#!/usr/bin/python3
# written by andrewt@unsw.edu.au as a COMP(2041|9044) example

# Repeatedly download a specified web page
# until a specified regexp matches its source
# then notify the specified email address.

# implemented using subprocess

import re
import subprocess
import sys
import time

REPEAT_SECONDS = 300  # check every 5 minutes

if len(sys.argv) == 4:
    url = sys.argv[1]
    regexp = sys.argv[2]
    email_address = sys.argv[3]
else:
    print(f"Usage: {sys.argv[0]} <url> <regex> <email-address>", file=sys.stderr)
    sys.exit(1)