code: def validate_links(links):
  	
  	valid_links = []
  	for link in links:
  		if link[:7] in "http://" or link[:8] in "https://":
  			valid_links.append(link)
  	
  	if not valid_links:
  		print("No files found.")
  		sys.exit(0)
  
  	# checking valid urls for return code
  	urls = {}
  	for link in valid_links:
  		if 'github.com' and '/blob/' in link:
  			link = link.replace('/blob/', '/raw/')
  		urls[link] = {'code': get_url_nofollow(link)}
  		
  	
  	# printing valid urls with return code 200
  	available_urls = []
  	for url in urls:
  		print("code: %d\turl: %s" % (urls[url]['code'], url))
  		if urls[url]['code'] != 0:
  			available_urls.append(url)
  
  	return available_urls
docs: function to validate urls based on http(s) prefix and return code