MBox: support for ~ paths and skipping non-existing mboxes

5 files changed, 56 insertions, 34 deletions

diff --git a/NEWS b/NEWS
index 295a99f..10038c3 100644
--- a/NEWS
+++ b/NEWS
@@ -33,6 +33,8 @@ _New features_
     present CPUs (Ben Boeckel).
   - CpuFreq monitor uses just one decimal digit for GHz values (Petr
     Rockai).
+  - Mail plugin expands paths starting with "~/" (Ben Boeckel). Ditto
+    MBox.
   - New compilation flag, `all_extensions`.
   - Documentation and website updates.
 
@@ -46,6 +48,7 @@ _Bug fixes_
     boxes in monitors (Norbert Zeh).
   - TopMem and TopProc now use the `-L` and `-H` options correctly for
     memory template fields.
+  - MBox skips non-existent mbox paths instead of hanging.
 
 [issue 23]: http://code.google.com/p/xmobar/issues/detail?id=23
 [issue 24]: http://code.google.com/p/xmobar/issues/detail?id=24
diff --git a/Plugins/MBox.hs b/Plugins/MBox.hs
index 265e860..f24fa1c 100644
--- a/Plugins/MBox.hs
+++ b/Plugins/MBox.hs
@@ -16,6 +16,7 @@ module Plugins.MBox (MBox(..)) where
 
 import Prelude hiding (catch)
 import Plugins
+import Plugins.Utils (changeLoop, expandHome)
 
 import Control.Monad
 import Control.Concurrent.STM
@@ -65,7 +66,6 @@ data MBox = MBox [(String, FilePath, String)] [String] String
 instance Exec MBox where
   alias (MBox _ _ a) = a
   start (MBox ms args _) cb = do
-    vs <- mapM (const $ newTVarIO ("", 0 :: Int)) ms
 
     opts <- parseOptions args -- $ words args
     let dir = oDir opts
@@ -76,24 +76,26 @@ instance Exec MBox where
 
     dirExists <- doesDirectoryExist dir
     let ts = map (\(t, _, _) -> t) ms
-        sec = \(_, f, _) -> f
+        sec (_, f, _) = f
         md = if dirExists then (dir </>) . sec else sec
         fs = map md ms
         cs = map (\(_, _, c) -> c) ms
         ev = [CloseWrite]
 
+    xfs <- mapM expandHome fs
+    vs <- replicateM (length xfs) (newTVarIO ("", 0 :: Int))
     i <- initINotify
-    zipWithM_ (\f v -> addWatch i ev f (handleNotification v)) fs vs
 
-    forM_ (zip fs vs) $ \(f, v) -> do
+    forM_ (zip xfs vs) $ \(f, v) -> do
       exists <- doesFileExist f
       n <- if exists then countMails f else return 0
       atomically $ writeTVar v (f, n)
+      when exists $ addWatch i ev f (handleNotification v) >> return ()
 
     changeLoop (mapM (fmap snd . readTVar) vs) $ \ns ->
       let s = unwords [ showC uniq m n c | (m, n, c) <- zip3 ts ns cs
                                          , allb || n /= 0 ]
-      in cb (if length s == 0 then "" else pref ++ s ++ suff)
+      in cb (if null s then "" else pref ++ s ++ suff)
 
 showC :: Bool -> String -> Int -> String -> String
 showC u m n c =
@@ -112,13 +114,3 @@ handleNotification v _ =  do
   (p, _) <- atomically $ readTVar v
   n <- countMails p
   atomically $ writeTVar v (p, n)
-
-changeLoop :: Eq a => STM a -> (a -> IO ()) -> IO ()
-changeLoop s f = atomically s >>= go
- where
-    go old = do
-        f old
-        go =<< atomically (do
-            new <- s
-            guard (new /= old)
-            return new)
diff --git a/Plugins/Mail.hs b/Plugins/Mail.hs
index 89cac30..38cdaae 100644
--- a/Plugins/Mail.hs
+++ b/Plugins/Mail.hs
@@ -16,12 +16,12 @@ module Plugins.Mail where
 
 import Prelude hiding (catch)
 import Plugins
+import Plugins.Utils (expandHome, changeLoop)
 
 import Control.Monad
 import Control.Concurrent.STM
 
 import System.Directory
-import System.Environment
 import System.FilePath
 import System.INotify
 
