+/*
+ * if the file name is non-empty, try to play it.
+ * Return 0 if success, -1 if error, digit if interrupted by a digit.
+ * If digits == "" then we can simply check for non-zero.
+ */
+int ast_stream_and_wait(struct ast_channel *chan, const char *file,
+ const char *language, const char *digits);
+