[英]how to read multiple lines from stdin and store it in linked list
我正在尝试编写一个程序,从用户(来自STDIN)获取行,并将它们存储在链表中。
现在我只得到一行并终止程序。 如何更改代码以保持从stdin获取行?
另外,如果有人可以告诉我,我是否正在分配和释放内存,因为它应该是非常有用的。
谢谢。
#include <stdio.h>
#include <stdlib.h>
int BUFF_SIZE = 128;
struct Node {
char* data;
struct Node* next;
};
struct Node* head = NULL;
struct Node* tail = NULL;
void free_list(struct Node* head)
{
if (head != NULL)
{
free_list(head->next);
free(head);
}
}
int main()
{
int curr_size = 0;
char* pStr = malloc(BUFF_SIZE);
curr_size = BUFF_SIZE;
printf("%s", "please print multiple lines\n");
if (pStr != NULL)
{
char c;
int i = 0;
while ((c = getchar()) != '\n' && c != EOF)
{
pStr[i++] = c;
if (i == curr_size)
{
curr_size = i + BUFF_SIZE;
pStr = realloc(pStr, curr_size);
if (pStr == NULL) return;
}
}
pStr[i] = '\0';
struct Node* new_node = malloc(sizeof(struct Node*));
char* new_data = malloc(sizeof(pStr));
new_data = pStr;
new_node->data = new_data;
if (head == NULL)
{
head = new_node;
tail = new_node;
}
else
{
tail->next = new_node;
}
}
free_list(head);
}
几个问题:
截至目前,你正在终止阅读\\n
。
if (pStr == NULL) return; //error int c; int i = 0; while ((c = getchar()) != EOF) { /*New word, insert into linked list*/ if (c == '\\n'){ pStr[i] = '\\0'; struct Node* new_node = malloc(sizeof(*new_node)); char* new_data = malloc(i+1); strcpy(new_data, pStr); new_node->data = new_data; if (head == NULL) { head = new_node; tail = new_node; } else { tail->next = new_node; tail = new_node; } i = 0; //Reset the index } else { pStr[i++] = c; if (i == curr_size) { curr_size = i + BUFF_SIZE; pStr = realloc(pStr, curr_size); if (pStr == NULL) return; } } }
内存泄漏和节点data
将始终指向pStr
最新内容。
char* new_data = malloc(sizeof(pStr)); new_data = pStr; //Memory leak here new_node->data = new_data;
改为
char* new_data = malloc(i+1); strcpy(new_data, pStr); new_node->data = new_data;
sizeof(pStr)是指针的大小而不是字符串长度。
在将每个节点插入列表后,您需要更新tail
。
else { tail->next = new_node; }
至
else { tail->next = new_node; tail = new_node; }
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