From d0e82d0b9218a9ff3a693e066c4320c08d4d1c47 Mon Sep 17 00:00:00 2001
From: Joey Hess <joey@kitenet.net>
Date: Sun, 10 Oct 2010 00:18:10 -0400
Subject: [PATCH] add

---
 Utility.hs | 29 +++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)
 create mode 100644 Utility.hs

diff --git a/Utility.hs b/Utility.hs
new file mode 100644
index 0000000000..05b06dea79
--- /dev/null
+++ b/Utility.hs
@@ -0,0 +1,29 @@
+{- git-annex utility functions
+ -}
+
+module Utility where
+
+import System.IO
+import System.Posix.IO
+import Data.String.Utils
+
+{- Let's just say that Haskell makes reading/writing a file with
+ - file locking excessively difficult. -}
+openLocked file mode = do
+	handle <- openFile file mode
+	lockfd <- handleToFd handle -- closes handle
+	waitToSetLock lockfd (lockType mode, AbsoluteSeek, 0, 0)
+	handle' <- fdToHandle lockfd
+	return handle'
+		where
+			lockType ReadMode = ReadLock
+			lockType _ = WriteLock
+
+{- Returns the parent directory of a path. Parent of / is "" -}
+parentDir :: String -> String
+parentDir dir =
+	if length dirs > 0
+	then "/" ++ (join "/" $ take ((length dirs) - 1) dirs)
+	else ""
+		where
+			dirs = filter (\x -> length x > 0) $ split "/" dir