Parse arguments

parse.ml

open Arg;;
open Printf;;

(* Arguments *)
let files = ref [];;
let format = ref "";;
let height = ref 0;;
let percent = ref 0;;
let recursive = ref false;;
let version = "1.0";;
let width = ref 0;;

(* Functions *)
let show_version _ =
    printf "Parse arguments sample version %s\n" version;;
let get_files filename =
    files := !files @ [filename];;

let specs = [
    ("-w", Set_int width, "Resized image width");
    ("-h", Set_int height, "Resized image height");
    ("-p", Set_int percent, "Percent of source image");
    ("-r", Set recursive, "Set recursive mode");
    ("-f", Set_string format, "Resized image format (JPEG or PNG)");
    ("-v", Unit show_version, "Display version number");
    ("--width", Set_int width, "Resized image width");
    ("--height", Set_int height, "Resized image height");
    ("--percent", Set_int percent, "Percent of source image");
    ("--recursive", Set recursive, "Set recursive mode");
    ("--format", Set_string format, "Resized image format (JPEG or PNG)");
    ("--version", Unit show_version, "Display version number")
];;

Arg.parse specs get_files "Usage : resize [options] <src_filename> <dest_filename>";;
if (!width > 0 || !height > 0) && !percent > 0 then begin
    prerr_endline "Both width/height and percent can not be specified";
    exit 1;
end;;

(* Test *)
print_endline (string_of_int !width);;
print_endline (string_of_int !height);;
print_endline (string_of_int !percent);;
print_endline (string_of_bool !recursive);;
print_endline !format;;
List.iter (fun file -> print_endline file) !files;;