I'm stuck on this socket communication, I've looked everywhere but I haven't found an answer yet.
THE PROBLEM: I can only send 1 message from the client before it either gives me an error or ends the script.
I need to be able to send multiple messages to the server.
The server side (shown below) should be fine:
# Echo server program
import socket
import time
import os
#-----------------------------------------------------------------------------------------------------------------------
today = time.strftime('%Y.%m.%d')
logFileName = "log - " + today + ".txt"
HOST = '10.0.0.16'
PORT = 8080 # Reserve a port for your service
BUFFER_SIZE = 1024
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) # Create a socket object
s.bind((HOST, PORT)) # Bind to the port
def print_write(text):
log.write(time.strftime("%H:%M:%S") + " | " + text)
log.write("\n")
print text
#-----------------------------------------------------------------------------------------------------------------------
if os.path.isfile(logFileName) is True:
log = open(logFileName, 'a+')
print_write("[SERVER] Log for " + today + " already exists.")
print_write("[SERVER] Starting comms")
else:
print "[SERVER] Log doesn't exist"
log = open(logFileName, 'a+') # Create file -> log - %date%.txt
print_write("[SERVER] Log created")
while True:
s.listen(1)
conn, addr = s.accept()
data = conn.recv(BUFFER_SIZE)
if data == "Comms Shutdown":
print_write("------ REMOTE SHUTDOWN ------")
conn.close()
raise SystemExit
else:
print_write("[COMMS] " + str(addr) + " says: " + data)
log.close()
Sorry if it's very messy and confusing but i don't have much time to finish this project, if you have any question just ask.
For the client side I don't have much but here, I'll give you this:
import socket
HOST = '10.0.0.16' # The remote host
PORT = 8080 # The same port as used by the server
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
while True:
msg = raw_input()
s.sendall(msg)
print msg
I know it doesn't work, it's just to give you an idea of what I need.
Thank you in advance.
The problem is, that you only read the first message from each open connection before moving on to the next. The accept() methods waits for a new connection and gives you the information needed when a new one comes in. the recv() method on the other hand, receives data from a existing connection and waits if there is none. If you want to receive multiple messages from a single client, you can just wait for the first connection and then wait for data with recv(). This could look like this:
s.listen(1)
conn, addr = s.accept()
while True:
data = conn.recv(BUFFER_SIZE)
if data == "Comms Shutdown":
print_write("------ REMOTE SHUTDOWN ------")
conn.close()
raise SystemExit
else:
print_write("[COMMS] " + str(addr) + " says: " + data)
If you want to be able to also manage multiple clients, you will have to create a thread for each one from a while loop waiting for new connections. This is a bit more complicated:
def client_handler(conn):
while True:
data = conn.recv(BUFFER_SIZE)
if data == "Comms Shutdown":
print_write("------ REMOTE SHUTDOWN ------")
conn.close()
raise SystemExit
# this will kill the server (remove the line above if you don't want that)
else:
print_write("[COMMS] " + str(addr) + " says: " + data)
while True:
s.listen(1)
conn, addr = s.accept()
recv_thread = threading.Thread(target=client_handler, args=(conn, ))
recv_thread.start()
All this code is untested. Be aware, that I omitted the logging part and the socket creation part as well as all imports.
Related
I am working on Networking module,making connections with client ans server.
The Server code is as follows :
import socket
def Main():
host = '127.0.0.1'
port = 5000
s = socket.socket()
s.bind((host,port))
s.listen(1)
c, addr = s.connect()
print "Connection from: " + str(addr)
while True:
data = c.recv(1024)
if not data:
break
print "from connected user: " + str(data)
data = str(data).upper()
print "sending: " + str(data)
c.send(data)
c.close()
if __name__ == '__main__':
Main()
The Client code is as follows:
import socket
def Main():
host = '127.0.0.1'
port = 5000
s = socket.socket()
s.connect((host, port))
message = raw_input("-> ")
while message != 'q':
s.send(message)
data = s.recv(1024)
print 'Received from server: ' + str(data)
message = raw_input("-> ")
s.close()
if __name__ == '__main__':
Main()
But not able to execute the program successfully, gives the error address already in use.
Use the command netstat -nlp and find out the above mentioned port in the list.You will find the same port and the corrosponding PID also, either kill that process by kill -9 or you can go to your respective code and change the port number.
Secondly,it's preferrable to use localhost instead of '127.0.0.1'.
And there's an issue in your server code as well, instead of this statement 'c, addr = s.connect()' you need to write this one ' c, addr = s.connect()'.You need too accept the incoming connection and then connect with it.You are missing the acceptance of incoming connection.
