offsetof(3) - wariua/manpages-ko GitHub Wiki

#include <stddef.h>

size_t offsetof(type, member);

#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>

int
main(void)
{
    struct s {
        int i;
        char c;
        double d;
        char a[];
    };

    /* 컴파일러에 따라 출력이 다름 */

    printf("offsets: i=%zd; c=%zd; d=%zd a=%zd\n",
            offsetof(struct s, i), offsetof(struct s, c),
            offsetof(struct s, d), offsetof(struct s, a));
    printf("sizeof(struct s)=%zd\n", sizeof(struct s));

    exit(EXIT_SUCCESS);
}