I start learning socket programming and I created a simple server that should replay everything I send to him back to me.
And its work work and I manage to telnet to it and write things.
but I have two problems with my code:
First, every sigh I hit on the keyboard get immediately send and I get it back. it doesn't wait until I press enter.
Second, when I print to the client 'Welcome to the server. Type something and hit enter\n\n' the client see the cmd imput cursor in the middle of the new line, and not in the start of it.
here is part of my code:
#server in local host
class ClientConnection(threading.Thread):
def __init__(self,conn):
threading.Thread.__init__(self)
self.conn = conn
def run(self):
clientthread(self.conn)
#create a new thread for each connection
def clientthread(conn):
conn.send('Welcome to the server. Type something and hit enter\n\n'.encode())
while True:
data = conn.recv(2048).decode()
replay = 'OK....' + data
if not data:
break
conn.sendall(replay.encode())
conn.close()
... #socket get close in the end
How do I make the server response only if I the client press enter? I try to check if the recive = '\n' but it doesn't seem to work.
I will appreciate any help and tips
edit: my second question answard simply
Yes, the client will often send you data as the user types rather then only when the user hits return. Thus, it is up to you to check if the data has a return, and only respond if it does.
data = ""
while True:
chunk = conn.recv(2048).decode()
if not data:
break
# try to separate the chunk by newline, to see if you got one.
while True:
split = chunk.split("\r\n", num=1)
data += split[0]
if len(split) == 1:
break
# Now we have a completed newline, so send the response
replay = 'OK....' + data
conn.sendall(replay.encode())
data = ""
conn.close()
Related
Hey so I decided to create an IRC ChatBot whose sole purpose it is to read incoming messages from Twitch Chat and if a giveaway is recognized by a keyword it's supposed to enter the giveaway by sending !enter in Chat.
I build the Bot upon this source: https://github.com/BadNidalee/ChatBot. I only changed things in the Run.py so thats the only Code I'm going to post. The unaltered ChatBot does work but it has no reconnect ability and regularly stops receiving data because the socket closes or other reasons.
All I wanted to change was make it so that the ChatBot is stable and can just stay in the IRC Chat constantly without disconnecting. I tried to achieve this by setting a timeout of 8 seconds for my socket and catching timeout exceptions that would occur and reconnect after they occur.
And all in all it does seem to work, my Bot does what it's supposed to even when alot of messages are coming in, it recognizes when a Giveaway starts and answers acordingly. IRC Server PING Messages are also handled and answered correctly. If there is no message in Chat for over 8 seconds the Exception gets thrown correctly and the Bot also reconnects correctly to IRC.
BUT heres my Problem: After seemingly random times the socket will literally just Stop working. What I find strange is it will sometimes work for 20 minutes and sometimes for an hour. It doesn't occur when special events, like lots of messages or something else happens in Chat, it really seems random. It will not timeout there's just nothing happening anymore. If I cancel the program with CTRL-C at this point the console sais the last call was "readbuffer = s.recv(1024)" But why is it not throwing a timeout exception at that point? If s.recv was called the socket should timeout if nothing is received after 8 seconds but the program just stops and there is no more output until you manually abort it.
Maybe I went about it the wrong way completely. I just want a stable 24/7-able ChatBot that scans for one simple keyword and answers with one simple !enter.
This is also my first Time programming in Python so If I broke any conventions or made any grave mistakes let me know.
The getUser Method returns the username of the line of chat that is scanned currently.
The getMessage Method returns the message of the line of chat that is scanned.
The openSocket Method opens the Socket and sends JOIN NICK PASS etc to the IRC
#!/usr/bin/python
import string
import socket
import datetime
import time
from Read import getUser, getMessage
from Socket import openSocket, sendMessage
from Initialize import joinRoom
connected = False
readbuffer = ""
def connect():
print "Establishing Connection..."
irc = openSocket()
joinRoom(irc)
global connected
connected = True
irc.settimeout(8.0)
print "Connection Established!"
return irc
while True:
s = connect()
s.settimeout(8.0)
while connected:
try:
readbuffer = s.recv(1024)
temp = string.split(readbuffer, "\n")
readbuffer = temp.pop()
for line in temp:
if "PING" in line:
s.send(line.replace("PING", "PONG"))
timern = str(datetime.datetime.now().time())
timern = timern[0:8]
print timern + " PING received"
break
user = getUser(line)
message = getMessage(line)
timern = str(datetime.datetime.now().time())
timern = timern[0:8]
print timern +" " + user + ": " + message
if "*** NEW" in message:
sendMessage(s, "!enter")
break
except socket.timeout:
connected = False
print "Socket Timed Out, Connection closed!"
break
except socket.error:
connected = False
print "Socket Error, Connection closed!"
break
I think you've missunderstood how timeout work on the socket.
s.settimeout(8.0)
Will only set s.connect(...) to timeout if it can't reach the destination host.
