Develop Reference

TCP Multithread Python

I am new to Python and also Thread and I'm trying to make a TCP server in python.
The client connect good to the server but can only put 1 command, then it crash, here is the code :
serverSocket = socket(AF_INET, SOCK_STREAM)
def Main():
serverPort = 7722
print("The server is ready to receive on port", serverPort)
serverSocket.bind(('', serverPort))
serverSocket.listen(1)
def start_socket(connectionSocket):
while True:
print('Connection requested from', clientAddress)
client_code_number = connectionSocket.recv(2048)
server_code_number = client_code_number.decode()
if (server_code_number == "1"):
print("Command 1\n\n")
message = connectionSocket.recv(2048)
modifiedMessage = message.decode().upper()
connectionSocket.send(modifiedMessage.encode())
connectionSocket.close()
if __name__ == '__main__':
Main()
while True:
(connectionSocket, clientAddress) = serverSocket.accept()
os.system('cls')
print('connexion from: ' + str(clientAddress))
_thread.start_new_thread(start_socket, (connectionSocket,))
serverSocket.close()
Here is the client :
def start_socket():
init_text()
choice_number = input('Input option: ')
#GET THE USER NUMBER
clientSocket.send(choice_number.encode())
while True:
if choice_number == "1":
sentence_caps = input('Input sentence: ')
clientSocket.send(sentence_caps.encode())
modifiedMessage = clientSocket.recv(2048)
print('\nReply from server:', modifiedMessage.decode())
start_socket()
else:
start_socket()
And here is my error :
File "BasicTCPServer.py", line 33, in start_socket
client_code_number = connectionSocket.recv(2048)
OSError: [Errno 9] Bad file descriptor

The root cause is that the socket is being closed.
def start_socket(connectionSocket):
while True:
print('Connection requested from', clientAddress) # <-- where does client address come from
client_code_number = connectionSocket.recv(2048) # <-- this works the first time round
server_code_number = client_code_number.decode()
if (server_code_number == "1"):
...
connectionSocket.close() # <-- this closes the socket
Your code is complaining about the second time through the loop. connectionSocket has been closed, so it is a bad file descriptor.

python broadcasting message via server

I am trying to broadcast a message to the subnet and i am giving the subnet address to the server to connect and the client throws error saying name or service unknown and not receiving the packet. Could anyone please tell me how do i broadcast message to my subnet such that client can also get that message or packet. exactly in the address area. My main doubts are about. which address is given at the client side and server side.
Error i get at client side is :
sending
Traceback (most recent call last):
File "/Threaded-server.py", line 11, in <module>
sent=s.sendto(msg.encode(),address)
socket.gaierror: [Errno -2] Name or service not known
closing socket
Process finished with exit code 1
Thanks
client
import socket
import sys
import json
connected = False
#connect to server
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client_socket.connect((' ',10000))
connected = True
while connected == True:
#wait for server commands to do things, now we will just display things
data = client_socket.recv(1024)
cmd = json.loads(data) #we now only expect json
if(cmd['type'] == 'bet'):
bet = cmd['value']
print('betting is: '+bet)
elif (cmd['type'] == 'result'):
print('winner is: '+str(cmd['winner']))
print('payout is: '+str(cmd['payout']))
##Server
import socket, time, sys
import threading
import pprint
TCP_IP = '192.168.1.255'
TCP_PORT = 10000
BUFFER_SIZE = 1024
clientCount = 0
class server():
def __init__(self):
self.CLIENTS = []
def startServer(self):
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((TCP_IP,TCP_PORT))
s.listen(10)
while 1:
client_socket, addr = s.accept()
print ('Connected with ' + addr[0] + ':' + str(addr[1]))
global clientCount
clientCount = clientCount+1
print (clientCount)
# register client
self.CLIENTS.append(client_socket)
threading.Thread(target=self.playerHandler, args=(client_socket,)).start()
s.close()
except socket.error as msg:
print ('Could Not Start Server Thread. Error Code : ') #+ str(msg[0]) + ' Message ' + msg[1]
sys.exit()
#client handler :one of these loops is running for each thread/player
def playerHandler(self, client_socket):
#send welcome msg to new client
client_socket.send(bytes('{"type": "bet","value": "1"}', 'UTF-8'))
while 1:
data = client_socket.recv(BUFFER_SIZE)
if not data:
break
#print ('Data : ' + repr(data) + "\n")
#data = data.decode("UTF-8")
# broadcast
for client in self.CLIENTS.values():
client.send(data)
# the connection is closed: unregister
self.CLIENTS.remove(client_socket)
#client_socket.close() #do we close the socket when the program ends? or for ea client thead?
def broadcast(self, message):
for c in self.CLIENTS:
c.send(message.encode("utf-8"))
def _broadcast(self):
for sock in self.CLIENTS:
try :
self._send(sock)
except socket.error:
sock.close() # closing the socket connection
self.CLIENTS.remove(sock) # removing the socket from the active connections list
def _send(self, sock):
# Packs the message with 4 leading bytes representing the message length
#msg = struct.pack('>I', len(msg)) + msg
# Sends the packed message
sock.send(bytes('{"type": "bet","value": "1"}', 'UTF-8'))
if __name__ == '__main__':
s = server() #create new server listening for connections
threading.Thread(target=s.startServer).start()
while 1:
s._broadcast()
pprint.pprint(s.CLIENTS)
print(len(s.CLIENTS)) #print out the number of connected clients every 5s
time.sleep(5)

