Or do it in a language with lazy I/O and don't worry so much about memory requirements. import Data.ByteString.Lazy as LBS areFilesEqual x y = (==) <$> LBS.re

Or do it in a language with lazy I/O and don't worry so much about memory requirements. import Data.ByteString.Lazy as LBS areFilesEqual x y = (==) <$> LBS.readFile x <*> LBS.readFile y (EDIT: added line break)