#include int main() { if (sizeof(void*) == 8) // Assume 64-bit Linux if pointers are 8 bytes. printf("-DLIN64 "); else printf("-DLIN "); printf("-DSIZEOF_VOID_P=%d -DSIZEOF_LONG=%d -DSIZEOF_INT=%d\n", (int)sizeof(void*), (int)sizeof(long), (int)sizeof(int) ); return 0; }