monex.py

#!/usr/bin/env python                                                                    
# encoding: utf-8                                                                       
"""
MONitor & EXecute
Yong-Yeol Ahn (http://yongyeol.com/)
This script monitors multiple files and executes the given command when
any of those files is changed.
"""

import sys
import os
import time
import subprocess
from glob import glob
from optparse import OptionParser
from itertools import izip

def do(command):
    _PIPE = subprocess.PIPE
    p = subprocess.Popen(command.split(" "), close_fds=True, shell=True, stdin=_PIPE, stdout=_PIPE, stderr=_PIPE)
    (out, err) = p.communicate(input=None)
    if p.returncode is not 0:
        print out + '\n' + err
    else:
        print '%s\tDone (%s).' % (time.strftime('%X %x %Z'), command)

def get_filelist(args):
    files = set()
    for arg in args:
        files |= set(glob(arg))
    return sorted(files)

if __name__=='__main__':
    usage = 'usage: %prog -c "command" file1 file2 ...'
    parser = OptionParser(usage=usage)
    parser.add_option("-c", "--command", dest='command',
                      help="command to be executed")

    (options, args) = parser.parse_args()
    if not options.command:
        parser.error('-c option is needed')
    command = options.command.strip('"')
    files = get_filelist(args)
    print 'monitoring the following files...'
    print '\n'.join(files)
    time.sleep(2)

    old_timestamps = [os.stat(x).st_mtime for x in files]
    do(command)

    while(True):
        curr_timestamps = [os.stat(x).st_mtime for x in files]
        if any(curr != old for curr, old in izip(curr_timestamps, old_timestamps)):     
            do(command)
            old_timestamps = curr_timestamps
        else:
            time.sleep(1)