9. (C) Design a editor for appending and editing the files

9. (C) Design a editor for appending and editing the files

	#include<iostream.h> #include<conio.h>
	#include<fstream.h>
	class student
	{
	char name[30];
	int age;
	float percent;
	public:
	void getdata()
	{
	cout<<endl<<"Enter name: ";
	cin>>name;
	cout<<endl<<"Enter age: ";
	cin>>age;
	cout<<endl<<"Enter percentage: ";
	cin>>percent;
	}
	void showdata()
	{
	cout<<endl<<name;
	cout<<"\t\t"<< age;
	cout<<"\t\t"<<percent;
	}
	};
	void main()
	{
	clrscr();
	student st;
	fstream freadwrite("Student.txt", ios::ate | ios::in | ios::out | ios::trunc);
	for(int i=0;i<4;i++)
	{
	st.getdata();
	freadwrite.write((char*)&st,sizeof(st));
	}
	freadwrite.seekg(0,ios::beg);
	cout<<endl<<"Current contents of file";
	while(freadwrite.read((char*)&st,sizeof(st)))
	st.showdata();
	freadwrite.clear();
	cout<<endl<<"Enter details for one more student";
	st.getdata();
	//char c;
	//cin.get(c);
	freadwrite.write((char*)&st, sizeof(st));
	freadwrite.seekg(0);
	cout<<endl<<"After addition of one more student";
	cout<<endl<<"Name \t\t Age \t\t Percentage";
	while(freadwrite.read((char*)&st, sizeof(st)))
	{
	st.showdata();
	}
	int n = freadwrite.tellg() / sizeof(st);
	cout<<endl<<"Total no. of student record: "<<n;
	cout<<endl<<"Enter student number to be updated: ";
	int num;
	cin>>num;
	//cin.get(c);
	int l=(num-1) * sizeof(st);
	if(freadwrite.eof())
	freadwrite.clear();
	freadwrite.seekp(l);
	cout<<endl<<"Enter new values for the student";
	st.getdata();
	//cin.get(c);
	freadwrite.write((char*)&st, sizeof(st))<<flush;
	freadwrite.seekg(0);
	cout<<endl<<"After updation contents are";
	cout<<endl<<"Name \t\t Age \t\t Percentage";
	while(freadwrite.read((char*)&st, sizeof(st)))
	{
	st.showdata();
	}
	freadwrite.close();
	getch();
	}