I'm playing around with python lately and trying to learn how to build a python server, using TCP connections.
I have this code that runs a server...
import socket
from threading import *
import datetime
import time
serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = "localhost"
port = 8000
print (host)
print (port)
serversocket.bind((host, port))
class client(Thread):
def __init__(self, socket, address):
Thread.__init__(self)
self.sock = socket
self.addr = address
self.start()
def run(self):
while 1:
st = datetime.datetime.fromtimestamp(time.time()).strftime('%Y-%m-%d %H:%M:%S')
#cName =
print(self.sock.recv(1024).decode()+' sent # '+ st + ':' , self.sock.recv(1024).decode())
self.sock.send(b'Processing!')
serversocket.listen(5)
print ('server started and listening')
while 1:
clientsocket, address = serversocket.accept()
client(clientsocket, address)
And two of these client.py
import socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host ="localhost"
port =8000
cName = 'client 2' # or client 1
s.connect((host,port))
def ts(str):
s.sendall(cName.encode())
s.send('e'.encode())
data = ''
data = s.recv(1024).decode()
print (data)
while 2:
r = input('enter')
ts(s)
s.close ()
I want to know how to allow the server to count and keep track of how many times it recieves a message from both client 1 and client 2.
For example, if server starts at count of 0 (e.g. count = 0). And each time client 1 or client 2 sends back a message or in this case, hits enter, the count will go up (count += 1). If I call for a print(count), the output should be 1.
Thanks?
I think you can create a global variable (say count=0) in your first script (server script) and keep incrementing the value every time you receive the message from a client.
So your run method can become,
def run(self):
global count
while 1:
st = datetime.datetime.fromtimestamp(time.time()).strftime('%Y-%m-%d %H:%M:%S')
#cName =
print(self.sock.recv(1024).decode()+' sent # '+ st + ':' , self.sock.recv(1024).decode())
count += 1
self.sock.send(b'Processing!')
If you want the count to be client specific then create a dictionary of counts instead of a single integer and keep incrementing the respective integer on verifying some thing about a client.
Related
I'm trying to send the command from the server to the connected clients and trying to receive the response.
But connectionList[i].recv(2048) breaking the while loop. I want the server to ask for the "Enter the command" repeatedly. but the loop is not repeating once it's receiving the response from clients
Here is my code
import socket
import sys
from _thread import *
import threading
# Create a TCP/IP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Bind the socket to the port
host = socket.gethostname()
server_address = ("0.0.0.0", 8765)
sock.bind(server_address)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
#Listen for incoming connections
sock.listen(5)
print ("Waiting for connection...")
#Variable for the number of connections
numbOfConn = 0
ThreadCount = 0
#Name of list used for connections
addressList = []
connectionList = []
#Function that continuosly searches for connections
def clients(connectionList, addressList):
while True:
cmd=input("Enter input command:")
#for loop to send message to each
for i in range(0,numbOfConn):
connectionList[i].sendto(str.encode(cmd), addressList[i])
while True:
for i in range(0,numbOfConn):
response = connectionList[i].recv(2048)
#break
print("response")
if(response.decode('utf-8') =="done"):
print("Exiting the loop")
break
#connection.close()
while True:
#accept a connection
connection, address = sock.accept()
print ('Got connection from', address)
numbOfConn += 1
addressList.append((address))
connectionList.append((connection))
#Thread that calls the function: clients and stores them in a tuple called connection
start_new_thread(clients, (connectionList, addressList))
ThreadCount += 1
print('Thread Number: ' + str(ThreadCount))
sock.close()
could you please help me to find out the issue?
I am a beginner of socket programming using python. I am working on my course project. Part of my project requires sending and receiving UDP messages with different port. The server program called robot is provided and I need to write the client program called student which can interact with the robot. Thus, I cannot show all source code in the server program.
This is the part related to the UDP socket in the server program
############################################################################# phase 3
# Create a UDP socket to send and receive data
print ("Preparing to receive x...")
addr = (localhost, iUDPPortRobot)
s3 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s3.bind(addr)
x, addr = s3.recvfrom(1)
print ("Get x = %d" % (int(x)))
############################################################################# phase 3
time.sleep(1)
print ("Sending UDP packets:")
messageToTransmit = ""
for i in range(0,int(x) * 2):
messageToTransmit += str(random.randint(0,9999)).zfill(5)
print ("Message to transmit: " + messageToTransmit)
for i in range(0,5):
s3.sendto(messageToTransmit.encode(),(studentIP,iUDPPortStudent))
time.sleep(1)
print ("UDP packet %d sent" %(i+1))
############################################################################# phase 4
This is my client program. s3 is the UDP socket. I can send message to the server program successfully but I cannot receive the message from it. Is this due to the difference in the ports? If yes, what should I do in order to fix it?
