autocmd.py

#!/usr/bin/env python
"""$ python autocmd.py /exam/ple .txt,.html /pri/vate some_script.pl

Answer for http://stackoverflow.com/questions/1533923/monitor-folder-for-new-files-using-unix-ksh-shell-script-or-perl-script-and-trigg

Adopted from autocompile.py [1] example.

[1] http://git.dbzteam.org/pyinotify/tree/examples/autocompile.py

Advantages:

- easier to install than ``inocron`` due to pyinotify is pure Python
- event-driven -- less impact than the perl script

Dependencies:

Linux, Python 
"""
import os, shutil, subprocess, sys

import pyinotify
from pyinotify import log

class Handler(pyinotify.ProcessEvent):
    def my_init(self, **kwargs):
        self.__dict__.update(kwargs)

    def process_IN_CLOSE_WRITE(self, event):
        # file was closed, ready to move it
        if event.dir or os.path.splitext(event.name)[1] not in extensions:
           # directory or file with uninteresting extension
           return # do nothing
       
        try:
            log.debug('==> moving %s' % event.name)
            shutil.move(event.pathname, os.path.join(self.destdir, event.name))
            cmd = self.cmd + [event.name]
            log.debug("==> calling %s in %s" % (cmd, self.destdir))
            subprocess.call(cmd, cwd=self.destdir)
        except (IOError, OSError, shutil.Error), e:
            log.error(e)

    def process_default(self, event):
        pass


def mainloop(path, handler):
    wm = pyinotify.WatchManager()
    notifier = pyinotify.Notifier(wm, default_proc_fun=handler)
    wm.add_watch(path, pyinotify.ALL_EVENTS, rec=True, auto_add=True)
    log.debug('==> Start monitoring %s (type c^c to exit)' % path)
    notifier.loop()


if __name__ == '__main__':
    if len(sys.argv) < 5:
       print >> sys.stderr, "USAGE: %s dir ext[,ext].. destdir cmd [args].." % (
           os.path.basename(sys.argv[0]),)
       sys.exit(2)

    path = sys.argv[1] # dir to monitor
    extensions = set(sys.argv[2].split(','))
    destdir = sys.argv[3]
    cmd = sys.argv[4:]

    log.setLevel(10) # verbose

    # Blocks monitoring
    mainloop(path, Handler(path=path, destdir=destdir, cmd=cmd))