let read_procmem pid =
  let cin = open_in (Printf.sprintf "/proc/%i/status" pid) in
  let matchline s =
    try
      Scanf.sscanf s " VmHWM: %i kB" (fun i -> Some i)
    with
      | _ -> None
  in
  let rec loop () =
    match matchline (input_line cin) with
	Some i -> i
      | None -> loop ()
  in
  let s = try loop() with _ -> -1 in
  close_in cin;
  s
;;

let rec monitor pid timeout mem =
  let p, s = Unix.waitpid [ Unix.WNOHANG ] pid in
  if p == 0 then
    if (Unix.gettimeofday() > timeout || (read_procmem pid) >= mem)
    then Unix.kill pid Sys.sigkill
    else
      let () = Unix.sleep 1 in
      monitor pid timeout mem
;;


let run args timeout mem =
  let pid = Unix.fork () in
  if pid == 0 then
    Unix.execvp args.(0) args
  else monitor pid timeout mem
;;

let () = 
  if Array.length Sys.argv < 4 then exit 1
  else
    try
      let timeout = Unix.gettimeofday () +. float_of_string Sys.argv.(1) in
      let mem = int_of_string Sys.argv.(2) in
      let command = Array.sub Sys.argv 3 ((Array.length Sys.argv) - 3) in
      run command timeout mem;
      exit 0
    with
	_ -> exit 2
;;