open TextIO;        (* i.e. the I/O library *)

fun cat fileName =
  let
    fun f inS =
      if endOfStream inS then
           ( closeIn inS; print "<eof>\n" )
      else ( print (inputN(inS, 1));  f inS )
  in f(openIn fileName)
  end;

(* e.g. *) cat "cat.sml";

(* Copy file to std output, L.A., 11/4/2005 *)
(* Also see I/O, Ch 4,                      *)
(* Ullman "Elements of ML Programming" 1998 *)