>> I can't believe nobody else has written a quick little script to do just this

I'm sure lots of people have, though maybe not that exact problem. Here is how to do what the Java program does on one line on the command-line prompt:

perl -Mutf8 -ne"print if /[^\0-\x7f]/"
[download]

(change the quotes to suit your shell and OS. "" on Windows, usually '' on Unix)

So, no need to wade through public static void main... the Perl program's already finished by then.

—John