Further more, usually what you want to use instead if s.setblocking(0) however this alone won't help you either (probably).
Instead what you want to use is:
import select
ready = select.select([s], [], [], timeout_in_seconds)
if ready[0]:
data = s.recv(1024)
What select does is check the buffer to see if any incoming data is available, if there is you call recv() which in itself is a blocking operation. If there's nothing in the buffer select will return empty and you should avoid calling recv().
If you're running everything on *Nix you're also better off using epoll.
from select import epoll, EPOLLIN
poll = epoll()
poll.register(s.fileno(), EPOLLIN)
events = poll.poll(1) # 1 sec timeout
for fileno, event in events:
if event is EPOLLIN and fileno == s.fileno():
data = s.recv(1024)
This is a crude example of how epoll could be used.
But it's quite fun to play around with and you should read more about it
Ok, I have a socket and I'm handling one line at a time and logging it. The code below works great for that. The cout function is what I use to send data to the log. The for loop I use so I can process one line at a time.
socket.connect((host, port))
readbuffer = ""
while True:
readbuffer = readbuffer+socket.recv(4096).decode("UTF-8")
cout("RECEIVING: " + readbuffer) #Logs the buffer
temp = str.split(readbuffer, "\n")
readbuffer=temp.pop( )
for line in temp:
#Handle one line at a time.
The I ran into a problem where when the server disconnected me, all of the sudden I had a massive file full of the word "RECEIVING: ". I know this is because when a python socket disconnects the socket starts receiving blank data constantly.
I have tried inserting:
if "" == readbuffer:
print("It disconnected!")
break
All that did was immediately break the loop, and say that it disconnected, even on a successful connection.
I also know that I can detect a disconnection by sending data, but I can't do that, because anything I send gets broadcasted to all the other clients on the server, and this is meant to debug those clients so I it would interfere.
What do I do. Thank you in advanced.
You need to check the result of the recv() separately to the readbuffer
while True:
c = socket.recv(4096)
if c == '': break # no more data
readbuffer = readbuffer + c.decode("UTF-8")
...
I send data to socket on one side every second, but I can read that data on another side in any moment. Here's the writer:
from settings import Config
filename = Config.NAVIGATION_SOCKET_FILE
client = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
client.settimeout(None)
while True:
try:
client.connect(filename)
break
except Exception:
continue
messages = ["$GPRMC,125504.049,A,5542.2389,N,03741.6063,E,0.06,25.82,200906,,,*17",
"$GPRMC,155604.049,A,5542.2389,N,03741.6063,E,0.06,25.82,200906,,,*19",]
while True:
msg = random.choice(messages)
client.send(msg)
print msg
time.sleep(1)
And here's reader:
navigation_socket = socket.socket(socket.AF_UNIX, socket.SOCK_DGRAM)
if os.path.exists(app.config['NAVIGATION_SOCKET_FILE']):
os.remove(app.config['NAVIGATION_SOCKET_FILE'])
navigation_socket.bind(app.config['NAVIGATION_SOCKET_FILE'])
class NavigationInfo(restful.Resource):
def get(self):
msg = navigation_socket.recv(1024)
regex = re.compile(r"^\$GPRMC,(?P<time>\d{6}\.\d{3}),(?P<status>A|V),"
r"(?P<latitude>\d{4}\.\d{4}),(?P<lat_n_s>N|S),"
r"(?P<longitude>\d{5}\.\d{4}),(?P<long_e_w>E|W),"
r"(?P<hor_speed>\d+.\d+),(?P<track_angle>\d+.\d+),"
r"(?P<date>\d{6}),(?P<magnetic_declination>\d+\.\d+)?,"
r"(?P<magnetic_decl_direction>\d)?,"
r"(?P<mode>A|D|E|N)?\*(?P<checksum>\d\d)")
result = regex.match(msg)
navigation_info = result.groupdict()
return navigation_info
So the first problem is that writer just stops writing data to socket when buffer is full (at least that's what I see) and when I request data on the other side, it's too old.
