How do I write an asynchronous port checker?

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4

Thanks for the help! I think I'm getting somewhere now. The code provided had a few issues, but now, when I try running this, I get no prints at all! This is really confusing me because I'm pretty sure I'm following everything correctly.

async fn resolvable(ip: String, port: u32, timeout_seconds: u64) -> Result<tokio::net::TcpStream, Box<dyn std::error::Error + Send + Sync>> {
    tokio::time::timeout(std::time::Duration::from_secs(timeout_seconds), tokio::net::TcpStream::connect(format!("{}:{}", ip, port)))
        .await?
        .map_err(|err| Box::new(err) as Box<dyn std::error::Error + Send + Sync>)
}

#[tokio::main]
async fn main() {
    let mut jhs = Vec::new();
    for port in 0..101 {
        let jh = tokio::spawn(async move {
            match resolvable("127.0.0.1".into(), port, 5).await {
                Ok(_) => println!("Port {} open!", port),
                Err(err) => println!("Error: timed out: {} Port {} closed.", err, port),
            }
        });
        jhs.push(jh);
    }
    for jh in jhs {
        jh.await;
    }
}

Am I overlooking anything?

I discovered this post:

I'm not sure why, but doing the vector solution solved all my issues. If anyone can expand on why, this would help me a ton!

Other than that, thanks I finally figured it out!!!