[tools]: add menconfig silent mode

tools/kconfig-frontends/frontends/mconf/mconf.c

@@ -954,20 +954,31 @@ static void conf_save(void)
 
 static int handle_exit(void)
 {
-	int res;
+    int res = 0;
 
     save_and_exit = 1;
     reset_subtitle();
     dialog_clear();
     if (conf_get_changed())
+    {
+        if (silent)
+        {
+            /* save change */
+            res = 0;
+        }
+        else
+        {
             res = dialog_yesno(NULL,
                        _("Do you wish to save your new configuration?\n"
                          "(Press <ESC><ESC> to continue kernel configuration.)"),
                        6, 60);
+        }
+        
+    }
     else
         res = -1;
     
-	end_dialog(saved_x, saved_y);
+    if (!silent) end_dialog(saved_x, saved_y);
 
     switch (res) {
     case 0:
@@ -1038,6 +1049,18 @@ int main(int ac, char **av)
 
     set_config_filename(conf_get_configname());
     conf_set_message_callback(conf_message_callback);
+    
+    if (ac > 2 && strcmp(av[2], "-n") == 0)
+    {
+        fprintf(stderr, N_("Debug mode,don't display menuconfig window.\n"));
+        silent = 1;
+        /* Silence conf_read() until the real callback is set up */
+        conf_set_message_callback(NULL);
+        av++; 
+        res = handle_exit();
+        return 1;
+     } 
+
     do {
         conf(&rootmenu, NULL);
         res = handle_exit();