Hello!
On Fri, May 28, 1999 at 08:00:27AM +0200, Friedrich Dominicus wrote:
> I wrote before with my trouble understanding hugsIsEOF. But I don't have
> found a clean way just to write a cat. Can s.o give me a hand?
import System(getArgs)
file2stdout :: String {- filename -} -> IO ()
file2stdout filename = do
let realname = case filename of "-" -> "/dev/stdin"; _ -> filename
content <- readFile realname
putStr content
main = do
args <- getArgs
case args of
[] -> file2stdout "-"
_ -> mapM_ file2stdout args
Due to lazy evaluation and the laziness of readFile, the file won't be
sucked in completely before outputting, but will be read in chunks.
That program just doesn't support the usual cat options
(cat [-benstuv] [file | - ...]).
Regards, Hannah.
