C / C++ / MFC

template <typename _CountofType, size_t _SizeOfArray>
char (*__countof_helper(UNALIGNED _CountofType (&_Array)[_SizeOfArray]))[_SizeOfArray];
#define _countof(_Array) sizeof(*__countof_helper(_Array))

class MyClass {
    friend ostream& operator <<(ostream& stream, const MyClass& obj);
    friend istream& operator >>(istream& stream,       MyClass& obj);
}
ostream& operator <<(ostream& stream, const MyClass& obj) {
    // How do I do the following?
    if ([stream is opened for binary writes]) {
        ...
    } else {
        ...
    }
}
istream& operator >>(istream& stream,       MyClass& obj) {
    // How do I do the following?
    if ([stream is opened for binary reads]) {
        ...
    } else {
        ...
    }
}

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

#define STOP 0
#define TRUE 1
#define OK   1
#define FILE_NAME ("my.text")

typedef struct List
{
	long lNum;
	char cpsName[30];
	long lCScore;
	long lMathScore;
	long atol(long i);
	struct List *next;
}Stu;

Stu stuList[3] = 
{
	{1, "asd", 32, 44, 0},
	{2, "ffg", 66, 66, 0},
	{3, "dgd", 55, 44, 0},
};

Stu *CreateList()
{
	Stu *head = NULL;
	Stu *NewNode = NULL;
	int i = 0;

	for (i=0; i<3; i++)
	{
		NewNode = (Stu*)malloc(sizeof(Stu));

		NewNode->lNum = stuList[i].atol(stuList[i].lNum);
		strncpy(NewNode->cpsName, stuList[i].cpsName, 30);
		NewNode->lCScore = stuList[i].atol(stuList[i].lCScore);
		NewNode->lMathScore = stuList[i].atol(stuList[i].lMathScore);
		NewNode->next = NULL;

		if (NULL == head)
		{
			head = NewNode;
		}
		else
		{
			head->next = NewNode;
			head = NewNode;
		}
	}

	return head;	
	
}

int SaveToFiles(Stu *head)
{
	Stu *p = head;
	FILE *fp;
	char cFileName[1024] = {0};
    //strcpy(cFileName, FILE_NAME);
	
	if ((fp = fopen(FILE_NAME, "wb")) == NULL)
	{
		printf( "Open file error!\n" );
		exit (1);
	}

	while (p != NULL)
	{
		if (fwrite(p, sizeof(Stu), 1, fp) == 1)
		{
			p = p->next;
		}
		else
		{
			printf("Write file error!\n");
			exit(1);
		}
	
	}
	fclose(fp);

	printf( "Save file succeed!\n" );
	return OK;
}

int OpenFiles()
{

	char cFileName[256] = {0};
	FILE *fp;
	if (0 == (fp = fopen(FILE_NAME, "r")))
	{
		printf("Open file error!\n");
		exit(0);
	}
	
    fgets(cFileName, 250, fp);
	printf("%s", cFileName);
	fclose(fp);
	return OK;
}

int main()
{
	Stu *head = NULL;

	head = CreateList();
	SaveToFiles(head);
	OpenFiles();
	//Print(head);

    return 0;
}