[Haskell-beginners] getChar and keyboard reading
matthias.guedemann at ovgu.de
Sun Jan 24 15:49:59 EST 2010
I wrote a program which should read the number of key presses in a
given time. It forks a thread which calls getChar and increases a MVar
each time getChar suceeds. After a delay (here 2s) the MVar is read,
its value is printed and the program exits.
increaseEveryPush mVCount = do
_ <- getChar
inh <- takeMVar mVCount
putMVar mVCount (inh + 1)
main = do
x <- newMVar 0
forkIO (increaseEveryPush x)
inh <- takeMVar x
putStr $ "\n" ++ (show inh) ++ " times button pushed\n"
But this does not work, as getChar does not succeed if there is no EOF
given (^D). It normally just exits with 0 as value in the MVar. Is
there a way toread the keyboard without having to terminate with EOF?
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