%% From the Erlang shell, or in a program, match {ok, []}.
%% If this works the directory is empty.
3> {ok, []} = file:list_dir_all("/usr").
** exception error: no match of right hand side value
{ok,["X11R6","X11","standalone","share","sbin","local",
"libexec","lib","bin"]}
4> {ok, []} = file:list_dir_all("/asd").
** exception error: no match of right hand side value {error,enoent}
5> {ok, []} = file:list_dir_all("./empty").
{ok,[]}