env_variable/
env_variable.rs

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//! Consume a named argument with fallback to environment variable

use bpaf::*;

#[allow(dead_code)]
#[derive(Clone, Debug)]
struct Opts {
    pub key: String,
}

pub fn main() {
    let key = long("key")
        .env("ACCESS_KEY")
        .help("access key to use")
        .argument::<String>("KEY");

    let opts = construct!(Opts { key }).to_options().run();

    println!("{:?}", opts);
}