system-posix-redirect 1.1 → 1.1.0.1

raw patch · 2 files changed

+63/−62 lines, 2 files

Files

• System/Posix/Redirect.hs +26/−25
• system-posix-redirect.cabal +37/−37

@@ -1,4 +1,5 @@-{-# LANGUAGE EmptyDataDecls, ForeignFunctionInterface #-}+{-# LANGUAGE EmptyDataDecls #-}+{-# LANGUAGE ForeignFunctionInterface #-}  {- | Module      : System.Posix.Redirect@@ -34,20 +35,18 @@     , unsafeRedirectWriteFd     ) where -import System.Posix.Types-import System.Posix.IO-import System.IO--import Foreign-import Foreign.C.Types+import Control.Concurrent+import Control.Exception+import Control.Monad  import Data.ByteString as BS -import Control.Concurrent-import Control.Exception+import Foreign.C.Types+import Foreign.Ptr -dupTo_ :: Fd -> Fd -> IO ()-dupTo_ a b = dupTo a b >>= \_ -> return ()+import System.IO+import System.Posix.IO+import System.Posix.Types  -- | @'unsafeRedirectFd' fd f@ executes the computation @f@, passing as -- an argument a handle which is the read end of a pipe that@@ -56,24 +55,26 @@ -- handles with this descriptor that have unflushed buffers, they will -- not flush to the old file descriptor, but the new file descriptor. unsafeRedirectWriteFd :: Fd -> IO a -> IO (ByteString, a)-unsafeRedirectWriteFd fd f = do-    -- setup-    (rfd, wfd) <- createPipe-    old <- dup fd-    dupTo_ wfd fd+unsafeRedirectWriteFd fd f = bracket setup (hClose . fst) $+        \ (outHandle, (wfd, old)) -> do     -- fork a thread to consume output     outMVar <- newEmptyMVar-    outHandle <- fdToHandle rfd-    _ <- forkIO (BS.hGetContents outHandle >>= putMVar outMVar)+    void $ forkIO (BS.hGetContents outHandle >>= putMVar outMVar)     -- run the code-    r <- f-    -- cleanup-    dupTo_ old fd-    closeFd wfd+    r <- f `finally` do+        -- cleanup+        void $ dupTo old fd+        closeFd wfd     -- wait for output     out <- takeMVar outMVar-    hClose outHandle     return (out, r)+  where+    setup = do+        (rfd, wfd) <- createPipe+        old <- dup fd+        void $ dupTo wfd fd+        outHandle <- fdToHandle rfd+        return (outHandle, (wfd, old))  -- | @'redirectWriteHandle' oldFd oldHandle oldCHandle f@ executes the -- computation @f@, passing as an argument a handle which is the read@@ -84,11 +85,11 @@ redirectWriteHandle oldFd oldHandle cOldHandle f = do     hFlush oldHandle     hFlush stdout-    _ <- c_fflush cOldHandle+    void $ c_fflush cOldHandle     unsafeRedirectWriteFd oldFd $ do         r <- f         hFlush oldHandle-        _ <- c_fflush cOldHandle+        void $ c_fflush cOldHandle         return r  -- | @'redirectStdout' f@ redirects standard output during the execution

@@ -1,39 +1,39 @@-Name:               system-posix-redirect-Version:            1.1-Synopsis:           A toy module that allows you to temporarily redirect-                    a program's stdout.-Description:        Due to the design of POSIX, it is possible to-                    temporarily overload the file descriptors-                    corresponding to stdout and stderr to point to an-                    arbitrary pipe.  It is, however, tricky to get-                    right.  This module gets it right, as far as such-                    a terrible hack can be made right.  It can be used-                    to make misbehaving third-party C libraries stop-                    spewing to standard output. Warning: the module-                    author has concluded that due to lack of-                    portability, this module should not be used in any-                    serious sytem.  But, for those who like living-                    dangerously...-License:            BSD3-License-file:       LICENSE-Author:             Galois Inc.-Maintainer:         ezyang@galois.com-Copyright:          (c) 2010 Galois Inc.-Category:           System-Build-type:         Simple-Extra-source-files: include/*.h-                    cbits/*.c-Cabal-Version: >= 1.6+name: system-posix-redirect+version: 1.1.0.1+synopsis: A toy module to temporarily redirect a program's stdout.+description:+    Due to the design of POSIX, it is possible to temporarily overload the+    file descriptors corresponding to stdout and stderr to point to an+    arbitrary pipe. It is, however, tricky to get right. This module gets+    it right, as far as such a terrible hack can be made right. It can be+    used to make misbehaving third-party C libraries stop spewing to+    standard output. Warning: the module author has concluded that due to+    lack of portability, this module should not be used in any serious+    sytem. But, for those who like living dangerously...+license: BSD3+license-file: LICENSE+author: Galois Inc., Liyang HU+maintainer: system-posix-redirect@liyang.hu+copyright: (c) 2010 Galois Inc, 2013 Liyang HU+category: System+build-type: Simple+extra-source-files:+    include/hsredirect.h+    cbits/hsredirect.c+cabal-version: >= 1.6 -Source-Repository head-  Type:     git-  Location: https://github.com/liyang/system-posix-redirect+source-repository head+    type: git+    location: https://github.com/liyang/system-posix-redirect -Library-  Exposed-modules:      System.Posix.Redirect-  Extensions:           ForeignFunctionInterface,-                        EmptyDataDecls-  Build-depends:        base >= 4 && < 5, bytestring >= 0.9, unix >= 2.4.0-  C-sources:            cbits/hsredirect.c-  Include-dirs:         include-  Install-includes:     include/hsredirect.h+library+    exposed-modules:+        System.Posix.Redirect+    build-depends:+        base >= 4 && < 5,+        bytestring >= 0.9,+        unix >= 2.4.0+    ghc-options: -Wall+    c-sources: cbits/hsredirect.c+    include-dirs: include+    install-includes: include/hsredirect.h