c++ 文件读写

1 文件写



#include<fstream>
using namespace std;
int main()
{
    ofstream out("w.txt");
    if(out.is_open())
    {
        out << "this is a line" << endl;
        out << "this is anthor line";
        out.close();
    }
    return 0;
}

2 文件读
#include<iostream>
#include<fstream>
using namespace std;

int main()
{
    char buff[256];
    ifstream in("w.txt");
    while(!in.eof())
    {
        in.getline(buff, 100);
        cout << buff << endl;
    }
    return 0;
}
    按行读取
    std::ifstream fin(_path.c_str());
    while (!fin.eof()) {
        std::string line;
        getline(fin, line);
        
        //trim(line);

        if (site.empty()) {
            continue;
        }

        _sites.insert(site);
    }
    //std::cout << "sites num: " << _sites.size() << std::endl;
    fin.close();