1 files changed, 8 insertions, 4 deletions
diff --git a/light2.sh b/light2.sh
index 5f0c501..20e68a9 100755
--- a/light2.sh
+++ b/light2.sh
@@ -12,8 +12,12 @@ else
     val="$1"
 fi
 
-for backlight in "$listBacklight"
-do
-    echo "${val}" | sudo tee "/sys/class/backlight/${backlight}/brightness" 2>&1 /dev/null
-done
+if [ -n "$listBacklight" ] ; then
+    for backlight in "$listBacklight"
+    do
+        echo "${val}" | sudo tee "/sys/class/backlight/${backlight}/brightness" 2>&1 /dev/null
+    done
+else
+    echo 'No backlight detected'
+fi