1 files changed, 40 insertions, 0 deletions
diff --git a/Utility/Process.hs b/Utility/Process.hs
new file mode 100644
index 000000000..9f79efa81
--- /dev/null
+++ b/Utility/Process.hs
@@ -0,0 +1,40 @@
+{- System.Process enhancements
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Utility.Process where
+
+import System.Process
+import System.Exit
+import System.IO
+
+import Utility.Misc
+
+{- Waits for a ProcessHandle, and throws an exception if the process
+ - did not exit successfully. -}
+forceSuccessProcess :: ProcessHandle -> String -> [String] -> IO ()
+forceSuccessProcess pid cmd args = do
+	code <- waitForProcess pid
+	case code of
+		ExitSuccess -> return ()
+		ExitFailure n -> error $
+			cmd ++ " " ++ show args ++ " exited " ++ show n
+
+{- Like readProcess, but allows specifying the environment, and does
+ - not mess with stdin. -}
+readProcessEnv :: FilePath -> [String] -> Maybe [(String, String)] -> IO String
+readProcessEnv cmd args environ = do
+	(_, Just h, _, pid)
+		<- createProcess (proc cmd args)
+			{ std_in  = Inherit
+			, std_out = CreatePipe
+			, std_err = Inherit
+			, env = environ
+			}
+	output  <- hGetContentsStrict h
+	hClose h
+	forceSuccessProcess pid cmd args
+	return output