str not callable sendto python

attempting message encryption with a basic client to host connection
client code:
import socket
import datetime
import time
import threading
tLock = threading.Lock()
shutdown = False
def receving(name, sock):
while not shutdown:
try:
tLock.acquire()
while True:
data, addr = socket.recvfrom(1024)
print (str(data))
except:
pass
finally:
tLock.release()
host = '127.0.0.1'
port = 0
server = ('127.0.0.1',5000)
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind((host, port))
s.setblocking(0)
rT = threading.Thread(target=receving, args=("RecvThread",s))
rT.start()
alias = input("Name: ")
IP=int(socket.gethostbyname(socket.gethostname()).replace(".","5"))
time=(int(datetime.datetime.now().strftime("%Y%m%d%H%M%S")))
qw=(int(str((time)+(IP))))
a=int("934")
b=int("346")
c=int("926")
d=int("9522")
e=int("7334")
f=int("5856")
g=int("2432")
h=int("2027")
i=int("7024")
j=int("828")
k=int("798")
m=int("593")
n=int("662")
l=int("5950")
o=int("357")
p=int("506")
q=int("237")
r=int("98")
s=int("372")
t=int("636")
u=int("553")
v=int("255")
w=int("298")
x=int("8822")
y=int("458")
z=int("657")
space=("633")
msg=input("")
msg=msg.replace("a",(str(a)))
msg=msg.replace("b",(str(b)))
msg=msg.replace("c",(str(c)))
msg=msg.replace("d",(str(d)))
msg=msg.replace("e",(str(e)))
msg=msg.replace("f",(str(f)))
msg=msg.replace("g",(str(g)))
msg=msg.replace("h",(str(h)))
msg=msg.replace("i",(str(i)))
msg=msg.replace("j",(str(j)))
msg=msg.replace("k",(str(k)))
msg=msg.replace("m",(str(m)))
msg=msg.replace("n",(str(n)))
msg=msg.replace("l",(str(l)))
msg=msg.replace("o",(str(o)))
msg=msg.replace("p",(str(p)))
msg=msg.replace("q",(str(q)))
msg=msg.replace("r",(str(r)))
msg=msg.replace("s",(str(s)))
msg=msg.replace("t",(str(t)))
msg=msg.replace("u",(str(u)))
msg=msg.replace("v",(str(v)))
msg=msg.replace("w",(str(w)))
msg=msg.replace("x",(str(x)))
msg=msg.replace("y",(str(y)))
msg=msg.replace("z",(str(z)))
msg=msg.replace(" ",(str(space)))
print(msg)
msg=int(msg)
msg=int(msg)*(qw)
print(msg)
fileb=open("key.txt","w")
filec=fileb.write(str(qw))
fileb.close()
file=open("msg decrypt.txt","w")
filea=file.write(str(msg))
file.close()
msg=(str(e)(msg))
print(IP)
print(qw)
if msg != 'q':
if msg != '':
s.sendto(alias.encode() + ": ".encode() + (str(msg).encode)(), server)
tLock.acquire()
msg = input(alias + "-> ")
tLock.release()
shudown = True
rT.join()
s.close()
host code:
import socket
import time
host = '127.0.0.1'
port = 5000
clients = []
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind((host,port))
s.setblocking(0)
quitting = False
print ("Server Started.")
while not quitting:
try:
data, addr = s.recvfrom(1024)
if "Quit" in str(data):
quitting = True
if addr not in clients:
clients.append(addr)
print (time.ctime(time.time()) + str(addr) + ": :" + str(data))
for client in clients:
s.sendto(data, client)
except:
pass
s.close()
Im struggling as my poor excuse of a encryption is mostly numbers so therefore when im sending using the sendto function only uses str`s or so I think?
either way I get the error:
Traceback (most recent call last):
File "H:\client 2.py", line 103, in <module>
msg=(str(e)(msg))
TypeError: 'str' object is not callable

