from float/double to byte sequence

fd_bytes.cc

#include <cstdio>

void dump(unsigned char *p, int n) {
  for (int i = n - 1; i >= 0; i--) {
    printf("%02x ", p[i]);
  }
  printf("\n");
}

int main() {
  int i;
  union {
    double d;
    float f;
    unsigned char c[8];
  } uni;

  printf("数値：");
  scanf("%lf", &uni.d);
  printf("d = %lf\n", uni.d);
  dump(uni.c, 8);
  uni.f = uni.d;
  printf("f = %f\n", uni.f);
  dump(uni.c, 4);

  return 0;
}