Develop Reference

python UDP socket client need to send twice so that the server can receive the package

i have a client will send some string to my server. However, i need to send twice so that the server get the package. So for every package client wants to send the server, it needs to send twice. I do not understand why it went in this way.
my server's code that does listening:
sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
myIp = "0x2A"
myPort = 2222
targetPort = 0
myAddress = ("localhost",myPort)
bufferSize = 1024
def listen():
print('starting up on {} port {}'.format(*myAddress))
sock.bind(myAddress)
# sock.listen(1)
print("waiting for message")
# connection, client_address = sock.accept()
while True:
received = sock.recvfrom(bufferSize)[0]
address = sock.recvfrom(bufferSize)[1]
received = json.loads(received.decode())
source = received.get("source")
destination = received.get("destination")
length = received.get("length")
message = received.get("message")
protocol = received.get("protocol")
print("the source is: " + source)
if destination == myIp:
print("the message is: " + message)
print('sending back to sender...')
sock.sendto(message.encode(),address)
if protocol == 0:
print("protocol is: " + str(protocol))
elif protocol == 1:
print("protocol is: " + str(protocol))
print("write data to log file....")
f = open("log.txt","w")
f.write(message)
print('done!')
elif protocol == 2:
print("protocol is: " + str(protocol))
# sock.close()
print("exit")
sock.close()
sys.exit()
else:
print("this is not my package: \n" + "destination Ip is: " + destination + "\n my Ip is: " + myIp)
if not received:
break
my client's code that does the sending:
def send():
try:
sock.sendto(message.encode(),serverAddress)
print("message: " + message + " is sent")
finally:
print('closing socket')
sock.close()

received = sock.recvfrom(bufferSize)[0]
address = sock.recvfrom(bufferSize)[1]
The first recvfrom will do the first read. The second recvfrom will do another read. Voila: you need two reads. Instead you should do a single read:
received, address = socket.recvfrom(bufferSize)

Python multithreading: threaded input() pauses other threads in one program, but not the other?

I'm coding a small socket Chat Server for personal use, and have come across and issue.
My client is a simple program with two threads, one waiting on a user input, the other on the server; this code works perfectly:
import socket
import threading
from threading import Thread
username = input("Username? >")
host = input("host ip?")
port = 8000
Socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
Socket.connect((host,port))
Socket.send(username.encode())
print(Socket.recv(1024).decode())
def SendMessage():
while True:
Socket.send(input("").encode())
def RecvMessage():
while True:
print(Socket.recv(1024).decode())
msgthread = Thread(target = SendMessage, args = ())
recvthread = Thread(target = RecvMessage, args = ())
msgthread.start()
recvthread.start()
(Forgive the sloppy code, it was thrown together in ~20mins on a Monday evening)
As you can see, I am calling two threads, both of which have halting functions in them, and it works seamlessly.
The server, however, is where I am having problems:
import socket
import threading
from threading import Thread
connections = []
host = ""
port = 8000
threads = []
def ListenForCommands():
while True:
print(input())
def SearchForConnections():
global connections, threads
while True:
conn, addr = Socket.accept()
username = conn.recv(10).decode()
conn.send(("You have successfully connected to the server!").encode())
print(username + " (" + str(addr[0]) + ":" + str(addr[1]) + ") Joined")
for i in range(len(connections)):
if connections[i][0] != conn:
connections[i][0].send((username + " Joined").encode())
connections += [[conn,addr,username]]
threads += [Thread(target = Listen, args = (conn, ))]
threads[-1].start()
def Listen(conn):
global connections, threads
while True:
for i in range(len(connections)):
if connections[i][0] == conn:
username = connections[i][2]
try:
data = conn.recv(1024).decode()
print(username + ": " + data)
for i in range(len(connections)):
if connections[i][0] != conn:
connections[i][0].send((username + ": " + data).encode())
except:
print(username + " Disconnected")
for i in range(len(connections)):
if connections[i][0] == conn:
connections.remove(connections[i])
break
for i in range(len(connections)):
connections[i][0].send((username + " Disconnected").encode())
return;
Socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print("Server created")
Socket.bind((host,port))
Socket.listen(3)
ListenThread = Thread(target = ListenForCommands, args = ())
ListenThread.start()
SearchForConnections()
The source of the problem is in these functions:
def ListenForCommands():
while True:
print(input())
def SearchForConnections():
global connections, threads
while True:
conn, addr = Socket.accept()
username = conn.recv(10).decode()
conn.send(("You have successfully connected to the server!").encode())
print(username + " (" + str(addr[0]) + ":" + str(addr[1]) + ") Joined")
for i in range(len(connections)):
if connections[i][0] != conn:
connections[i][0].send((username + " Joined").encode())
connections += [[conn,addr,username]]
threads += [Thread(target = Listen, args = (conn, ))]
threads[-1].start()
The program seems to be halting when arriving at this line
print(username + " (" + str(addr[0]) + ":" + str(addr[1]) + ") Joined")
and works fine without it; however, on the Client Program, this does not seem to be the case.
the ListenForCommands function (as of now just printing out the user input) is being declared as a thread:
ListenThread = Thread(target = ListenForCommands, args = ())
ListenThread.start()
and the SearchForConnections function is being called normally. However, the entire program seems to be being halted until an input is taken from the user, unlike the client side which seems to be working perfectly.
I think I am missing something quite obvious, but have been at a loss for a few hours now, and would love it if someone could help me see the error in my ways!

