libary.cpp

实现图书的基本管理 包括:普通书籍、期刊信息的管理.使用文件流实现数据的存储.

#include <iostream.h>
#include <fstream.h>
#include <string>
#include <stdlib.h>

// The base class for books in the library.

class book_cl
{
protected:
	int book_cd;
	char book_nm[30];
	char publisher[30];

public:
	
	/* Function to accept the details common to both books and periodicals. 
		It takes the last book code as a parameter. */

	void getdata(int lcd)
	{
		char check;

		cout << "\n\n\tADD NEW BOOK/PERIODICAL DETAILS" << endl;
		book_cd=lcd+1;
		cout << "\n\nBook code: " << book_cd << endl;
		
		// Verify that the book name is not left blank.

		check='n';
		while(check=='n')
		{
			cout << endl << "Enter Book/Periodical name: ";
			cin.getline(book_nm, 30);

			if((strlen(book_nm))==0)
				cout << "\n\n\tBook/Periodical name must be entered.";
			else
				check='y';
		}

		// Verify that the publisher name is not left blank.

		check='n';
		while(check=='n')
		{
			cout << "\nEnter Publisher name: ";
			cin.getline(publisher, 30);

			if((strlen(publisher))==0)
				cout << "\n\n\tPublisher name must be entered.";
			else
				check='y';
		}
	}

	// Function to display the details common to books and periodicals.

	void dispdata(void)
	{
		cout <<"\nCode: " << book_cd;
		cout <<"\tName: " << book_nm;
	}
};

// The derived class for books in the library.

class book:public book_cl
{
protected:
	char author_nm[30];
	char pubdate[8];
	float price;
	char status;

public:
	
	/* Function to accept the book specific details. It takes the last book 
		code as a parameter. */

	void getdata(int lcode)
	{
		char check;

		// Invoke the function in the base class.

		book_cl::getdata(lcode);

		// Verify that the author name is not left blank.

		check='n';
		while(check=='n')
		{
			cout << "\nEnter Author Name: ";
			cin.getline(author_nm, 30);

			if((strlen(author_nm))==0)
				cout << "\n\n\tAuthor name must be entered.";
			else
				check='y';
		}

		cout << "\nEnter Publishing date: ";
		cin >> pubdate;
		cin.ignore();

		// Verify that the price is greater than 0.

		check='n';
		while(check=='n')
		{
			cout << "\nEnter price: ";
			cin >> price;
			cin.ignore();

			if(price<=0)
				cout << "\n\n\tBook price must be greater than 0.";
			else
				check='y';
		}

		// Set the new book's status as available. 

		status='A';
	}

	// Function to display the details specific to books.

	void dispdata(void)
	{
		book_cl::dispdata();
		cout <<"\tAuthor: " << author_nm;
	}

	// Function that returns the book code.

	int getcode(void)
	{	
		return book_cl::book_cd;
	}

	// Function to set the book status to the value received as a parameter.

	void setstatus(char pstatus)
	{
		status=pstatus;
	}

	// Function that returns the book status.

	char getstatus(void)
	{
		return status;
	}
};


// The derived class for periodicals in the library.

class periodical:public book_cl
{
protected:
	char periodicity;

public:
	
	/* Function to accept the periodical specific details. It takes the last 
		periodical code as a parameter. */

	void getdata(int lcode)
	{
		char check;

		// Invoke the function in the base class.
		
		book_cl::getdata(lcode);
		
		// Verify that a valid periodicity is entered.

		check='n';
		while(check=='n')
		{
			cout << "\nEnter Periodicity (F/M/S/Y): ";
			cin >> periodicity;

			if(periodicity>='a' && periodicity<='z')
				periodicity=periodicity-32;
			if(periodicity!='F' && periodicity!='M' && periodicity!='S' && periodicity!='Y')
				cout << "\n\n\tPeriodicity must be entered as F for Fortnightly, M for Monthly,S for Six-monthly, and Y for Yearly";
			else
				check='y';
		}
	}

	// Function that returns the book code.

	int getcode(void)
	{	return book_cl::book_cd;
	}

	// Function that returns the book name.

	char *getname(void)
	{	return book_cl::book_nm;
	}
};


// The class for periodical issues in the library.

class perissue
{
protected:
	int percode;
	int issno;
	char issdate[8];
	float price;
	char status;

public:
	
	/* Function to accept the details of an issue for a periodical.
		It takes the periodical code and issue number as parameters. */

	void getdata(int pcode, int issuenum)
	{
		char check;

		percode=pcode;
		issno=issuenum;

		cout << "\nEnter Issue date: ";
		cin >> issdate;

		// Verify that the price is greater than 0.

		check='n';
		while(check=='n')
		{
			cout << "\nEnter price: ";
			cin >> price;

			if(price<=0)
				cout << "\n\n\tIssue price must be greater than 0.";
			else
				check='y';
		}

		// Set the new issue's status as available. 

		status='A';
	}

	/* Function to display the details of the issue. It takes the periodical 
		name as a parameter. */

	void dispdata(char *fbooknm)
	{
		cout << "\nCode: " << percode;
		cout << "\tName: " << fbooknm;
		cout << "\tIssue: " << issno;
		cout <<"\tIssue date: " << issdate;
	}

	// Function that returns the issue number.

	int getissno(void)
	{	return issno;
	}

	// Function that returns the periodical code.

	int getpercd(void)
	{	return percode;
	}

	// Function that returns the availability status of the issue.

	char getstatus(void)
	{
		return status;
	}

	// Function to set the issue status to the value received as a parameter.

