我收到了一个来自valgrind的seg错误，我不确定这个错误到底是什么意思，也不知道如何修复它。我希望能澄清这个错误并找到可能的解决办法。这就是错误：我
==8063==命令：./main stock.dat coins.dat
==8063个==
==8063==读取大小1无效
==8063==at 0x4C2E1C7:strcpy（在/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so中）
==8063==by 0x401046:设置节点（in/home/joshua/Documents/Assignment 2/main）
==8063==by 0x400E78:main（in/home/joshua/Documents/Assignment 2/main）
==8063==Address 0x0不是stack'd、malloc'd或（最近）free'd
==8063个==
==8063个==
==8063==用信号11的默认动作终止进程（SIGSEGV）
==8063==Access不在地址0x0的映射区域内
==8063==at 0x4C2E1C7:strcpy（在/usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so中）
==8063==by 0x401046:设置节点（in/home/joshua/Documents/Assignment 2/main）
==8063==by 0x400E78:main（in/home/joshua/Documents/Assignment 2/main）
==8063==ERROR SUMMARY:1个上下文中的1个错误（不显示：0中的0）
#include "vm_menu.h"
#include "vm_type.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <malloc.h>
#define NUMARGS 3
void addNodeBottom(struct stock_item *val, struct stock_item *head);
struct stock_item* setupNode(char* line);
char* openFile(char fileName[]);
int main(int argc, char * argv[])
{
struct vm vm;
struct menu_item menu_items[NUM_MENU_ITEMS];
/* The UNUSED() function is designed to prevent warnings while your
* code is only partially complete. Delete these 4 function calls once
* you are using the data structures declared above in your own code */
UNUSED(argc);
UNUSED(argv);
UNUSED(vm);
UNUSED(menu_items);
//creates a the first element for the stock_items type in the data structure.
struct stock_item *root;
struct stock_item *item;
item = (struct stock_item *) malloc( sizeof(struct stock_item) );
/* Now rootNode points to a node struct */
root = (struct stock_item *) malloc( sizeof(struct stock_item) );
/* List of things to do in this function: */
/* check command line arguments */
if(argc!=3){
printf("insuffcient arguments \n");
return EXIT_SUCCESS;
}
/*open stock file*/
char* fileName = argv[1];
FILE *file;
file = fopen(fileName,"r+");
/*read file*/
long lSize;
char *buffer;
fseek( file , 0L , SEEK_END);
lSize = ftell( file);
rewind( file );
/* allocate memory for entire content */
buffer = calloc( 1, lSize+1 );
if( !buffer ) fclose(file),fputs("memory alloc fails",stderr),exit(1);
/* copy the file into the buffer */
if( 1!=fread( buffer , lSize, 1 , file) )
fclose(file),free(buffer),fputs("entire read fails",stderr),exit(1);
fclose(file);
/*parse the file using | as the delmeter case*/
//declare all variables used to store the string in.
int counter = 0;
const char newLine[2] = "\n";
char *saveptr;
char *line;
int size;
//parse the id and set it first.
size = sizeof(strtok(buffer,newLine)); // allocated memory to store the id in.
line = malloc(size); //allocates the memory
int active = 0;
line = strtok_r(buffer,newLine, &saveptr); // copies the first line from the text file into a char array. .
while (!active){
if (line == NULL) {
printf("\n%s", "Reached end of file while parsing.");
return(0);
}
printf("%s",line);
item = setupNode(line);
line = strtok_r(NULL,newLine, &saveptr);
addNodeBottom(item, root);
// free(item);
}
return 0;
}
char* openFile(char fileName[]){
FILE *file;
file = fopen(fileName,"r+");
/*read file*/
long lSize;
char *buffer;
fseek( file , 0L , SEEK_END);
lSize = ftell( file);
rewind( file );
/* allocate memory for entire content */
buffer = calloc( 1, lSize+1 );
if( !buffer ) fclose(file),fputs("memory alloc fails",stderr),exit(1);
/* copy the file into the buffer */
if( 1!=fread( buffer , lSize, 1 , file) )
fclose(file),free(buffer),fputs("entire read fails",stderr),exit(1);
//printf("%s", buffer);
// printf("%s",content);
free(buffer);
fclose(file);
return buffer;
}
struct stock_item* setupNode(char* line){
struct stock_item *roots = {NULL};
roots = (struct stock_item *) malloc( sizeof(struct stock_item)+1 );
char *ptr;
char *prices;
const char del[2] = "|";
const char delm[2] = ".";
strcpy(roots->id, strtok_r(line,del,&ptr)); // returns the ID and stores in in the root node.
strcpy(roots->name, strtok_r(NULL,del,&ptr)); // returns the description and stores it in the root node.
