add a checkPipe loop for waiting the pipe file

1 files changed, 15 insertions, 1 deletions

diff --git a/src/Plugins/PipeReader.hs b/src/Plugins/PipeReader.hs
index 42ae500..7efea60 100644
--- a/src/Plugins/PipeReader.hs
+++ b/src/Plugins/PipeReader.hs
@@ -16,6 +16,10 @@ module Plugins.PipeReader where
 
 import System.IO
 import Plugins
+import System.Posix.Files
+import Control.Concurrent(threadDelay)
+import Control.Exception
+import Control.Monad(when)
 
 data PipeReader = PipeReader String String
     deriving (Read, Show)
@@ -24,11 +28,21 @@ instance Exec PipeReader where
     alias (PipeReader _ a)    = a
     start (PipeReader p _) cb = do
         let (def, pipe) = split ':' p
+        when (not $ null def) (cb def)
+        checkPipe pipe
         h <- openFile pipe ReadWriteMode
-        cb def
         forever (hGetLineSafe h >>= cb)
       where
         forever a = a >> forever a
         split c xs | c `elem` xs = let (pre, post) = span ((/=) c) xs
                                    in (pre, dropWhile ((==) c) post)
                    | otherwise   = ([], xs)
+
+checkPipe :: FilePath -> IO ()
+checkPipe file = do
+    handle (\(SomeException _) -> waitForPipe) $ do
+    status <- getFileStatus file
+    if isNamedPipe status
+      then return ()
+      else waitForPipe
+    where waitForPipe = threadDelay 1000 >> checkPipe file