CPPLab2-2

#include "stdafx.h"
#include <iostream>
#include <string>
#include <fstream>
#include <iomanip>
using namespace std;
int FileOpenError(){
    cout << "Сan't create the file or file is busy. Exiting program...\n";
    system("pause");
    exit(1);
}
class AddressBook
{
private:
    string book_name;
    string lastname, firstname, phonenumber, email;
public:
    AddressBook(string book_name){
        ofstream adbook;
        adbook.open(book_name, ios::in);
        if (!adbook.is_open()) {
            FileOpenError();
        }
        else {
            cout << "File Successfully Opened!";
            adbook.close();
        }
    }
    void read(string book_name) {
        ifstream adbook;
            adbook.open(book_name, ios_base::in);    // открыть файл на чтение
            string str;            // статический буфер строки
             // Считывать и отображать строки в цикле, пока не eof
                while (getline(adbook, str))
                {
                    cout << str << '\n';
                }
            adbook.close();
    }
    void append(string book_name) {
        cout << "\nEnter firstname: "; cin >> firstname;
        cout << "\nEnter lastname: "; cin >> lastname;
        cout << "\nEnter phonenumber: "; cin >> phonenumber;
        cout << "\nEnter email: "; cin >> email;
        ofstream adbook;
        adbook.open(book_name, ios_base::in | ios_base::out | ios_base::app);
        adbook << firstname << "\t" << lastname << "\t" << phonenumber << "\t" << email << endl;
        adbook.close();
    }
    void rewrite(string book_name) {
        ofstream adbook;
        adbook.open(book_name, ios_base::in | ios_base::out | ios_base::trunc);
        adbook.close();
        append(book_name);
    }
};

int main(int argc, char* argv[])
{
    setlocale(LC_ALL, "Russian");
    string book_name;
    cout << "Enter a filename for addressbook: "; cin >> book_name;
    AddressBook book(book_name);
    cout << "\n\n" << "Select menu item: \n";
    cout << "1. Read the file\n";
    cout << "2. Append line to the file\n\n";
    cout << "5. Rewrite file\n";
    cout << "9. Exit\n";
    cout << "Item: ";
    int n;
    cin >> n; cout << endl;
    switch (n) {
    case 1: { book.read(book_name); break; }
    case 2: { book.append(book_name); break; }
    case 5: { book.rewrite(book_name); break; }
    case 9: { cout << "Выход из программы\n"; exit(1); }
    }
    system("pause");
    return 0;
}