Handy OUI lookup script reworked for Python 3+ and (hopefully) all platforms

oui3.py

#!/usr/bin/python
 
"""
Who owns the OUI? IEEE knows.
 
Auto-refreshes once a month.
Run with -u to force update.
"""
 
 
from urllib.request import urlopen
from getpass import getuser
import sys
import time
import os
import re
 
USER_HOME = "~" + getuser()
OUI_FILE_STORE = os.path.join(os.path.expanduser(USER_HOME), ".oui-cache")
CACHE_TIME = 2592000 # 30 days should be fine
IEEE_URL = "http://standards.ieee.org/develop/regauth/oui/oui.txt"
 
def clean_input(user_input):
    """
    Strip colons
    """
    return "".join(user_input.split(':')[:3])
 
def update_cache():
    """
    Update our local file from the IEEE OUI
    list
    """
    print(">>> Updating Cache")
    with open(OUI_FILE_STORE, 'wb') as outfile:
        for lne in urlopen(IEEE_URL).readlines():
            outfile.write(lne)
    print(">>> Done")
 
def process_args():
    """
    Parse our args
    """
    if sys.argv[1] == "-u":
        update_cache()
        if len(sys.argv) > 2:
            user_input = sys.argv[2]
        else:
            sys.exit(0)
    else:
        user_input = sys.argv[1]
 
    return clean_input(user_input)
 
CLEANED_USER_INPUT = process_args()
 
try:
    if time.time() - os.stat(OUI_FILE_STORE).st_ctime > CACHE_TIME:
        update_cache()
 
except OSError as err:
    if err.errno == 2:
        update_cache()
 
with open(OUI_FILE_STORE, 'r',encoding="utf-8") as oui_list:
    for line in iter(oui_list):
        if re.search(CLEANED_USER_INPUT, line, re.IGNORECASE):
            print(line)