$ perl ~/pm11142815.pl /Work/OmniGlyph/big_tmp_file 32
File size: 12854692173, record size=32
Read 10000 records from file between 0 and 6427346086
        took 52.865314s

Setting record size to 32 bytes
Read 10000 records from file between 6427346086 and 12854692173
        took 6.5254s