Python socket how to close command line connection

Question

I'm playing with sockets in python, and I can't find a way to close my "server" connection in the command line. ctrl+c, ctrl+z do not work.

my server.py file:

import socket

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((socket.gethostname(), 1235))
s.listen(5)

while True:
  clientsocket, address = s.accept()
  print(f"connection from {address} has been established!")
  clientsocket.send(bytes("Welcome to the server!", "utf-8"))
  clientsocket.close()

if I make updates to this file I have to close the terminal and rerun the script. I have to change the port number because the original port stays occupied. The guy in the tutorial has to do the same thing, but I can't imagine that this is the best way to do things. Is there a command that will close the connection, clear the ports, etc., allowing me to restart the script?

I'm on Windows 10
SO_REUSEADDR does allow me to restart the script on the same port, however I am still not able to stop the script. I still have to close the terminal to stop the script.

Oh Linux & BSD, control-C interrupts the server just fine. I would expect control-C to interrupt the server on windows also. I don't know why it doesn't for you. — Robᵩ, Nov 23 '19 at 14:18
It doesn't seam to work for anyone... it works with the flask server and django, just not this. — JSum, Nov 23 '19 at 14:19
The answer is SO_REUSEADDR or SO_REUSEPORT but this question is surely a duplicate of many, many others on SO. — Jean-Paul Calderone, Nov 23 '19 at 14:20
Does this answer your question? [Python: Binding Socket: "Address already in use"](https://stackoverflow.com/questions/6380057/python-binding-socket-address-already-in-use) — Steffen Ullrich, Nov 23 '19 at 15:03
SO_REUSEADDR does allow me to restart the script on the same port, however I am still not able to stop the script. I still have to close the terminal to stop the script. — JSum, Nov 23 '19 at 15:59
On windows if you know id or name proccess you could use taskkill command — erod, Nov 23 '19 at 16:15

score 0 · Answer 1 · answered Nov 23 '19 at 16:07

0

You can get all open listen ports with

netstat -tulpn | FINDSTR LISTEN | FINDSTR PORTNUMBER (maybe need a bit change - not sure about windows commands.)

then kill the process.

answered Nov 23 '19 at 16:07

ali sarkhosh

183
1
12

score 0 · Answer 2 · answered Nov 23 '19 at 16:25

You may also try below and see if it works

For closing server , use shutdown before close :

def close():
    server.shutdown(socket.SHUT_RDWR)
    server.close()

For reuse of address , use below before binding the socket :

server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

alekala · Answer 3 · 2019-11-23T16:40:33.363

Maybe try doing:

import sys

s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

while True:
  try:
    clientsocket, address = s.accept()
    print(f"connection from {address} has been established!")
    clientsocket.send(bytes("Welcome to the server!", "utf-8"))
    clientsocket.close()
  except KeyboardInterrupt:
    print(f"closing connection to {address}.")
    clientsocket.shutdown(socket.SHUT_RDWR)
    clientsocket.close()
    sys.exit()

This should allow you to use Ctrl + C to close your program AND let you restart it without changing the address.

Python socket how to close command line connection

3 Answers3