import os
import subprocess
import socket
import random
import time
sendPort = 3310
localhost = '127.0.0.1'
socket.setdefaulttimeout(10)
command = "python robot_for_python_version_3.py"
subprocess.Popen(command)
print("ROBOT IS STARTED")
sendSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sendSocket.connect((localhost, sendPort))
studentId = '1155127379'
sendSocket.send(studentId.encode())
s_2Port = sendSocket.recv(5)
sendSocket.close()
s_2 = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s_2.bind((localhost, int(s_2Port)))
s_2.listen(5)
s2, address = s_2.accept()
s_2.close()
step4Port = s2.recv(12)
iUDPPortRobot, dummy1 = step4Port.decode().split(",")
iUDPPortStudent, dummy2 = dummy1.split(".")
s3 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
num = random.randint(5,10)
time.sleep(3)
s3.sendto(str(num).encode(), (localhost, int(iUDPPortRobot)))
print("Test1")
charStr = s3.recvfrom(1024)
print("Test2")
print(charStr)
exit()
The reason why you are not receiving the message is because the server sends it to an endpoint that is not listening for messages. As the protocol is UDP (no guarantees, etc.), the server sends the message successfully to a non-listening endpoint, while the listening endpoint waits forever.
In more detail, addr as returned by x, addr = s3.recvfrom(1) is not (studentIP, iUDPPortStudent). Try the following to see the difference (note that you have omitted the piece where iUDPPortRobot is defined and shared, I set it to 50000 for illustration purposes):
# in one interactive session 1 (terminal), let's call it session 1
>>> import socket
>>> import random
>>> import time
>>>
>>> iUDPPortRobot = 50000
>>> addr = ('localhost', iUDPPortRobot)
>>> s3 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
>>> s3.bind(addr)
>>> x, addr = s3.recvfrom(1) # <= this will block
# in another interactive session (terminal), let's call it session 2
>>> import socket
>>> import random
>>> import time
>>>
>>> iUDPPortRobot = 50000
>>> s3 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
>>> num = random.randint(5,10)
>>> s3.sendto(str(num).encode(), ('localhost', int(iUDPPortRobot))) # <= this will unblock recvfrom in session 1, i.e., the message got received
1
# back to session 1
>>> addr <= check address, this is the main issue you are facing
('127.0.0.1', 60911)
>>> messageToTransmit = ""
>>> for i in range(0,int(x) * 2):
... messageToTransmit += str(random.randint(0,9999)).zfill(5)
...
>>> print ("Message to transmit: " + messageToTransmit)
Message to transmit: 06729020860821106419048530205105224040360495103025
# back to session 2, let's prepare for receiving the message
>>> charStr = s3.recvfrom(1024) # <= this will block
# back to session 1 to send a message
# you do not share what (studentIP,iUDPPortStudent), but from
# what you describe it is not ('127.0.0.1', 60911), let's say
# studentIP = 'localhost' and iUDPPortStudent = 50001
>>> studentIP = 'localhost'
>>> iUDPPortStudent = 50001
# now let send a message that will be sent successfully but not received, i.e.,
# it will not unblock recvfrom in session 2
>>> s3.sendto(messageToTransmit.encode(),(studentIP,iUDPPortStudent))
50
# ... but if try to send to the listening endpoint it will get received
>>> s3.sendto(messageToTransmit.encode(), addr)
50
# back to session 2, to check things
>>> charStr
(b'06729020860821106419048530205105224040360495103025', ('127.0.0.1', 50000)) # <= SUCCESS
There are two ways to fix this. The one shown above which involves changing the server code, which essentially involves what is shown above, i.e., send the message to a listening endpoint by modifying the address passed to s3.sendto. If I understand things correctly, this is not an option as you are trying to write the client code. The second way is to send the message to (studentIP, iUDPPortStudent), but have a listening endpoint at the other end. If studentIP and iUDPPortStudent are known to your "client" program, which I assume is the case, you can add code similar to what you have at the top of the server program code snippet.
Specifically, add in place of charStr = s3.recvfrom(1024) something like:
addr = (studentIP, iUDPPortStudent)
s4 = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
s4.bind(addr)
charStr = s4.recvfrom(1024) # <= this will block and unblock when you send the message using s3.sendto(messageToTransmit.encode(),(studentIP,iUDPPortStudent))
For completeness, you will need to change localhost to 'localhost' and if in your experiments you encounter a OSError: [Errno 98] Address already in use you will have to wait for the TIME-WAIT period to pass or set the SO_REUSEADDR flag by adding s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) before bind.
