let parse_args () =
begin try
let file_to_load = ref "" in
Arg.parse spec_list (fun s -> file_to_load := s) usage;
P.load_student_file !file_to_load;
with Sys_error s -> begin
Printf.printf "%s\n" usage;
List.iter (fun (a,_,c) -> Printf.printf " %s : %s\n" a c) spec_list;
Printf.printf "\nError : %s\n" s;
exit 1;
end; end