程序代码：

BOOK *store(BOOK *head)                          //存储
{
    FILE *fp;
    BOOK *ptr, *p;
    p = head;

    if((fp = fopen("bookinfo.txt","w")) == NULL){
        printf("File open error!\n");
        exit(0);
    }
                                                     

    for(ptr = head;ptr;ptr = ptr->next)
    fprintf(fp,"%d   %s   %s %6.2f\n",ptr->num,ptr->writer,ptr->name,ptr->price);
    if(fclose(fp)){
        printf("Can not close the file!\n");
        exit(0);
    }

    return head;
}

程序代码：

BOOK *store(BOOK *head)                          //存储
{
    FILE *fp;
    BOOK *ptr, *p;
    p = head;

    if((fp = fopen("bookinfo.txt","w")) == NULL){
        printf("File open error!\n");
        exit(0);
    }
                                                     

    for(ptr = head;ptr;ptr = ptr->next)
    fprintf(fp,"%d   %s   %s %6.2f\n",ptr->num,ptr->writer,ptr->name,ptr->price);
    if(fclose(fp)){
        printf("Can not close the file!\n");
        exit(0);
    }

    return head;
}

程序代码：

BOOK *read()
{
    BOOK *ptr, *head, *tail;
    head = tail = NULL;
    int num;
    char writer[CHAR], name[CHAR];
    double price;

    if((fp = fopen("bookinfo.txt","r")) == NULL){
        printf("open fail!\n");
        exit(0);
    }
    while(! feof(fp))
    {
        ptr=(BOOK *)malloc(size);
        if(head == NULL)
            head = ptr;
        else
            tail->next = ptr;
        tail = ptr;
        fscanf(fp,"%d %s %s %lf",&num, writer, name, &price);
        ptr->num = num;
        strcpy(ptr->writer, writer);
        strcpy(ptr->name, name);
        ptr->price = price;
    }
    tail = NULL;

    return head;
}