If msg is an index you should write :
msg = str(e)[msg]

python3 OSError: [Errno 107] Transport endpoint is not connected

I try to make a chat on Python3. Here is my code:
import socket
import threading
print("Server starts working")
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(("", 57054))
sock.listen(2)
conn, addr = sock.accept()
def get_message():
while True:
data = sock.recv(1024).decode()
if len(data) != 0:
print("Some guy: ", data)
def send_message():
while True:
message = input()
if len(message) != 0:
message = str.encode(message)
sock.send(message)
print("You: ", message)
def run():
get_message_thread = threading.Thread(target=get_message())
send_message_thread = threading.Thread(target=send_message())
get_message_thread.daemon = True
send_message_thread.daemon = True
get_message_thread.start()
send_message_thread.start()
run()
sock.close()
But after the execution and sending a message from other client I get an error message:
Server starts working
Traceback (most recent call last):
File "/home/ptrknvk/Documents/Study/Python/chat/chat.py", line 40, in <module>
run()
File "/home/ptrknvk/Documents/Study/Python/chat/chat.py", line 30, in run
get_message_thread = threading.Thread(target=get_message())
File "/home/ptrknvk/Documents/Study/Python/chat/chat.py", line 15, in get_message
data = sock.recv(1024).decode()
OSError: [Errno 107] Transport endpoint is not connected
Process finished with exit code 1
I've read, that there are some troubles with sock.accept(), but everything's alright here, as I think.

Your program has many flaws. As zondo mentioned, you are incorrectly passing the target. They should be like threading.Thread(target=get_message). Second problem is, you should use conn (and not sock) for sending and receiving data. Third problem is, main thread was blocking at accept call and will wait for the connection. But soon as it accepts a connection, it will exit. From the main thread, you should wait for get_message_thread and send_message_thread. Try the modified code:
import socket
import threading
print("Server starts working")
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(("", 57054))
sock.listen(2)
conn, addr = sock.accept()
def get_message():
while True:
data = conn.recv(1024).decode()
if len(data) != 0:
print("Some guy: ", data)
def send_message():
while True:
message = input()
if len(message) != 0:
message = str.encode(message)
conn.send(message)
print("You: ", message)
def run():
get_message_thread = threading.Thread(target=get_message)
send_message_thread = threading.Thread(target=send_message)
get_message_thread.daemon = True
send_message_thread.daemon = True
get_message_thread.start()
send_message_thread.start()
get_message_thread.join()
send_message_thread.join()
run()
sock.close()

Creating a simple Chat application in Python (Sockets)

I'm trying to create a simple chat application using sockets (python). Where a client can send a message to server and server simply broadcast the message to all other clients except the one who has sent it.
Client has two threads, which are running forever
send: Send simply sends the cleints message to server.
receive: Receive the message from the server.
Server also has two threads, which are running forever
accept_cleint: To accept the incoming connection from the client.
broadcast_usr: Accepts the message from the client and just broadcast it to all other clients.
But I'm getting erroneous output (Please refer the below image). All threads suppose to be active all the times but Some times client can send message sometimes it can not. Say for example Tracey sends 'hi' 4 times but its not broadcasted, When John says 'bye' 2 times then 1 time its message gets braodcasted. It seems like there is some thread synchronization problem at sever, I'm not sure. Please tell me what's wrong.
Below is the code.
chat_client.py
import socket, threading
def send():
while True:
msg = raw_input('\nMe > ')
cli_sock.send(msg)
def receive():
while True:
sen_name = cli_sock.recv(1024)
data = cli_sock.recv(1024)
print('\n' + str(sen_name) + ' > ' + str(data))
if __name__ == "__main__":
# socket
cli_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# connect
HOST = 'localhost'
PORT = 5023
cli_sock.connect((HOST, PORT))
print('Connected to remote host...')
uname = raw_input('Enter your name to enter the chat > ')
cli_sock.send(uname)
thread_send = threading.Thread(target = send)
thread_send.start()
thread_receive = threading.Thread(target = receive)
thread_receive.start()
chat_server.py
import socket, threading
def accept_client():
while True:
#accept
cli_sock, cli_add = ser_sock.accept()
uname = cli_sock.recv(1024)
CONNECTION_LIST.append((uname, cli_sock))
print('%s is now connected' %uname)
def broadcast_usr():
while True:
for i in range(len(CONNECTION_LIST)):
try:
data = CONNECTION_LIST[i][1].recv(1024)
if data:
b_usr(CONNECTION_LIST[i][1], CONNECTION_LIST[i][0], data)
except Exception as x:
print(x.message)
break
def b_usr(cs_sock, sen_name, msg):
for i in range(len(CONNECTION_LIST)):
if (CONNECTION_LIST[i][1] != cs_sock):
CONNECTION_LIST[i][1].send(sen_name)
CONNECTION_LIST[i][1].send(msg)
if __name__ == "__main__":
CONNECTION_LIST = []
# socket
ser_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# bind
HOST = 'localhost'
PORT = 5023
ser_sock.bind((HOST, PORT))
# listen
ser_sock.listen(1)
print('Chat server started on port : ' + str(PORT))
thread_ac = threading.Thread(target = accept_client)
thread_ac.start()
thread_bs = threading.Thread(target = broadcast_usr)
thread_bs.start()

