Undefined Value: Kris Johnson's Blog

Here's another one of those code snippets that I think I might want to find again someday. Nobody else will care.

This is a Python script that opens a port and accepts connections from clients. This is just a starting point for all the little mock servers I write with Python for testing and diagnostics. I'm tired of copying and pasting the little bits of various Python tutorials that I usually do whenever I have to make a new one of these, so here is my new standard starting point.

I can hack this up by changing the data_received() method to deal with requests coming from the client, and can also hack up run() to get the server to send data to the client unsolicited.

[UPDATE: See more advanced version: Python Server Start, Take 2]

#!/usr/bin/python
"""
Simple server

This is a simple Python script that simulates a server.
It is intended for use with the unit tests; this is not production code.

Currently, it has these features:

- Starts listening for connections on port 64123

- Prints all data received from clients

"""

import sys
import os
import socket
import threading

defaultAddr = 'localhost'
defaultPort = 64123


class ClientThread(threading.Thread):
  """
  Thread for handling communication with a single client.
  """
  def __init__(self, client, address):
    threading.Thread.__init__(self)
    self.client = client
    self.address = address

  def run(self):
    running = 1
    while running:
      data = self.client.recv(1024)
      if data:
        self.data_received(data)
      else:
        print "Connection", self.address, "closed"
        self.client.close()
        running = 0

  def data_received(self, data):
    """
    Called by run() when data is received
    """
    print "Data received %s: [%s]" % (self.address, data)

        
def RunServer():
  """
  Open server socket and accept connections
  """
  s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  print "Bind to %s:%d" % (defaultAddr, defaultPort)
  s.bind((defaultAddr, defaultPort))
  s.listen(5)
  print "Listening for connections..."
  while 1:
    (client, address) = s.accept()
    print 'Accepted connection from', address
    ct = ClientThread(client, address)
    ct.start()


#
# MAIN
#
if __name__ == "__main__":
  RunServer()

# posted by Kris Johnson @ 6/08/2007 01:01:00 PM