Hello Einar, Monday, December 12, 2005, 5:01:20 PM, you wrote: EK> 3) Using System.Posix.IO EK> Using the fd{Read,Close,Write} functions from System.Posix.IO EK> could solve the problem - except that there is no way to EK> write binary buffers (Ptr Word8) with the API. Thus no EK> solution. you can easily import these functions via FFI: foreign import ccall unsafe "HsBase.h read" c_read :: CInt -> Ptr CChar -> CSize -> IO CSsize moreover, they are already imported by System.Posix.Internals. and even more - it works both under Windows and Unix below is a part of file api i proposed for inclusion in ghc. i think it is exactly what you need: {-# OPTIONS_GHC -fvia-C -fglasgow-exts -fno-monomorphism-restriction#-} module FD where import Control.Monad import Data.Bits import Data.Int import Data.Word import Foreign.C.Types import Foreign.C.Error import Foreign.C.String import Foreign.Marshal.Alloc import Foreign.Ptr import System.IO import System.IO.Error import System.Posix.Internals import System.Posix.Types import System.Win32 type FD = CInt -- handle of open file type CWFilePath = CString -- filename in C land type CWFileOffset = COff -- filesize or filepos in C land type FileSize = Integer -- filesize or filepos in Haskell land withCWFilePath = withCString -- FilePath->CWFilePath conversion peekCWFilePath = peekCString -- CWFilePath->FilePath conversion fdOpen :: String -> CInt -> CMode -> IO FD fdOpen name access mode = modifyIOError (`ioeSetFileName` name) $ withCWFilePath name $ \ p_name -> throwErrnoIfMinus1Retry "fdOpen" $ c_open p_name access mode fdClose :: FD -> IO () fdClose fd = throwErrnoIfMinus1Retry_ "fdClose" $ c_close fd fdGetBuf :: FD -> Ptr a -> Int -> IO Int fdGetBuf fd buf size = fromIntegral `liftM` (throwErrnoIfMinus1Retry "fdGetBuf" $ c_read fd (castPtr buf) (fromIntegral size)) fdPutBuf :: FD -> Ptr a -> Int -> IO () fdPutBuf fd buf size = throwErrnoIfMinus1Retry_ "fdPutBuf" $ c_write fd (castPtr buf) (fromIntegral size) -- to do: check that result==size? fdTell :: FD -> IO FileSize fdTell fd = fromIntegral `liftM` throwErrnoIfMinus1Retry "fdTell" (c_tell fd) fdSeek :: FD -> SeekMode -> FileSize -> IO () fdSeek fd mode offset = throwErrnoIfMinus1Retry_ "fdSeek" $ c_lseek fd (fromIntegral offset) whence where whence = case mode of AbsoluteSeek -> sEEK_SET RelativeSeek -> sEEK_CUR SeekFromEnd -> sEEK_END fdFileSize :: FD -> IO FileSize fdFileSize fd = fromIntegral `liftM` throwErrnoIfMinus1Retry "fdFileSize" (c_filelength fd) {-open/close/truncate/dup new_fd <- throwErrnoIfMinus1 "dupHandle" $ c_dup (fromIntegral (haFD h_)) new_fd <- throwErrnoIfMinus1 "dupHandleTo" $ c_dup2 (fromIntegral (haFD h_)) (fromIntegral (haFD hto_)) -} foreign import ccall unsafe "HsBase.h tell" c_tell :: CInt -> IO COff foreign import ccall unsafe "HsBase.h filelength" c_filelength :: CInt -> IO COff foreign import ccall unsafe "__hscore_bufsiz" dEFAULT_BUFFER_SIZE :: Int foreign import ccall unsafe "__hscore_seek_cur" sEEK_CUR :: CInt foreign import ccall unsafe "__hscore_seek_set" sEEK_SET :: CInt foreign import ccall unsafe "__hscore_seek_end" sEEK_END :: CInt i=fromIntegral -- Best regards, Bulat mailto:bulatz@HotPOP.com