c - 请告诉我我的错误

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                                7年前关闭。
            
                    
此代码应该“打开”输入的已保存的txt文件，并且用户可以对其进行编辑...

例如，我在save.txt中保存了“ Bob 12345 17”和“ Max 123456 18” ...当我打开文件文件并在链接列表中全部打印时，它仅显示：“ Max 123456 18” ...并且每当我关闭程序并尝试先打开save.txt而不覆盖它时，当我在链接列表中打印所有内容时，它什么都不显示...

FILE* open;
char filenameopen[100];

printf ("\nType the name of the file you want to open: ");
scanf ("%s", filenameopen);
printf ("\n");

open = fopen (filenameopen, "r");
if (filenameopen == NULL)
    printf ("No such file exists\n\n");
else
{
    phonebook_t *openentry = (phonebook_t*) malloc (sizeof(phonebook_t));
    openentry = head;

    while (1)
    {
        fscanf (open, "%s %s %d", openentry -> name, openentry -> tel, &openentry -> age);
        if (feof (open))
        {
            openentry -> next = NULL;
            break;
        }
        openentry -> next = (phonebook_t*) malloc (sizeof(phonebook_t));
        openentry = openentry -> next;
    }

    fclose(open);
}

最佳答案

看起来在while循环中，当您将链接列表的标题分配给下一个节点时，它会丢失标题的头...因此，一旦完成，您将无法打印整个列表与循环。

将您的代码调整为如下所示：

//declare you head-pointer outside the scope of the if-statement
phonebook_t *ll_head = (phonebook_t*) malloc (sizeof(phonebook_t));

if (...)
{
    //...
}
else
{
    //assign a temporary pointer to use in your while-loop
    phonebook_t* openentry = ll_head;

    //...rest of your code
}

现在，当您完成while循环时，从ll_head开始打印，因为它仍指向链接列表的开始，而不是最后一个节点。

关于c - 请告诉我我的错误，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/12621687/