ref is correct, however you can do it yourself if you want to .. (don't know why you would) you can

my %test = ('test1'=>'value',
            'test2'=>'value');

my $hash_ref = \%test;

print "hash ref" if($hash_ref =~ m{HASH});
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I used that once(before I knew about ref). I don't know if that's horribly bad practice or not, but it works. So basically you could go to the trouble (again I don't know why you would want to) of setting up your own ref via a case statement of regex's