python sockets, trying to make a log in interaction betwen server and client

Hello so i have my server with a database (dictironay) and another passworddatabase
import socket
import sys
from _thread import *
host = ""
port = 8000
serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print("Socket Created")
try:
serversocket.bind((host, port))
except socket.error as e:
print(str(e))
sys.exit()
database = {"name1" :{"hair" : "red", "size" : 1.50}}
password_database = {"name1": "1234",
"name2": "4321"}
def client_thread(conn): #threader client
welcome = "Welcome to the server. Type something and hit enter \n"
conn.send(welcome.encode("UTF-8"))
login(conn)
while True: # NOT IMPORTANT KEEP READING
data = conn.recv(24)
reply = data.decode("UTF-8")
if reply == "1":
menu1 = "Menu 1: Buy \n"
conn.send(menu1.encode("UTF-8"))
else:
wrong = "wrong option \n"
conn.send(wrong.encode("UTF-8"))
def login(conn): #MY LOGIC PROBLEM IS HERE
log = "Log in MENU: \n"
logi = log.encode("UTF-8")
conn.send(logi)
us = "Username: \n"
use = us.encode("UTF-8")
conn.send(use)
userr = conn.recv(24)
user = userr.decode("UTF-8")
pa = "Password: \n"
pasw = pa.encode("UTF-8")
conn.send(pasw)
passr = conn.recv(24)
passw = passr.decode("UTF-8")
tries = 0
while tries < 3:
if user in passwordDictionary and passwordDictionary[user] == passw:
print("Logged in")
menu()
else:
print("Wrong Username Or Password \n")
tries += 1
print("You failed the login too many times, blocking you out")
conn.close()
while 1: # NOT IMPORTANT
conn, addr = serversocket.accept()
print("Connected with " + addr[0] + ":" + str(addr[1]))
start_new_thread(client_thread, (conn, ))
serversocket.close()
Whats working:
The server is working fine, i'm having troubles doing the login on the client side.
client.py ==> client DOESNT go into the if data == Log in menu
is there a better way to do this?
#! /usr/bin/python3
import socket
clientsocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
clientsocket.connect(('localhost', 8000))
print("Connected")
datae = clientsocket.recv(24)
data = datae.decode("UTF-8")
clientsocket.send(datae)
while data != "!q":
if data == "Log in MENU: \n":
usere = input()
user = usere.encode("UTF-8")
clientsocket.send(user)
What would be the best way to create an log in interaction with the server?
the server has the usernames and passwords, i need to log in and then i need to edit the database depending on what user was chossen, but i'm having a hard time doing the algorithm

theres problems with the code you provided... however ill assume it actually works for you somehow and rather than copy paste you manually typed it
you are recieveing the first message here
datae = clientsocket.recv(24)
data = datae.decode("UTF-8") # GOT A MESSAGE
You then have the message datae = b'Welcome to the server. '
which does not match "Log in MENU: \n", and data != "!q" so it goes back into your loop and checks if data == "Log in MENU: \n" it doesnt so it repeats ... but you never get the next message instead try something like this second message
data = ""
while data != "!q":
if data == "Log in MENU: \n":
usere = input()
user = usere.encode("UTF-8")
clientsocket.send(user)
data = clientsocket.recv(24).decode("UTF-8") # GET THE NEXT MESSAGE!
but even then you are going to have problems because your server continues to write so you will get something like "Log in MENU: \nUsername" or something .... basically you need to work out a better message passing scheme than recv(24)

