rust-tuto/src/main.rs

use std::env;

/* Not used, example of an enum
#[derive(Debug)]
enum Maybe<T> {
  Just(T),
  Nothing
}
*/

fn main() {
    let arg = env::args().nth(1);

    // println!("{:?}", Maybe::Just(42));

    match arg {
        Some(result) => {
            let ip = ip_to_int(&result);
            println!("{:b}", ip);
        }
        None => println!("need one arg"),
    }
}

fn ip_to_int(ip_str: &str) -> u32 {
    let mut tbl: Vec<&str> = ip_str.split('.').collect();
    tbl.reverse();

    let mut ip = 0_u32;

    for (idx, s) in tbl.iter().enumerate() {
        let nbr: u8 = s.parse().expect("parse fail");
        ip += (nbr as u32) << (8 * idx);
    }
    ip
}