Simple script to cat a serial port at a given baud

serialcat.rs

#!/usr/bin/env -S cargo +nightly -Zscript
---
[dependencies]
serialport = "4.8.1"
---

use std::{
    env,
    error::Error,
    io::{ErrorKind, Write},
    time::Duration,
};

fn main() -> Result<(), Box<dyn Error>> {
    let Some(serial_port) = env::args().nth(1) else {
        return Err(format!(
            "usage: {} [serial_port] [baud]",
            std::env::args().next().as_deref().unwrap_or("serialcat")
        )
        .into());
    };
    let Some(Ok(baud)) = env::args().nth(2).map(|baud| baud.parse::<u32>()) else {
        return Err("Baudrate is required".into());
    };

    let mut serial_port = serialport::new(serial_port, baud)
        .timeout(Duration::from_secs(1))
        .open()?;
    let mut stdout = std::io::stdout().lock();
    loop {
        let mut buffer = [0u8; 1024];
        let count = match serial_port.read(&mut buffer) {
            Ok(0) => break,
            Ok(count) => count,
            Err(e) if e.kind() == ErrorKind::TimedOut => continue,
            Err(e) => {
                eprintln!("Got error: {e}");
                return Err(e.into());
            }
        };
        stdout.write_all(&buffer[0..count])?;
        stdout.flush()?;
    }
    Ok(())
}