SafeIO: Haskell library for safe (atomic) IO
This is a simple module, which enables writing in atomic mode. It implements the following 4 step procedure:
- Open a temporary file in the same directory as the final output.
- Write to this temporary file.
- Close and sync the file.
- Atomically rename the file to its final destination.
import System.IO.SafeWrite ... main = do withOutputFile "output.txt" $ \hout -> do hPutStrLn hout "Hello World"
import qualified Data.Conduit as C import Data.Conduit ((.|)) import Data.Conduit.SafeWrite main = C.runConduitRes $ C.yield "Hello World" .| safeSinkFile "hello.txt"
In any case, only successful termination of the process will result in the output file being written. Early termination by throwing an exception will cause the temporary file to be removed and no output will be produced.