# Input: %btree is already tied to a $DB_BTREE file
#        $first and $last define the range to search for
# It's assumed that the btree uses the default sort order
my $db = tied %btree;
my $key = $first;
my $value;
for (my $status = $db->seq($key, $value, R_CURSOR);
        $status == 0 && $key le $last;
        $status = $db->seq($key, $value, R_NEXT))
{
  print "$key = $value\n";
}