1 -- | Provide convenience functions for logging to the HSLogger \"root\"
3 module Network.Services.TSN.Logging (
11 import Control.Monad ( when )
12 import System.Environment ( getProgName )
13 import System.Log.Formatter ( simpleLogFormatter )
14 import System.Log.Handler ( setFormatter )
15 import System.Log.Handler.Simple ( GenericHandler, fileHandler )
16 import System.Log.Handler.Syslog (
19 import System.Log.Logger (
32 -- | Log a message at the 'DEBUG' level.
33 log_debug :: String -> IO ()
34 log_debug = debugM rootLoggerName
36 -- | Log a message at the 'ERROR' level.
37 log_error :: String -> IO ()
38 log_error = errorM rootLoggerName
40 -- | Log a message at the 'INFO' level.
41 log_info :: String -> IO ()
42 log_info = infoM rootLoggerName
44 -- | Log a message at the 'WARNING' level.
45 log_warning :: String -> IO ()
46 log_warning = warningM rootLoggerName
49 -- | Set up the logging. All logs are handled by the global \"root\"
50 -- logger provided by HSLogger. We remove all of its handlers so that
51 -- it does nothing; then we conditionally add back two handlers -- one
52 -- for syslog, and one for a normal file -- dependent upon the
53 -- @syslog@ and @log_file@ arguments.
55 -- If @syslog@ is 'False' and @log_file@ is 'Nothing'; then nothing
56 -- will be logged and the @log_level@ will essentially be ignored
57 -- (even though the root logger will have its level set).
59 init_logging :: Priority -- ^ The priority at and above which
61 -> Maybe FilePath -- ^ Path to the log file (optional)
62 -> Bool -- ^ Log to syslog?
64 init_logging log_level log_file syslog = do
65 -- First set the global log level and clear the default handler.
66 let no_handlers = [] :: [GenericHandler a]
67 updateGlobalLogger rootLoggerName (setLevel log_level .
68 setHandlers no_handlers)
72 let sl_level = if log_level < min_level then min_level else log_level
74 -- The syslog handle gets its own level which will cowardly refuse
75 -- to log all debug info (i.e. the entire feed) to syslog.
76 sl_handler' <- openlog rootLoggerName [] USER sl_level
78 -- Syslog should output the date by itself.
79 program_name <- getProgName
80 let sl_formatter = simpleLogFormatter $
81 program_name ++ "[$pid] $prio: $msg"
82 let sl_handler = setFormatter sl_handler' sl_formatter
84 updateGlobalLogger rootLoggerName (addHandler sl_handler)
89 lf_handler' <- fileHandler lf log_level
90 let lf_formatter = simpleLogFormatter "$time: htsn[$pid] $prio: $msg"
91 let lf_handler = setFormatter lf_handler' lf_formatter
92 updateGlobalLogger rootLoggerName (addHandler lf_handler)