C++ std::fstream how to move to a certain line and column of a file

Question

So I have been searching on how to move to a certain line and column in a file , but I can't seem to find an answer . I want something like this :

std::fstream file("example.txt");
file.move_to( line number , column number );

Answer 1

The following function can do just you want:

std::string GetLine(std::istream& fs, long long index)
{
    std::string line;
    for (size_t i = 0; i <= index; i++)
    {
        std::getline(fs, line);
    }
    return line;
}

The above function gets the line at index (index == 0 - 1st line, index == 2 - 3rd line, etc.).

Usage:

#include <iostream>
#include <string>
#include <fstream>

std::string GetLine(std::istream& fs, long long index)
{
    std::string line;
    for (size_t i = 0; i <= index; i++)
    {
        std::getline(fs, line);
    }
    return line;
}

int main()
{
    std::ifstream fs("input.txt"); // fstream works too
    std::cout << GetLine(fs, 1);
}

input.txt

This is
a
test file

Output:

a