import time

import logging

import os

import stat

def now():

    return time.strftime("%Y-%m-%d %H:%M:%S");

def log(msg):

    logging.log(logging.DEBUG, msg)

    new_msg = "[%s] %s" % (now(), msg)

    return new_msg

bin_path_list = os.environ["PATH"].split(os.pathsep)

def which(prg):

    for d in bin_path_list:

        path = os.path.join(d, prg)

        if os.path.exits(path):

            st = os.stat(path)

            if st[stat.ST_MODE] & 0111:

                return path

    return ""