C中的棘手段錯誤

Question

我正在嘗試為我的大學任務運行一個C項目，並且我在以下代碼段中的“while（current-> next！= NULL）{”行中遇到了一個seg錯誤：

FILE* f = fileOpen("test.txt");
if (f != NULL){
    functionList = fileReadToMemory(f, &graphParams);//functionList is a pointer to the first value of the linked list it creates
    current = functionList;

    while (current->next != NULL) {
        printf("%d %d %d %s", current->red, current->green, current->blue, current->expression);//Prints value of linked list
        current = current -> next;
    }
}

gdb給我的錯誤如下：

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_INVALID_ADDRESS at address: 0x000000000000003a
0x0000000100000b30 in main () at main.c:23
23          while (current->next != NULL) {

我究竟做錯了什么？

提前致謝！

Answer 1

你需要這樣做

while (current != NULL) 

代替

current->next != NULL 

因為列表中的最后一個元素會導致段錯誤。