@bar = qw( one small step for man );
$foo = \@bar;
$foo->[1] = "big";
print "@bar";  # one big step for man

##</code><code>##

@bar = qw( one small step for man );
$foo = \@bar;
$foo = [qw( one big step for man )];
print "@bar";  # one small step for man

##</code><code>##

sub tie_session {
  my ($hash) = @_; 

  eval {
    tie %$hash, 'Apache::Session::File', undef, {
      Directory     => $r->dir_config('Blah'),
      LockDirectory => $r->dir_config('Blah'),
    };
  };
  return $@ if $@;
  return $hash;  # not actually necessary, but it returns true
}

##</code><code>##

sub function {
  my ($hash) = @_;
  MyModule::tie_session($hash);
  $hash->{auth}->{user} = "jacques";
}