我試圖動態分配一個結構數組,但是每當我運行程序時,我不斷得到:a.out(6487,0x7fff7ecb8300)malloc:*對象0x7fff6f670000錯誤:指針爲realloc'沒有被分配d *設置malloc_error_break斷點調試指針被realloced沒有分配
struct node {
char course[25];
char category[20];
char prereq[50];
char notes[50];
};
int main(int argc, char* argv[])
{
FILE *fp;
char *filename = argv[1];
char *token;
char buffer[100];
char *del = ",\n";
int num = 5, i = 0, j =0, count = 0;
struct node *d = malloc(num * sizeof(struct node));
char** complete = malloc(num * sizeof(char*));
printf("%s\n", filename);
if((fp = fopen(filename, "r")) == NULL)
{
printf("unable to open %s\n", filename);
exit(1);
}
while(fgets(buffer, sizeof(buffer), fp) != NULL)
{
if(count == num)
{
num = num + 5;
struct node *d = realloc(d, sizeof(d)*num);
printf("Reallocating\n");
}
token = strtok(buffer, del);
if(strncmp(token, "#", 1) != 0)
{
strcpy(d[count].course, token);
printf("%s\n", d[count].course);
strcpy(d[count].category, strtok(NULL, del));
printf("%s\n", d[count].category);
strcpy(d[count].prereq, strtok(NULL, del));
printf("%s\n", d[count].prereq);
strcpy(d[count].notes, strtok(NULL, del));
printf("%s\n", d[count].notes);
count++;
}
}
在使用'argv [1]'之前,檢查'argc == 2'。只是一個建議。 –
警告:在'malloc'(等等)中調用'sizeof' [你應該總是把它寫成](http://stackoverflow.com/a/17258659/1151654)作爲'ptr = malloc(sizeof(* ptr) * ...);'而不是'ptr = malloc(sizeof(ptrtype *)* ...);'。 – Eregrith
因此'struct node * d = realloc(d,sizeof(d)* num);'是錯誤的:應該使用'sizeof(* b)'而不是'sizeof(b)' – Eregrith