Создание файлов

#ifndef _BOOK_H_
#define _BOOK_H_
    
#include <iostream>
#include <string>
    
#define DEFAULT_FILE "books.txt"
#define SEP_LINE "--------------------------------------------------------------------------------"
#define MAX_PLACES 100
    
using namespace std;
 
class Book {
private:
    string m_author;
    string m_name;
    int m_year;
    int m_place;
public:
    Book();
    Book(string, string, int, int);
    string getAuthor() const;
    void setAuthor(string);
    string getName() const;
    void setName(string);
    int getYear() const;
    void setYear(int);
    int getPlace() const;
    void setPlace(int);
    
    friend ostream& operator<<(ostream&, const Book&);
    friend istream& operator>>(istream&, Book&);
};
 
 
#endif // _BOOK_H_

#include "book.h"
    
Book::Book(){
    // empty
}
 
Book::Book(string author, string name, int year, int place){
    setAuthor(author);
    setName(name);
    setYear(year);
    setPlace(place);
}
 
string Book::getAuthor() const{
    return m_author;
}
 
void Book::setAuthor(string author){
    m_author = ( author.empty() ) ? "Unknown" : author;
}
 
string Book::getName() const{
    return m_name;
}
 
void Book::setName(string name){
    m_name = ( name.empty() ) ? "Untitled" : name;
}
 
int Book::getYear() const {
    return m_year;
}
 
void Book::setYear(int year){
    m_year = ( year > 1600 && year < 2020 ) ? year : 0;
}
 
int Book::getPlace() const {
    return m_place;
}
 
void Book::setPlace(int place){
    m_place = ( place > 0 && place < MAX_PLACES ) ? place : 0;
}
 
ostream& operator<<(ostream& ost, const Book& book){
    ost << book.m_author << endl << book.m_name << endl << book.m_year << endl << book.m_place << endl;
    return ost;
}
 
istream& operator>>(istream& ist, Book& book){
    getline(ist, book.m_author);
    getline(ist, book.m_name);
    ist >> book.m_year;
    ist.ignore();
    ist >> book.m_place;
    ist.ignore();
    return ist;
}

#include <fstream>
#include "book.h"
    
void viewBook(const Book& book){
    cout << SEP_LINE << endl;
    cout << "Author: " << book.getAuthor() << endl;
    cout << "Name: " << book.getName() << endl;
    cout << "Year: " << book.getYear() << endl;
    cout << "Place: " << book.getPlace() << endl;
    cout << SEP_LINE << endl;
}
 
void newBook(Book& book){
    string tmp_str;
    int tmp_int;
    cout << "Author: ";
    getline(cin, tmp_str);
    book.setAuthor(tmp_str);
    cout << "Name: ";
    getline(cin, tmp_str);
    book.setName(tmp_str);
    cout << "Year: ";
    cin >> tmp_int;
    book.setYear(tmp_int);
    cout << "Place: ";
    cin >> tmp_int;
    book.setPlace(tmp_int);
}
 
int main(int argc, char **argv){
    char *store_file_name;
    string answer;
    Book book("Unknown", "Untitled", 0, 0);
    ofstream store_file;
    
    if ( argc == 2 )
        store_file_name = argv[1];
    else
        store_file_name = DEFAULT_FILE;
    
    store_file.open(store_file_name, ios::out | ios::app);
    if ( !store_file.is_open() ) {
        cerr << "Can't open file " << store_file_name << endl;
        return 1;
    }
    
    do {
        cout << SEP_LINE << endl;
        newBook(book);
        cout << "Confirm:" << endl;
        viewBook(book);
        cout << "It is correct? (yes/no): ";
        cin >> answer;
        if ( answer == "yes" || answer == "YES" ){
            store_file << book;
            if ( store_file.fail() ) {
                cerr << "Can't write to file " << store_file_name << endl;
                store_file.close();
                return 1;
            }
            else {
                cout << "Saved to file." << endl;
            }
        }
        cout << endl << "One more time? (yes/no): ";
        cin >> answer;
        cin.ignore();
    } while ( answer == "yes" || answer == "YES" );
    
    store_file.close();
    return 0;
}

#include <fstream>
#include <vector>
#include <iomanip>
#include "book.h"
 
void prnHeader(){
    cout << SEP_LINE << endl;
    cout << setiosflags(ios::left) << setw(3) << "#" << setw(25) << "Author" << setw(35) << "Name"
        << setw(6) << "Year" << setw(6) << "Plase" << endl << SEP_LINE << endl;
}
 
void prnLine(int line_number, const Book& book){
    cout << setiosflags(ios::left) << setw(3) << line_number << setw(25) << book.getAuthor() 
        << setw(35) << book.getName() << setw(6) << book.getYear() << setw(6) << book.getPlace() << endl;
}
 
int main(int argc, char **argv){
    char *input_file_name;
    char answer;
    bool stop;
    int line;
    Book book;
    vector<Book> books;
    vector<Book>::iterator bi;
    ifstream input_file;
    string str_val;
    int int_val;
    
    if ( argc == 2 )
        input_file_name = argv[1];
    else
        input_file_name = DEFAULT_FILE;
    
    input_file.open(input_file_name, ios::in);
    if ( !input_file.is_open() ) {
        cerr << "Can't open file " << input_file_name << endl;
        return 1;
    }
    
    while ( input_file >> book )    
        books.push_back(book);
    
    input_file.close();
    
    stop = false;
    while ( !stop ) {
        cout << SEP_LINE << endl;
        cout << books.size() << " books in database. Allowed actions is:" << endl;
        cout << "0 - exit; 1 - show all; 2 - search place by author and name; 3 - show all same author; "
            << "4 - count by same year" << endl << "Choice one: ";
        cin >> answer;
        cin.ignore();
        switch ( answer ) {
            case '0' :
                stop = true;
                break;
            case '1' :
                prnHeader();
                for ( line = 1, bi = books.begin(); bi != books.end(); bi++, line++ )
                    prnLine(line, *bi);
                cout << SEP_LINE << endl;
                break;
            case '2' :
                cout << endl << "Author: ";
                getline(cin, str_val);
                book.setAuthor(str_val);
                cout << "Name: ";
                getline(cin, str_val);
                book.setName(str_val);
                for ( bi = books.begin(); bi != books.end(); bi++ )
                    if ( (*bi).getAuthor() == book.getAuthor() && (*bi).getName() == book.getName() )
                        cout << endl << "*** Found at place " << (*bi).getPlace() << endl;
                break;
            case '3' :
                cout << "Author: ";
                getline(cin, str_val);
                prnHeader();
                for ( line = 1, bi = books.begin(); bi != books.end(); bi++, line++ )
                    if ( (*bi).getAuthor() == str_val )
                        prnLine(line, *bi);
                break;
            case '4' :
                cout << "Year: ";
                cin >> int_val;
                book.setYear(int_val);
                for ( int_val = 0, bi = books.begin(); bi != books.end(); bi++ )
                    if ( (*bi).getYear() == book.getYear() )
                        int_val++;
                cout << endl << "*** Found " << int_val << " books of year " << book.getYear() << endl;
                break;
            default:
                cout << "Unknown command - " << answer << endl;
        }
    }
    
    return 0;
}