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我承認是一個C型的新手，但這讓我難住了。我正在練習了鏈表的實現，而且我通過簡單地增加一個變量來split_node功能得到段錯誤：Segfault從添加變量
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
struct Node {
struct Node *child;
char *content;
};
void print_list(struct Node node);
void split_node(struct Node *node, int position);
int main() {
struct Node head, second, third;
head.content = "first";
second.content = "second";
third.content = "i'm third";
head.child = &second;
second.child = &third;
print_list(head);
split_node(&head, 3);
print_list(head);
return 0;
}
void print_list(struct Node node) {
printf("%s\n", node.content);
if(node.child) print_list(*node.child);
}
/*
Split node into two nodes, with the first position characters of the node's content remaining with node, and the remainder being copied to the new node. (It doesn't yet truncate the first node's string, but does do the copy.)
*/
void split_node(struct Node *node, int position) {
if(position >= strlen((*node).content)) return;
struct Node newNode;
newNode.child = (*node).child;
(*node).child = &newNode;
int length = (strlen((*node).content) - position);
newNode.content = malloc(sizeof(char) * (length + 1));
strncpy(newNode.content, (*node).content + sizeof(char) * position, length);
newNode.content[length] = '\0';
//int foo;
}
此代碼編譯器（gcc -o -Wall名單list.c）並且運行良好：
$ ./list
first
second
i'm third
first
st
second
i'm third
但是，如果我在split_node年底取消註釋int foo，編譯並運行，我得到：
$ ./list
first
second
i'm third
first
st
Segmentation fault
GDB給了我這個回溯：
#0 0x91d6ae70 in strlen()
#1 0x91dd3126 in puts()
#2 0x00001f21 in print_list (node={child = 0xbcec815b, content = 0x8b000000 <Address 0x8b000000 out of bounds>}) at list.c:41
#3 0x00001f3c in print_list (node={child = 0x8fe0154b, content = 0x1ff6 "i'm third"}) at list.c:42
#4 0x00001f3c in print_list (node={child = 0xbffff568, content = 0x1fef "second"}) at list.c:42
#5 0x00001f3c in print_list (node={child = 0xbffff570, content = 0x1fe9 "first"}) at list.c:42
#6 0x00001ee0 in main() at list.c:33
爲什麼添加變量定義會導致段錯誤？它似乎是粉碎新創建的節點的內容指針。我很困惑;任何幫助？