rendered paste body#include <iostream>#include <stdio.h>#include <time.h>#include <fstream>using namespace std;int ch;void entry_book();void issue_book();void return_book();void search();void search_book();char *tym();class book { public: char b_name[50],b_pub[20],b_pur[12]; long int b_no; public: friend istream &operator >> (istream &in,book &temp); friend ostream &operator << (ostream &out,book &temp); friend ofstream &operator << (ofstream &bookout,book &temp); friend ifstream &operator >> (ifstream &bookin,book &temp); }var;class library:public book { public: char *i_dat,*r_dat,stud_name[20],clas[10]; long int b_no; public: friend ostream &operator<<(ostream &out,library & temp); friend ofstream &operator<<(ofstream &libout,library &temp); friend ifstream &operator>>(ifstream &libin,library &temp); }var2;char *tym(){ time_t rawtime; struct tm * timeinfo; time ( &rawtime ); timeinfo = localtime ( &rawtime ); return ( asctime (timeinfo) );}void entry_book(){ cout<<"\nEnter Book No:"; cin>>var.b_no; cout<<"\nEnter Book name:"; cin>>var.b_name; cout<<"\nPub Name:"; cin>>var.b_pub; cout<<"\nPurchase date:"; cin>>var.b_pur; ofstream book_file; book_file.open ("book.txt"); book_file<<var; // << "\t R \n" R is set as the default state of book.when it issued the state will become I book_file.close();}void issue_book(){ int temp_no; //string i_date; cout<<"\n Enter the Book Number:"; cin>>temp_no; ifstream book_file2; ofstream lib_file; book_file2.open("book.txt"); book_file2>>var; while(!book_file2.eof()) { if(temp_no==var.b_no) { var2.i_dat=tym(); cout<<"\nEnter Student Name:"; cin>>var2.stud_name; cout<<"\nEnter Class:"; cin>>var2.clas; lib_file.open("library.txt"); lib_file<<var.b_no<<"\t"<<var.b_name<<"\t"<<var2.stud_name<<"\t"<<var2.clas<<"\t"<<*var2.i_dat<<"\t"<<"------------------------"<<" I"<<"\n"; lib_file.close(); } book_file2>>var; } book_file2.close();} void return_book(){ int temp_no,temp_ptr=0; char chr[10],chr1[10]; //string r_date; cout<<"\nEnter the Book Number:"; cin>>temp_no; ifstream lib_file2; ofstream lib_file3; lib_file2.open("library.txt"); lib_file2>>var2; lib_file2.seekg(0); while(!lib_file2.eof()) { if(temp_no==var2.b_no) { var2.r_dat=tym(); //temp_ptr=lib_file2.tellg(); lib_file2.get(chr[0]); while(strcmp(chr,"-")!=0) temp_ptr++; lib_file3.seekp(temp_ptr); lib_file3<<*var2.r_dat; temp_ptr+=2; lib_file3<<" R \n"; } }}void search_book(){ int temp_no; cout<<"\nEnter the Book Number:"; cin>>temp_no; ifstream book_file3; book_file3.open("book.txt"); book_file3>>var; while(!book_file3.eof()) { if(temp_no==var.b_no) { cout<<"\nBook No:"<<var.b_no; cout<<"\nBook Name:"<<var.b_name; cout<<"\nBook Publisher:"<<var.b_pub; cout<<"\nBook Purchase date:"<<var.b_pur<<"\n"; } }}int main () { ofstream myfile ("example.txt"); cout<<"\n Enter your choice:\n1.Book entry \n2.Book issue \n3.Book Return \n4.Search \nchoice:"; cin>>ch; switch(ch) { case 1:entry_book(); case 2:issue_book(); case 3:return_book(); case 4:search_book(); default:cout<<"\n Wrong choice.only 1-4 is valid."; }}