//打开给定的文件并读取其内容
#include<iostream>
#include<string>
#include<stdexcept>
#include<fstream>
using namespace std;
istream &f(istream & in)
{
    string ival;
    while(in>>ival,!in.eof())
    {
        if(in.bad())
            throw runtime_error("IO stream corrupted");
        if(in.fail())
        {
            cerr<<"bad data,try again:";
            in.clear();
            in.setstate(istream::eofbit);
            continue;
        }
        cout<<ival<<endl;
    }
    in.clear();
    return in;
}

int openFile(string fName)
{
    fstream fOpen;
    fOpen.clear();
    fOpen.open(fName.c_str());
    if(!fOpen)
    {
        cerr<<"打开文件失败"<<endl;
        return -1;
    }
    string s;
    while(fOpen>>s)
    {
        f(fOpen);
        cout<<s<<" ";
    }
    fOpen.close();
    return 1;
}

int main(void)
{
    cout<<"请输入你要打开的文件名:"<<endl;
    string fName;
    cin>>fName;
    openFile(fName);
    system("pause");
    return 0;
}

路径问题   如果是新手，建议你使用绝对路径