To avoid Errors try using a header with something like 64 Bytes wich always is the first message send. This Header is then used to send the actual length of the following message to the server. For example:
def send_response(conn, msg):
message = msg.encode(FORMAT)
send_length = len(str(len(message)).encode(FORMAT))
res_len = bytes(len(message)) + (b' ' * (HEADER - send_length))
print(f"[SENDING MESSAGE] {msg}")
conn.send(res_len)
conn.send(response)

Multiprocessing and sockets, simplified

I am trying to make my IRC bot handle multiple messages at a time, but it's not sending back messages.
Behavior: Process(target=func) is called, func() calls a function that has socket.socket().send(message) in it, but the message doesn't send. Suspect is that the socket isn't passed to the sending function.
Code:
import socket
import re
import requests
import urllib
import config # just my file of variables
import math
import time
import sys
import winsound
import string
import random
import multiprocessing
# import traceback
# CONNECTION COMMANDS
ircsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server = config.server # Server
password = config.password # Password
botnick = config.botnick # Your bots nick
adminname = config.adminname # Your IRC nickname
exitcode = config.exitcode
ircsock.settimeout(300)
def connection(host, port, password, nick, realname):
ircsock.connect((host, port))
ircsock.send(bytes("PASS " + password + "\n", "UTF-8"))
ircsock.send(bytes("USER " + botnick + " " + botnick + " " + botnick + " " + botnick + "\n", "UTF-8"))
ircsock.send(bytes("NICK " + botnick + "\n", "UTF-8"))
def ping(): # respond to server Pings.
ircsock.send(bytes("PONG :pingis\n", "UTF-8"))
print("Ponged after " + str(time.time() - last_ping) + " seconds from last ping!")
def sendmsg(msg, target): # sends messages to the target.
# it enters here, no problem
ircsock.send(bytes("PRIVMSG " + target + " :" + msg + "\n", "UTF-8")) ### At this point, when using multiprocessing, the bot fails ###
print("Sending: [" + str(msg) + "] to: " + str(target))
# MAIN
if __name__ == '__main__':
connection(server, 6667, password, botnick, botnick)
# joinchan(channel)
while 1:
# print("Connected!")
ircmsg = ircsock.recv(1024).decode("UTF-8")
ircmsg = ircmsg.strip('\n\r')
if ircmsg.find("PRIVMSG") != -1:
try:
# “:[Nick]!~[hostname]#[IP Address] PRIVMSG [channel] :[message]”
name = ircmsg.split('PRIVMSG', 1)[0].split(':')[-1].split("!")[0] # ircmsg.split('!', 1)[0][1:]
message = ircmsg.split('PRIVMSG', 1)[1].split(':', 1)[1].splitlines()[0] # .strip()[0]
me = ircmsg.split('PRIVMSG', 1)[1].split(':', 1)[0].split()[0]
# print(me)
print("name: " + name + ", message: " + message)
if len(name) < 17:
if me == botnick:
if message.find("Hi!") != -1:
process1 = multiprocessing.Process(target=sendmsg, args=("Hello!", name))
process1.daemon = True
process1.start()
if name.lower() == adminname.lower() and message.rstrip() == exitcode:
sendmsg("Bot is quitting.", name)
ircsock.send(bytes("QUIT \n", "UTF-8"))
sys.exit()
time.sleep(1)
except:
pass
elif ircmsg.find("PING") != -1:
ping()
Please word your answers as simply as possible, since I am not that experienced in Python. The code above can be run with a correct config.py file.
Format:
password = "" # password to open the server
exitcode = "" # What is typed to stop the bot
server = "" # Server
botnick = "" # Your bots nick
adminname = "" # Your IRC nickname

