http://perlmonks.org/?parent=565470;node_id=3333
  http://example.com
  http://example.com/blah.html
  http://example.com/blah.foo
  http://example.com/blah.htm
  http://example.com/blah.php
  http://example.com/blah.cgi
  http://example.com/blah.pl
  http://example.com/blah.asp
  http://example.com/blah/foo/
  http://example.com/blah.exe    # even this, if someone so configured the web server