dist/build/System/Posix/Process/ByteString.hs

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{-# LANGUAGE ForeignFunctionInterface #-}
{-# LINE 2 "System/Posix/Process/ByteString.hsc" #-}

{-# LINE 3 "System/Posix/Process/ByteString.hsc" #-}
{-# LANGUAGE Trustworthy #-}

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-----------------------------------------------------------------------------
-- |
-- Module : System.Posix.Process.ByteString
-- Copyright : (c) The University of Glasgow 2002
-- License : BSD-style (see the file libraries/base/LICENSE)
-- 
-- Maintainer : libraries@haskell.org
-- Stability : provisional
-- Portability : non-portable (requires POSIX)
--
-- POSIX process support. See also the System.Cmd and System.Process
-- modules in the process package.
--
-----------------------------------------------------------------------------

module System.Posix.Process.ByteString (
 -- * Processes

 -- ** Forking and executing

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 forkProcess,

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 executeFile,
 
 -- ** Exiting
 exitImmediately,

 -- ** Process environment
 getProcessID,
 getParentProcessID,

 -- ** Process groups
 getProcessGroupID,
 getProcessGroupIDOf,
 createProcessGroupFor,
 joinProcessGroup,
 setProcessGroupIDOf,

 -- ** Sessions
 createSession,

 -- ** Process times
 ProcessTimes(..),
 getProcessTimes,

 -- ** Scheduling priority
 nice,
 getProcessPriority,
 getProcessGroupPriority,
 getUserPriority,
 setProcessPriority,
 setProcessGroupPriority,
 setUserPriority,

 -- ** Process status
 ProcessStatus(..),
 getProcessStatus,
 getAnyProcessStatus,
 getGroupProcessStatus,

 -- ** Deprecated
 createProcessGroup,
 setProcessGroupID,

 ) where


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import Foreign
import System.Posix.Process.Internals
import System.Posix.Process.Common

import Foreign.C hiding (
 throwErrnoPath,
 throwErrnoPathIf,
 throwErrnoPathIf_,
 throwErrnoPathIfNull,
 throwErrnoPathIfMinus1,
 throwErrnoPathIfMinus1_ )

import Data.ByteString (ByteString)
import qualified Data.ByteString.Char8 as BC

import System.Posix.ByteString.FilePath


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-- | @'executeFile' cmd args env@ calls one of the
-- @execv*@ family, depending on whether or not the current
-- PATH is to be searched for the command, and whether or not an
-- environment is provided to supersede the process's current
-- environment. The basename (leading directory names suppressed) of
-- the command is passed to @execv*@ as @arg[0]@;
-- the argument list passed to 'executeFile' therefore 
-- begins with @arg[1]@.
executeFile :: RawFilePath -- ^ Command
 -> Bool			 -- ^ Search PATH?
 -> [ByteString] -- ^ Arguments
 -> Maybe [(ByteString, ByteString)] -- ^ Environment
 -> IO a
executeFile path search args Nothing = do
 withFilePath path $ \s ->
 withMany withFilePath (path:args) $ \cstrs ->
 withArray0 nullPtr cstrs $ \arr -> do
	pPrPr_disableITimers
	if search 
	 then throwErrnoPathIfMinus1_ "executeFile" path (c_execvp s arr)
	 else throwErrnoPathIfMinus1_ "executeFile" path (c_execv s arr)
 return undefined -- never reached

executeFile path search args (Just env) = do
 withFilePath path $ \s ->
 withMany withFilePath (path:args) $ \cstrs ->
 withArray0 nullPtr cstrs $ \arg_arr ->
 let env' = map (\ (name, val) -> name `BC.append` ('=' `BC.cons` val)) env in
 withMany withFilePath env' $ \cenv ->
 withArray0 nullPtr cenv $ \env_arr -> do
	pPrPr_disableITimers
	if search 
	 then throwErrnoPathIfMinus1_ "executeFile" path
		 (c_execvpe s arg_arr env_arr)
	 else throwErrnoPathIfMinus1_ "executeFile" path
		 (c_execve s arg_arr env_arr)
 return undefined -- never reached

foreign import ccall unsafe "execvp"
 c_execvp :: CString -> Ptr CString -> IO CInt

foreign import ccall unsafe "execv"
 c_execv :: CString -> Ptr CString -> IO CInt

foreign import ccall unsafe "execve"
 c_execve :: CString -> Ptr CString -> Ptr CString -> IO CInt