释放getline()缓冲区后，丢失了大约c：bytes个字节

bytes lost after freeing getline() buffer

我到处寻找有关使用getline()时valgrind内存泄漏的帖子。

本质上，我的代码所做的是使用getline()在一行中读取的。

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int main(){
LL A;
LLinit(&A);
size_t len = 5;
char *lineOrigin = (char *)malloc(len);
char *line_ptr = lineOrigin;
getline(&line_ptr,&len,stdin);
int status, val;
while( (status = sscanf(line_ptr,"%d",&val) ) >= 0){
printf("%d
",status);
//if(isBadInput(line_ptr)){...}
if(status == 0){
printf("ENCOUNTERED BAD INPUT. STOPPING
");
return 1;
}
Node *node_ptr = (Node *)malloc(sizeof(Node));
node_ptr->val = val;
append(&A,node_ptr);
line_ptr = lookPastSpace(line_ptr);
}
printLL(&A);
freeLL(&A);
free(lineOrigin);
return 0;

}

如您所见，我为char * lineOrigin分配了一些内存，然后有第二个指针* line_ptr，它指向* lineOrigin，在以后的代码中进行了突变。

此代码块几乎从stdin读取整数并将它们按顺序存储到LinkedList中。

每次sscanf将int读入＆val时，我都会使用lookPastSpace()在字符串中的非空格字符上移动* line_ptr，直到遇到另一个空格为止，然后再将指针移动一个缺口，以便line_ptr现在指向字符串中可以读取新int的下一个位置

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line_ptr ="123 456 789
"
line_ptr = lookPastSpace(line_ptr)
line_ptr ="456 789
"
...
line_ptr ="" -->sscanf stops.

事后，我走下链表，释放了每个分配的节点，并且由于节点没有分配内存的内容，所以我不得不释放LL的内存。

然后，稍后，我释放char * lineOrigin，这大概应该可以工作，因为它是最初分配的缓冲区，但是没有。

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tylerjgabb@lectura:~/HW6/medianDir$ make mem
valgrind median
==11827== Memcheck, a memory error detector
==11827== Copyright (C) 2002-2013, and GNU GPL'd, by Julian Seward et al.
==11827== Using Valgrind-3.10.1 and LibVEX; rerun with -h for copyright info
==11827== Command: median
==11827==
123 456 789
1
1
1
[123, 456, 789]
==11827== Invalid free() / delete / delete[] / realloc()
==11827== at 0x4C2BDEC: free (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==11827== by 0x400B37: main (in /p3/ht/tylerjgabb/HW6/medianDir/median)
==11827== Address 0x51ff040 is 0 bytes inside a block of size 5 free'd
==11827== at 0x4C2CE8E: realloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==11827== by 0x4EA5F9A: getdelim (iogetdelim.c:106)
==11827== by 0x400A73: main (in /p3/ht/tylerjgabb/HW6/medianDir/median)
==11827==
==11827==
==11827== HEAP SUMMARY:
==11827== in use at exit: 13 bytes in 1 blocks
==11827== total heap usage: 5 allocs, 5 frees, 66 bytes allocated
==11827==
==11827== LEAK SUMMARY:
==11827== definitely lost: 13 bytes in 1 blocks
==11827== indirectly lost: 0 bytes in 0 blocks
==11827== possibly lost: 0 bytes in 0 blocks
==11827== still reachable: 0 bytes in 0 blocks
==11827== suppressed: 0 bytes in 0 blocks
==11827== Rerun with --leak-check=full to see details of leaked memory
==11827==
==11827== For counts of detected and suppressed errors, rerun with: -v
==11827== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 0 from 0)
tylerjgabb@lectura:~/HW6/medianDir$

我有点卡住了，很困惑。有什么想法吗？

-------------- TYPEDEFS和LL函数的说明-----------------
LLfuncs.c

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#include"LinkedListHeader.h"
#include <stdlib.h>

void LLinit(LL *LL_ptr){
LL_ptr->head_ptr = NULL;
LL_ptr->tail_ptr = NULL;
LL_ptr->length = 0;
}

void freeLL(LL *LL_ptr){
Node *curr_ptr = LL_ptr->head_ptr;
while(curr_ptr != NULL){
Node *next_ptr = curr_ptr->next_ptr;
free(curr_ptr);
curr_ptr = next_ptr;
}
}

以上只是我的LLfuncs.c的一小部分

LinkedListHeader.h

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/* This is a header file containing typedefs and macros for linked lists *Tyler J Gabb
*For assignment 6a. Shuffle.
*/
#include <stdio.h>
#define showLocs(LL) printf("head_ptr = %p, tail_ptr = %p length = %d
",LL.head_ptr,LL.tail_ptr,LL.length)

typedef struct LinkedListNode {
int val;
struct LinkedListNode *next_ptr;
} Node;

typedef struct LinkedList {
Node *head_ptr;
Node *tail_ptr;
int length;
} LL;

LLinit()初始化任何最近声明的LL类型，使其头和尾为0x0，长度为0。这有助于使LL发生变化的其他函数

---------------------------一些其他有趣的信息-----------------

如果输入字符串的大小小于len的原始值，那么我不会出现内存泄漏(有时)