Question

Is there a way to find out if the machine is 32-bit or 64-bit by writing some code in C?

Answer 1

#include <limits.h>
/* ... */
printf("This machine's pointers to void, in a program "
       "compiled with the same options as this one and "
       "with the same compiler, use %d bits\n",
    (int)sizeof (void*) * CHAR_BIT);