我的程序崩溃，我无法找到位置。我几乎在每一行都尝试使用printf进行调试，但我无法找到错误。 我认为它可能属于readLine功能，但我完全迷失了。
我使用的输入文件是
*HallStudyCellarKitchen*StudyHallGarden*CellarHall*KitchenHallGarden*GardenStudyKitchen
这意味着每一个＆＃39; *＆＃39;将一个新房间分开，然后显示该房间的门通向哪里。
我的程序代码
#include <stdio.h>
#include <stdlib.h>
#define MAX 10
#define BMAX 100
struct room * rooms[MAX];
int rp; // room count
// struct room - name, array of up to 4 doors, number of doors
struct room {char * name; struct door * doors[4]; int dp;};
// struct door - name for the room it connects to, & a pointer to that room
struct door {char * name; struct room * room;};
struct door * newDoor(char * name){
struct door * d; // pointer d to the address of door
d = (struct door *) malloc(sizeof(struct door));
d->name = name; // name of new door is name
d->room = NULL; // NULL room pointer
return d;
};
struct room * newRoom(char * name){
struct room * r; // pointer r to the address of room
printf("New room is %s\n",name);
r = (struct room *) malloc(sizeof(struct room));
r->name = name; // name of new room is name
r->dp = 0; // no doors
return r;
};
showRoom(struct room * r){
int i;
printf("room name: %s\n", r->name);
for (i = 0; i < (r->dp); r++){
printf("%d %s\n", i,r->doors[i]->name);
}
}
showRooms(){
int i;
for (i = 0; i < rp; i++){
showRoom(rooms[i]);
}
}
char * readLine(FILE * fin){
char buffer[BMAX];
int i,j;
char ch;
char * l;
i = 0;
ch = getc(fin);
if (ch == EOF)
return NULL;
while (ch!='\n' && i < (BMAX - 1)){
buffer[i] = ch;
i++;
ch = getc(fin);
}
if (ch != '\n')
while (ch != '\n')
ch = getc(fin);
buffer[i] = '\0';
l = malloc((i+1) * sizeof(char));
for (j = 0; j <= i; j++)
l[j] = buffer[j];
l[j] = '\0';
return l;
}
readRooms(FILE * fin)
{ char * l;
rp = 0;
// printf("3"); fflush(stdout);
while((l = readLine(fin)) != NULL)
{
if(rp > MAX)
{
printf("it's too many rooms\n");
exit(0);
}
//printf("%s",l);
rooms[rp] = newRoom(l);
//l = readLine(fin);
if (strncmp(l,"*")==0){
//printf("2"); fflush(stdout);
rp++;
}
while(strncmp(l,"*")!=0)
{
//printf("1"); fflush(stdout);
if((rooms[rp] -> dp) > 4)
{ printf("it's too many doors\n");
exit(0);
}
rooms[rp] -> doors[rooms[rp] -> dp] = newDoor(l);
rooms[rp] -> dp++;
l = readLine(fin);
}
//rooms[rp] -> dp = 0;
//rp++;
//l = readLine(fin);
}
}
connect()
{ int i,j,k;
for(i = 0; i < rp; i++)
for(j = 0; j < rooms[i]->dp; j++)
{ for(k = 0; k < rp; k++)
if(strcmp(rooms[k]->name,rooms[i]->doors[j]->name) == 0)
{ rooms[i]->doors[j]->room = rooms[k];
break;
}
if(k == rp)
{ printf("can't find %s\n",rooms[i]->doors[j]->name);
exit(0);
}
}
}
int main(int argc,char ** argv){
FILE * fin;
struct room * r; // current room
// struct door * d;
int d;
if((fin=fopen(argv[1],"r"))==NULL)
{ printf("cannot open %s\n",argv[1]);
exit(EXIT_FAILURE);
}
printf("11"); fflush(stdout);
readRooms(fin);
printf("22");
fclose(fin);
showRooms();
connect();
r = rooms[0];
while(1)
{ showRoom(r);
printf("enter door number> ");
scanf("%d",&d);
if(d >= (r->dp))
printf("bad door number\n");
else
r = r->doors[d]->room;
}
return EXIT_SUCCESS;
}
可能导致崩溃的原因，我该如何解决？
答案 0 :(得分：0)
readLine函数确实看起来有点容易出错：
char * readLine(FILE * fin){
char buffer[BMAX];
int i,j;
char ch;
char * l;
i = 0;
ch = getc(fin);
if (ch == EOF)
return NULL;
while (ch!='\n' && i < (BMAX - 1)){
buffer[i] = ch;
i++;
ch = getc(fin);
}
// The test on the next line is not necessary: it will be caught
// by the first run of the following while loop.
