http://www.perlmonks.org?node_id=967948


in reply to totally lost

Precedence. You're matching badinput against the negation of $input. Use: 
if ($input !~ /badinput/) { ... }

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instead.

Or 

if (!($input =~ /badinput/)) { ... }

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but that's more typing, and less idiomatic.

In Section Seekers of Perl Wisdom