+enum {
+ /*
+ * Line discipline option states: off, on, up to the backend.
+ */
+ LD_YES, LD_NO, LD_BACKEND
+};
+
+enum {
+ /*
+ * Line discipline options which the backend might try to control.
+ */
+ LD_EDIT, /* local line editing */
+ LD_ECHO /* local echo */
+};
+