c++文件读写

先上一张镇楼图

再来一个demo

#include <iostream>
#include <fstream>
#include <string>

#define BUFFER_SIZE 128

using namespace std;

struct Person
{
    string name = "xiaoming";
    int age = 18;
    bool isHe = false;
};

int main()
{
    ofstream writer("test.txt");
    
    if (!writer.is_open()) {
        cout << "ofstream open file failed" << endl;
        return 1;
    }
    
    writer << "first line\n";
    writer << 100 << "\n";
    writer << "third line\n";
    writer << "fourth line";
    
    writer.close();
    
    ifstream reader("test.txt");
    
    char buffer[BUFFER_SIZE];
    while (reader.getline(buffer, BUFFER_SIZE)) {
        cout << "current line: " << buffer << endl;
    }
    
    reader.close();
    cout << "read done" << endl;
    
    writer.open("test.bin", ios::binary);
    
    Person daming;
    daming.name = "daming";
    daming.age = 28;
    daming.isHe = true;
    
    writer.write((char*)&daming, sizeof(struct Person));
    writer.close();
    
    reader.open("test.bin", ios::binary);
    
    Person target;
    reader.read((char*)&target, sizeof(struct Person));
    
    cout << target.name << endl;
    cout << target.age << endl;
    cout << target.isHe << endl;
    
    cout << "read done" << endl;
}

 

PS:

http://www.cplusplus.com/reference/cstdio/sscanf/