Update command-line parsing (e.g. double-dash support) and help output

exec/dupefind.js

@@ -7,31 +7,32 @@ load("file_size.js");
 
 "use strict";
 
-if(argv.indexOf("-help") >= 0 || argv.indexOf("-?") >= 0) {
+var detail = 0;
+var min_size = 1024;
+var dir_list = [];
+var exclude = [];
+var hash_type;
+var options = {};
+for(var i = 0; i < argc; i++) {
+	var arg = argv[i];
+	if(arg[0] == '-') {
+		var opt = arg;
+		while(opt[0] == '-')
+			opt = opt.slice(1);
+		if(opt == "help" || opt == "?") {
 			writeln("usage: [-options] [[dir_code] [...]]");
 			writeln("options:");
 			writeln("  -lib=<name>     search for duplicates in specified library only");
 			writeln("  -min=<bytes>    specify minimum file size to compare hash/sum");
-    writeln("  -ex=<filename>  add to excluded file name list");
+			writeln("  -ex=<filename>  add to excluded file name list (case-insensitive)");
+			writeln("  -names          search for duplicate file names (case-insensitive)");
+			writeln("  -sha1           search for duplicate SHA-1 sums (the default)");
 			writeln("  -crc32          search for duplicate CRC-32 sums");
 			writeln("  -md5            search for duplicate MD5 sums");
-	writeln("  -sha1           search for duplicate SHA-1 sums (the default)");
-	writeln("  -names          search for duplicate file names (case-insensitive)");
 			writeln("  -json           use JSON formatted output");
 			writeln("  -v              increase verbosity of output");
 			exit(0);
 		}
-
-var detail = 0;
-var min_size = 1024;
-var dir_list = [];
-var exclude = [];
-var hash_type;
-var options = {};
-for(var i = 0; i < argc; i++) {
-	var arg = argv[i];
-	if(arg[0] == '-') {
-		var opt = arg.slice(1);
 		if(opt.indexOf("ex=") == 0) {
 			exclude.push(opt.slice(3).toUpperCase());
 			continue;