#include <sys/pstat.h>

main()
{
struct pst_static pst;
long bytes, Mb;

if (pstat_getstatic(&pst, sizeof(pst), (size_t)1, 0) != -1) {
   bytes= pst.physical_memory*pst.page_size;
   Mb = bytes / 1024 / 1024;
   printf("phys_memory is %d bytes (%d MB)\n", bytes, Mb);
   }
else{
   perror("pstat_getstatic");
   }
}