Want a solution for printf

Possible Duplicate:
how to printf uint64_t?

I want to print u_int64_t in C. I want to know the format specifier for this? I am a C user, I want to do a printf().

#include <inttypes.h>
#include <stdio.h>

uint64_t t = 42;
printf("%" PRIu64 "\n", t);