[Haskell-cafe] How to cut a file effciently?

Hi, Let us say I have a text file of a million lines, and I want to cut it into smaller (10K lines) ones. How to do this? I have tried a few ways, none I think is lazy (I mean not reading the file all at the start). -- 竹密岂妨流水过 山高哪阻野云飞