C++文件输入输出小例子

#include <fstream>

#include <string>

#include <iostream>

using namespace std;



int main()

{

	ifstream infile;

	ofstream outfile;

	string str;

	infile.open("in.txt");

	outfile.open("out.txt");

	if (!infile)

	{

		cerr<<"error:unable to open input file:"

			<<infile<<endl;

		return -1;

	}

	while(infile>>str)

		outfile<<str<<endl;

	infile.close();

	outfile.close();

	return 0;

}