Prototyping has a use when running with the strict 'subs' pragma. While it is in effect, you will have to prototype your subs to use the bareword style when calling:

sub mysub;
print mysub;
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or, use the ampersand or parens:

print mysub();
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*** Special thanks to Nat Torkington. I've been reading Jon Orwant's Computer Science and Perl Programming book lately. Good information, and a good review of perl topics you may have forgotten. Pick it up if you don't have it.