#include <stdio.h>                            //  Union.c
#include <string.h>

typedef union  {  char name[8];
                           double value;
                           int rank;            }   MyUnion;

int main ( int argc, char * argv[] )  {
  MyUnion u;
  strncpy( u.name,  argc > 1 ? argv[1] : "McMaster", 8);
  printf("size=%d\nvalue=%g\nrank=%d\n", sizeof(u), u.value, u.rank);
}