I am creating a simple chat in python 3 using socket
here are the code
CLIENT
#!/bin/python
import socket
import threading
import time
tLock = threading.Lock()
poweroff = False
def receving(name, sock):
while not poweroff:
try:
tLock.acquire()
while True:
data, addr = sock.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("Username: ")
time.sleep(0.2)
message = input(alias + ">>> ")
while message != 'q':
if message != "":
s.sendto(str(alias + ": " + message).encode('utf-8'), server)
tLock.acquire()
message = input(alias + ">>> ")
tLock.release()
time.sleep(0.2)
poweroff = True
rT.join()
s.close()
SERVER
#!/bin/python
import socket
import time
hostname = '127.0.0.1'
port = 5000
clients = []
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s.bind((hostname, port))
s.setblocking(0)
iQuit = False
print ("Server Started.")
while not iQuit:
try:
data, addr = s.recvfrom(1024)
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()
How do i print a string to the server when a user connect?
I have tried to add this string after you have insert the name
s.sendto(str(alias + " Connected").encode('utf-8'), server)
but the output is orrible for me
Another Question:
Why i get something like this when seding a message?
Username: User_A
User_A>>> Hello
User_A>>> How Are you?
b'User:A: Hello'
User_A>>>
b'User_A: How Are you?'
b'User_B: Hi'
Concerning your second question: You are printing binary strings, see here for more information.
Use str(data.decode('utf-8')) instead of str(data) when printing the message on the server or the client.
Concerning the first question: This should work if you send the "Connected" string just after asking for the user name.
The string is decoded the same way as a common message if you include the decode('utf-8') and looks normal to me.
i have to press enter to see if user_B send something to me.
You enforced this behavior by locking out the receiving thread during the input of a message. You have to make up your mind whether you want this or want incoming data to be printed while typing.
You might want to cf. Simultaneous input and output for network based messaging program.
Here is my server code.
# chat_server.py
import sys, socket, select
HOST = ''
SOCKET_LIST = []
RECV_BUFFER = 4096
PORT = 9009
def chat_server():
server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server_socket.bind((HOST, PORT))
server_socket.listen(10)
# add server socket object to the list of readable connections
SOCKET_LIST.append(server_socket)
print "Chat server started on port " + str(PORT)
while 1:
# get the list sockets which are ready to be read through select
# 4th arg, time_out = 0 : poll and never block
ready_to_read,ready_to_write,in_error = select.select(SOCKET_LIST,[],[],0)
for sock in ready_to_read:
# a new connection request recieved
if sock == server_socket:
sockfd, addr = server_socket.accept()
SOCKET_LIST.append(sockfd)
print "Client (%s, %s) connected" % addr
broadcast(server_socket, sockfd, "[%s:%s] entered our chatting room\n" % addr)
# a message from a client, not a new connection
else:
# process data recieved from client,
try:
# receiving data from the socket.
data = sock.recv(RECV_BUFFER)
if data:
# there is something in the socket
broadcast(server_socket, sock, "\r" + '[' + str(sock.getpeername()) + '] ' + data)
else:
# remove the socket that's broken
if sock in SOCKET_LIST:
SOCKET_LIST.remove(sock)
# at this stage, no data means probably the connection has been broken
broadcast(server_socket, sock, "Client (%s, %s) is offline\n" % addr)
# exception
except:
broadcast(server_socket, sock, "Client (%s, %s) is offline\n" % addr)
continue
server_socket.close()
# broadcast chat messages to all connected clients
def broadcast (server_socket, sock, message):
for socket in SOCKET_LIST:
# send the message only to peer
if socket != server_socket and socket != sock :
try :
socket.send(message)
except :
# broken socket connection
socket.close()
# broken socket, remove it
if socket in SOCKET_LIST:
SOCKET_LIST.remove(socket)
if __name__ == "__main__":
sys.exit(chat_server())
Here is my client code.
# chat_client.py
import sys, socket, select
def chat_client():
if(len(sys.argv) < 3) :
print 'Usage : python chat_client.py hostname port'
sys.exit()
host = sys.argv[1]
port = int(sys.argv[2])
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.settimeout(2)
# connect to remote host
try :
s.connect((host, port))
except :
print 'Unable to connect'
sys.exit()
# TEST
person = raw_input ('Please enter your username: ')
print 'Connected to remote host. You can start sending messages.'
sys.stdout.write( person + '[Me]: ' ); sys.stdout.flush()
while 1:
socket_list = [sys.stdin, s]
# Get the list sockets which are readable
read_sockets, write_sockets, error_sockets = select.select(socket_list , [], [])
for sock in read_sockets:
if sock == s:
# incoming message from remote server, s
data = sock.recv(4096)
if not data :
print '\nDisconnected from chat server'
sys.exit()
else :
#print data
sys.stdout.write(data)
sys.stdout.write( person + '[Me]: '); sys.stdout.flush()
else :
# user entered a message
msg = sys.stdin.readline()
s.send(msg)
sys.stdout.write( person + '[Me]: '); sys.stdout.flush()
if __name__ == "__main__":
sys.exit(chat_client())
I'm currently trying to work on adding sort of a "handle" system into the chat client. If you were to run this code, you'll notice that the handle you choose is only displayed on your client, and not anybody else's. I've done hours of research already, and I can't for the life of me figure out how to have a client's chosen handle displayed onto other clients.
I'm still relatively new to Python, and especially new to TCP/IP programming. Any help, advice, and constructive criticism will be welcomed. Thanks in advance!