Ok I lied in my comment earlier, sorry. The issue is actually in the broadcast_usr() function on the server. It is blocking in the recv() method and preventing all but the currently selected user from talking at a single time as it progresses through the for loop. To fix this, I changed the server.py program to spawn a new broadcast_usr thread for each client connection that it accepts. I hope this helps.
import socket, threading
def accept_client():
while True:
#accept
cli_sock, cli_add = ser_sock.accept()
uname = cli_sock.recv(1024)
CONNECTION_LIST.append((uname, cli_sock))
print('%s is now connected' %uname)
thread_client = threading.Thread(target = broadcast_usr, args=[uname, cli_sock])
thread_client.start()
def broadcast_usr(uname, cli_sock):
while True:
try:
data = cli_sock.recv(1024)
if data:
print "{0} spoke".format(uname)
b_usr(cli_sock, uname, data)
except Exception as x:
print(x.message)
break
def b_usr(cs_sock, sen_name, msg):
for client in CONNECTION_LIST:
if client[1] != cs_sock:
client[1].send(sen_name)
client[1].send(msg)
if __name__ == "__main__":
CONNECTION_LIST = []
# socket
ser_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# bind
HOST = 'localhost'
PORT = 5023
ser_sock.bind((HOST, PORT))
# listen
ser_sock.listen(1)
print('Chat server started on port : ' + str(PORT))
thread_ac = threading.Thread(target = accept_client)
thread_ac.start()
#thread_bs = threading.Thread(target = broadcast_usr)
#thread_bs.start()

I tried to get around the bug you said #Atinesh. The client will be asked a username once and this 'uname' will be included in the data to be sent. See what I did to the 'send' function.
For easier visualization, I added a '\t' to all received messages.
import socket, threading
def send(uname):
while True:
msg = raw_input('\nMe > ')
data = uname + '>' + msg
cli_sock.send(data)
def receive():
while True:
data = cli_sock.recv(1024)
print('\t'+ str(data))
if __name__ == "__main__":
# socket
cli_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# connect
HOST = 'localhost'
PORT = 5023
uname = raw_input('Enter your name to enter the chat > ')
cli_sock.connect((HOST, PORT))
print('Connected to remote host...')
thread_send = threading.Thread(target = send,args=[uname])
thread_send.start()
thread_receive = threading.Thread(target = receive)
thread_receive.start()
You also have to modify your server code accordingly.
server.py
import socket, threading
def accept_client():
while True:
#accept
cli_sock, cli_add = ser_sock.accept()
CONNECTION_LIST.append(cli_sock)
thread_client = threading.Thread(target = broadcast_usr, args=[cli_sock])
thread_client.start()
def broadcast_usr(cli_sock):
while True:
try:
data = cli_sock.recv(1024)
if data:
b_usr(cli_sock, data)
except Exception as x:
print(x.message)
break
def b_usr(cs_sock, msg):
for client in CONNECTION_LIST:
if client != cs_sock:
client.send(msg)
if __name__ == "__main__":
CONNECTION_LIST = []
# socket
ser_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# bind
HOST = 'localhost'
PORT = 5023
ser_sock.bind((HOST, PORT))
# listen
ser_sock.listen(1)
print('Chat server started on port : ' + str(PORT))
thread_ac = threading.Thread(target = accept_client)
thread_ac.start()
The things that changed in the server side are: the user who connected and the user who spoke is not seen anymore. I don't know if it would mean that much if your purpose is to connect clients. Maybe if you want to strictly monitor clients via the server, there could be another way.