+/*
+ * Check if variable "name" can be changed from oldval to newval,
+ * and if so, apply the changes (e.g. baudrate).
+ * When (flag & H_FORCE) is set, it does not print out any error
+ * message and forces overwriting of write-once variables.
+ */
+int env_check_apply(const char *name, const char *oldval,
+ const char *newval, int flag);
+