import System.IO

main = 
do
        putStrLn "Enter file name (Including full path) to write"
        fileName  getLine
        fileHandle  Openfile Filename WriteMode
        endocoding  mkTextEncoding "UTF-32LE"
        hSetEncoding fileHandle endocoding

        hPutStrLn fileHandle "我愛PTR"

        hClose fileHandle

        fileHandle  openFile fileName ReadMode
        hSetEncoding fileHandle endocoding
        info  hGetContents fileHandle

        putStrLn info

$ runghc FileUtil.hs
Enter file name (Including full path) to write
temp.txt
我愛PTR