I am having issue with below code in TCP python socket prog. I am trying to send integer messages from (lets say) 3 clients. So, There is 3 clients, so the proxy knows that N = 3, and it will wait until it receives 3 numbers. 1st client sends 10 to the proxy, 2nd client sends 20 to the proxy, and the 3rd client sends 30 to the proxy. Because N is reached, the proxy starts to transmit to the server. It will send (in order): 10, 20, 30, END (where every comma indicates a new message). The server receives the 4 messages, and after receiving the END message, it starts to calculate the average. The average is 20, so the server sends 20 to the proxy, and closes the connection. The proxy receives 20, and sends it to all the 3 clients, and then closes the connection. The clients receive 20.
Please check below code and let me know where I am making mistake... I am able to send number from client but not getting response from proxy/server. Am I doing any mistake ?
For client:
#!/usr/bin/env python
import socket
HOST = 'localhost'
PORT = 21001
proxysock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
proxysock.connect((HOST, PORT))
while True:
try:
data = str(raw_input())
except valueError:
print 'invalid number'
proxysock.sendall(data)
data = proxysock.recv(1024)
print 'server reply:' +data
proxysock.close()
For Proxy:
#!/usr/bin/env python
import select
import sys
import socket
from thread import *
HOST = 'localhost'
PORT = 21001
PORT1 = 22000
max_conn = 5
buffer_size = 2048
proxyserversock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
proxyserversock.bind((HOST, PORT))
proxyserversock.listen(max_conn)
input = [proxyserversock,sys.stdin]
running = 1
while running:
inputready,outputready,exceptready = select.select(input,[],[])
for proxysock in inputready:
if proxysock == proxyserversock:
client_sock, addr = proxyserversock.accept()
input.append(client_sock)
elif proxysock == sys.stdin:
junk = sys.stdin.readline()
running = 0
else:
data = proxysock.recv(buffer_size)
if data:
proxysock.send(data)
else:
proxysock.close()
input.remove(proxysock)
serversock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversock.connect((HOST, PORT1))
serversock.sendall(data,END)
serversock.recv(buffer_size)
client_sock.sendall()
serversock.close()
client_sock.close()
For Server:
#!/usr/bin/env python
import socket
HOST = 'localhost'
PORT1 = 22000
serversock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serversock.bind((HOST, PORT1))
serversock.listen(10)
while 1:
serversock, addr = serversock.accept()
data = serversock.recv(2048)
data.pop()
average = float(sum(data))/len(data)
serversock.sendall(average)
print 'avg' + average
serversock.close()
All my clients sockets do the same thing: send a package every second(22 bytes)
Server code as below:
import select
import socket
import datetime
SList = []
class Tserver:
def __init__(self, portNum):
host = '127.0.0.1'
self.server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
self.server.bind((host, portNum))
self.server.listen(1)
def GETPACK():
# function for CRC check
def CRC(DATA_STR):
return 1
# generate 100 sockets to listen
for x in range(100):
SList.append(Tserver(x+10000))
inputs = []
# put in inputs
for x in range(100):
inputs.append(SList[x].server)
while(True):
ready_socks, _, _ = select.select(inputs, [], [])
for sock in ready_socks:
c, addr = sock.accept()
while(True):
data = c.recv(22)
if len(data) == 22: # To make sure the data-length is 22
# Turn the pack string into bytearray
data_bytes = bytearray()
data_bytes.extend(data)
if CRC(data_bytes) == 1:
print "Connected from client IP Address:" + str(addr)
# ID
ID = 256*data_bytes[1] + data_bytes[2]
print "ID: ", ID
now = datetime.datetime.now()
print "now: ", str(now)
if __name__ == "__main__":
GETPACK()
My server can only print the packages sent by the first connected socket.
And my question is how to print out all message from each ports whenever a package is sent to the server.
See this PyMOTW entry for a detailed explanation of how to use the select module to write a select-based server.
The main differences between that example and your code are:
You just create one listening socket - server. There is no need to listen on multiple ports.
The variable inputs will be a list consisting of server and any other open socket connections to clients.
Your service loop will look like:
while true:
readable, _, _ = select.select(inputs, [], [])
for r in readable:
if r is server:
# handle a new incoming connection
# this will add an entry to the variable inputs
else:
# read some data from socket r and process it
When you attempt to read from a client socket and get an EOF condition, you can close that socket and remove it from the inputs variable.
#ErikR Thanks for your help, i changed my code, and it worked fine.
The reason that my code doesn't work was because of two things:
1.I only create one connection to recv data from my clients.
