src/Logging.hs

   1 module Logging (
   2   init_logging,
   3   log_debug,
   4   log_error,
   5   log_info,
   6   log_warning )
   7 where
   8
   9 import System.Log.Handler.Simple ( GenericHandler )
  10 import System.Log.Logger (
  11   Priority ( DEBUG, INFO ),
  12   debugM,
  13   errorM,
  14   infoM,
  15   rootLoggerName,
  16   setHandlers,
  17   setLevel,
  18   updateGlobalLogger,
  19   warningM )
  20
  21 log_debug :: String -> IO ()
  22 log_debug = debugM rootLoggerName
  23
  24 log_error :: String -> IO ()
  25 log_error = errorM rootLoggerName
  26
  27 log_info :: String -> IO ()
  28 log_info = infoM rootLoggerName
  29
  30 log_warning :: String -> IO ()
  31 log_warning = warningM rootLoggerName
  32
  33 init_logging :: Bool -> IO ()
  34 init_logging use_syslog = do
  35   let max_level = if use_syslog then INFO else DEBUG
  36   -- We need to specify the type here; otherwise, setHandlers won't
  37   -- accept the empty list as an instance of [LogHandler a].
  38   let no_handlers = [] :: [GenericHandler a]
  39   -- Removes the default "echo to stdout" handler.
  40   updateGlobalLogger rootLoggerName (setLevel max_level
  41                                      . setHandlers no_handlers)