On 12.12 12:06, Duncan Coutts wrote:
It states in the Haskell Report 21.2.3:
Thanks, for the pointer, but am looking for an extension in the non-haskell98 API to do it. It seems that things are quite problematic: 1) Use openFile or GHC.Handle.openFd Works in Hugs, fails as the standard mandates in GHC due to locking. This is fine. 2) Use openFile + handleToFd + unlockFile This seems like a good plan. Except handleToFd will close the Handle. 3) Using System.Posix.IO Using the fd{Read,Close,Write} functions from System.Posix.IO could solve the problem - except that there is no way to write binary buffers (Ptr Word8) with the API. Thus no solution. 4) Use System.Posix.IO.openFd + fdToHandle This appears to be nice on surface. Except fdToHandle locks the file, thus back to drawing board. 5) Use System.Posix.IO.openFd + fdToHandle + unlockFile Thus we have: * lock mutex - otherwise there is a race condition * System.Posix.IO.openFd - open the file emulating openFile * fdToHandle - convert the file to Handle locking it * unlockFile (fromIntegral fd) - now unlock the original fd * unlock mutex Is this really the most simple way of doing things? Most of the operations will also hit the disk, and be slow (safe) FFI calls. - Einar Karttunen