I'm trying to write a program that will copy an arbitrarily large text file to a destination, and duplicate it 100 times. Thus: ./myprog < Input > Output would be the same as running: cat Input > Output # once cat Input >> Output # 99 times My first attempt was this: import IO main = disp 100 disp 0 = return () disp n = do c <- getContents putStr c hSeek stdin AbsoluteSeek 0 disp (n-1) That failed, though, because getContents closes the file after it's been completely read (ugh -- why?). So then I tried to work on various options around hGetLine and hPutStrLn. But I couldn't figure out a way to make this either properly tail-recursive while handling the exception, or to avoid polling for EOF each time through the function. I also don't want to store the entire file in memory -- the idea is to seek back to the beginning for each iteration. I'm assuming that stdin is a seekable fd. I checked the wiki for a pattern here but didn't see any. Suggestions?