PyGTK/GIO: monitor directory for changes recursively

Question

Take the following demo code (from the GIO answer to this question), which uses a GIO FileMonitor to monitor a directory for changes:

import gio

def directory_c         


        

Answer 1

I'm not sure if GIO allows you to have more than one monitor at once, but if it does there's no* reason you can't do something like this:

import gio
import os

def directory_changed(monitor, file1, file2, evt_type):
    if os.path.isdir(file2):    #maybe this needs to be file1?
        add_monitor(file2) 
    print "Changed:", file1, file2, evt_type

def add_monitor(dir):
    gfile = gio.File(dir)
    monitor = gfile.monitor_directory(gio.FILE_MONITOR_NONE, None)
    monitor.connect("changed", directory_changed) 

add_monitor('.')

import glib
ml = glib.MainLoop()
ml.run()

*when I say no reason, there's the possibility that this could become a resource hog, though with nearly zero knowledge about GIO I couldn't really say. It's also entirely possible to roll your own in Python with a few commands (os.listdir among others). It might look something like this

import time
import os

class Watcher(object):
    def __init__(self):
        self.dirs = []
        self.snapshots = {}

    def add_dir(self, dir):
        self.dirs.append(dir)

    def check_for_changes(self, dir):
        snapshot = self.snapshots.get(dir)
        curstate = os.listdir(dir)
        if not snapshot:
            self.snapshots[dir] = curstate
        else:
            if not snapshot == curstate:
                print 'Changes: ',
                for change in set(curstate).symmetric_difference(set(snapshot)):
                    if os.path.isdir(change):
                        print "isdir"
                        self.add_dir(change)
                    print change,

                self.snapshots[dir] = curstate
                print

    def mainloop(self):
        if len(self.dirs) < 1:
            print "ERROR: Please add a directory with add_dir()"
            return

        while True:
            for dir in self.dirs:
                self.check_for_changes(dir)
            time.sleep(4) # Don't want to be a resource hog

w = Watcher()
w.add_dir('.')


w.mainloop()