use strict;

$SIG{__WARN__} = \&mywarn;
sub mywarn { print "here!\n @_\n"; }

{ test ('arf', undef, 'dog'); }

sub test {
   @_ == 3 or die "Incorrect number of arguments";
   my ($a, $b, $c) = @_;
   my %hash = ('arf' => {'spot' => {'dog' => 3}});
   print $hash {$a}->{$b}->{$c};
}

##</code><code>##

here!
 Use of uninitialized value in hash element at test.txt line 23.

here!
 Use of uninitialized value in hash element at test.txt line 23.

here!
 Use of uninitialized value in print at test.txt line 23.