根据结构体里面元素的某个地址计算机构体地址

#include <stdio.h>

#include <stdlib.h>

#define CONTAINER_OF(ptr, type, member)((type *)((char *)ptr - (char *)&((type*)0)->member))

#define ARRAY_SIZE(a)(sizeof(a) / sizeof((a)[0]))

struct user_data

{

char a;

char b;

int c;

};

int main(int argc, char *argv[])

{

struct user_data *tmp;

char *h;

struct user_data = (struct user_data *)malloc (sizeof(struct user_data));

if(p_data ==NULL)

{

printf("no memory!\n");

return -1;

}

h = &p_data->b;

printf("p_data's address is 0x%p\n", p_data);

printf("h's address is 0x%p\n", h);

tmp = CONTAINER_OF(h, struct user_data, b);

printf("tmp's address is 0x%p\n", tmp);

return 0;

}