[Haskell-cafe] [Beginner's Question] How to read filenames from a DirStream

[David Brown]

Albert Lee wrote:

> and I write that in haskell:
>
> -----
> import System.Posix
> import System.IO
>
> main = do
>     dp <- openDirStream "/"
>     df <- readDirStream dp  
>     putStrLn df
>     closeDirStream dp

Some code snippets out of harchive, which uses DirStream:

  bracket (openDirStream path) closeDirStream (getNames [])

  -- Extract the names in the given DirStream, eliminating "." and "..",
  -- and sorting the result.
  getNames :: [String] -> DirStream -> IO [String]
  getNames names str = do
     name <- readDirStream str
     case name of
        "" -> return (sort names)
        "." -> getNames names str
        ".." -> getNames names str
        _ -> getNames (name:names) str

You may not need the names sorted.  This also may hold onto some
memory on large directories, I haven't looked if something might need
to be made more strict.

Dave