rust_net.rs

use std::net::TcpListener;
use std::net::UdpSocket;
use std::net::TcpStream;
use std::net::Shutdown;
use std::thread;
use std::io::BufReader;
use std::io::Write;
use std::io::BufRead;

fn session(mut ios: TcpStream) -> Result<(), std::io::Error> {
    let peer_tag = ios.peer_addr()
        .map(|addr| format!("{:?}", addr))
        .unwrap_or("<unknown>".to_string());
    ios.write(format!("HELLO {}\n", peer_tag).as_bytes())?;
    let mut rdr = BufReader::new(ios.try_clone()?);
    loop {
        let mut message = String::new();
        rdr.read_line(&mut message)?;
        if message.len() == 0
            || message.to_lowercase().starts_with("bye") {
            break;
        }
        println!("IN {}: {}", peer_tag, message);
        ios.write(message.as_bytes())?;
    }
    ios.write(b"\nBYE\n")?;
    ios.flush()?;
    println!("BYE {}\n", peer_tag);
    ios.shutdown(Shutdown::Both)?;
    Ok(())
}

fn echo_server() {
    let listener = TcpListener::bind("127.0.0.1:9123").unwrap();
    println!("Listening on TCP port 9123, ready to accept");
    for stream in listener.incoming() {
        thread::spawn(|| {
            session(stream.unwrap()).unwrap();
        });
    }
}

fn udp_server() {
    let socket = UdpSocket::bind("127.0.0.1:9124").unwrap();
    println!("Listening on UDP port 9124, ready to accept");
    loop {
        let mut buf = [0; 10];
        let (cnt, src) = socket.recv_from(&mut buf).unwrap();
        let msg = &mut buf[..cnt];
        socket.send_to(format!("OK: {}\n", std::str::from_utf8(msg).unwrap()).as_bytes(), &src).unwrap();
    }
}

fn main() {
    thread::spawn(echo_server);
//    thread::spawn(udp_server);
    udp_server();
}