TCP Multithread Python - 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.

Related

How to break while loop when a new message arrives?

I have used Python socket in ESP as a server and Laptop as a client. I customized the socket codes from this site. When I send the loop as the client input, I enter a loop on the server. I don't know how the while loop is broken when I send a word other than loop, For example "Hello".
server.py:
import socket
host = ''
port = 5560
def setupServer():
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print("Socket created.")
try:
s.bind((host, port))
except socket.error as msg:
print(msg)
print("Socket bind comlete.")
return s
def setupConnection():
s.listen(1)
conn, address = s.accept()
print("Connected to: " + address[0] + ":" + str(address[1]))
return conn
def Hello_():
print('Hello')
def Loop_():
while True:
print('yes')
def dataTransfer(conn):
while True:
data = conn.recv(1024)
data = data.decode('utf-8')
dataMessage = data.split(' ', 1)
command = dataMessage[0]
if command == 'loop':
Loop_()
if command == 'Hello':
Hello_()
else:
print("X")
conn.close()
s = setupServer()
while True:
try:
conn = setupConnection()
dataTransfer(conn)
except:
break
client.py
import socket
host = '192.168.56.1'
port = 5560
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
while True:
command = input("Enter your command: ")
s.send(str.encode(command))
s.close()
I know your time is valuable and I appreciate your attention for spending time for help me.
If you want the Loop_() method to return when more data is received on the socket, you can modify the method so that it calls select() to poll the socket to see if more data has arrived, as shown below. (Note that I've added a conn argument to the Loop_() method so I can pass in the socket to check it)
import select
[...]
def Loop_(conn):
while True:
print('yes')
inReady, outReady, exReady = select.select([conn], [], [], 0.0)
if (conn in inReady):
print('more data has arrived at the TCP socket, returning from Loop_()')
break
def dataTransfer(conn):
while True:
data = conn.recv(1024)
data = data.decode('utf-8')
dataMessage = data.split(' ', 1)
command = dataMessage[0]
if command == 'loop':
Loop_(conn)
if command == 'Hello':
Hello_()
else:
print("X")
conn.close()

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)

Chat Program Threaded

I am trying to build a small chat server/client using python. So far I think I managed to set it up but I am running into issues. I wanted to set the program up to be multithreaded to keep the server listening for connections, and to also continue to listen for data and then have the main program loop stay in the client send. Here is my code, and I am running into an issue when starting the listen function, it tells me the argument must be an iterable not socket.
import socket
import platform
import os
import threading
'''Define Globals'''
HOST = ""
PORT = 25000
ADDR = (HOST, PORT)
BUF = 1024
def client_send():
server_ip = input("[+] Server's IP to connect to: ")
client_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
client_socket.connect((server_ip, 25000))
data_thread = threading.Thread(target=client_listen, args=(client_socket))
data_thread.start()
while True:
data = input("[%s] => " % os.getlogin())
client.send(str.encode("[%s] => " + data % os.getlogin()))
def client_listen(client):
while True:
print(client.recv(BUF))
def server_loop():
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind(ADDR)
server.listen(10)
print("[+] Server started on %s" %platform.node())
print("[+] Awaitiing connection from client..")
while True:
client_socket, client_addr = server.accept()
print("[+] New Connection from %s" %client_addr[0])
def main():
server_thread = threading.Thread(target=server_loop)
while True:
try:
print("Select Operating Mode")
print("---------------------")
print("1. Server Mode")
print("2. Client Mode")
mode = int(input("Enter mode of operation: "))
print("")
print("")
if mode in [1,2]:
break
else:
raise ValueError
except ValueError:
print("Enter either (1) for Server or (2) for Client")
if mode == 1:
server_thread.start()
elif mode == 2:
client_send()
main()
You need to make the arguments a tuple.
You should supply an extra comma after the argument list as in:
data_thread = threading.Thread(target=client_listen, args=(client_socket,))
The difference can be seen when you look into the types of both:
>>> type((client_socket))
<class 'socket._socketobject'>
>>> type((client_socket,))
<type 'tuple'>

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.

Python Networked Chat

I was working on a networked chat by following a tutorial. I have two modules, chatServer.py3 and chatClient.py3. On starting the server and then a client and attempting to send a message I get the following error:
Traceback (most recent call last): File "chatClient.py3", line 49,
in <module>
Main() File "chatClient.py3", line 38, in Main
s.sendto(alias+": "+message, server)
socket.error: [Errno 57] Socket is not connected
Please keep in mind that I am a rookie and therefore I would appreciate if the solutions along with their explanations were simplistic.
chatClient.py3
import socket, time, threading
tLock = threading.Lock()
shutdown = False
def recieveing(name,sock):
locked = False
while not shutdown:
try:
tLock.aquire()
locked = True
while True:
data , addr = sock.recv(1024)
print str(data)
except:
pass
finally:
if locked:
tLock.release()
def Main():
host = '127.0.0.1'
port = 0
server = ('127.0.0.1', 5000)
s = socket.socket()
s.bind((host,port))
s.setblocking(0)
rT = threading.Thread(target=recieveing,args=("RecivedThread",s))
rT.start()
alias = raw_input("Name: ")
message = raw_input(alias+"-> ")
while message != "q":
if message != "":
s.sendto(alias+": "+message, server)
tLock.aquire()
message = raw_input(alias+"-> ")
tLock.release()
time.sleep(0.2)
shutdown = True
rT.join()
s.close()
if __name__ == '__main__':
Main()
chatServer.py3
import socket,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()
You don't need to bind your client to the host and port. The bind command defines where the server needs to listen. The client needs to connect to the server. Like this:
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
server = ('127.0.0.1', 5000)
s.connect(server)

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