读出istream对象cin中的回车换行符

file name:
boy
向磁盘文件中写入数据
beyonce
if i were a boy
love on top
The data in disk file is:

beyonce
if i were a boy
love on top

／／文件名下多了一空行，令我百思不得其解。经研究发现cin中残存了回车换行符！





#include<iostream>
#include<fstream>
#include<string>
using namespace std;

ofstream & openFile(ofstream &out,const string &fileName)
{
	out.close();
	out.clear();
	out.open(fileName.c_str());
	return out;
}

ifstream & openFile(ifstream &in,const string &fileName)
{
	in.close();
	in.clear();
	in.open(fileName.c_str());
	return in;
}

ofstream & write(ofstream &out)
{
	//向磁盘文件中写入数据
	cout<<"向磁盘文件中写入数据"<<endl;
	string line,str;
	//getline(cin,str); //读出cin中的回车换行符

	while(getline(cin,line))
		out<<line<<endl; 
	return out;
}

ifstream & read(ifstream &in)
{
	//读取磁盘文件中的数据
	cout<<"The data in disk file is:"<<endl;
	string str;
	while(getline(in,str))
		cout<<str<<endl; //并输出到终端屏幕上
	return in;
}

int main()
{
	string fileName;
	cout<<"file name:"<<endl;
	cin>>fileName;
	cin.clear();
	
	//写文件
	ofstream outFile;
	openFile(outFile,fileName);
	write(outFile);

	//读文件
	ifstream inFile;
	openFile(inFile,fileName);
	read(inFile);

	inFile.close();

	return 0;
}

／／加上 getline(cin,str);就行了