how to use threading with a 'neverending' process

I'm attempting to add an irc client to a django web application I'm working on. I'd like the server side code for the irc communication to use python and connect through the sockets library. I'll then use gevent-socketio to send and receive data from the irc channel to the client side in the browser. So far I have a very basic gevent-socketio server and client that can be used for realtime broadcasting amongst multiple clients, however, when I start to connect clients to IRC they connect to the IRC server successfully using a nick passed from the client, but then it appears that this is ongoing keepalive/listening process is blocking be from sending any messages from the client.
Python IRC code
import socket
class pycli:
def __init__(self,user):
self.nick = user
self.chan = "#testchannel"
self.owner = "Bluebot"
self.sock = socket.socket()
print "irc conn"
def send_msg(self,message):
self.sock.send("PRIVMSG " + self.chan + " : " + message + "\r\n")
## misc setup
def keep_alive(self):
self.sock.connect(("irc.freenode.net",6667))
self.sock.send("USER " + self.nick + " 0 * :" + self.owner + "\r\n")
self.sock.send("NICK " + self.nick + "\r\n")
while 1:
## keep checking for data
data = self.sock.recv(512)
datalen = len(data.split(" "))
sender = ""
msg_type = ""
msg_rcpt = ""
message = ""
###----------------------------------------------
## reply to keep alive pings
if data[0:4] == "PING":
self.sock.send(data.replace("PING", "PONG"))
if data[0]!=':':
continue
if data.split(" ")[1] == "001":
self.sock.send("MODE " + self.nick + " +B\r\n")
self.sock.send("JOIN " + self.chan + "\r\n")
###-----------------------------------------------
##split and assign data parts
## parse out the actual sender
send_data = data.split(" ")[0]
send_data = send_data[1:]
sender = send_data.split('!')[0]
## mode
msg_type = data.split(" ")[1]
## if it exists get the recipient (room or private)
if datalen > 2:
msg_rcpt = data.split(" ")[2]
## get the actual message body
if datalen > 3:
message = (" ".join(data.split(" ")[3:])).lower()[1:]
print data
I know this functionality is super basic, but I can expand on it once I get it working through the client.
The relevant parts of my server code basically looks like:
def on_login(self, nick):
if self.nick:
self._broadcast('exit', self.nick)
self.nick = nick
self._broadcast('enter', nick)
self.emit('users',
[ ns.nick
for ns in self._registry.values()
if ns.nick is not None ])
t = threading.Thread(target=self.make_start_irc(nick),daemon=True)
t.start()
def on_chat(self, message):
if self.nick:
self._broadcast('chat', dict(u=self.nick, m=message))
self._irc_nicks[self.nick].send_msg("this is a test")
else:
self.emit('chat', dict(u='SYSTEM', m='You must first login'))
def make_start_irc(self,nick):
if nick not in self._irc_nicks.values():
self._irc_nicks[nick] = pycli.pycli(nick)
print self._irc_nicks
self._irc_nicks[nick].keep_alive()
def _broadcast(self, event, message):
for s in self._registry.values():
s.emit(event, message)
def chat(environ, start_response):
if environ['PATH_INFO'].startswith('/socket.io'):
return socketio_manage(environ, { '/chat': ChatNamespace })
else:
return serve_file(environ, start_response)
def serve_file(environ, start_response):
path = os.path.normpath(
os.path.join(public, environ['PATH_INFO'].lstrip('/')))
assert path.startswith(public), path
if os.path.exists(path):
start_response('200 OK', [('Content-Type', 'text/html')])
with open(path) as fp:
while True:
chunk = fp.read(4096)
if not chunk: break
yield chunk
else:
start_response('404 NOT FOUND', [])
yield 'File not found'
if __name__ == "__main__":
from gevent import monkey
monkey.patch_all()
sio_server = SocketIOServer(
('', 8080), chat,
policy_server=False)
t2 = threading.Thread(target=sio_server.serve_forever())
t2.start()
When I eventually give up and use ctrl-C, I see the following stacktrace which leads me to believe something about the way I'm threading is blocking.
Traceback (most recent call last):
File "socketio_test.py", line 92, in <module>
t2 = threading.Thread(target=sio_server.serve_forever())
File "/Users/andrewscott/Desktop/wham/pycli/wham/lib/python2.7/site-packages/gevent/baseserver.py", line 284, in serve_forever
self._stop_event.wait()
File "/Users/andrewscott/Desktop/wham/pycli/wham/lib/python2.7/site-packages/gevent/event.py", line 77, in wait
result = self.hub.switch()
File "/Users/andrewscott/Desktop/wham/pycli/wham/lib/python2.7/site-packages/gevent/hub.py", line 338, in switch
return greenlet.switch(self)
KeyboardInterrupt
If anyone has any idea how I can change the irc process to be non-blocking, or any general suggestions they'd be greatly appreciated.

You should remove the call:
t2 = threading.Thread(target=sio_server.serve_forever())
And properly pass the method:
t2 = threading.Thread(target=sio_server.serve_forever)