seek.cpp

#include <iostream>
#include <fstream>
#include <string>
using namespace std;

int main() {
    fstream file;
    string data;

    // Step 1: Write data to file
    file.open("sample.txt", ios::out);  // open file for writing
    if (!file) {
        cout << "Error creating file!" << endl;
        return 0;
    }

    file << "Hello, this is a C++ file handling demo.\n";
    file << "File operations are fun to learn!";
    file.close();
    cout << "Data written successfully.\n";

    // Step 2: Read and display data from file
    file.open("sample.txt", ios::in);
    if (!file) {
        cout << "Error opening file for reading!" << endl;
        return 0;
    }

    cout << "\n--- File Content ---\n";
    while (getline(file, data))
        cout << data << endl;
    file.close();

    // Step 3: Demonstrate seekg() - move read pointer
    file.open("sample.txt", ios::in);
    if (!file) {
        cout << "Error opening file for seekg demo!" << endl;
        return 0;
    }

    file.seekg(7, ios::beg); // Move read pointer to 7th byte from beginning
    cout << "\nUsing seekg(7, ios::beg):\n";
    while (getline(file, data))
        cout << data << endl;
    file.close();

    // Step 4: Demonstrate seekp() - move write pointer and modify data
    file.open("sample.txt", ios::in | ios::out);
    if (!file) {
        cout << "Error opening file for seekp demo!" << endl;
        return 0;
    }

    file.seekp(0, ios::beg); // Move write pointer to beginning
    file << "Hi"; // Modify first few characters

    file.close();

    // Step 5: Display modified content
    file.open("sample.txt", ios::in);
    cout << "\n--- Modified File Content ---\n";
    while (getline(file, data))
        cout << data << endl;

    file.close();
    return 0;
}