-extern void command_print(command_context_t *context, char *format, ...);
-extern void command_print_sameline(command_context_t *context, char *format, ...);
+
+extern void command_print(command_context_t *context, char *format, ...)
+ __attribute__ ((format (printf, 2, 3)));
+extern void command_print_sameline(command_context_t *context, char *format, ...)
+ __attribute__ ((format (printf, 2, 3)));