[Haskell-cafe] problem reading /proc/interrupts with ByteString

[Leandro Lisboa Penz]

Hi

I'm having some problems using ByteString.Char8.readFile to read 
"/proc/interrupts". I reads nothing. I guess maybe that's because the 
file is sort of special, but I could read it by opening and using 
ByteString.Char8.hGetContents.

The part of interest is:

findInterrupts :: B.ByteString -> Int
findInterrupts str = findI
	where
		findI = read $ B.unpack $ getNums $ skipSpaces $ skip1
		from1 = case B.findSubstring (B.pack "1:") str of
				Nothing -> error $ "Not found in [" ++ B.unpack str ++ "]"
				Just a -> a
		skip1 = B.drop from1 str
		skipSpaces = B.dropWhile (\c -> c == ' ')
		getNums = B.takeWhile (\c -> c `elem` "1234567890")

getNumInterrupts :: IO Int
getNumInterrupts = do
	h <- openFile "/proc/interrupts" ReadMode
	c <- B.hGetContents h
	hClose h
	-- c <- B.readFile "/proc/interrupts"
	-- With readFile the contents are emtpy
	-- B.putStrLn c
	return $ findInterrupts c


Whole code can be found at http://hpaste.org/63

Thanks in advance
Leandro Penz