Watch Directory For Changes (python)

watchdir.py

import os, time, sys, fnmatch

path_to_watch = "D:/Projects/consumer-purchase-webapp/WebContent/js"

def findCoffeeFiles():
  matches = []
  for root, dirnames, filenames in os.walk(path_to_watch):
    for filename in fnmatch.filter(filenames, '*.coffee'):
      matches.append(os.path.join(root, filename))
  return matches


def out(str):
  print str
  sys.stdout.flush()


def findModified(before, after):
  modified = []
  for (bf,bmod) in before.items():
    if (after[bf] and after[bf] > bmod):
      modified.append(bf)
  return modified
      


out("HELLO")

before = dict ((f, os.path.getmtime(f)) for f in findCoffeeFiles())

while 1:
  time.sleep (1)
  after = dict ((f, os.path.getmtime(f)) for f in findCoffeeFiles())
  added = [f for f in after.keys() if not f in before.keys()]
  removed = [f for f in before.keys() if not f in after.keys()]
  modified = findModified(before,after)
  if added: out("Added: " + ", ".join (added))
  if removed: out("Removed: " + ", ".join (removed))
  if modified: out("Changed: " + ", ".join (modified))
  if (added or removed or modified):
    out("Recompiling...")
    os.chdir("D:/Projects/consumer-purchase-webapp/build")
    os.system("C:/apache-ant-1.7.0/bin/ant compileCoffeescripts")
  before = after

You might just consider inotify functionality to have the kernel watch the directory for you.

I'm using python 3.4 and try to use this script, everything is ok when adding some files, but it goes an error when delete or rename a file. any idea?

This part needs to be modified like this:

after = dict ((f, os.path.getmtime(f)) for f in findCoffeeFiles()) added = [f for f in after.keys() if not f in before.keys()] removed = [f for f in before.keys() if not f in after.keys()] if not removed: modified = findModified(before,after) if added: out("Added: " + ", ".join (added)) if removed: out("Removed: " + ", ".join (removed)) if modified: out("Changed: " + ", ".join (modified))