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这段代码应该“打开”输入的保存的txt文件，用户可以编辑......

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我的链接列表中打印所有内容时，它只显示：“Max 123456 18”...和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不会显示任何内容...

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);
}
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1 回答 1

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看起来在您的while循环中，当您将链表分配给下一个节点时，您丢失了链表的头部......所以一旦您完成循环，您将无法打印整个列表.

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 循环后，开始打印，ll_head因为它仍然指向链表的开头，而不是最后一个节点。

于 2012-09-27T12:47:18.737 回答