2.The same connection can't be accepted again for recv, if the clients does't reconnect.(my code doesn't check the exception when clients shutdown)
Code as below:
import select, socket, datetime
SList = []
SconnList = []
class Tserver:
def __init__(self, portNum):
host = '127.0.0.1'
self.server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR,1)
self.server.bind((host,portNum))
self.server.listen(1)
print "Server ports: "+str(portNum)
class Sconn:
def __init__(self, sock):
self.conn, self.addr = sock.accept()
def GETPACK():
# function for CRC check
def CRC(DATA_STR):
return 1
# generate 100 sockets to listen
for x in range(100):
SList.append(Tserver(x+10000))
inputs = []
# put in inputs
for x in range(100):
inputs.append(SList[x].server)
while(True):
ready_socks,_,_ = select.select(inputs, [], [])
for sock in ready_socks:
try:
SconnList.append(Sconn(sock))
SconnList.reverse()
inputs.append(SconnList[0].conn)
except:
data = sock.recv(22)
if len(data) == 22: # To make sure the data-length is 22
#Turn the pack string into bytearray
data_bytes = bytearray()
data_bytes.extend(data)
if CRC(data_bytes) == 1:
print "IP Address:" + str(sock.getsockname())
#ID
ID = 256*data_bytes[1] + data_bytes[2]
print "ID: ",ID
now = datetime.datetime.now()
print "now: ",str(now)
print ""
print ""
if __name__ == "__main__":
GETPACK()
I am trying to write a program that works as an intermedium. (M)
I can only use telnet to connect :
A needs to connect to M, B connects to M.
A sends data to M on a socket, M needs to pass it to B
B sends data to M on another socket
I tried this by starting four threads with a shared list
The problem is it seems it is not writing to the other socket, or even accepting writing.
Does anyone know a better way to implement this and pass it through to another socket
My code :
import sys
import arduinoReadThread
import arduinoWriteThread
import socket
class ControllerClass(object):
'''
classdocs
'''
bolt = 0
socketArray=list()
def __init__(self):
self.readAndParseArgv()
self.createThreads()
def readAndParseArgv(self):
array = sys.argv
print sys.argv
if len(array) != 3:
print "Too few arguments : ./script host:port host:port"
else:
for line in array:
if ":" in line:
splitted = line.split(':')
HOST = splitted[0]
print HOST
PORT = int(splitted[1])
print PORT
s=socket.socket(socket.AF_INET, socket.SOCK_STREAM ) #create an INET, STREAMing socket
s.bind((HOST,PORT)) #bind to that port
print "test"
s.listen(1) #listen for user input and accept 1 connection at a time.
self.socketArray.append(s)
def createThreads(self):
print "Creating Threads"
sharedArray1 = list()
sharedArray2 = list()
s1 = self.socketArray.pop()
s2 = self.socketArray.pop()
sT1 = arduinoWriteThread.writeThread().run(self.bolt,sharedArray1,s2)
sT2 = arduinoReadThread.readThread().run(self.bolt,sharedArray1,s1)
sT3 = arduinoReadThread.readThread().run(self.bolt,sharedArray2,s2)
sT4 = arduinoWriteThread.writeThread().run(self.bolt,sharedArray2,s1)
sT1.start()
sT2.start()
sT3.start()
sT4.start()
x = ControllerClass()
x
Two Threads :
Write Thread :
import threading
class writeThread ( threading.Thread ):
def run ( self,bolt,writeList,sockeToWriteTo ):
s = sockeToWriteTo
while(bolt == 0):
conn, addr = s.accept()
if len(writeList) > 0:
socket.send(writeList.pop(0))
Read Thread
import threading
class readThread ( threading.Thread ):
def run ( self,bolt,writeList,socketToReadFrom ):
s = socketToReadFrom
while(bolt == 0):
conn, addr = s.accept()
f = conn.rcv()
print f
writeList.append(f)
You don't really need threads for this...
When a new connection is accepted, add it to a list. When receiving anything from one of the connection in the list, send to all connections except the one you got the message from.
Use select to see which connections have send data to you.
Edit
Example using select:
# serversocket: One server socket listening on some port, has to be non-blocking
# all_sockets : List containing all connected client sockets
while True:
readset = [serversocket]
readset += all_sockets
# Wait for sockets to be ready, with a 0.1 second timeout
read_ready = select.select(readset, None, None, 0.1)
# If the listening socket can be read, it means it has a new connection
if serversocket in read_ready:
new_connection = serversocket.accept()
new_connection.setblocking(0); # Make socket non-blocking
all_sockets += [new_connection]
read_ready.remove(serversocket) # To not loop over it below
for socket in read_ready:
# Read data from socket
data = socket.recv(2048)
for s in all_sockets:
# Do not send to self
if s != socket:
s.send(data)
Disclaimer I have never really used the Python socket functions, the code above was made from reading the manual pages just now. The code is probably not optimal or very Pythonic either.