use std::collections::HashMap;
use std::io::{self};
use std::process::Command;
use std::process::Child;

fn execute(children: &mut HashMap<u32, Child>, arg: &str) {
    let child = Command::new("/usr/bin/echo")
        .arg(arg)
        .spawn();

    match child {
        Ok(child) => {
            // QUESTION: this appears to work, but should be &child to avoid copying?
            // doing merely that fails claiming the lifetime expires, so how to do it correctly?
            children.insert(child.id(), child);
        }
        Err(err) => {
            eprintln!("failed to spawn: {}", err);
        }
    }
}

fn main() {
    let mut children: HashMap<u32, Child> = HashMap::new();

    let stdin = io::stdin();
    for line in stdin.lines() {
        let input = String::from(&line.unwrap());
        for word in input.split_whitespace() {
            execute(&mut children, word);
        }
    }

    dbg!(&children);
}