如何将文件加载到链表 c 编程

Question

这只是我整个代码的一部分，一切正常，保存功能正常，但是当我加载文件时，它只能从文件中检索 1 条记录，当我加载它时并在没有文件的情况下保存，它会先在记录中创建空数据，我应该发送整个代码吗？

对不起，我还是新手，这就是为什么我只做我的讲座所说的，她使用 fflush stdin，gets 和东西，我仍然不知道哪个是更好的关键字来改变它。谢谢

void savefile()
{
FILE *fp;
fp = fopen("airrecord.txt","w");
curr=start;
while(curr)
{
    fprintf(fp, "Booking ID      = %10s\n",curr->booking_id);
    fprintf(fp, "Seat Number     = %10s\n",curr->seatno);
    fprintf(fp, "Name            = %10s\n",curr->name);
    fprintf(fp, "Passport Number = %10s\n",curr->passno);
    fputc('\n',fp);
    curr=curr->next;
}
fclose(fp);
}

void loadfile()
{
FILE *fp =fopen("airrecord.txt","r");
int c;

while((c = getchar()) != EOF)
{
    curr=start;

    if(start==NULL)
    {
        start=curr=(struct passenger *)calloc(1, sizeof(struct passenger));
        fscanf(fp, "Booking ID      = %10s\n",curr->booking_id);
        fscanf(fp, "Seat Number     = %10s\n",curr->seatno);
        fscanf(fp, "Name            = %10s\n",curr->name);
        fscanf(fp, "Passport Number = %10s\n",curr->passno);
        curr->next=NULL;
        break;
    }

        while(curr->next=NULL)
            curr=curr->next;

        curr->next=(struct passenger *)calloc(1, sizeof(struct passenger));
        curr=curr->next;

        fscanf(fp, "Booking ID      = %10s\n",curr->booking_id);
        fscanf(fp, "Seat Number     = %10s\n",curr->seatno);
        fscanf(fp, "Name            = %10s\n",curr->name);
        fscanf(fp, "Passport Number = %10s\n",curr->passno);
        curr->next=NULL;
        break;

}
fclose(fp);
}

int main()
{
FILE *fp;
void reserve_seat(), cancel_seat(), modify_seat(), display_layout(), exit();
int choice;
start=curr=NULL;
loadfile();


do
{

    system("cls");
    printf("\n\n*************************************************");
    printf("\n\n**************AIRLINE RESERVATION MENU***********");
    printf("\n\n*************************************************");
    printf("\n\n* 1. Reserve seat\t\t\t\t*");
    printf("\n\n* 2. Modify seat\t\t\t\t*");
    printf("\n\n* 3. Cancel seat\t\t\t\t*");
    printf("\n\n* 4. Display seat layout\t\t\t*");
    printf("\n\n* 5. save and exit Exit\t\t\t\t\t*");
    printf("\n\n*************************************************");
    printf("\n\n\tEnter your choice: ");
    scanf("%d",&choice);fflush(stdin);
    switch (choice)
    {
    case 1:
        reserve_seat();
        break;

    case 2:
        modify_seat();
        break;

    case 3:
        cancel_seat();
        break;

    case 4:
        display_layout();
        break;
    case 5:
        {
        savefile();
        break;
        }
    default:
        printf("invalid choice!!, please try again");
    }
    getch();

}while (choice != 5);

}

Answer 1

loadfile() 函数内if(start==NULL) 条件块末尾的break 语句将退出循环，因此您将只读取第一条记录。

还要注意while(curr->next=NULL) 可能不是您想要的，您需要将= 替换为==。