Can just I store one value in buffer and then rewrite it? Or maybe I'm getting it all wrong?
I think that you are using the solution in reverse.
Instead of pushing messaging, while not pulling messages ?
Your server may look like:
Wait for a connection
Give a random message
go to step 1
And your client may just connect to the server when he needs a message.
In your case, the connection is "opened all the time", in my solution the socket is opened only when needed. and closed right after the message is delivered.
I've tried looking about for an answer but I can't seem to find one that answers my specific problem.
Perhaps I don't know how to articulate the problem correctly.
I think I've pinpointed what it is, but the thing is I just don't know how to fix it.
EDIT: I was trying to use two clients on one TCP Socket. Can't do that. I'll have to think of another way. Solved, I guess.
So what I've got is are
1: Two Clients
2: One Server
The objective is this:
Have the server distribute new usernames to all the clients as they connect.
This is what happens when I run the program:
Server: Define Host, and Port, initialize it. Check
Client 1: Connects to the server. Check
Client 1: Once connected, sends a string to the server. Check
Server: Receives a string, checks if the string is in a list is created. If it is: Pass, if it's not, send to everyone the new string. Check
Client 1: [Now waiting to receive data] Recieves data, checks if the string received matches the one it sent. If it does, print("It's one of ours!"), else, make the new string = to Client 2 Username. Check
Client 2: Connects to server: Check
Server: [If it receives a string, prints it.] (Works) Checks if the new string is in the list. [It isn't] So It sends the new username to everyone, and then prints ("Sent to everyone") Check
But, when client 2 receives the string, it prints it. However, client 1 never recives the string.
And when running client one in IDLE, I noticed something went wrong as Client 1 tried to receive the data. (The while loop that the data = s.recv began looping real fast, instead of waiting)
I've asked around in chat, but it seems nobody's around right now. I've tried looking this up but I really can't find an answer. What I suspect is happening is that when my server sends to 'connection' the second time, it somehow overrides the original client connection.
Here's my server code:
from socket import *
import threading
import os
import csv
Username_List = []
host = input("Host: ")
port = input("Port: ")
ss = socket(AF_INET,SOCK_STREAM)
ss.bind((host,int(port)))
ss.listen(2)
while True:
try:
connection,address = ss.accept()
data = connection.recv(1024)
if data:
translated_data = data.decode()
print(translated_data)
if translated_data in Username_List:
pass
else:
Username_List.append(translated_data)
connection.sendall(translated_data.encode())
print("Sent new username to everyone")
except IOError:
connection.close()
print("An exception with a connected user occured")
break
And here is my client code: [The only difference between client 1 and 2 is I changed the username variable]
# Sample Username Client Service Handler.
from socket import *
import threading
import os
import csv
Username = ("Owatch")
host = input("Host: ")
port = input("Port: ")
try:
ss = socket(AF_INET,SOCK_STREAM)
ss.connect((host,int(port)))
except IOError:
print("Aw no man")
ss.send(Username.encode())
while True:
try:
print("Waiting to Recieve Data")
data = ss.recv(1024)
if data:
translated_data = data.decode()
print(translated_data)
if translated_data == Username:
print("It's one of ours!")
else:
Client_Username = translated_data
print (Client_Username)
except Exception as e:
print (vars(e))
If you could please help I'd be grateful.
If you know of an answer to my question that's already been asked, please tell me and I'll remove this post to avoid breaking rules. Thanks!
Right then I started with what you had then changed it till it worked what I've done is created a client class which starts a thread with each connection and adds it to a list of threads (please if I'm doing something horribly wrong smarter people correct me), the thread runs gets some data checks if that's in the list of user names if its not sends out a message to all the clients in the thread list with that name then the thread just chills out. Anyway on to the code.
