a simple wrapper to mplayer

mplayer.hs

import System.IO
import System.IO.Unsafe (unsafePerformIO)
import System.Process
import Control.Concurrent
 
mhin = unsafePerformIO newEmptyMVar 
mhout = unsafePerformIO newEmptyMVar
ended = unsafePerformIO newEmptyMVar

main = do
    forkIO mpgLoop
    forkIO wait
    forkIO $ play []
    getChar >>= print

mpgLoop = do
    let sh = "mplayer -msglevel global=6:statusline=6 -slave -idle -really-quiet -cache 2048 -cache-min 5 -novideo"
    (Just hin, Just hout, Just herr, hdl) <- 
        createProcess (shell sh) { std_in  = CreatePipe
                                 , std_out = CreatePipe
                                 , std_err = CreatePipe 
                                 }
    putMVar mhin hin
    putMVar mhout hout
    waitForProcess hdl
    hClose herr     -- Keep `herr` alive until explicitly closed here.

wait = do
    hout <- readMVar mhout
    line <- hGetLine hout
    case line of
         "EOF code: 1  " -> do
             putMVar ended ()
         _ -> return ()
    wait

play [] = do
    let playlist = [ "/home/rnons/Music/01.mp3"
                   , "/home/rnons/Music/02.mp3"
                   , "/home/rnons/Music/03.mp3"
                   ]
    play playlist
play (x:xs) = do
    hin <- readMVar mhin
    let cmd = "loadfile " ++ x
    hPutStrLn hin cmd 
    hFlush hin
    putStrLn cmd
    takeMVar ended
    putStrLn "next"
    play xs