如何在struct中引用struct
我有两个彼此密切相关的结构,所以我希望一个结构引用另一个结构。像这样:如何在struct中引用struct,c,struct,segmentation-fault,C,Struct,Segmentation Fault,我有两个彼此密切相关的结构,所以我希望一个结构引用另一个结构。像这样: //inside maze.h typedef struct{ char * maze; int height, length, cols, rows; } maze_t; //inside walker.h typedef struct { int row, col, end_row, end_col, dir, origin; maze_t * maze; } walker_t; 但我
//inside maze.h
typedef struct{
char * maze;
int height, length, cols, rows;
} maze_t;
//inside walker.h
typedef struct {
int row, col, end_row, end_col, dir, origin;
maze_t * maze;
} walker_t;
但我的问题是:当我想打印字符串walker->maze->maze时,我遇到了一个分割错误。这是很多代码,但我不知道我在哪里犯了错误。分段故障发生在移动\u walker
功能中
我的代码:
A.c:
#include "maze.h"
#include "string.h"
#include "stdio.h"
#include "stdlib.h"
/* Incomplete definitions of the maze support function . */
void init_maze(maze_t* maze, FILE * pFile) {
int result;
// obtain file size:
fseek(pFile , 0 , SEEK_END);
int lSize, stringPtr;
lSize= ftell(pFile);
rewind (pFile);
// allocate memory to contain the whole file:
char* string = malloc (sizeof(lSize);
if (string == NULL) {fputs ("Memory error",stderr); exit (2);}
// copy the file into the buffer:
result = fread (string,1,lSize,pFile);
if (result != lSize) {fputs ("Reading error",stderr); exit (3);}
fclose(pFile);
maze->maze = malloc (strlen(string) + 1);
stringPtr = find_letter_in_string('\n', string);
strcpy(maze->maze, &string[stringPtr+1]);
maze->rows = atoi(string);
stringPtr = find_letter_in_string(',', string);
maze->cols = atoi(&string[stringPtr+1]);
printf("Maze has %d rows and %d columns \n", maze->rows, maze->cols);
return;
}
walker.h:
#include "maze.h"
#include "walker.h"
#include "stdlib.h"
#include "stdio.h"
walker_t* init_walker(maze_t * maze) {
walker_t* walker = malloc(sizeof(walker_t));
walker->dir = 0;
printf("Made room for walker.\n");
walker->maze = maze;
locate(maze, 'S',&walker->row, &walker->col);
printf("Start coordinates: %d, %d.\n", walker->row, walker->col);
locate(maze, 'E',&walker->end_row, &walker->end_col);
return walker;
}
int move_walker(walker_t * walker, int row, int col) {
printf("maze: %s", walker->maze->maze);
printf("check: %d\n", check_move(walker->maze, row, col));
if(! check_move(walker->maze, row, col)){
printf("hello world");
return 0;
}
walker->row = row;
walker->col = col;
return 1;
}
主要条款c:
maze = malloc( sizeof (maze_t));
FILE * pFile = fopen(argv[1],"r");
if(pFile == NULL){
printf("No such file!\n");
return 0;
}
init_maze(maze, pFile);
printf("Scrambled the maze.\n");
walker = init_walker(maze);
printf("Woken the walker.\n");
很抱歉拼写错误等,除了这不是我的母语之外,我还有诵读困难症。至少这部分是错的:
result = fread (string,1,lSize,pFile);
// …
maze->maze = (char*)malloc (strlen(string) + 1);
fread
不使用NUL terminatestring
,因此不能在其上可靠地使用strlen
,因为它查找终止的“\0”
,从而继续在分配的缓冲区外扫描result
实际上包含在这种情况下读取的字节数,您可以使用string[result]='\0'
终止字符串,或者直接使用fgets
读取。strlen
本身是不必要的,因为您已经知道读取的字节数
在这两种情况下,您还需要为字符串中的NUL多分配一个字节:
char* string = malloc(lSize + 1);
通过sizeof(char)
(始终为1)的乘法和对char*
的转换也可以删除,以获得更好的样式,如图所示。在函数init\u maze
和init\u walker
中,你在哪里为maze\u t
和分配内存?在我的主函数中,你必须为walker->maze=maze分配内存->maze@Abhay抱歉,忘记从main.c添加一些代码