#include<iostream>
#include<fstream>
#include<string.h>
#include<stdlib.h>
using namespace std;
class student
{
string usn,name,sem,buffer;
public:
void unpack();
void read();
void read_file();
void write_file();
void display();
void pack();
int del(string);
void modify(string);
int search1(string);
}s;
main()
{
int ch;
string regno;
cout<<"\nVARIABLE LENGTH RECORDS";
while(1){
cout<<"\n1:Pack 2:Unpack 3:Search 4:Modify 5:exit\n";
cin>>ch;
switch(ch)
{
case 1: s.read();
s.pack();
s.write_file();
break;
case 2: s.read_file();
break;
case 3: cout<<"Enter regno to search\n";
cin>>regno;
s.search1(regno);
break;
case 4: cout<<"Enter regno to search\n";
cin>>regno;
s.modify(regno);
break;
default : exit(0);
}//switch
}//while
}
void student::read()
{
cout<<"Enter details[USN,Name,Sem]\n";
cin>>usn>>name>>sem;
}
void student::pack()
{
buffer.erase();
buffer+=usn+"|"+name+"|"+sem+"$\n";
