单链表的小例子（三）链表读取和保存

#include <stdio.h>
#include <malloc.h>
#include <string.h> 

struct address
{
	int a;
	int b;
	char c;
	struct address *next;
}; 

void SaveToFile(struct address *p, FILE *fp)
{
	if(p != NULL)
	{
		do
		{
			fwrite(p, sizeof(struct address), 1, fp);
			p = p->next;
		} while(p != NULL);
	}
} 

int load(FILE *fp, struct address **head)
{
	int n=0;
	struct address *p1,*p2;
	*head = (struct address *) malloc(sizeof(struct address));
	memset(*head, 0, sizeof(struct address));
	if( fread(*head, sizeof(struct address), 1, fp) != 1)
	{
		free(*head);
		*head = NULL;
		return(0);
	}
	p2 = *head;
	n++;
	while( !feof(fp))
	{
		p1 = (struct address *) malloc(sizeof(struct address));
		fread(p1, sizeof(struct address), 1, fp);
		p2->next = p1;
		p2 = p1;
		n++;
	}
	p2->next = NULL;
	return(n);
} 

void main()
{
	struct address *head;
	struct address *Test[10] = {0};
	int i = 0;
	FILE *fp = NULL; 

	for(i=0; i < 10; i++)
	{
		Test[i] = (struct address *)malloc(sizeof(struct address));
		if(Test[i] != NULL)
		{
			memset(Test[i], 0, sizeof(struct address));
			Test[i]->a = 65 + i;
			Test[i]->b = 65 + i;
		} 

	}
	for(i = 0; i < 10; i++)
	{
		if(i < 10)
		{
			Test[i]->next = Test[i+1];
		}
	}
	if((fp = fopen("addrbook.txt", "wb")) != NULL)
	{
		SaveToFile(Test[0], fp);
		fclose(fp);
	}
	if((fp = fopen("addrbook.txt", "rb")) != NULL)
	{
		load(fp, &head);
	}
}