Tool that functions like ‘tool.exe -d xyz.com -s’, where ‘-s’ is a flag that indicates whether subdomains are allowed

Question

I’ve encountered an error: ‘a value is required for –subdomains <Subdomains> but none was supplied’. This error occurs when I run the command cargo run – -d xyz.com -s. I want -s to act just as a flag, but it’s causing an error. Here’s the code I’m working with:

use clap::{command, Arg};
use reqwest::{Client};

#[tokio::main]
async fn main() {
    println!("Waybackurls");
  
    let arguments = command!()
        .about("Retrieves encoded emails from the application and subsequently decodes them")
        .author("Anonymous")
        .version("1.0.0")
        .arg(
            Arg::new("Domain")
                .short('d')
                .long("domain")
                .required(true)
                .help("Domain here")
        )
        .arg(
            Arg::new("Subdomains")
                .short('s')
                .long("subdomains")
                .required(false)
                .help("To fetch subdomains from the urls")
        )
        .get_matches();
    
    let domain = arguments.get_one::<String>("Domain");

    // variable
    let subdomains = if arguments.contains_id("Subdomains") {
        "*.".to_string()
    } else {
        "".to_string()
    };
    
    let http_get = Client::new();
    // let mut urls: Vec<String> = Vec::new();

    
    let waybakck_url = match domain {
        Some(domain) => {
            format!("http://web.archive.org/cdx/search/cdx?url={}{}/*&output=json&fl=original&collapse=urlkey",subdomains,domain)
        },
        None => String::from("Provide valid domain")
    };

    let response = http_get.get(waybakck_url)
        .send()
        .await
        .expect("Error fetching wayback machine urls");

    if response.status().is_success() {
        let wburls = response.text().await.expect("Error");
        print!("{}",wburls.replace("[", "").replace("]", "").replace("\"", "").replace(",", ""));
    }
}

I attempted to use the default_value() function, but I’m still encountering the same error.