And you should of course be aware of source code injection. Suppose the user specifies: "a/; system( 'some evil command' ); m/a" and your code is:

eval "m/$query/";
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But that's not the code! Read the post. The code is:

my $re = $_->regex;
$matchtext =~ /$re/i;
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There's no danger of source code injection here (unless there's an unseen use re 'eval' in an enclosing scope.

Abigail