A simple shell executor (OCaml)

simplepsshell.ml

let int_of_status s =
  match s with
  | Unix.WEXITED n -> n
  | Unix.WSIGNALED n -> n
  | Unix.WSTOPPED n -> n

let psshell ?exe:(exe="/bin/sh") cmd =
  match Unix.fork() with
  | 0 -> Unix.execvp exe [| exe; "-c"; cmd |]
  | child_pid -> child_pid

let main () =
  let pid = psshell "ls -la" in
  let pid', s = Unix.waitpid [] pid in
  Printf.printf "Child %d exit code: %d\n" pid' (int_of_status s)

let () = Unix.handle_unix_error main ()