To store student detail in file and to display the same :-

#include<iostream.h>
#include<conio.h>
#include<fstream.h>
#include<stdio.h>
#include<stdlib.h>

class student
 {
    int sno;
      char name[25],stream[10];
      public:
      void get()
       {
          cout<<"\nEnter Student Number : ";
            cin>>sno;
            cout<<"\nEnter Student Name : ";
            gets(name);
            cout<<"\nEnter Student's Stream : ";
            gets(stream);
         }
      void show()
       {
          cout<<"\nStudent Number : "<<sno;
            cout<<"\nStudent Name  : "<<name;
            cout<<"\nStudent's Stream : "<<stream;
         }
   };

void main()
 {
    fstream file("stud.txt",ios::in|ios::out|ios::ate);
    student s;
      int c;
      while(1)
       {
          cout<<"\n\nPress 1 - to enter student detail\nPress 2 - to view all student detail\nPress 4 - to exit :\n";
            cin>>c;
          if(c==1)
             {
                   s.get();
                     file.write((char*)&s,sizeof(s));                     
               }
            else if(c==2)
             {
                 file.seekg(ios::beg);
                   while(!(file.eof()))
                      {
                         file.read((char*)&s,sizeof(s));
                     s.show();
                        }
               }
            else if(c==4)
             {
                   exit(0);
               }
            else
             {
                    cout<<"\nINVALID OPTION !!\n choose correct option from menu......";
               }
         }
   }