strcpy(roots->description, strtok_r(NULL,del,&ptr)); // returns the description and stores it in the root node.
prices = strtok_r(NULL,del,&ptr); // returns a string of the price for vm_item.
int dol = atoi(strtok(prices,delm));
int cent = atoi(strtok(NULL,delm));
roots->price.dollars = dol;
roots->price.cents = cent;
int quantity = atoi(strtok_r(NULL,del,&ptr)); // returns how many items are in stock.
roots->on_hand = quantity;
return roots;
}
void addNodeBottom(struct stock_item *val, struct stock_item *head){
//create new node
struct vm_node *newNode = (struct vm_node*)malloc(sizeof(struct vm_node));
if(newNode == NULL){
printf("%s", "Unable to allocate memory for new node\n");
exit(-1);
}
newNode->data= val;
// printf("%s",newNode->data->id);
newNode->next = NULL; // Change 1
//check for first insertion
if(head->next == NULL){
head->next = newNode->data;
printf("\nadded at beginning\n");
}
else
{
//else loop through the list and find the last
//node, insert next to it
struct vm_node *current = head;
while (TRUE) { // Change 2
if(current->next == NULL)
{
current->next = newNode;
printf("\nadded later\n");
break; // Change 3
}
current = current->next;
};
}
}
代码运行时的输出为：
I0001 |可乐| 75毫升一罐可乐| 3.50 | 50
在开头添加
I0002 |百事可乐| 375ml罐装百事可乐| 3.00 | 20
稍后添加
I0003 |柠檬芝士蛋糕|美味，1/8大小的芝士蛋糕| 4.00 | 10片
稍后添加
I0004 |火星酒吧|一个美味的50克火星酒吧，您喜欢的方式冷藏。| 3.00 | 20
稍后添加
I0005 |柠檬馅饼|美味的柠檬黄油馅饼，以糕点为基础| 3.75 | 12
稍后添加
分析时已到达文件结尾。
这个输出是使用eclipse生成的，当我在终端中运行它时，它只是用segfault响应而没有显示。
#ifndef VM_TYPE
#define VM_TYPE
#define IDLEN 5
#define NAMELEN 40
#define DESCLEN 255
#define NUMDENOMS 8
#define UNUSED(var) (void)var
#define COIN_COUNT 20
#define DEFAULT_ONHAND 20
/* Type definition for our boolean type */
typedef enum truefalse
{
FALSE, TRUE
} BOOLEAN;
/* Each price will have a dollars and a cents component */
struct price
{
unsigned dollars,cents;
};
/* The different denominations of coins available */
enum denomination
{
FIVE_CENTS, TEN_CENTS, TWENTY_CENTS, FIFTY_CENTS, ONE_DOLLAR,
TWO_DOLLARS, FIVE_DOLLARS, TEN_DOLLARS
};
/* Each coin in the coins array will have a denomination (20 cents,
* 50 cents, etc) and a count - how many of that coin do we have on hand
*/
struct coin
{
enum denomination denom;
unsigned count;
};
/* The data structure that holds the data for each item of stock
*/
struct stock_item
{
char id[IDLEN+1];
char name[NAMELEN+1];
char description[DESCLEN+1];
struct price price;
unsigned on_hand;
struct stock_item *next;
};
/* The data structure that holds a pointer to the stock_item data and a
* pointer to the next node in the list
*/
struct vm_node
{
struct stock_item * data;
struct vm_node * next;
};
/* The head of the list - has a pointer to the rest of the list and a
* stores the length of the list
*/
struct vm_list
{
struct vm_node * head;
unsigned length;
};
/* This is the head of our overall data structure. We have a pointer to
* the vending machine list as well as an array of coins.
*/
struct vm
{
struct vm_list * item_list;
struct coin coins[NUMDENOMS];
char * foodfile;
char * coinsfile;
};
#endif
这些都是def类型
这是正在读取的文件结构。
I0001 |可乐| 75毫升一罐可乐| 3.50 | 50
I0002 |百事可乐| 375ml罐装百事可乐| 3.00 | 20
I0003 |柠檬芝士蛋糕|美味，1/8大小的芝士蛋糕| 4.00 | 10片
I0004 |火星酒吧|一个美味的50克火星酒吧，您喜欢的方式冷藏。| 3.00 | 20
I0005 |柠檬馅饼|美味的柠檬黄油馅饼，以糕点为基础| 3.75 | 12
最佳答案
错误Address 0x0 is not stack'd, malloc'd or (recently) free'd意味着strcpy的源是一个NULL指针。显然，strtok_r返回的是NULL而不是您所期望的。
您应该以这样的方式重写代码：如果输入的格式不正确，您将检测到NULL而不是崩溃。（您的代码还有其他问题）。