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Rust program to count the total number of lines of a text file

Rust | File I/O Example: Write a program to count the total number of lines of a text file.
Submitted by Nidhi, on October 31, 2021

Problem Solution:

In this program, we will open a text file and count the total number of lines in a text file and print the result.

Program/Source Code:

The source code to count the total number of lines of a text file is given below. The given program is compiled and executed on UBUNTU 18.04 successfully.

// Rust program to count the total number 
// of lines of a text file

use std::io::{BufRead, BufReader};
use std::fs::File;

pub fn main() {
    let file = BufReader::new(File::open("sample.txt").expect("Unable to open file"));
    let mut cnt  = 0;
    
    for _ in file.lines() {
        cnt = cnt + 1;
    }
    
    println!("Total lines are: {}",cnt);
}

Output:

$ rustc main.rs

$ ./main
Total lines are: 2

$ cat sample.txt 
Hello World
Hello India

Explanation:

Here, we opened the "sample.txt" file and count the total number of lines in the file and printed the result.