1 files changed, 15 insertions, 10 deletions

diff --git a/Presence/FGConsole.hs b/Presence/FGConsole.hs
index 623fb493..03aaebf2 100644
--- a/Presence/FGConsole.hs
+++ b/Presence/FGConsole.hs
@@ -11,7 +11,6 @@ import Unsafe.Coerce
 import Control.Exception as E
 -- import Prelude as E
 import Control.Monad
-import Foreign.C.Error
 import Foreign.C
 
 import Logging
@@ -19,12 +18,13 @@ import System.Posix.Signals
 
 -- c_monitorTTY fd = trace "c_monitorTTY" (return ()) -- (trace "WTF" todo)
 
-foreign import ccall "monitorTTY" c_monitorTTY :: Fd -> IO ()
+foreign import ccall "monitorTTY" c_monitorTTY :: Fd -> IO CInt
 foreign import ccall "closeTTY" c_closeTTY :: IO ()
 
-monitorTTY :: (Word8 -> IO ()) -> IO (Fd,ThreadId)
-monitorTTY handler =  do
+forkTTYMonitor :: (Word8 -> IO ()) -> IO (Maybe (Fd,ThreadId))
+forkTTYMonitor handler =  do
     (rfd,wfd) <- createPipe
+    retvar <- newEmptyMVar
     thread <- forkIO $ do
         let cleanup = do
                 trace "quitting monitorTTY thread." (return ())
@@ -32,8 +32,10 @@ monitorTTY handler =  do
                 closeFd rfd `E.catch` \(e::IOException) -> return ()
                 c_closeTTY
         -- rh <- fdToHandle rfd
-        c_monitorTTY wfd
-        let monitor = 
+        didfork <- c_monitorTTY wfd
+        putMVar retvar didfork
+        when (didfork == 0) $ do
+        let monitor =
                 (do
                     threadWaitRead rfd
                     (cs,cnt) <- fdRead rfd 1
@@ -45,13 +47,16 @@ monitorTTY handler =  do
                         case () of
                          _ | err==eAGAIN -> monitor
                          _ | otherwise   -> cleanup
-                `E.catch` 
+                `E.catch`
                       \(e ::  AsyncException) -> cleanup
         monitor
-    return (rfd,thread)
+    didfork <- takeMVar retvar
+    if didfork == 0
+        then return $! Just (rfd,thread)
+        else return $! Nothing
 
-unmonitorTTY :: (Fd, ThreadId) -> IO ()
-unmonitorTTY (rfd,thread) = do
+killTTYMonitor :: (Fd, ThreadId) -> IO ()
+killTTYMonitor (rfd,thread) = do
     closeFd rfd
     yield
     killThread thread