c-结构中的链表

Question

我是C的新手，我正试图在一个小型测试应用程序中为我正在开发的程序计算逻辑。

其目的是从数据库中读取值，将数据添加到结构中，但在该结构中，将包含与顶级结构相关的其他值的链接列表。我似乎在结构和链表中添加了一些不错的东西，但当我尝试检索值时，它就会崩溃。

以下是我的结构的定义

typedef struct CallLogStructure
{
    char * date;
    char * time;
    char * bParty;
    char * aParty;
    float duration;
    char * cleardownCause;
    struct Node *outBoundLegs;
} callLogStructure;
typedef struct Node
{
    char * target;
    float targetDuration;
    char * targetCleardownCause;
    struct Node *next;
}node;

以下是我如何初始化结构，然后调用方法将数据添加到链表中。

char *outboundTarget = "0";
    float outboundDuration = 0;
    char *outboundCleardown = "0";
    callLogStructure * callLog = NULL;
    node *temp = NULL;
    int dataRow = 0;
    callLog = malloc(dataRow+1 * sizeof(callLog));
    //start = (node*)malloc(sizeof(node));
    callLog[0].outBoundLegs = NULL;
    callLog[0].outBoundLegs = (node*)malloc(sizeof(node));
    if (callLog[0].outBoundLegs == NULL)
    {
        printf("Failed to allocate RAMn");
    }
    temp = &callLog[0].outBoundLegs;
    temp->next = NULL;
    callLog[0].outBoundLegs->target = "0";
    callLog[0].outBoundLegs->targetDuration = 0;
    callLog[0].outBoundLegs->targetCleardownCause = "0";
    //Insert first inbound leg
    callLog[0].date = "16/05/2011";
    callLog[0].time = "00:00:03";
    callLog[0].aParty = "12345";
    callLog[0].bParty = "67890";
    callLog[0].duration = 0;
    callLog[0].cleardownCause = "unanswered";
    outboundTarget = "98765";
    outboundDuration = 0;
    outboundCleardown = "Unanswered";
    insertOutBoundLeg(&callLog[0].outBoundLegs, outboundTarget, outboundDuration, outboundCleardown);

    printf("NEWLY INSERTED OUTBOUND TARGET: %s", callLog[0].outBoundLegs->target); //This is where it's crashing.

以下是insertOutBoundLeg功能

void insertOutBoundLeg(struct Node *pointer, char * target, float targetDuration, char * targetCleardownCause)
{
    if (pointer->target == NULL)
    {
        asprintf(&pointer->target, "%s", target);
        pointer->targetDuration = targetDuration;
        asprintf(&pointer->targetCleardownCause, "%s", targetCleardownCause);
        //pointer->target = target;
        //pointer->targetDuration = targetDuration;
        //pointer->targetCleardownCause = targetCleardownCause;
    }
    else
    {
        while (pointer->next != NULL)
        {
            pointer = pointer->next;
        }
        pointer->next = (node *)malloc(sizeof(node));
        pointer = pointer->next;
        //pointer->target = target;
        //pointer->targetDuration = targetDuration;
        //pointer->targetCleardownCause = targetCleardownCause;
        asprintf(&pointer->target, "%s", target);
        pointer->targetDuration = targetDuration;
        asprintf(&pointer->targetCleardownCause, "%s", targetCleardownCause);
        pointer->next = NULL;
    }
}

其想法是，最终当构建该结构时，该结构以及该结构中包含的链表将被传递给一个单独的函数，该函数将数据导出到一个文件中，我曾尝试过首先打印outboundlegs（链表）的值，但这也会崩溃，然而，顶级结构（callLog）的值是可以的。

感谢您提供的任何帮助。

Answer 1

有多个问题，从开始

callLog = malloc(dataRow+1 * sizeof(callLog));

将其更改为

callLog = malloc(dataRow+1 * sizeof(*callLog));

---

将callLog[0].outBoundLegs初始化为0作为memset(callLog[0].outBoundLegs, 0, sizeof(*callLog[0].outBoundLegs))或使用calloc()

callLog[0].outBoundLegs = calloc(1, sizeof(node));

---

callLog[0].outBoundLegs->target = "0";

不要那样初始化字符串，做

callLog[0].outBoundLegs->target = strdup("0");

但是，请记住在适当的时候释放内存。