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-rw-r--r--src/Xmobar/Plugins/StdinReader.hs42
-rw-r--r--src/Xmobar/System/Utils.hs11
2 files changed, 25 insertions, 28 deletions
diff --git a/src/Xmobar/Plugins/StdinReader.hs b/src/Xmobar/Plugins/StdinReader.hs
index a29c1ad..4d5c438 100644
--- a/src/Xmobar/Plugins/StdinReader.hs
+++ b/src/Xmobar/Plugins/StdinReader.hs
@@ -1,3 +1,5 @@
+{-# LANGUAGE ViewPatterns #-}
+
-----------------------------------------------------------------------------
-- |
-- Module : Plugins.StdinReader
@@ -22,30 +24,36 @@ import Prelude
import System.Posix.Process
import System.Exit
import System.IO
+import System.IO.Error (isEOFError)
import Xmobar.Run.Exec
import Xmobar.X11.Actions (stripActions)
-import Xmobar.System.Utils (onSomeException)
-import Control.Monad (when)
+import Control.Concurrent (threadDelay)
+import Control.Exception
+import Control.Monad (forever)
data StdinReader = StdinReader | UnsafeStdinReader
deriving (Read, Show)
instance Exec StdinReader where
- start stdinReader cb = do
- -- The EOF check is necessary for certain systems
- -- More details here https://github.com/jaor/xmobar/issues/442
- eof <- isEOF
- when eof $
- do hPrint stderr "xmobar: eof at an early stage"
- exitImmediately ExitSuccess
- s <-
- getLine `onSomeException`
- (\e -> do
- let errorMessage = "xmobar: Received exception " <> show e
- hPrint stderr errorMessage
- cb errorMessage)
- cb $ escape stdinReader s
- start stdinReader cb
+ start stdinReader cb = forever $ (cb . escape stdinReader =<< getLine) `catch` handler
+ where
+ -- rethrow async exceptions like ThreadKilled, etc.
+ handler (fromException -> Just e) = throwIO (e :: SomeAsyncException)
+ -- XMonad.Hooks.DynamicLog.statusBar starts new xmobar on every xmonad
+ -- reload and the old xmobar is only signalled to exit via the pipe
+ -- being closed, so we must unconditionally terminate on EOF, otherwise
+ -- there'd be a pileup of xmobars
+ handler (fromException -> Just e) | isEOFError e = exitImmediately ExitSuccess
+ -- any other exception, like "invalid argument (invalid byte sequence)",
+ -- is logged to both stderr and the bar itself, throttled to avoid
+ -- excessive CPU usage whenever someone pipes garbage into xmobar, and
+ -- then discarded without terminating, so a single charset error doesn't
+ -- break the entire xmobar
+ handler e = do
+ let errorMessage = "xmobar: Received exception " <> show e
+ hPutStrLn stderr errorMessage
+ cb $ stripActions errorMessage
+ threadDelay 1000000
escape :: StdinReader -> String -> String
escape StdinReader = stripActions
diff --git a/src/Xmobar/System/Utils.hs b/src/Xmobar/System/Utils.hs
index 53052ea..24c655e 100644
--- a/src/Xmobar/System/Utils.hs
+++ b/src/Xmobar/System/Utils.hs
@@ -20,7 +20,6 @@
module Xmobar.System.Utils
( expandHome
, changeLoop
- , onSomeException
, safeIndex
) where
@@ -31,7 +30,6 @@ import Data.Maybe (fromMaybe)
import System.Environment
import System.FilePath
-import Control.Exception
expandHome :: FilePath -> IO FilePath
expandHome ('~':'/':path) = fmap (</> path) (getEnv "HOME")
@@ -47,15 +45,6 @@ changeLoop s f = atomically s >>= go
guard (new /= old)
return new)
--- | Like 'finally', but only performs the final action if there was an
--- exception raised by the computation.
---
--- Note that this implementation is a slight modification of
--- onException function.
-onSomeException :: IO a -> (SomeException -> IO b) -> IO a
-onSomeException io what = io `catch` \e -> do _ <- what e
- throwIO (e :: SomeException)
-
(!!?) :: [a] -> Int -> Maybe a
(!!?) xs i
| i < 0 = Nothing