hi,

If the source string contains a '%' you will find yourself in undefined behaviour land.

Could you explain, please? As I know, sprintf() has not "source string"; it is defined as:

int sprintf(buffer,format_string[,argument...]);

If you meant "If the format string contains a '%'" then there is nothing wrong with it: format string contains `%` often and often. If you meant that "If the argument contains a '%'" then there is nothing wrong with it as well - sometimes it may happen that %` is placed into argument which is string itself.

Regards,
Oleg