while (scanf("%s", buff) != EOF)如何终止？

答：ctrl z+换行 是规定，ctrl c 是发送信号杀死进程（一般不建议ctrl c）。

int main()
{string str;while (cin >> str) // operator>>(cin, str){cout << str << endl;}char buff[128];while (scanf("%s", buff) != EOF){printf("%s\n", buff);}return 0;
}

1.operator bool

operator bool：本质是为了支持Date对象转换成bool

#include
#include
#include
#include
using namespace std;
class Date
{friend ostream& operator << (ostream& out, const Date& d);friend istream& operator >> (istream& in, Date& d);
public:Date(int year = 1, int month = 1, int day = 1):_year(year), _month(month), _day(day){}// 支持Date对象转换成booloperator bool(){// 这里是随意写的，假设输入_year为0，则结束if (_year < 1)return false;elsereturn true;}
private:int _year;int _month;int _day;
};int main()
{Date d1 = -1;Date d2 = { 2022, 10, 11 };bool ret1 = d1;bool ret2 = d2;cout << ret1 << endl;cout << ret2 << endl;if (d1)    这里本质上也是调用了operator bool{}return 0;
}

2.文件读取 ifstream

（1）get()每次读一个字符

#include
#include
using namespace std;int main()
{ifstream ifs("Test.cpp");while (ifs){char ch = ifs.get();cout << ch;}return 0;
}

（2）>> 自动过滤空格和换行

 >>认为空格/换行只是一个间隔，会自动忽略

#include
#include
using namespace std;int main()
{ifstream ifs("Test.cpp");char ch;while (ifs>>ch){cout << ch;}return 0;
}

（3）拷贝文件

（4）二进制读写

#include
#include
using namespace std;
struct ServerInfo
{char _address[256]; 
这里只能用数组，不能string，string是指针，进程A写入，进程B读取string时就是野指针//string _address;int _port;
};struct ConfigManager
{
public:ConfigManager(const char* filename):_filename(filename){}void WriteBin(const ServerInfo& info){//  1 2 4 8 16ofstream ofs(_filename, ios_base::out | ios_base::binary);ofs.write((const char*)&info, sizeof(info));}void ReadBin(ServerInfo& info){ifstream ifs(_filename, ios_base::in | ios_base::binary);ifs.read((char*)&info, sizeof(info));}
private:string _filename; // 配置文件
};
int main()
{ServerInfo winfo = { "https://legacy.cplusplus.com/reference/ios/ios/eof/", 80 };二进制写：ConfigManager cf_bin("test.bin");    //打开文件test.bin即可看到cf_bin.WriteBin(winfo);二进制读：ServerInfo rbinfo;cf_bin.ReadBin(rbinfo);cout << rbinfo._address << "  " << rbinfo._port << "  ";return 0;
}

（5）

struct ServerInfo
{string _address;int _port;Date _d;
};struct ConfigManager
{
public:ConfigManager(const char* filename):_filename(filename){}// 文本读写void WriteText(const ServerInfo& info){//  1 2 4 8 16ofstream ofs(_filename);ofs << info._address << endl;ofs << info._port << endl;ofs << info._d << endl;}void ReadText(ServerInfo& info){ifstream ifs(_filename);ifs >> info._address;ifs >> info._port;ifs >> info._d;}private:string _filename; // 配置文件
};int main()
{ServerInfo winfo = { "https://legacy.cplusplus.com/reference/ios/ios/eof/", 80, {2022, 10, 11} };ConfigManager cf_txt("test.txt");cf_txt.WriteText(winfo);ConfigManager cf_text("test.txt");ServerInfo rtinfo;cf_text.ReadText(rtinfo);cout << rtinfo._address << "  " << rtinfo._port << "  " << rtinfo._d << endl;return 0;
}