# creating empty placeholder in index
		if not url in index:
			index[url] = {}
		reload = False

		# creating file name from url
		file_name = options.dir + re.compile('%20').sub(' ', url)
		print('Checking file:', url)

		# forcibly checking file if no file present
		if not os.access(file_name, os.R_OK):
			print('File not found or inaccessible.')
			reload = True

		# forcibly checking file if file size doesn't match with index data
		elif 'Content-Length' in index[url] and os.stat(file_name).st_size != int(index[url]['Content-Length']):
			print('File size is', os.stat(file_name).st_size, 'and stored file size is', index[url]['Content-Length'])
			reload = True

		# forcibly checking file if index hods Pragma header
		if 'Pragma' in index[url] and index[url]['Pragma'] == 'no-cache':
			print('Pragma on: recheck iminent.')
			reload = True

		# skipping file processing if there's no need to recheck it and we have checked it at least 4 hours ago
		if not reload and '__time__' in index[url] and (datetime.datetime.now() - datetime.timedelta(hours = 4) - index[url]['__time__']).days < 0:
			continue
		print('Checking file:', url)
		try:
			print('Contacting website.')
			with urllib.request.urlopen(options.root + url) as source:
				new_headers = {}
				headers = source.info()

				# stripping unneeded headers (XXX make this inplace?)
				for header in headers:
					if header in desc_fields:

				old_keys = set(index[url].keys())
				old_keys.discard('__time__')
				old_keys.discard('Pragma')
				more_keys = set(new_headers.keys()) - old_keys
				more_keys.discard('Pragma')
				less_keys = old_keys - set(new_headers.keys())
				if len(more_keys) > 0:
					if len(old_keys) == 0:
						print('No data on that file yet.')
					else:
					print('More headers appear:', more_keys)
						print('More headers appear:', more_keys)
					reload = True
				elif len(less_keys) > 0:
					print('Less headers appear:', less_keys)
					reload = True
				else:
					for key in index[url].keys():
						if key not in ('__time__', 'Pragma') and not index[url][key] == new_headers[key]: