-----------------------------------------------------------------------------
-- |
-- Module : XMonad.Util.Run
-- Copyright : (C) 2007 Spencer Janssen, Andrea Rossato, glasser@mit.edu
-- License : BSD-style (see LICENSE)
--
-- Maintainer : Christian Thiemann <mail@christian-thiemann.de>
-- Stability : unstable
-- Portability : unportable
--
-- This modules provides several commands to run an external process.
-- It is composed of functions formerly defined in "XMonad.Util.Dmenu" (by
-- Spencer Janssen), "XMonad.Util.Dzen" (by glasser\@mit.edu) and
-- XMonad.Util.RunInXTerm (by Andrea Rossato).
--
-----------------------------------------------------------------------------
module XMonad.Util.Run (
-- * Usage
-- $usage
runProcessWithInput,
runProcessWithInputAndWait,
safeSpawn,
safeSpawnProg,
unsafeSpawn,
runInTerm,
safeRunInTerm,
seconds,
spawnPipe,
hPutStr, hPutStrLn -- re-export for convenience
) where
import Codec.Binary.UTF8.String
import System.Posix.IO
import System.Posix.Process (createSession, executeFile, forkProcess)
import Control.Concurrent (threadDelay)
import System.IO
import System.Process (runInteractiveProcess)
import XMonad
import Control.Monad
-- $usage
-- For an example usage of 'runInTerm' see "XMonad.Prompt.Ssh"
--
-- For an example usage of 'runProcessWithInput' see
-- "XMonad.Prompt.DirectoryPrompt", "XMonad.Util.Dmenu",
-- "XMonad.Prompt.ShellPrompt", "XMonad.Actions.WmiiActions",
-- "XMonad.Prompt.WorkspaceDir"
--
-- For an example usage of 'runProcessWithInputAndWait' see
-- "XMonad.Util.Dzen"
-- | Returns the output.
runProcessWithInput :: MonadIO m => FilePath -> [String] -> String -> m String
runProcessWithInput cmd args input = io $ do
(pin, pout, perr, _) <- runInteractiveProcess (encodeString cmd)
(map encodeString args) Nothing Nothing
hPutStr pin input
hClose pin
output <- hGetContents pout
when (output == output) $ return ()
hClose pout
hClose perr
-- no need to waitForProcess, we ignore SIGCHLD
return output
-- | Wait is in μ (microseconds)
runProcessWithInputAndWait :: MonadIO m => FilePath -> [String] -> String -> Int -> m ()
runProcessWithInputAndWait cmd args input timeout = io $ do
_ <- xfork $ do
(pin, pout, perr, _) <- runInteractiveProcess (encodeString cmd)
(map encodeString args) Nothing Nothing
hPutStr pin input
hFlush pin
threadDelay timeout
hClose pin
hClose pout
hClose perr
-- no need to waitForProcess, we ignore SIGCHLD
return ()
return ()
-- | Multiplies by ONE MILLION, for functions that take microseconds.
--
-- Use like:
--
-- > (5.5 `seconds`)
--
-- In GHC 7 and later, you must either enable the PostfixOperators extension
-- (by adding
--
-- > {-# LANGUAGE PostfixOperators #-}
--
-- to the top of your file) or use seconds in prefix form:
--
-- > 5.5 seconds
seconds :: Rational -> Int
seconds = fromEnum . (* 1000000)
{- | 'safeSpawn' bypasses 'spawn', because spawn passes
strings to \/bin\/sh to be interpreted as shell commands. This is
often what one wants, but in many cases the passed string will contain
shell metacharacters which one does not want interpreted as such (URLs
particularly often have shell metacharacters like \'&\' in them). In
this case, it is more useful to specify a file or program to be run
and a string to give it as an argument so as to bypass the shell and
be certain the program will receive the string as you typed it.
Examples:
> , ((modm, xK_Print), unsafeSpawn "import -window root $HOME/xwd-$(date +%s)$$.png")
> , ((modm, xK_d ), safeSpawn "firefox" [])
Note that the unsafeSpawn example must be unsafe and not safe because
it makes use of shell interpretation by relying on @$HOME@ and
interpolation, whereas the safeSpawn example can be safe because
Firefox doesn't need any arguments if it is just being started. -}
safeSpawn :: MonadIO m => FilePath -> [String] -> m ()
safeSpawn prog args = io $ void_ $ forkProcess $ do
uninstallSignalHandlers
_ <- createSession
executeFile (encodeString prog) True (map encodeString args) Nothing
where void_ = (>> return ()) -- TODO: replace with Control.Monad.void / void not in ghc6 apparently
-- | Simplified 'safeSpawn'; only takes a program (and no arguments):
--
-- > , ((modm, xK_d ), safeSpawnProg "firefox")
safeSpawnProg :: MonadIO m => FilePath -> m ()
safeSpawnProg = flip safeSpawn []
-- | An alias for 'spawn'; the name emphasizes that one is calling out to a
-- Turing-complete interpreter which may do things one dislikes; for details, see 'safeSpawn'.
unsafeSpawn :: MonadIO m => String -> m ()
unsafeSpawn = spawn
-- | Open a terminal emulator. The terminal emulator is specified in the default configuration as xterm by default. It is then
-- asked to pass the shell a command with certain options. This is unsafe in the sense of 'unsafeSpawn'
unsafeRunInTerm, runInTerm :: String -> String -> X ()
unsafeRunInTerm options command = asks (terminal . config) >>= \t -> unsafeSpawn $ t ++ " " ++ options ++ " -e " ++ command
runInTerm = unsafeRunInTerm
-- | Run a given program in the preferred terminal emulator; see 'runInTerm'. This makes use of 'safeSpawn'.
safeRunInTerm :: String -> String -> X ()
safeRunInTerm options command = asks (terminal . config) >>= \t -> safeSpawn t [options, " -e " ++ command]
-- | Launch an external application through the system shell and return a @Handle@ to its standard input.
spawnPipe :: MonadIO m => String -> m Handle
spawnPipe x = io $ do
(rd, wr) <- createPipe
setFdOption wr CloseOnExec True
h <- fdToHandle wr
hSetBuffering h LineBuffering
_ <- xfork $ do
_ <- dupTo rd stdInput
executeFile "/bin/sh" False ["-c", encodeString x] Nothing
closeFd rd
return h
