On Thu, 2007-12-13 at 16:27 +0300, Bulat Ziganshin wrote:
Hello Duncan,
Thursday, December 13, 2007, 4:10:26 PM, you wrote:
i need to run external command with parameter and get its stdout, smth
temporary file. It seems it is not possible to use pipes to get the stdout and have the resulting code be portable between Haskell implementations (it's a favourite peeve of mine).
i don't need to interact with program, just get its whole output (one line) after it was finished. btw, afair, there was problems in windows with redirection of cmd.exe output (in particular when running executables from command files)
separate windows and unix versions are ok for me, i just need them both. and i need only ghc support
taking this all into account, where i should look?
Use just the GHC bit from the code I pointed at: bracket (liftM2 (,) (openTempFile tmpDir "cmdstdout") (openFile devNull WriteMode)) -- We need to close tmpHandle or the file removal fails on Windows (\((tmpName, tmpHandle), nullHandle) -> do hClose tmpHandle removeFile tmpName hClose nullHandle) $ \((tmpName, tmpHandle), nullHandle) -> do cmdHandle <- runProcess path args Nothing Nothing Nothing (Just tmpHandle) (Just nullHandle) exitCode <- waitForProcess cmdHandle output <- readFile tmpName evaluate (length output) return (output, exitCode)