Hi,

here is a solution that seems to work. The function Stdinbuf.lines
returns a list of available lines. It works with or without
   Unix.select [Unix.stdin] [] [] delay

Christoph Bauer


(* Stdinbuf.ml *)

let () = Unix.set_nonblock Unix.stdin 

let buf = ref (String.create 256) 
let pos = ref 0

let rec lines stdin = 
  let len = String.length !buf in
  let r = 
    try Unix.read stdin !buf !pos (len - !pos) 
    with Unix.Unix_error( Unix.EAGAIN, _ , _ ) -> 0 in 
    pos := r + !pos;
    if !pos >= len then
      let s' = String.create (len*2) in
	String.blit !buf 0 s' 0 len;
	buf := s';
	lines stdin
    else
      try 
	let e = String.rindex_from !buf !pos '\n' in
	let c = String.sub !buf 0 e in
	  String.blit !buf e !buf 0 (!pos-e);
	  pos := !pos - e;
	  StringUtils.split ~sep:'\n' c 
      with Not_found -> []
(* eof *)

For completeness:

(* stringUtils.ml *)
(* ... * )

let split ?(sep = ' ') ?(empty = false) s =
  let rec loop acc i =
    let s, idx =
      try
        let idx = String.rindex_from s i sep in
          String.sub s (idx+1) (i-idx), (idx-1)
      with Not_found ->
        String.sub s 0 (i+1), ~-1
    in let acc' =
        if empty || s <> "" then s::acc
        else acc
      in
        if idx = ~-1 then acc'
        else loop acc' idx 
  in loop [] (String.length s -1)




-- 
let () = let rec f a w i j = Printf.printf "%.20f\r" a; let a1 = a *. i /. j in
if w then f a1 false (i +. 2.0) j else f a1 true i (j +. 2.0) in f 2.0 false 2.0 1.0