	void setstatus(char pstatus)
	{
		status=pstatus;
	}
};

void main(void)
{
	int choice=0;

	// Function declarations.

	void addbook(void);
	void addper(void);
	void issueret(void);
	void delissue(void);
	void viewavail(void);

	// Loop to display the menu.
	
	while(choice!=6)
	{
		system("cls");
		cout << "\n\n\tLIBRARY MANAGEMENT SYSTEM";
		cout << "\n\n1. Add new Book details";
		cout << "\n2. Add new Periodical details";
		cout << "\n3. Record Issue/Return details";
		cout << "\n4. Delete old Periodical Issue details";
		cout << "\n5. View Available Books/Periodicals";
		cout << "\n6. Exit";
		cout << "\n\n\tEnter choice: ";
		
		// Accept user input menu choice.
		
		cin >> choice;
		cin.ignore();

		// Check user input menu choice and invoke appropriate function.

		if(choice==1)
			addbook();
		else if(choice==2)
			addper();
		else if(choice==3)
			issueret();
		else if(choice==4)
			delissue();
		else if(choice==5)
			viewavail();
		else if(choice==6)
			return;
		else
			cout << "\n\n\tINVALID CHOICE! Valid choices are 1 to 6.";
	}
}


// Function to accept and add new book details to the Book.dat file.

void addbook(void)
{

	// Declare objects of the book class.

	book book1, book2;
	
	int lastcode;
	
	system("cls");
	
	// Open Book.dat file for reading.

	fstream finout("Book.dat", ios::in);
	if(!finout)
	{		cout << "Could not open Book.dat file.";
			return;
	}
	
	// Obtain the book code of the last book in the file.

	finout.seekg(0);
	while(finout.read((char *)&book1, sizeof(book1))){}
	lastcode=book1.getcode();
	
	/* If the details of the first book are being entered, set last 
		book code to 0.*/

	if(lastcode<0)
		lastcode=0;
	
	// Close the file.
	
	finout.close();

	/* Invoke the function to accept book details and pass the last book 
		code as a parameter to it. */

	book2.getdata(lastcode);

	// Reopen Book.dat file for adding the new record.

	finout.open("Book.dat", ios::app);
	if(!finout)
	{	cout << "Could not open Book.dat file.";
		return;
	}

	// Write the new record to the file.

	finout.write((char *)&book2, sizeof(book2));
	
	// Close the file.
	
	finout.close();
	return;
}


/* Function to accept and add new periodical details to the Periodical.dat 
	file, or new issue details to the Issue.dat file. */

void addper(void)
{
	char reply, check;

	system("cls");
	
	// Accept whether Periodical of Issue details are being input.
	
	check='n';
	while(check=='n')
	{
		cout << "\n\nAdd Periodical details or Issue details? (P/I): ";
		cin >> reply;
		cin.ignore();

		if(reply!='P' && reply!='I' && reply!='p' && reply!='i')
			cout << "\n\n\tPlease enter P for periodical entry or I for Issue entry.";
		else
			check='y';
	}

	if(reply=='P' || reply=='p')	
	{
		// Declare objects of the class periodical.
		
		periodical per1, per2;
		int lastcode;

		// Open Periodical.dat file for reading.
	
		fstream finout("Periodical.dat", ios::in);
		if(!finout)
		{	cout << "Could not open Periodical.dat file.";
			return;
		}
		
		// Obtain the periodical code of the last periodical in the file.

		finout.seekg(0);
		while(finout.read((char *)&per1, sizeof(per1))){}
		lastcode=per1.getcode();
	
	/* If the details of the first periodical are being entered, set last 
		book code to 0.*/

		if(lastcode<0)
			lastcode=0;
	
		// Close the file.
	
		finout.close();

		/* Invoke the function to accept periodical details and pass the 
			last periodical code as a parameter to it. */

		per2.getdata(lastcode);

		// Reopen Periodical.dat file for adding the new record.

		finout.open("Periodical.dat", ios::app);
		if(!finout)
		{	cout << "Could not open Periodical.dat file.";
			return;
		}

		// Write the new record to the file.

		finout.write((char *)&per2, sizeof(per2));
	
		// Close the file.
	
		finout.close();
		return;
	}
	else
	{
		// Declare objects of the class perissue and periodical.
		
		perissue issue1, issue2;
		periodical per1;
		
		int issnum1, issnum2, percd1, percd2;
		char check='n';
		fstream finout1, finout2;

		// Open Periodical.dat file for reading.

		finout1.open("Periodical.dat", ios::in);
		if(!finout1)
		{	cout << "Could not open Periodical.dat file.";
			return;
		}

		/* Accept the periodical code for which the issue details are being 
			entered and ensure that it exists in Periodical.dat. */

		while(check=='n')
		{
			cout << "\n\nEnter Periodical code: ";
			cin >> percd1;

			finout1.seekg(0);
			int j=0;
			while(finout1.read((char *)&per1, sizeof(per1)))
			{	
				j++; 
				percd2=per1.getcode();
				if(percd1==percd2)
				{
					check='y';
					break;
				}
			}
			if(j==0)
				check='y';
			if(check=='n')
				cout << "\n\n\tINVALID PERIODICAL CODE! Please re-enter.";
		}

		// Close the Periodical.dat file.
		
		finout1.close();	

		// Open Issue.dat file for reading.

		finout2.open("Issue.dat", ios::in);
		if(!finout2)
		{	cout << "Could not open Issue.dat file.";
			return;
		}

		/* Accept the issue number and ensure that the issue details for 
			the specified periodical do not exist in Issue.dat. */

		check='n';
		while(check=='n')