git-annex/Utility/LogFile.hs
2012-12-13 00:24:19 -04:00

31 lines
677 B
Haskell

{- 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