my $t = 'test';
print eval '$t';  # test

##</code><code>##

my $t1 = 'test1';
sub show { print eval "\$$_" for @_; }
my $t2 = 'test2';
show(qw( t1 t2 ));  # test1, but not test2

##</code><code>##

{
   my $t = 'test';
   sub show { print eval "\$$_" for @_; }
}
show(qw( t ));  # Nothing

##</code><code>##

{
   my $t = 'test';
   sub foo { $t }
   sub show { print eval "\$$_" for @_; }
}
show(qw( t ));  # Nothing

##</code><code>##

{
   my $t = 'test';
   sub show { $t; print eval "\$$_" for @_; }
}
show(qw( t ));  # test