LinuxConfig -

Here is a small example of C++ code on how to read a characters from a file as well as to count the number lines of any particular file consist of. The code will check for "\n" the "new line character" and increase the number of lines stored in number_of_lines integer variable. Every iteration will also print single character including "\n" to an output.
First create a file called my-input-file.txt which will contain some text. For example:

welcome to
linuxconfig.org
c++

Then copy c++ code below to a file called read-characters.cpp:

#include <iostream>
#include <fstream>

using namespace std;

int main() {

ifstream fin;
fin.open("my-input-file.txt", ios::in);

char my_character ;
int number_of_lines = 0;

	while (!fin.eof() ) {

	fin.get(my_character);
	cout << my_character;
		if (my_character == '\n'){
			++number_of_lines;
		}
	}
cout << "NUMBER OF LINES: " << number_of_lines << endl;

}

and compile it with:

g++ read-characters.cpp -o read-characters

Execute new compiled binary file:

./read-characters

NOTE: your text file must be located in the same directory as your executable read-characters program.

NOTE: while loop and fin.get will add extra new line character so you may start with :

int number_of_lines = -1

OUTPUT:

welcome to
linuxconfig.org
c++

NUMBER OF LINES: 4