Rust: How do you work with environment variables?

1use std::env;
2
3// Get variable
4match env::var("DATABASE_URL") {
5    Ok(url) => println!("{}", url),
6    Err(e) => println!("Not set: {}", e),
7}
8
9// With default
10let port = env::var("PORT").unwrap_or_else(|_| "8080".into());

1env::set_var("MY_VAR", "value");

1for (key, value) in env::vars() {
2    println!("{} = {}", key, value);
3}