daemonize git annex watch

Utility/LogFile.hs

@@ -0,0 +1,31 @@
+{- log files
+ -
+ - Copyright 2012 Joey Hess <joey@kitenet.net>
+ -
+ - Licensed under the GNU GPL version 3 or higher.
+ -}
+
+module Utility.LogFile where
+
+import Common
+
+import System.Posix
+
+openLog :: FilePath -> IO Fd
+openLog logfile = do
+	rotateLog logfile 0
+	openFd logfile WriteOnly (Just stdFileMode)
+		defaultFileFlags { append = True }
+
+rotateLog :: FilePath -> Int -> IO ()
+rotateLog logfile num
+	| num >= 10 = return ()
+	| otherwise = whenM (doesFileExist currfile) $ do
+		rotateLog logfile (num + 1)
+		renameFile currfile nextfile
+	where
+		currfile = filename num
+		nextfile = filename (num + 1)
+		filename n
+			| n == 0 = logfile
+			| otherwise = logfile ++ "." ++ show n