Two formatted output conversion functions are defined (see also wprintf() §7.3.4 page ):
int printf(char * format, ...)
printf places output on stdout and returns the number of output characters. The conversion characters taken into account are %diopuxXcs with associated flags and fields. Use your preferred man for more information.
char * sprintf(char * str, char * format, ...)
sprintf sets output on str and returns str. The conversion characters taken into account are the same as printf ones.