module System.Cmd
( system, -- :: String -> IO ExitCode
-#ifdef __GLASGOW_HASKELL__
rawSystem, -- :: FilePath -> [String] -> IO ExitCode
-#endif
) where
import Prelude
+import System.Exit ( ExitCode )
+
#ifdef __GLASGOW_HASKELL__
import System.Process
-import System.Exit ( ExitCode )
import GHC.IOBase ( ioException, IOException(..), IOErrorType(..) )
+#if !defined(mingw32_HOST_OS)
+import System.Process.Internals
+import System.Posix.Signals
+#endif
#endif
#ifdef __HUGS__
#ifdef __GLASGOW_HASKELL__
system :: String -> IO ExitCode
system "" = ioException (IOError Nothing InvalidArgument "system" "null command" Nothing)
-system cmd = do
- p <- runCommand cmd
+system str = do
+#if mingw32_HOST_OS
+ p <- runCommand str
waitForProcess p
+#else
+ -- The POSIX version of system needs to do some manipulation of signal
+ -- handlers. Since we're going to be synchronously waiting for the child,
+ -- we want to ignore ^C in the parent, but handle it the default way
+ -- in the child (using SIG_DFL isn't really correct, it should be the
+ -- original signal handler, but the GHC RTS will have already set up
+ -- its own handler and we don't want to use that).
+ old_int <- installHandler sigINT Ignore Nothing
+ old_quit <- installHandler sigQUIT Ignore Nothing
+ (cmd,args) <- commandToProcess str
+ p <- runProcessPosix "runCommand" cmd args Nothing Nothing
+ Nothing Nothing Nothing
+ (Just defaultSignal) (Just defaultSignal)
+ r <- waitForProcess p
+ installHandler sigINT old_int Nothing
+ installHandler sigQUIT old_quit Nothing
+ return r
+#endif /* mingw32_HOST_OS */
+#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
+
+#if mingw32_HOST_OS
p <- runProcess cmd args Nothing Nothing Nothing Nothing Nothing
waitForProcess p
-#endif /* __GLASGOW_HASKELL__ */
+#else
+ old_int <- installHandler sigINT Ignore Nothing
+ old_quit <- installHandler sigQUIT Ignore Nothing
+ p <- runProcessPosix "rawSystem" cmd args Nothing Nothing
+ Nothing Nothing Nothing
+ (Just defaultSignal) (Just defaultSignal)
+ r <- waitForProcess p
+ installHandler sigINT old_int Nothing
+ installHandler sigQUIT old_quit Nothing
+ return r
+#endif
+
+#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__ */