@@ -58,10 +58,6 @@ instance Exec Mail where
 modifyTVar :: TVar a -> (a -> a) -> STM ()
 modifyTVar v f = readTVar v >>= writeTVar v . f
 
-expandHome :: FilePath -> IO FilePath
-expandHome ('~':'/':path) = fmap (</> path) (getEnv "HOME")
-expandHome p              = return p
-
 handle :: TVar (Set String) -> Event -> IO ()
 handle v e = atomically $ modifyTVar v $ case e of
     Created  {} -> create
@@ -72,13 +68,3 @@ handle v e = atomically $ modifyTVar v $ case e of
  where
     delete = S.delete (filePath e)
     create = S.insert (filePath e)
-
-changeLoop :: Eq a => STM a -> (a -> IO ()) -> IO ()
-changeLoop s f = atomically s >>= go
- where
-    go old = do
-        f old
-        go =<< atomically (do
-            new <- s
-            guard (new /= old)
-            return new)
diff --git a/Plugins/Utils.hs b/Plugins/Utils.hs
new file mode 100644
index 0000000..1dbcd40
--- /dev/null
+++ b/Plugins/Utils.hs
@@ -0,0 +1,39 @@
+------------------------------------------------------------------------------
+-- |
+-- Module: Plugins.Utils
+-- Copyright: (c) 2010 Jose Antonio Ortega Ruiz
+-- License: BSD3-style (see LICENSE)
+--
+-- Maintainer: Jose A Ortega Ruiz <jao@gnu.org>
+-- Stability: unstable
+-- Portability: unportable
+-- Created: Sat Dec 11, 2010 20:55
+--
+--
+-- Miscellaneous utility functions
+--
+------------------------------------------------------------------------------
+
+
+module Plugins.Utils (expandHome, changeLoop) where
+
+import Control.Monad
+import Control.Concurrent.STM
+
+import System.Environment
+import System.FilePath
+
+
+expandHome :: FilePath -> IO FilePath
+expandHome ('~':'/':path) = fmap (</> path) (getEnv "HOME")
+expandHome p              = return p
+
+changeLoop :: Eq a => STM a -> (a -> IO ()) -> IO ()
+changeLoop s f = atomically s >>= go
+ where
+    go old = do
+        f old
+        go =<< atomically (do
+            new <- s
+            guard (new /= old)
+            return new)
diff --git a/README b/README
index 5201334..132e44a 100644
--- a/README
+++ b/README
@@ -546,11 +546,12 @@ Monitors have default aliases.
 `Mail Args`
 
 - aliases to `Mail`
-- Args: list of maildirs in form `[("name1","path1"),("name2","path2")]`
+- Args: list of maildirs in form
+  `[("name1","path1"),("name2","path2")]`. Paths may start with a '~'
+  to expand to the user's home directory.
 - This plugin requires inotify support in your linux kernel and the
   [hinotify] package. To activate, pass `--flags="with_inotify"`
   during compilation.
-- Paths may start with a '~' to expand to the user's home directory.
 
 `MBox Mboxes Opts Alias`
 
@@ -566,15 +567,16 @@ Monitors have default aliases.
                       of displayed mail coints
    -s suffix --suffix suffix  a string giving a suffix for the list
                       of displayed mail coints
+- Paths may start with a '~' to expand to the user's home directory.
 - This plugin requires inotify support in your linux kernel and the
   [hinotify] package. To activate, pass `--flags="with_inotify"`
   during compilation.
 - Example. The following command look for mails in `/var/mail/inbox`
-  and `/foo/mbox`, and will put a space in front of the printed string
+  and `~/foo/mbox`, and will put a space in front of the printed string
   (when it's not empty); it can be used in the template with the alias
   `mbox`:
 
-         Run MBox [("I ", "inbox", "red"), ("O ", "/foo/mbox", "")]
+         Run MBox [("I ", "inbox", "red"), ("O ", "~/foo/mbox", "")]
                   ["-d", "/var/mail/", "-p", " "] "mbox"
 
 ## Monitor Plugins Commands Arguments