minimal program to sum values from stdin, in rust.

sum.rs

use std::{io, io::prelude::*};

pub fn main() {
    let mut sum = 0;
    for line in io::stdin().lock().lines() {
        sum = sum + line.unwrap().parse::<i32>().unwrap();
    }
    println!("{}", sum);
}

awk
BEGIN{SUM=0}{SUM+=$1}END{print SUM}