refactor: replace recursion with while loop in settings

scripts/menus/2_settings.sh

@@ -4,12 +4,14 @@
 [ -n "$__IS_MODULE_2_SETTINGS_LOADED" ] && return
 __IS_MODULE_2_SETTINGS_LOADED=1
 
-settings() { #功能设置
+# 功能设置
+settings() {
+    while true; do
         # 获取设置默认显示
         [ -z "$skip_cert" ] && skip_cert=ON
         [ -z "$sniffer" ] && sniffer=OFF
         [ -z "$dns_mod" ] && dns_mod='redir_host'
-    #
+
         echo "-----------------------------------------------"
         echo -e "\033[30;47m欢迎使用功能设置菜单：\033[0m"
         echo "-----------------------------------------------"
@@ -28,7 +30,8 @@ settings() { #功能设置
         echo "-----------------------------------------------"
         read -p "请输入对应数字 > " num
         case "$num" in
-    0)
+        "" | 0)
+            break
             ;;
         1)
             if [ "$USER" != "root" -a "$USER" != "admin" ]; then
@@ -39,17 +42,14 @@ settings() { #功能设置
                 set_redir_mod
             fi
             sleep 1
-        settings
             ;;
         2)
             . "$CRASHDIR"/menus/dns.sh && set_dns_mod
             sleep 1
-        settings
             ;;
         3)
             . "$CRASHDIR"/menus/fw_filter.sh && set_fw_filter
             sleep 1
-        settings
             ;;
         4)
             echo "-----------------------------------------------"
@@ -61,7 +61,6 @@ settings() { #功能设置
                 skip_cert=OFF
             fi
             setconfig skip_cert $skip_cert
-        settings
             ;;
         5)
             echo "-----------------------------------------------"
@@ -81,7 +80,6 @@ settings() { #功能设置
                 sniffer=OFF
             fi
             setconfig sniffer $sniffer
-        settings
             ;;
         6)
             if [ -n "$(pidof CrashCore)" ]; then
@@ -95,11 +93,9 @@ settings() { #功能设置
             else
                 set_adv_config
             fi
-        settings
             ;;
         8)
             set_ipv6
-        settings
             ;;
         9)
             echo "-----------------------------------------------"
@@ -135,8 +131,11 @@ settings() { #功能设置
             ;;
         *)
             errornum
+            sleep 1
+            break
             ;;
         esac
+    done
 }
 
 set_redir_mod() { #路由模式设置