node.js - Why Python Tcp client send close sign automatically?

Question

I guess Python automatically send a close sign when shuts down(ctr+c) the client.

python tcp server

import socket

HOST = '127.0.0.1'  # Standard loopback interface address (localhost)
PORT = 12345        # Port to listen on (non-privileged ports are > 1023)

with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
    s.bind((HOST, PORT))
    s.listen()
    conn, addr = s.accept()
    with conn:
        print('Connected by', addr)
        while True:
            data = conn.recv(1024)
            #if not data:break
            conn.sendall(data)
            print(data)

python tcp client

import socket

HOST = '127.0.0.1'  # The server's hostname or IP address
PORT = 12345        # The port used by the server

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.sendall(b'Hello, world')
data = s.recv(1024)

print('Received', data)
#s.close()

When executing this code, the server continues to receive null data (maybe close sign) by the client that ended without closing.

Connected by ('127.0.0.1', 55305)
b'Hello, world'
b''
b''
b''
b''
b''
...

---

This error occurs when run node.js client and shutdown(ctr+c) without close sign. The python tcp server occurs error but not print null. node.js tcp client

const Net = require('net');

const client = new Net.Socket();
client.setEncoding('utf8');

client.connect({ port: 12345, host: '127.0.0.1' })
client.write('Hello, world');
/*client.end()*/

Connected by ('127.0.0.1', 56685)
b'Hello, world'
Traceback (most recent call last):
  File "C:/.../server.py", line 13, in <module>
    data = conn.recv(1024)
ConnectionResetError: [WinError 10054]An existing connection was forcibly closed by the remote host

I know that the server and the client need to send and receive the exit sign, but I wonder why the Python client automatically sends the close sign when it is closed. Where can I get information about this?

question from:https://stackoverflow.com/questions/65878403/why-python-tcp-client-send-close-sign-automatically

Answer 1

Waitting for answers