git-annex/Utility/LogFile.hs
Joey Hess 8ea5f3ff99
explict export lists
Eliminated some dead code. In other cases, exported a currently unused
function, since it was a logical part of the API.

Of course this improves the API documentation. It may also sometimes
let ghc optimize code better, since it can know a function is internal
to a module.

364 modules still to go, according to
git grep -E 'module [A-Za-z.]+ where'
2019-11-21 16:08:37 -04:00

68 lines
1.2 KiB
Haskell

{- log files
-
- Copyright 2012 Joey Hess <id@joeyh.name>
-
- License: BSD-2-clause
-}
{-# LANGUAGE CPP #-}
module Utility.LogFile (
openLog,
listLogs,
maxLogs,
#ifndef mingw32_HOST_OS
redirLog,
redir,
#endif
) where
import Common
#ifndef mingw32_HOST_OS
import System.Posix.Types
import System.Posix.IO
#endif
openLog :: FilePath -> IO Handle
openLog logfile = do
rotateLog logfile
openFile logfile AppendMode
rotateLog :: FilePath -> IO ()
rotateLog logfile = go 0
where
go num
| num > maxLogs = return ()
| otherwise = whenM (doesFileExist currfile) $ do
go (num + 1)
rename currfile nextfile
where
currfile = filename num
nextfile = filename (num + 1)
filename n
| n == 0 = logfile
| otherwise = rotatedLog logfile n
rotatedLog :: FilePath -> Int -> FilePath
rotatedLog logfile n = logfile ++ "." ++ show n
{- Lists most recent logs last. -}
listLogs :: FilePath -> IO [FilePath]
listLogs logfile = filterM doesFileExist $ reverse $
logfile : map (rotatedLog logfile) [1..maxLogs]
maxLogs :: Int
maxLogs = 9
#ifndef mingw32_HOST_OS
redirLog :: Fd -> IO ()
redirLog logfd = do
mapM_ (redir logfd) [stdOutput, stdError]
closeFd logfd
redir :: Fd -> Fd -> IO ()
redir newh h = do
closeFd h
void $ dupTo newh h
#endif