Hello.
In order to experiment with the Binary module
distributed with nhc98, I wrote the attached
program which writes a binary file and then
reads it. When executed, I got an extra
byte (8) that I cannot explain:
[65,66,67,68,8]
Any clues why it appears?
Regards,
Romildo
--
Prof. Jos� Romildo Malaquias <[EMAIL PROTECTED]>
Departamento de Computa��o
Universidade Federal de Ouro Preto
Brasil
module Main where
import IO (IOMode(ReadMode,WriteMode))
import Binary (openBin,closeBin,getBits,putBits,isEOFBin,
BinIOMode(RO,WO),BinLocation(File),BinHandle)
-- convert from IOMode to BinIOMode
ioModeToBinIOMode :: IOMode -> BinIOMode
ioModeToBinIOMode ReadMode = RO
ioModeToBinIOMode WriteMode = WO
-- open a binary file
openBinaryFile :: FilePath -> IOMode -> IO BinHandle
openBinaryFile path mode = openBin (File path (ioModeToBinIOMode mode))
-- write a list of integers (8 bits) to binary file
writeBinaryFile :: FilePath -> [Int] -> IO ()
writeBinaryFile fileName xs =
do f <- openBinaryFile fileName WriteMode
let writeToBin [] = return ()
writeToBin (x:xs) = do putBits f 8 x
writeToBin xs
writeToBin xs
closeBin f
-- read a list of integers (8 bits) from binary file
readBinaryFile :: FilePath -> IO [Int]
readBinaryFile fileName =
do f <- openBinaryFile fileName ReadMode
let readFromBin = do eof <- isEOFBin f
if eof
then return []
else do x <- getBits f 8
xs <- readFromBin
return (x:xs)
xs <- readFromBin
closeBin f
return xs
-- test the above
main = do writeBinaryFile "test.bin" [65,66,67,68]
xs <- readBinaryFile "test.bin"
putStrLn (show xs)
