http://hackage.haskell.org/package/fsutils
fsutils is a collection of file system odds and ends that don't seem to be in
any easily accessible place. Included is a walk function similar to Python's
os.walk, copyDir for copying directories recursively, and fileList for
getting a depth-first list of files recursively in a directory, among other
things.
Also included (because I don't really want to have a separate library just for
it) is an mtreeList function that is similar to tree-seq from Clojure. A lot
of the file system functions included are written in terms of it.