二级指针的一个疑问

Question

问题的产生

要实现一个函数，函数内部 malloc申请一块内存，然后针对这块内存做一系列操作，操作这部分忽略不计，不是探讨的问题，我们要返回申请的这片内存的地址.

#include <stdio.h>
#include <stdlib.h>

/*获取malloc内存的地址*/
int getaddress(int **address)
{
    int * tmp = NULL;
    int size = 64;
    tmp = malloc(size *sizeof(int));
    *address = tmp;
    printf("Address of malloc memory is:%p\n",tmp);
    return 0;
}
int main()
{
    int *pointer = NULL;
    getaddress(&pointer);
    printf("Address of pointer is:%p\n",pointer);
    return 0;
}

输出结果终于符合我们预期：
Address of malloc memory is:0x100202350
Address of pointer is:0x100202350
Program ended with exit code: 0

pointer的值就是我们在函数中所申请的内存地址.
写道这里我有疑问，函数getaddress中是否真正需要tmp中间变量呢？

/*
    Name: 二级指针
    Copyright: segment
    Author: 风清扬
    Date: 13/06/17 22:15
    Description: pointer
 */

#include <stdio.h>
#include <stdlib.h>

/*获取malloc内存的地址*/
int getaddress(int **address)
{
    int size = 64;
    *address = malloc(size *sizeof(int));
    printf("Address of malloc memory is:%p\n",address);
    return 0;
}

int main()
{
    int *pointer = NULL;
    getaddress(&pointer);
    printf("Address of pointer is:%p\n",pointer);
    return 0;
}

运行结果居然是：
Address of malloc memory is:0x7fff5fbff7b0
Address of pointer is:0x100300000
Program ended with exit code: 0
那么为什么会是这样呢？
tmp只是中间变量，我现在去掉了中间变量，仅此而已.

Answer 1

去掉中间变量是没有问题的，但是，getaddress函数里面应该是printf("Address of malloc memory is:%p\n",*address);才对。address前面有个*。

另外多说两句，比较推荐的写法是：

#include <stdio.h>
#include <stdlib.h>

/*获取malloc内存的地址*/
int* getaddress()
{
    int * tmp = NULL
    int size = 64;
    tmp = malloc(size *sizeof(int));
    printf("Address of malloc memory is:%p\n",tmp);
    return tmp;
}
int main()
{
    int *pointer = NULL;
    pointer = getaddress();
    printf("Address of pointer is:%p\n",pointer);
    return 0;
}

Answer 2

没明白为什么要使用 二级指针