I'm not quite sure what is actually implemented there...

My guess is that the programmer's directory has 3 files starting with "www" in it. <\w{3,4}> in some shells will match a file that begins with www or wwww. The angle brackets would cause a directory glob, setting $_ to file names matching what's inside once per loop.

On the other hand, according to "perldoc File::Glob", that pattern should match only files named "w3" or "w4". And even if the shell was interpreting it, it would only match files "www" or "wwww" with nothing following, since it doesn't end with a "*". So I'm a bit at a loss as well.