struct cmdline *cmdline_new(cmdline_parse_ctx_t *ctx, const char *prompt, int s_in, int s_out);
void cmdline_set_prompt(struct cmdline *cl, const char *prompt);
void cmdline_free(struct cmdline *cl);
-void cmdline_printf(const struct cmdline *cl, const char *fmt, ...);
+void cmdline_printf(const struct cmdline *cl, const char *fmt, ...)
+ __attribute__((format(printf,2,3)));
int cmdline_in(struct cmdline *cl, const char *buf, int size);
int cmdline_write_char(struct rdline *rdl, char c);
void cmdline_interact(struct cmdline *cl);