You can do it on the server or the client side
Server side
To implement it server side, you need to maintain some kind of mapping in the server between client sockets and handles, so that when you broadcast a message from a socket, you can retrieve its handle and prepend it to the message before sending.
In order to know the handle of the clients, they can send it to the server as the first message when they connect. The server will interpret this first message as the handle, and store it mapping it to the socket from what it has been received.
The advantage of this approach is that the server can validate the handle before it accepts it from the clients, and if it is already in use, reject the handle or abort the connection. Also, the clients cannot fake their handle later in the conversation, as it is the server that sends them.
Client side
This is the easiest implementation, as you only need to modify the client and prepend the handle before sending each message.
# user entered a message
msg = sys.stdin.readline()
s.send(person + ": " + msg)
sys.stdout.write( person + '[Me]: '); sys.stdout.flush()
The drawbacks of this approach are that a malicious client can fake the handle to pretend to be another person, and that two clients can have the same handle at the same time, making them indistinguishable from each other.
First as a disclaimer: I'm not the greatest at Python(or programming in general).
Having said that, I am having issues with Python Sockets. I am trying to build a simple chat client/server program, however, I am unable to have the server send the corresponding message(s) received from one client's socket, to the rest of the connected clients.
Here is the server code:
#!/usr/bin/python
import socket
import fnmatch
import thread
serverSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
## Allow socket to be reused by application - doesn't force timeout.
serverSocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
host = socket.gethostname()
port = 9000
serverSocket.bind((host,port))
connectedUsers = []
serverSocket.listen(5)
def threadedClient(clientStream):
while True:
clientMessage = clientStream.recv(1024).decode()
print clientMessage
if "Username:" in clientMessage:
username = clientMessage.replace("Username:","")
print str(username) + " has connected!"
connectedUsers.append(clientAddress)
print str(username) + "" + str(clientAddress) + " has connected to server"
for users in connectedUsers:
clientStream.sendto(str(username) + " has connected!", users)
if "Text:" in clientMessage:
receievedText = clientMessage.replace("Text:","")
for users in connectedUsers:
clientStream.sendto(receievedText.encode(), users)
print "Sending message " + str(receievedText) +" to:" + str(users)
if not clientMessage:
break
while True:
clientStream, clientAddress = serverSocket.accept()
thread.start_new_thread(threadedClient,(clientStream,))
Here is the client code:
#!/usr/bin/python
import socket
clientSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = "127.0.0.1"
port = 9000
username = raw_input("Please enter username: ")
clientSocket.connect((host, port))
clientSocket.send("Username:" + username)
def receiveServerMessage():
serverMessage = clientSocket.recv(1024).decode()
print serverMessage + '\n'
while True:
receiveServerMessage()
command = raw_input(username + " > ")
if command != None:
clientSocket.send("Text:" + str.encode(command))
if command == str("q"):
exit()
clientSocket.close()
The iteration seems to be awry when attempting to send the message to the other connected clients. I'm not sure if "sendto" is the proper way of handling this situation...especially since I believe it is UDP based. Any suggestions on how to handle socket stream correctly?
the problem is that the client is listening to the keyboard input before listening to the server socket , the best way to solve this is by using select() which similar to select() in c
here is a good example https://pymotw.com/2/select/
I have a server program that can maintain connection with multiple clients. I want to be able to close the socket in response to the message CLOSE by client, or for some other reason. The problem is that the server is stuck on the accept() method and does not care if I close the socket in some other place.
I can use some flag in the main server while, and close the socket after this while, however that means I will have to connect to the server myself after the client request, in order for the while condition to be checked, which smells like really terrible programming.
The code:
import socket
import sys
from thread import *
HOST = '' # Symbolic name meaning all available interfaces
PORT = 9992 # Arbitrary non-privileged port
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print 'Socket created'
#Bind socket to local host and port
try:
s.bind((HOST, PORT))
except socket.error , msg:
print 'Bind failed. Error Code : ' + str(msg[0]) + ' Message ' + msg[1]
sys.exit()
print 'Socket bind complete'
#Start listening on socket
s.listen(10)
print 'Socket now listening'
#Function for handling connections. This will be used to create threads
def clientthread(conn):
#Sending message to connected client
conn.send('Welcome to the server. Type something and hit enter\r\n') #send only takes string
data=''
#infinite loop so that function do not terminate and thread do not end.
while True:
#Receiving from client
data += conn.recv(1024)
print data
if data == 'CLOSE':
global s
conn.sendall('You have requested to destroy the connection...')
conn.close()
s.close()
return
if data.find('\n') != -1:
conn.sendall('OK...' + data + '\r\n')
data=''
#now keep talking with the client
while 1:
#wait to accept a connection - blocking call
try:
conn, addr = s.accept()
print 'Connected with ' + addr[0] + ':' + str(addr[1])
#start new thread takes 1st argument as a function name to be run, second is the tuple of arguments to the function.
start_new_thread(clientthread ,(conn,))
except:
print 'socket issue sorry'
break