为什么 telnet 刚连上服务端就退出了？

Question

import asyncio
from asyncio.base_events import Server


async def handle_client(reader, writer):
    while True:
        data = await reader.readline()
        if not data:
            break
        writer.write(data)
    writer.close()


async def main():
    server: Server = await asyncio.get_running_loop().create_server(
        handle_client, '127.0.0.1', 8888)

    async with server:
        await server.serve_forever()

asyncio.run(main())

用 python 的 asyncio 写了一个 demo

但是我用 telnet 连接这个 demo 的时候，会直接退出，不知道为什么？

╰─➤  telnet 127.0.0.1 8888                                                                                                           1 ↵
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Connection closed by foreign host.

Answer 1

async def handle_client(reader, writer):
    welcome_message = "Welcome to the server!\n"
    writer.write(welcome_message.encode())
    await writer.drain()

    while True:
        data = await reader.read(100)
        if not data:
            break
        writer.write(data)
        await writer.drain()