SERVER!!!
import csv
class client(threading.Thread):
Username_List = []
def __init__(self, conn):
super(client, self).__init__()
self.conn = conn
def run(self):
print "Client thread started"
data = self.conn.recv(1024)
print "Received: {0}".format(data)
if data in client.Username_List:
self.send_msg("Welcome Back!")
else:
for cnt in threadz:
cnt.send_msg(data)
print("Sent new username to everyone")
client.Username_List.append(data)
while True:
# dont need nothing now
pass
def send_msg(self,msg):
self.conn.send(msg)
host = input("Host: ")
port = input("Port: ")
ss = socket() #AF_INET,SOCK_STREAM)
ss.bind((host,int(port)))
print "Server Opening on port: {0}".format(port)
ss.listen(2)
threadz = []
print "Begining Wait for connections"
while True:
try:
connection, address = ss.accept()
print "Got ONE!"
c = client(connection)
print "Recevied connection from:{0} On port:{1}".format(address[0],address[1])
c.start()
threadz.append(c)
print "Client appended to threadz, currently {0} threadz active".format(len(threadz))
except IOError,KeyboardInterrupt:
connection.close()
print("An exception with a connected user occured")
break
The CLIENT:
# Sample Username Client Service Handler.
from socket import *
import threading
import os
import csv
Username = ("ShyGuy")
host = input("Host: ")
port = input("Port: ")
try:
ss = socket() #AF_INET,SOCK_STREAM)
ss.connect((host,int(port))) #I was using ("localhost",1234) for testing
ss.send(Username)
except IOError:
print("Aw no man")
print("Waiting to Recieve Data")
while True:
try:
data = ss.recv(1024)
if data:
translated_data = data.decode()
print(translated_data)
if translated_data == Username:
print"Name: {0} has been registered on server!".format(translated_data)
else:
Client_Username = translated_data
print "New client name received: {0}".format(Client_Username)
except Exception as e:
print (vars(e))
That works on python 2.7 with two clients locally. Needs to use a semaphore to stop the threads printing at the same time as the main server loop prints: http://en.wikipedia.org/wiki/Semaphore_(programming)
This code does nothing graceful with client disconnects, but once you can work with the exceptions that a raised when that happens I'm sure you'll learn some more.
Im currently working on a client/server multi player cardgame solution in python using twisted libraries. Im pretty new to python, and this game actually is a proof of concept to myself, as i just want to show myself, that i can do such stuff. but im stuck ~8 hours on this problem now, and i need some advice.
following lines and the following description should let you know, what im trying to do here:
Description:
Server ist started
as soon as the demo client connects, server does some stuff in the background (registering, creating pile of cards for the player)
the demo client now starts() the cardgame
remote_start is called and calls function hoststart if its started by certain player (to be implemented)
the cards from the players pile are sent to the client and print out
the client should now be able to press a number (number of card), which then should be sent back to the server to print out the number (only printing doesnt make sense, but its the only thing that came to my mind right now :P)
now here starts the problem:
as soon as the reactor.run() is started, it seems as whole script is executed (user registered, game started) and the input at the client is done after the whole script is executed. so the sending of the entered number is done, before the number is entered within the input function and therefore returns 0 to the server.
I think this is very complex to explain, so please ask any questions which may come up.
How can i resolve this problem?
Can i somehow make the server wait an amount of seconds so that the client is able to input the Number during that time?
Do i need to open a new connection which allways opens if have to wait for input on the client?
client.py:
PICK = 0
factory = pb.PBClientFactory()
reactor.connectTCP("localhost", PORT, factory)
def1 = factory.getRootObject()
def1.addCallbacks(got_obj1, err_obj1)
ret = reactor.run()
def got_obj1(obj1):
def2 = obj1.callRemote("register","User A")
def2 = obj1.callRemote("start","User A")
def2.addCallback(show)
obj1.callRemote("pick",PICK) # Problem
def show(*var)
data_string = json.dumps(var)
decoded = json.loads(data_string)
for card in decoded[0]:
print(str(card['name'])
PICK = Input("Which card do you want to pick?") # Problem
server.py:
print("Starting server on ", PORT)
rpc = RPCs()
reactor.listenTCP(PORT, pb.PBServerFactory(rpc))
reactor.run()
class RPCs(pb.Root):
sessions = []
def remote_pick(self,pick):
print("picked: ", pick)
def remote_start(self, username):
for session in self.sessions :
if (session.getName() == username):
ret = self.hoststart(username)
return ret
def hoststart(self,username):
pile4client = []
card4pile {}
for session in self.sessions:
if (session.getName() == username):
ret = session.showpile(0)
for card in ret:
card4pile = { "name" : card.getName()}
pile4client .append(card4pile)
return pile4client
class Session():
piles = []
def showpile(self, num):
return self.piles[num]
Pass obj1 to show and call its callRemote in show. Something like this:
def got_obj1(obj1):
...
def2.addCallback(show, obj1)
def show(value, obj1):
...
PICK = Input("Which card do you want to pick?")
obj1.callRemote("pick",PICK)