如何用rand实现产生固定长度的随机数？结构体字符数组赋值？以及如何拷贝字符串？

总的代码如下；

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

#define shell_command "aaaasdff"
#define snprintf(dest, size, format, ...) _snprintf_s(dest, size, size - 1, format, ## __VA_ARGS__)

typedef struct NOde
{
	char szname[300];
}NODE;

int main()
{
	NODE *node;
	node = (NODE*)malloc(sizeof(NODE)); 

	char snz[100];
	char name[100] = "asdasdf";
	char session_key[9];
	int i;
	char buf[10];
	strncpy(node->szname, name, sizeof(name));

	//strcpy(node->szname, name);

	srand((unsigned)time(NULL));
	snprintf(session_key, sizeof(session_key), "%08x", rand());

	puts(session_key);

	strncpy(node->szname, session_key, sizeof(session_key));

	puts(node->szname);

	memcpy(node->szname, session_key, 8);

	puts(node->szname);


	system("pause");
	return 0;
}

字符串拷贝函数：strncpy和memcpy的区别

产生固定长度的随机数函数：snprintf()。