+__printf_2_3 int para_printf(struct para_buffer *b, const char *fmt, ...);
+typedef int line_handler_t(char *, void *);
+int for_each_line(char *buf, size_t size, line_handler_t *line_handler,
+ void *private_data);
+int for_each_line_ro(char *buf, size_t size, line_handler_t line_handler,
+ void *private_data);