I want to use python sockets to create a server that multiple clients can connect to and echo text inputs. Is there a basic server I can setup with few lines of code? I already have the clients ready to connect I just need to know what a basic python socket server would look like for these client connections.

If you want more than two users I would suggest you check if it wouldn't be better to install a xmmp/jabber server instead.

Python Sockets

Pythons socket documentation also has a few simple examples which show simple chat functionality. See: http://docs.python.org/2/library/socket.html#example.

Here is a small snippet that should do the trick. It doesn't produce nice output, but it should work. It uses two threads to avoid starting up two different scripts.

# Echo server program
import socket
import threadTARGET = None
DEFAULT_PORT = 45000def reciever():""" Recive messages... """s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.bind(('', DEFAULT_PORT)) # Listens on all interfaces... s.listen(True) # Listen on the newly created socket... conn, addr = s.accept()while True:data = conn.recv(1024)print "\nMessage> %s\n" % datadef sender():""" The 'client' which sends the messages """s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)s.connect((TARGET, DEFAULT_PORT)) # Connect... while True: msg = raw_input("\nMe> ")s.sendall(msg)s.close()while not TARGET:TARGET = raw_input("Please specify the other client to connect to: ")thread.start_new_thread(reciever, ())
thread.start_new_thread(sender, ())while True:pass

XMLRPC

You could also look into Pythons XMLRPC capabilities if you want more than two users. For example...

Server:

This mini-server lets users send messages for users. The server then persists them into a small json file. A client can then ask for new messages for a given user.

import json
import os.pathfrom SimpleXMLRPCServer import SimpleXMLRPCServer""" 
Saves messages as structure: {'client1':['message1', 'message2'], 'client2':['message1', 'message2']
}
"""STORAGE_FILE = 'messages.json'def save(messages):msg_file = open(STORAGE_FILE, 'w+')json.dump(messages, msg_file)def get():if os.path.exists(STORAGE_FILE):msg_file = open(STORAGE_FILE, 'r')return json.load(msg_file)else: return {}def deliver(client, message):""" Deliver the message to the server and persist it in a JSON file..."""print "Delivering message to %s" % clientmessages = get()if client not in messages:messages[client] = [message]else: messages[client].append(message)save(messages)return Truedef get_messages(client):""" Get the undelivered messags for the given client. Remove them frommessages queue. """messages = get()if client in messages:user_messages = messages[client]messages[client] = []save(messages)return user_messageselse: return []server = SimpleXMLRPCServer(("localhost", 8000))
print "Listening on port 8000..."
server.register_function(deliver, 'deliver')
server.register_function(get_messages, 'get_messages')
server.serve_forever()

"Client"

Example usage to send a message and get messages for a user.

import xmlrpclib# Connect to the 'Server'...
proxy = xmlrpclib.ServerProxy("http://localhost:8000/")# Send a message...
proxy.deliver('username', 'The message to send')# Recieve all messages for user..
for msg in proxy.get_messages('username'):print "Message> %s" % msg

Please Note: These are just quick examples. Both are not really secure as no sender/reciever verification is done. Also there is no trasport-security so messages can get lost.

For lots of users it would also be better to use a DBMS system instead of a simple JSON file.

As Nick ODell said, if you want a simple shell script I would also suggest you use netcat.