open Arg
open Unix
open Scanf
open Printf


let files = ref [];;

let main dir = 
    let _ = Printf.printf "list directory %s" dir in
    (*let files =  ref [""] in*)
    let dirfd = opendir dir in
    try
        while true do 
            let fname = readdir dirfd in
            let _ = (Printf.printf "%s\n" fname) in
            files := List.append !files [fname]
        done 
    with End_of_file -> closedir dirfd

let rec print_list lst =
    match lst with
    | [] -> []
    | hd::tl -> 
        let _ = Printf.printf "%s\n" hd in 
        print_list tl

let num = Array.length Sys.argv
let _ = if num == 2 then
    begin
    (*Printf.printf "%s\n" Sys.argv.(1) *)
    let _ = main Sys.argv.(1) in
    let _ = print_list !files in
    Printf.printf "\n"
    end
    else
    begin
    main "."
    end