tokio

入门

[dependencies]
tokio = { version = "1.38.1", features = ["full"] }

//! A simple client that opens a TCP stream, writes "hello world\n", and closes
//! the connection.
//!
//! To start a server that this client can talk to on port 6142, you can use this command:
//!
//!     ncat -l 6142
//!
//! And then in another terminal run:
//!
//!     cargo run --example hello_world

#![warn(rust_2018_idioms)]

use tokio::io::AsyncWriteExt;
use tokio::net::TcpStream;

use std::error::Error;

#[tokio::main]
pub async fn main() -> Result<(), Box<dyn Error>> {
    // Open a TCP stream to the socket address.
    //
    // Note that this is the Tokio TcpStream, which is fully async.
    let mut stream = TcpStream::connect("127.0.0.1:6142").await?;
    println!("created stream");

    let result = stream.write_all(b"hello world\n").await;
    println!("wrote to stream; success={:?}", result.is_ok());

    Ok(())
}

use tokio::net::TcpListener;
use tokio::io::{AsyncReadExt, AsyncWriteExt};

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let listener = TcpListener::bind("127.0.0.1:8080").await?;

    loop {
        let (mut socket, _) = listener.accept().await?;

        tokio::spawn(async move {
            let mut buf = [0; 1024];

            // In a loop, read data from the socket and write the data back.
            loop {
                let n = match socket.read(&mut buf).await {
                    // socket closed
                    Ok(n) if n == 0 => return,
                    Ok(n) => n,
                    Err(e) => {
                        eprintln!("failed to read from socket; err = {:?}", e);
                        return;
                    }
                };

                // Write the data back
                if let Err(e) = socket.write_all(&buf[0..n]).await {
                    eprintln!("failed to write to socket; err = {:?}", e);
                    return;
                }
            }
        });
    }
}