-export UDEV_CONFIG_DIR=$PWD/
-export UDEV_ROOT=$PWD/udev/
-export UDEV_DB=udev.tdb
-export UDEV_CONFIG_FILE=replace_test.config
-export UDEV_PERMISSION_FILE=udev.permissions
+export UDEV_CONFIG_FILE=$PWD/$CONFIG
+
+cat > $RULES << EOF
+KERNEL="ttyUSB0", NAME="visor"
+EOF
+
+cat > $CONFIG << EOF
+udev_root="$PWD/udev/"
+udev_db="$PWD/udev/.udev.tdb"
+udev_rules="$PWD/$RULES"
+udev_permissions="$PWD/udev.permissions"
+EOF
+
+mkdir udev