为什么说没有初始化指针？

Z时代
2024-01-10
分类：IT

#include <stdio.h>
#include <malloc.h>
#include <string.h>
typedef struct _Info1
{
    int value;
    char name[64];
}Info1,*pInfo1;
typedef struct _Info2
{
    int value;
    char *name;
}Info2,*pInfo2;
typedef struct _Info3
{
    int value;
    size_t length;        //通过length来控制name的长度
    char name[1];
}Info3,*pInfo3;
int main()
{
    Info1 *pi1 = (Info1 *)malloc(sizeof(Info1));
    if (pi1 == NULL)
    {
        goto err;
    }
    memset(pi1, 0,sizeof(Info1));
    strcpy_s(pi1->name, 64, "lucy");
    pi1->value = 78;
    Info2 *pi2 = (Info2 *)malloc(sizeof(Info2));
    if (pi2 == NULL)
    {
        goto err;
    }
    memset(pi2, 0, sizeof(Info2));
    size_t len = sizeof("lucy") + 1;
    pi2->value = 78;
    pi2->name = (char *)malloc(len);
    if (pi2->name == NULL)
    {
        goto err;
    }
    memset(pi2->name, 0, len);
    strcpy_s(pi2->name, len, "lucy");
    Info3 *pi3 = (Info3 *)malloc(sizeof(Info3)+strlen("lucy")+1-1);
    if (pi3 == NULL)
    {
        goto err;
    }
    memset(pi3, 0, sizeof(Info3) + strlen("lucy") + 1 - 1);
    pi3->value = 78;
    pi3->length = strlen("lucy") + 1;
    strcpy_s(pi3->name, pi3->length, "lucy");
    printf("1:score:%d ,name:%s\n", pi1->value, pi1->name);
    printf("2:score:%d ,name:%s\n", pi2->value, pi2->name);
    printf("3:score:%d ,name:%s\n", pi3->value, pi3->name);
err:
    if (pi1)
        free(pi1);
    if (pi2)
        free(pi2);
    if (pi2->name)
        free(pi2->name);
    if (pi3)
        free(pi3);
    return 0;
}