How to print 5 byte integer values?

Question

I've just started reading C and have a question about a macro.
How can I print a 5 byte integer value (that happens to be defined in a macro)? For example:

#define MAX 0xdeadbeaf12
int main(){
printf(" 0x %2x \n", MAX);
}  

This code prints adbeaf12 but not deadbeaf12.

How do I get all the bytes printed?

Answer 1

#define MAX 0xdeadbeaf12LL

Will tell the compiler to use the longest available integer type (which will then be cast to an appropriate type wherever MAX is used).

On most platforms, the numeric literal suffix LL will correspond to signed long long, this is 64bit (8 bytes) on a 32 bit system. C's excellent typing system and compiler warnings will take care of the rest for you.

Your printf then needs to use the ll modifier:

printf(" 0x %2llx \n", MAX);

Answer 2

I prefer to make my assumptions about the size of a variable explicit. The following uses standard (though often unused) macros to define a 64-bit constant and print such a quantity as a hex value.

#include <stdio.h>

// Pull in UINT64_C and PRIx64 macros
#include <inttypes.h>

// Make this a 64-bit literal value
#define MAX UINT64_C(0xdeadbeaf12)

int main()
{
    // Use PRIx64 which inserts the correct printf specifier for
    // a hex format of a 64-bit value
    printf(" 0x%" PRIx64 " \n", MAX);
}