open Printf

let iterations = 100;;

(*============================================================================*)

let get_byte str off =								(*1*)
  int_of_char(str.[off]);;  							(*2*)

let get_duo str off =								(*3*)
  ((int_of_char (str.[off])) lsl 8) lor						(*4*)
  (int_of_char (str.[off+1]));;							(*5*)

let get_triplet str off = 							(*6*)
  ((int_of_char (str.[off])) lsl 16) lor					(*7*)
  ((int_of_char (str.[off+1])) lsl 8) lor					(*8*)
  (int_of_char (str.[off+2]));;							(*9*)

let uu_encode_byte byteval string init_offset =					(*10*)
  (string.[init_offset] <- char_of_int(((byteval lsr 2) land 63)+32);		(*11*)
   string.[init_offset+1] <- char_of_int(((byteval lsl 4) land 63)+32);		(*12*)
   string.[init_offset+2] <- char_of_int 61; 					(*13*)
   string.[init_offset+3] <- char_of_int 61);; 					(*14*)

let uu_encode_duo duo string init_offset =					(*15*)
  (string.[init_offset] <- char_of_int(((duo lsr 10) land 63)+32);		(*16*)
   string.[init_offset+1] <- char_of_int(((duo lsr 4) land 63)+32);		(*17*)
   string.[init_offset+2] <- char_of_int(((duo lsl 2) land 63)+32); 		(*18*)
   string.[init_offset+3] <- char_of_int 61);; 					(*19*)

let uu_encode_triplet triplet string init_offset =				(*20*)
  (string.[init_offset] <- char_of_int(((triplet lsr 18) land 63)+32); 		(*21*)
   string.[init_offset+1] <- char_of_int(((triplet lsr 12) land 63)+32);	(*22*) 
   string.[init_offset+2] <- char_of_int(((triplet lsr 6) land 63)+32);		(*23*) 
   string.[init_offset+3] <- char_of_int((triplet land 63)+32));; 		(*24*)

let preamble fname access =							(*25*)
  let u = char_of_int((access lsr 6) + 48)					(*26*)
  and g = char_of_int(((access lsr 3) land 7) + 48)				(*27*)
  and a = char_of_int((access land 7) + 48)					(*28*)
  in
  let astring = String.create 4 in						(*29*)
  (astring.[0] <- u; astring.[1] <- g; astring.[2] <- a;			(*30*)
   astring.[3] <- char_of_int 32);						(*31*)
  let prefix = "begin " ^ astring ^ fname ^ " \n" 				(*32*)
  in prefix;;									(*33*)

let rec put_uu_line0 str offset limit res resind =				(*34*)
  if offset<limit								(*35*)
  then
    (uu_encode_triplet (get_triplet str offset) res resind;			(*36*)
     put_uu_line0 str (offset+3) limit res (resind+4))				(*37*)
  else res;;									(*38*)

let put_uu_line str offset = 							(*39*)
  let s = String.create 62 							(*40*)
  in
  (s.[0] <- char_of_int 77; s.[61] <- char_of_int 10;				(*41*)
   put_uu_line0 str offset (offset+45) s 1);;					(*42*)

let extra_bytes x =								(*43*)
  if x==0 then 0 else 4;;							(*44*)

let need_uu_bytes rembytes =							(*45*)
  ((rembytes / 3) * 4) + (extra_bytes (rembytes - ((rembytes/3)*3)));;		(*46*)

let rec put_last_line0 str offset limit res resind =				(*47*)
  let rembytes = (limit-offset) 						(*48*)
  in
  if rembytes >= 3								(*49*)
  then
    (uu_encode_triplet (get_triplet str offset) res resind;			(*50*)
     put_last_line0 str (offset+3) limit res (resind+4))			(*51*)
  else if rembytes == 0								(*52*)
  then res									(*53*)
  else if rembytes == 1								(*54*)
  then  
    (uu_encode_byte (get_byte str offset) res resind; res)			(*55*)
  else
    (uu_encode_duo (get_duo str offset) res resind; res);; 			(*56*)

let put_last_line str offset rembytes = 					(*57*)
  let ssize = ((need_uu_bytes rembytes)+2)					(*58*)
  in
  let s = String.create ssize							(*59*)
  in
  (s.[0] <- char_of_int (rembytes+32) ; 					(*60*)
   s.[ssize-1] <- char_of_int 10;						(*61*)
   put_last_line0 str offset (offset+rembytes) s 1) ;;				(*62*)
  
let rec do_encode str offset acc =						(*63*)
  let rem_bytes = ((String.length str) - offset)				(*64*)
  in
  if rem_bytes >= 45 								(*65*)
  then
    do_encode str (offset+45) ((put_uu_line str offset)::acc)			(*66*)
  else
    ((put_last_line str offset rem_bytes)::acc);;				(*67*)
    
    
    
let uuencode fname str access = 						(*68*)
  let res = " \nend"::(do_encode str 0 [(preamble fname access)])		(*69*)
  in
  String.concat "" (List.rev res);; 						(*70*)

(*============================================================================*)

let get_file fname = 
  let handle = open_in fname
  in
  let  len = (in_channel_length handle); 
  in
  let s = String.create len 
  in
  (really_input handle s 0 len;
   s);;

let rec iter n f =
  if n>1
  then
    (f(); iter (n-1) f)
  else
    f();;

let main inname outname =    
  let str = get_file inname
  in
  let start = Sys.time() in
  let res = (iter iterations (function () -> uuencode inname str 0o640)) 
  in
  let stop = Sys.time () in
  let outfile = open_out outname in
  let time = (stop -. start) in
  (output outfile res 0 (String.length res);
   printf "%.3f" time;
   flush stdout) ;; 
 
let () = 
  let w = (Array.get Sys.argv 1) 
  in
  let x = w ^ ".ocaml" in
  main w x;;