while (sysread(CSV, $record, 66)) {
    my %map
    my $count=0;
    $map{substr($record, 18, 14)}->{substr($record, 3, 15)} = substr($record, 36, 29);
    while (sysread(CSV, $record, 66)) {
        $map{substr($record, 18, 14)}->{substr($record, 3, 15)} = substr($record, 36, 29);
        if ($count++ > 1000) {
                &process(\%map);
                last;
        }
    }
    &process
}