From 643c10d77702baf4126a054ad312fb903b27ac7d Mon Sep 17 00:00:00 2001
From: Thomas von Dein <tom@izb.net>
Date: Sun, 13 Dec 2020 14:24:14 +0100
Subject: [PATCH] catch invalid usage

---
 jaildk | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/jaildk b/jaildk
index 7fc404e..10c122d 100755
--- a/jaildk
+++ b/jaildk
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-version=1.10
+version=1.11
 
 usage_jaildk() {
     beg=`tput -T ${TERM:-cons25} md`
@@ -196,6 +196,10 @@ jaildk_build() {
         esac
     done
 
+    if test -z "$jail"; then
+        usage_build
+    fi
+
     if test -z "$mode"; then
         mode=start
     fi