#include <stdio.h>
#include <assert.h>
#include <stdlib.h>
#include <inttypes.h>
 
 
//http://androidxref.com/7.1.1_r6/xref/external/avahi/avahi-compat-howl/text-test.c#33
static void hexdump(const void* p, size_t size) {
    const uint8_t *c = p;
    assert(p);
 
    printf("Dumping %u bytes from %p:\n", size, p);
 
    while (size > 0) {
        unsigned i;
 
        for (i = 0; i < 16; i++) {
            if (i < size)
                printf("%02x ", c[i]);
            else
                printf("   ");
        }
 
        for (i = 0; i < 16; i++) {
            if (i < size)
                printf("%c", c[i] >= 32 && c[i] < 127 ? c[i] : '.');
            else
                printf(" ");
        }
 
        printf("\n");
 
        c += 16;
 
        if (size <= 16)
            break;
 
        size -= 16;
    }
}
 
//默認8的倍數(shù)對齊 4+1+10=15=>16
typedef struct Person
{
    int age;
    char sex;
    char city[10];
} Person;
 
//默認8的倍數(shù)對齊 4+4+10=18=>24
typedef struct Student2
{
    Person* parent; //4 //存在指針到文件中的話，指針對應的數(shù)據(jù)會丟失，因為你只存儲了他的地址，沒有保存他的數(shù)據(jù)
    int weight;//4
    char classroom[10];//10+6
} Student2;
 
int main(void)
{
 
    Person person;
    person.age=26;
    person.sex='m';
    strcpy(person.city,"shenzhen");
 
     hexdump(&person,sizeof(person));
 
    Student2 stu;
    stu.parent=&person;//16
    stu.weight=140;
    memset(stu.classroom,0,sizeof(stu.classroom));//清零，否則是隨機值
    strcpy(stu.classroom,"204");
 
    hexdump(&stu,sizeof(stu));
 
    FILE* fp=fopen("student2.struct.bin","wb");
    fwrite(&stu,sizeof(stu),1,fp);
    fclose(fp);
    printf("write_Student2_struct sizeof=%d ok!\n",sizeof(stu));//24
 
    printf("Hello World!\n");
    return 0;
}

(10條消息) linux c之hexdump的實現(xiàn)_云守護的專欄-CSDN博客