Python example of Joe's Erlang websocket example

python, websocket

Solution

For those who are interested this was the solution

import threading
import socket

def start_server():
    tick = 0
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.bind(('localhost', 1234))
    sock.listen(100)
    while True:
        print 'listening...'
        csock, address = sock.accept()
        tick+=1
        print 'connection!' 
        handshake(csock, tick)
        print 'handshaken'
        while True:
            interact(csock, tick)
            tick+=1
            
            
def send_data(client, str_):
    #_write(request, '\x00' + message.encode('utf-8') + '\xff')
    str_ = '\x00' + str_.encode('utf-8') + '\xff'
    return client.send(str_)
def recv_data(client, count):
    data = client.recv(count)    
    return data.decode('utf-8', 'ignore')

def handshake(client, tick):
    our_handshake = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n"+"Upgrade:     WebSocket\r\n"+"Connection: Upgrade\r\n"+"WebSocket-Origin: http://localhost:8888\r\n"+"WebSocket-Location: "+" ws://localhost:1234/websession\r\n\r\n"
    shake = recv_data(client, 255)
    print shake
    #We want to send this without any encoding
    client.send(our_handshake)
         
def interact(client, tick):
    data = recv_data(client, 255)
    print 'got:%s' %(data)
    send_data(client, "clock ! tick%d" % (tick))
    send_data(client, "out ! %s" %(data))

if __name__ == '__main__':
    start_server()

Edit for liwp's request:

You can view a diff of the file here. Essentially my problem was the way I was decoding / encoding strings prior to sending / receiving. There's a websocket module being worked on for Apache on google code which I used to find out where I was going wrong.

Problem

I've just been working through the erlang websockets example from Joe Armstrong's blog I'm still quite new to erlang so I decided to write a simple server in python that would help teach me about websockets (and hopefully some erlang by interpreting joe's code). I'm having two issues: 1) Data I receive from the page includes a 'ÿ' as the last char. This doesn't appear in the erlang version and I can't work out where it's coming from Fixed - This was because the strings where encoded in utf-8 and I wasn't decoding them 2) I seem to be sending data from the server (through the websocket) - which can be confirmed by looking at how many bytes client.send() makes. But nothing is appearing on the page. Fixed, I wasn't encoding the string correctly I've put all the code here. Here's my python version incase i'm missing anything obvious ``` import threading import socket def start_server(): tick = 0 sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.bind(('localhost', 1234)) sock.listen(100) while True: print 'listening...' csock, address = sock.accept() tick+=1 print 'connection!' handshake(csock, tick) print 'handshaken' while True: interact(csock, tick) tick+=1 def handshake(client, tick): our_handshake = "HTTP/1.1 101 Web Socket Protocol Handshake\r\n"+"Upgrade: WebSocket\r\n"+"Connection: Upgrade\r\n"+"WebSocket-Origin: http://localhost:8888\r\n"+"WebSocket-Location: "+" ws://localhost:1234/websession\r\n\r\n" shake = client.recv(255) print shake client.send(our_handshake) def interact(client, tick): data = client.recv(255) print 'got:%s' %(data) client.send("clock ! tick%d\r" % (tick)) client.send("out ! recv\r") if __name__ == '__main__': start_server() ``` For those who haven't run through joe's example but still want to help, you just need to serve up interact.html through a web server and then start your server (The code assumes the webserver is running on localhost:8888)

Original source