filesize -package:hackage-security -package:http-conduit -package:turtle -package:ghc -package:unix -package:tar -package:language-bash

fileSizeFromMetadata :: Metadata -> Integer
directory System.Directory.Internal
hFileSize :: Handle -> IO Integer
base System.IO GHC.IO.Handle
For a handle hdl which attached to a physical file, hFileSize hdl returns the size of that file in 8-bit bytes.
hSetFileSize :: Handle -> Integer -> IO ()
base System.IO GHC.IO.Handle
hSetFileSize hdl size truncates the physical file with handle hdl to size bytes.
fdFileSize :: FD -> IO Integer
base System.Posix.Internals
getFileSize :: FilePath -> IO Integer
directory System.Directory
Obtain the size of a file in bytes.