Yes.
You can do $x = file_get_contents("http://news.ycombinator.com) and it will work (well, in that case it wouldn't as the machine had locked down network access, but you get the idea).
Yes, I am aware php allows one to open urls via the file*-procedures (unless it has been disabled on the server -- which is generally a good idea for production deployment). I meant -- what did you end up using for the challenge (url/$filename and $attempt)?
filename=file_that_doesnt_exist&attempt=
Yes, for non_existent_file I got it -- I was actually asking gee what (s)he ended up with, using "root url".