From 8c69c28e5ab5ef5a5ed64411e1213e504a6a309e Mon Sep 17 00:00:00 2001
From: Michael Orlitzky <michael@orlitzky.com>
Date: Sat, 21 Dec 2013 15:57:22 -0500
Subject: [PATCH] Attempt to implement syslog logging; fail at least with
 metalog.

---
 src/Logging.hs | 26 ++++++++++++++++----------
 src/Main.hs    |  2 +-
 2 files changed, 17 insertions(+), 11 deletions(-)

diff --git a/src/Logging.hs b/src/Logging.hs
index db7260a..94f4f7a 100644
--- a/src/Logging.hs
+++ b/src/Logging.hs
@@ -6,7 +6,11 @@ module Logging (
   log_warning )
 where
 
-import System.Log.Handler.Simple ( GenericHandler )
+import System.Log.Handler.Simple ( fileHandler )
+import System.Log.Handler.Syslog (
+  Facility ( USER ),
+  Option ( PID ),
+  openlog )
 import System.Log.Logger (
   Priority ( DEBUG, INFO ),
   debugM,
@@ -30,12 +34,14 @@ log_info = infoM rootLoggerName
 log_warning :: String -> IO ()
 log_warning = warningM rootLoggerName
 
-init_logging :: Bool -> IO ()
-init_logging use_syslog = do
-  let max_level = if use_syslog then INFO else DEBUG
-  -- We need to specify the type here; otherwise, setHandlers won't
-  -- accept the empty list as an instance of [LogHandler a].
-  let no_handlers = [] :: [GenericHandler a]
-  -- Removes the default "echo to stdout" handler.
-  updateGlobalLogger rootLoggerName (setLevel max_level
-                                     . setHandlers no_handlers)
+init_logging :: FilePath -> Priority -> Bool -> IO ()
+init_logging log_file log_level syslog
+  | syslog == True = do
+      handler <- openlog rootLoggerName [PID] USER level
+      updateGlobalLogger rootLoggerName (setLevel level . setHandlers [handler])
+  | otherwise = do
+      handler <- fileHandler log_file level
+      updateGlobalLogger rootLoggerName (setLevel level . setHandlers [handler])
+  where
+    min_level = if syslog then INFO else DEBUG
+    level = if log_level < min_level then min_level else log_level
diff --git a/src/Main.hs b/src/Main.hs
index f2febcb..0182e38 100644
--- a/src/Main.hs
+++ b/src/Main.hs
@@ -247,7 +247,7 @@ main = do
   -- logging before the missing parameter checks below so that we can
   -- log the errors.
   let cfg = (def :: Configuration) `merge_optional` opt_config
-  init_logging (syslog cfg)
+  init_logging (log_file cfg) (log_level cfg) (syslog cfg)
 
   -- Check the optional config for missing required options. This is
   -- necessary because if the user specifies an empty list of
-- 
2.43.2