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file_handling_part3.cpp
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file_handling_part3.cpp
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/* A sample program to see the use of seekg and seekp function*/
#include <iostream>
#include <fstream>
using namespace std;
int main()
{
char ch,ch1;
int pos;
system("clear");
fstream f;
/*
f.open("myfile.txt",ios::in);
f.seekg(-1,ios_base::cur); // taking value from the 2 position before the current poistion of the get pointer which is at 0;
f.get(ch); // inserting that element from the file to ch character varaible
cout<<"The value you demanded is \n";
cout<<ch<<endl;
*/
/*
f.seekg(3,ios_base::beg); // taking the value 4 position after the begning poistion of the get pointer which is at 0;
f.get(ch);
cout<<"The value you demanded is \n";
cout<<ch<<endl;
f.seekg(-3,ios_base::end);
f.get(ch);
cout<<"the value you demanded is\n";
cout<<ch<<endl;
f.close();
*/
f.open("myfile.txt", ios::out |ios::app | ios::ate );
pos=f.tellp();
cout<<"current position of pointer is\n";
cout<<pos<<endl;
cout<<"after calling seekp the pointer is pointing to this position\n";
f.seekp(5,ios_base::beg);
cout<<f.tellp()<<endl;
// NOTE:- we cannot make changes in the middle of the file without creating a new file
// so when i tried to replace or add characters in middle or beg of file they are added automaticaly to the end of file
/*cout << "enter a character you want to insert in the file\n";
cin>>ch;
f<<ch;
cout << "character inserted\n";
cout << "enter a character you want to insert in the file\n";
cin>>ch1;
f.seekp(-1,ios_base::cur);
f.put(ch1);
cout << "character inserted\n";*/
f.close();
return 0;
}