add options to disable/enable interactive mode

gentooup.sh

@@ -51,6 +51,18 @@ while [[ $# -gt 0 ]]; do
         PORTAGE_UPGRADE_OPTIONS+=("--with-bdeps=y")
         shift
         ;;
+      --batch)
+        echo "We do not ask questions"
+        PORTAGE_ASK=""
+        INTERACTIVE=0
+        shift
+        ;;
+      --interactive)
+        echo "We do ask questions"
+        INTERACTIVE=1
+        PORTAGE_ASK="-a"
+        shift
+        ;;
       --*)
         echo "Unknown option $1"
         shift