-----------------------------------------------------------------------------
module System.Cmd
- ( system -- :: String -> IO ExitCode
+ ( system, -- :: String -> IO ExitCode
+ rawSystem, -- :: FilePath -> [String] -> IO ExitCode
) where
import Prelude
-import System.Exit
-#ifndef __HUGS__
-import Foreign.C
-#endif
+import System.Exit ( ExitCode )
#ifdef __GLASGOW_HASKELL__
-import GHC.IOBase
+import System.Process
+import GHC.IOBase ( ioException, IOException(..), IOErrorType(..) )
#endif
#ifdef __HUGS__
import Hugs.System
#endif
+#ifdef __NHC__
+import System (system)
+#endif
+
-- ---------------------------------------------------------------------------
-- system
passes the command to the Windows command interpreter (@CMD.EXE@ or
@COMMAND.COM@), hence Unixy shell tricks will not work.
-}
-#ifndef __HUGS__
+#ifdef __GLASGOW_HASKELL__
system :: String -> IO ExitCode
system "" = ioException (IOError Nothing InvalidArgument "system" "null command" Nothing)
-system cmd =
- withCString cmd $ \s -> do
- status <- throwErrnoIfMinus1 "system" (primSystem s)
- case status of
- 0 -> return ExitSuccess
- n -> return (ExitFailure n)
-
-foreign import ccall unsafe "systemCmd" primSystem :: CString -> IO Int
-#endif /* __HUGS__ */
+system cmd = do
+ p <- runCommand cmd
+ waitForProcess p
+#endif /* __GLASGOW_HASKELL__ */
+
+{-|
+The computation @'rawSystem' cmd args@ runs the operating system command
+@cmd@ in such a way that it receives as arguments the @args@ strings
+exactly as given, with no funny escaping or shell meta-syntax expansion.
+It will therefore behave more portably between operating systems than 'system'.
+
+The return codes and possible failures are the same as for 'system'.
+-}
+rawSystem :: String -> [String] -> IO ExitCode
+#ifdef __GLASGOW_HASKELL__
+rawSystem cmd args = do
+ p <- runProcess cmd args Nothing Nothing Nothing Nothing Nothing
+ waitForProcess p
+#else /* ! __GLASGOW_HASKELL__ */
+-- crude fallback implementation: could do much better than this under Unix
+rawSystem cmd args = system (unwords (map translate (cmd:args)))
+
+translate :: String -> String
+#if defined(mingw32_HOST_OS)
+-- copied from System.Process (qv)
+translate str = '"' : snd (foldr escape (True,"\"") str)
+ where escape '"' (b, str) = (True, '\\' : '"' : str)
+ escape '\\' (True, str) = (True, '\\' : '\\' : str)
+ escape '\\' (False, str) = (False, '\\' : str)
+ escape c (b, str) = (False, c : str)
+#else /* ! mingw32_HOST_OS */
+translate str = '\'' : foldr escape "'" str
+ where escape '\'' cs = '\'' : '\\' : '\'' : '\'' : cs
+ escape c cs = c : cs
+#endif /* ! mingw32_HOST_OS */
+#endif /* ! __GLASGOW_HASKELL__ */