42 lines
973 B
Haskell
42 lines
973 B
Haskell
{- log files
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-
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- Copyright 2012 Joey Hess <joey@kitenet.net>
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-
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- Licensed under the GNU GPL version 3 or higher.
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-}
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module Utility.LogFile where
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import Common
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import System.Posix
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openLog :: FilePath -> IO Fd
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openLog logfile = do
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rotateLog logfile 0
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openFd logfile WriteOnly (Just stdFileMode)
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defaultFileFlags { append = True }
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rotateLog :: FilePath -> Int -> IO ()
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rotateLog logfile num
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| num > maxLogs = return ()
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| otherwise = whenM (doesFileExist currfile) $ do
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rotateLog logfile (num + 1)
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renameFile currfile nextfile
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where
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currfile = filename num
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nextfile = filename (num + 1)
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filename n
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| n == 0 = logfile
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| otherwise = rotatedLog logfile n
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rotatedLog :: FilePath -> Int -> FilePath
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rotatedLog logfile n = logfile ++ "." ++ show n
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{- Lists most recent logs last. -}
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listLogs :: FilePath -> IO [FilePath]
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listLogs logfile = filterM doesFileExist $ reverse $
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logfile : map (rotatedLog logfile) [1..maxLogs]
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maxLogs :: Int
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maxLogs = 9
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