use Data::Dumper;
use Search::Dict::Object;

my $d = Search::Dict::Object->new(
    file => "/tmp/dict.txt",
    keyval_xfrm => sub { split /\t/ },
    comp => sub { $_[0] cmp $_[1] }, # should correspond to file sort order
);

print Dumper {
    aaa => $d->get('aaa'),
    foo => $d->get('foo'),
    bar => $d->get('bar'),
    baz => $d->get('baz'),
    zzz => $d->get('zzz'),
};

__END__
$VAR1 = {
          'bar' => '789',
          'baz' => '456',
          'aaa' => undef,
          'foo' => '123',
          'zzz' => undef
        };