C++ program to search the record in binary file

#include<iostream>
#include<conio.h>
#include<fstream>
#include<process.h>
#include<string.h>
#include<iomanip>
#include<stdio.h>

using namespace std;


class rec
{
    private:
        char name[100];
    public:
        char roll[100];

        void input()
        {
            std::cout<<"Enter the full name = ";
            gets(name);
            std::cout<<"Enter the roll = ";
            gets(roll);
        }

        void dis()
        {
            system("cls");
            puts(name);
            puts(roll);
        }
};

int main()
{
    char froll[100];
    int t = 0;
    long int rn = 0;
    char ch = 'y';
    rec r;

    system("cls");

    ofstream fir("abc.rec",ios::binary);

    if(!fir)
    {
        cerr<<"File opening error";
        getch();
        exit(0);
    }

    std::cout<<"Enter the names in file"<<std::endl;

    while(ch != 'n')
    {
        r.input();
        fir.write((char *)&r, sizeof(r));
        std::cout<<"Do you want to enter new record (Y/N) = ";
        std::cin>>ch;
    }

    fir.close();
    ifstream sec("abc.rec",ios::binary);

    if(!sec)
    {
        cerr<<"File opening error";
        getch();
        exit(0);
    }

    std::cout<<std::endl;
    std::cout<<"Enter the roll number = ";
    std::cin>>froll;

    while(sec.read((char*)&r, sizeof(r)))
    {
        if(strcmp(froll,r.roll) == 0)
        {
            rn = (rn-1)*sizeof(r);
            sec.seekg(rn);
            r.dis();
            sec.close();
            t = 1;
        }
        rn++;
    }

    if(t==0)
        std::cout<<"Name does not exist";

    getch();
}

Enter the names in file
Enter the full name = ABC
Enter the roll = 1
Do you want to enter new record (Y/N) = y
Enter the full name = XYZ
Enter the roll = 2
Do you want to enter new record (Y/N) = n

Enter the roll number = 2
XYZ
2