fstream的自实现

fstream的自实现

#include "stdafx.h"
#include <iostream>
using namespace std;
#include <fstream>

class Stream
{
public:
	Stream(char* path = NULL, char* mode = NULL)
	{
		//为实现open功能，创建对象时没有初值直接返回，避免fopen参数为NULL出错
		if (path == NULL || mode == NULL)
			return;
		_fp = fopen(path, mode);
		if (_fp == NULL)
			cout << "open error!" << endl;
	}

	void open(char* path, char* mode)
	{
		_fp = fopen(path, mode);
	}

	void put(char ch)
	{
		fputc(ch, _fp);
	}

	void close()
	{
		fclose(_fp);
		_fp = NULL;
	}

	~Stream()
	{
		if (_fp != NULL)
			fclose(_fp);
	}

private:
	FILE* _fp;
};



int _tmain(int argc, _TCHAR* argv[])
{
	//fstream ifs("aa.txt", ios::in | ios::out | ios::trunc); //fopen("aa.txt",rw);

	//if (!ifs)  //对 ！符号进行重载 判断是否成功
	//	cout << "open error!" << endl;

	fstream ifs;
	ifs.open("aa.txt", ios::in | ios::out | ios::trunc);

	ifs.put('a');
	ifs.put('b');
	ifs.close();

	cout << "================================" << endl;

	//Stream s("cc.txt", "w+");

	Stream s;
	s.open("cc.txt", "w+");
	s.put('a');
	s.put('b');
	s.put('c');
	s.put('d');

	s.close();

	return 0;
}