use getopt_long option definition

instead of numeric value.

src/main.c

@@ -32,10 +32,10 @@ const char *root = ".";
 int max_redirect = 0;
 
 static struct option tip_repo_opts[] = {
-	{ "max-clients", 1, 0, 'n' },
-	{ "redirect", 2, 0, 'r' },
-	{ "root", 1, 0, 't' },
-	{ "daemon", 0, 0, 'd' },
+	{ "max-clients",	required_argument,	0,	'n' },
+	{ "redirect",		optional_argument,	0,	'r' },
+	{ "root",		required_argument,	0,	't' },
+	{ "daemon",		no_argument,		0,	'd' },
 	{ NULL },
 };