读取二进制文件时出问题了
程序代码：#include <stdio.h>
#include <stdlib.h>
#include <malloc.h>
struct student
{
char name[10];
char num[12];
int age;
struct student *next;
};
int main(void)
{
struct student *creat(void);
void myprint(const struct student *);
void save(FILE *, const struct student *);
struct student *read_bin(FILE *);
FILE *fp;
struct student *head_1, *head_2;
head_1 = creat();
myprint(head_1);
fp = fopen("file", "wb");
save(fp, head_1);
fclose(fp);
fp = fopen("file", "rb");
head_2 = read_bin(fp);
myprint(head_2);
fclose(fp);
system("pause");
return 0;
}
//建立单向链表
struct student *creat(void)
{
struct student *head, *p1, *p2;
int flag;
head = NULL;
do
{
p2 = (struct student *)malloc(sizeof(struct student));
printf("input student's name,number and age:\n");
scanf("%s%s%d", p2->name, p2->num, &p2->age);
if (head == NULL)
head = p2;
else
p1->next = p2;
p1 = p2;
printf("\ninput 1 to keep on or input 0 to end:");
scanf("%d", &flag);
} while (flag);
p1->next = NULL;
return head;
}
//输出单向链表
void myprint(const struct student *head)
{
struct student *p = (struct student *)head;
while (p)
{
printf("%-10s\t%12s\t%2d\n", p->name, p->num, p->age);
p = p->next;
}
}
//保存链表至二进制文件
void save(FILE *fp, const struct student *head)
{
struct student *p = (struct student *)head;
while (p)
{
fwrite(p, sizeof(p->next) + sizeof(p->num) + sizeof(p->age), 1u, fp);
p = p->next;
}
}
//创建链表读取二进制文件中的信息
struct student *read_bin(FILE *fp)
{
struct student *head, *p1, *p2;
head = NULL;
while (!feof(fp))
{
p2 = (struct student *)malloc(sizeof(struct student));
fread(p2, sizeof(p2->name) + sizeof(p2->num) + sizeof(p2->age), 1u, fp);
if (head == NULL)
head = p2;
else
p1->next = p2;
p1 = p2;
}
p1->next = NULL;
return head;
}运行过程：
我输入了两行信息，却读出四行...
[此贴子已经被作者于2019-1-12 20:07编辑过]
