Writing 64 bit value in hex to a string

How do I write a 64 bit value, example
0xffffffffffffffff to a buffer?
My code:
sprintf( buffer , "%016llx\n" , 0xffffffffffffffff ) ;

This gives me output in buffer as 0x00000000ffffffff.

An earlier thread suggested using %016llx or %016llX with
printf to actually print out the output.
But this does not seem to work with the above function.

Please help.

Thanks,
Rahul.

Code:

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  sprintf( buffer , "%016llx\n", 0xffffffffffffffffull ) ;

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You need to explicitly make the constant an unsigned long long

Perhaps this?

Code:

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

int main( void )
{
  unsigned long long value = -1ULL;
  printf("value = 0x%016"PRIX64"\n", value);
  return 0;
}

/* my output
value = 0xFFFFFFFFFFFFFFFF
*/

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