Add more code documentation.

[dead/htsn.git] / src / Unix.hs

diff --git a/src/Unix.hs b/src/Unix.hs
index 893132624165566232ae1da28bd698faea2f6465..a4389bee0e844ea7cd7024d608e3e126033bc926 100644 (file)
--- a/src/Unix.hs
+++ b/src/Unix.hs
@@ -1,3 +1,5 @@
+-- | Non-portable code for daemonizing on unix.
+--
 module Unix
 where
 
@@ -28,22 +30,39 @@ import Configuration (
                  run_as_user ))
 import Logging ( log_info )
 
+-- | Retrieve the uid associated with the given system user name. We
+--   take a Maybe String as an argument so the user name can be passed
+--   in directly from the config.
+--
 get_user_id :: Maybe String -> IO UserID
 get_user_id Nothing  = getRealUserID
 get_user_id (Just s) = fmap userID (getUserEntryForName s)
 
+
+-- | Retrieve the gid associated with the given system group name. We
+--   take a Maybe String as an argument so the group name can be
+--   passed in directly from the config.
+--
 get_group_id :: Maybe String -> IO GroupID
 get_group_id Nothing  = getRealGroupID
 get_group_id (Just s) = fmap groupID (getGroupEntryForName s)
 
+
+-- | This function will be called in response to a SIGTERM; i.e. when
+--   someone tries to kill our process. We simply delete the PID file
+--   and signal our parent thread to quit (successfully).
 graceful_shutdown :: Configuration -> ThreadId -> IO ()
 graceful_shutdown cfg main_thread_id = do
   log_info "SIGTERM received, removing PID file and shutting down."
   removeLink (pidfile cfg)
   throwTo main_thread_id ExitSuccess
 
+
+-- | Write a PID file, install a SIGTERM handler, drop privileges, and
+--   finally do the daemonization dance.
+--
 full_daemonize :: Configuration -> IO () -> IO ()
-full_daemonize cfg program = do
+full_daemonize cfg program =
   -- This is the 'daemonize' from System.Posix.Daemonize.
   daemonize program'
   where