDisk()
notifier = pyinotify.Notifier( wm, read_freq=5, default_proc_fun=handler )

# The reason why we only check every 5 seconds is that we coalesce 
# multiple open-write-close notifications 
notifier.coalesce_events()

wm.add_watch( '/home/colettace/tmp', pyinotify.IN_CLOSE_WRITE )# , rec=True, auto_add=True ) 

try:
	notifier.loop()
finally:
	notifier.stop()