bufread.rs

// use std::fs::File;
use itertools::Itertools;
use std::io::{self, BufRead, BufReader, BufWriter, Write};

use serde::{Deserialize, Serialize};
// use std::path::Path;

#[derive(Serialize, Deserialize)]
struct Item<'a> {
    id: i64,
    val: &'a str,
}

fn main() -> io::Result<()> {
    let reader = BufReader::new(io::stdin());
    let mut writer = BufWriter::new(io::stdout());

    for lines in reader.lines().chunks(6).into_iter() {
        for (i, line) in lines.enumerate() {
            let l_ = format!("\tLine {}\n", i);
            writer.write(l_.as_bytes()).unwrap();
            if let Ok(mut line) = line {
                line.push('\n');
                writer.write(line.as_bytes()).unwrap();
            }
        }
    }

    Ok(())
}