duncan.coutts:
On Tue, 2008-04-22 at 15:35 -0700, Bryan O'Sullivan wrote:
Neil Mitchell wrote:
I would have thought (ExitCode,String) was more appropriate.
Yes, definitely.
Yes, I mentioned this to Don previously when he published his popen code. I think he agreed.
Duncan
I'd changed, but not pushed out, process-light: -- -- | readProcess forks an external process, reads its standard output -- strictly, blocking until the process terminates, and returns either the output -- string, or, in the case of non-zero exit status, an error code, and -- any output. -- -- Output is returned strictly, so this is not suitable for -- interactive applications. -- -- Users of this library should compile with -threaded if they -- want other Haskell threads to keep running while waiting on -- the result of readProcess. -- -- > > readProcess "date" [] [] -- > Right "Thu Feb 7 10:03:39 PST 2008\n" -- -- The argumenst are: -- -- * The command to run, which must be in the $PATH, or an absolute path -- -- * A list of separate command line arguments to the program -- -- * A string to pass on the standard input to the program. -- readProcess :: FilePath -- ^ command to run -> [String] -- ^ any arguments -> String -- ^ standard input -> IO (Either (ExitCode,String) String) -- ^ either the stdout, or an exitcode and any output readProcess cmd args input = C.handle (return . handler) $ do (inh,outh,errh,pid) <- runInteractiveProcess cmd args Nothing Nothing output <- hGetContents outh outMVar <- newEmptyMVar forkIO $ (C.evaluate (length output) >> putMVar outMVar ()) when (not (null input)) $ hPutStr inh input takeMVar outMVar ex <- C.catch (waitForProcess pid) (\_e -> return ExitSuccess) hClose outh hClose inh -- done with stdin hClose errh -- ignore stderr return $ case ex of ExitSuccess -> Right output ExitFailure _ -> Left (ex, output) where handler (C.ExitException e) = Left (e,"") handler e = Left (ExitFailure 1, show e)