if (ch != '\n')
while (ch != '\n')
ch = getc(fin);
buffer[i] = '\0';
// Allocate a region of memory of (probably) i+1 bytes
l = malloc((i+1) * sizeof(char));
// j will range from zero to i, terminating when j = i+1
for (j = 0; j <= i; j++)
l[j] = buffer[j];
// j now equals i+1 and l[j] is one beyond the size of the memory allocated at l.
l[j] = '\0';
return l;
}
通过更改循环上的条件
来解决此问题 // j will range from zero to i-1, terminating when j = i
for (j = 0; j < i; j++)
l[j] = buffer[j];
// j now equals i and l[j] is the last element of the memory allocated at l.
l[j] = '\0';
注意：
1）您应该始终检查malloc的返回值。
2）malloc分配的内存的实际大小可能超过请求的大小，具体取决于堆实现，处理器体系结构和使用的实际库函数。
此外，您应该很好，并使用free在您指定的每个指针上调用malloc。当进程终止时（如果它在相当常见的操作系统中运行），内存将被最终清理，但是做家务管理是一种好习惯，特别是在readLine返回的临时缓冲区上。
您可能还想查看if(rp > MAX)中的readRooms行，看看是否会导致第11个房间过度运行。
答案 1 :(得分：0)
2个地方int strncmp(const char *s1, const char *s2, size_t n);的使用不正确。建议替换为strcmp()。
// if (strncmp(l,"*")==0)
if (strcmp(l,"*")==0)
如果编译器没有对此发出警告，请启用更多警告或获取新编译器。
怀疑关闭1
// if (rp > MAX)
if (rp >= MAX)
// if((rooms[rp] -> dp) > 4)
if ((rooms[rp] -> dp) >= 4)
readLine()的小修补程序
char * readLine(FILE * fin){
char buffer[BMAX];
int i,j;
// char ch;
int ch;
char * l;
i = 0;
ch = getc(fin);
if (ch == EOF)
return NULL;
// while (ch!='\n' && i < (BMAX - 1)){
while (ch!='\n' && ch!= EOF && i < (BMAX - 1)){
buffer[i] = ch;
i++;
ch = getc(fin);
}
if (ch != '\n')
// while (ch != '\n')
while (ch != '\n' && ch!= EOF)
ch = getc(fin);
buffer[i] = '\0';
// l = malloc((i+1) * sizeof(char));
l = malloc(i+1); // sizeof(char) is always 1
if (l == NULL) Handle_OOM();
for (j = 0; j <= i; j++)
l[j] = buffer[j];
l[j] = '\0';
return l;
}
答案 2 :(得分：0)
可能导致崩溃的原因，我该如何解决？
崩溃的一个可能（和可能的）原因是readRooms()：
while(strncmp(l,"*")!=0)
{
//printf("1"); fflush(stdout);
if((rooms[rp] -> dp) > 4)
{ printf("it's too many doors\n");
exit(0);
}
rooms[rp] -> doors[rooms[rp] -> dp] = newDoor(l);
rooms[rp] -> dp++;
l = readLine(fin);
}
当达到EOF时，循环结束时的l = readLine(fin)将l设置为NULL，并且此空指针被错误地传递给strncmp()（也就是说，正如chux所说，错过了第三个论点。）
在您解决这个问题之前，您必须决定输入文件的格式，也就是说房间是否在同一条线上，就像您的问题一样 - 那么您就无法阅读目前形式为readLine()的单人间 - 或者房间分开。