Develop Reference

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()

Getting TypeError: a bytes-like object is required, not 'str' when client starts

So when I run the client module, terminal sends back an error: "TypeError: a bytes-like object is required, not 'str'". I encoded the message sent by the client so i'm not sure what is wrong. Any help on figuring out the problem would be appreciated!
Here's my client.py:
import socket
def client_program():
host = socket.gethostname()
port = 5000
client_socket = socket.socket()
client_socket.connect((host, port))
message = input(" -> ")
while message.lower().strip() != 'bye':
client_socket.send(message.encode())
data = client_socket.recv(1024).decode()
print('Received from server: ' + data)
message = input(" -> ")
client_socket.close()
if __name__ == '__main__':
client_program()
Here's my server.py:
import socket
import sys
from _thread import start_new_thread
HOST = ''
PORT = 5000
try:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
except socket.error as msg:
print("Could not create socket. Error Code: ", str(msg[0]), "Error: ", msg[1])
sys.exit(0)
print("[-] Socket Created")
try:
s.bind((HOST, PORT))
print("[-] Socket Bound to port " + str(PORT))
except socket.error as msg:
print("Bind Failed. Error Code: {} Error: {}".format(str(msg[0]), msg[1]))
sys.exit()
s.listen(10)
print("Listening...")
def client_thread(conn):
conn.send("Welcome to the Server. Type messages and press enter to send.\n")
while True:
data = conn.recv(1024)
if not data:
break
reply = "OK . . " + data
conn.sendall(reply)
conn.close()
while True:
conn, addr = s.accept()
print("[-] Connected to " + addr[0] + ":" + str(addr[1]))
start_new_thread(client_thread, (conn,))
s.close()

How to send files in "chunks" by socket?

I'm trying to send a large file (.avi) over socket by sending the content of the file in chunks (a little bit like torrents). The problem is that the script doesn't send the file. I'm out of ideas here.
Any help or twerking of the script would be very appreciated.
Server:
import socket
HOST = ""
PORT = 8050
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind((HOST, PORT))
sock.listen(1)
conn, addr = sock.accept()
print("Connected by ", str(addr))
while 1:
data = conn.recv(1024)
if data.decode("utf-8") == 'GET':
with open(downFile,'rb') as output:
l = output.read(1024)
while (l):
conn.send(l)
l = output.read(1024)
output.close()
conn.close()
Client:
import socket
HOST = "localhost"
PORT = 8050
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((HOST,PORT))
while 1:
message = input()
sock.send(bytes(message,'UTF-8'))
conn.send(str.encode('GET'))
with open(downFile, 'wb+') as output:
while True:
rec = str(sock.recv(1024), "utf-8")
if not rec:
break
output.write(rec)
output.close()
print('Success!')
sock.close()

Here are a working client and server that should demonstrate transferring a file over a socket. I made some assumptions about what your code was supposed to do, for example, I assumed that the initial message the client sent to the server was supposed to be the name of the file to download.
The code also includes some additional functionality for the server to return an error message to the client. Before running the code, make sure the directory specified by DOWNLOAD_DIR exists.
Client:
import socket
import sys
import os
HOST = "localhost"
PORT = 8050
BUF_SIZE = 4096
DOWNLOAD_DIR = "downloads"
def download_file(s, down_file):
s.send(str.encode("GET\n" + down_file))
rec = s.recv(BUF_SIZE)
if not rec:
return "server closed connection"
if rec[:2].decode("utf-8") != 'OK':
return "server error: " + rec.decode("utf-8")
rec = rec[:2]
if DOWNLOAD_DIR:
down_file = os.path.join(DOWNLOAD_DIR, down_file)
with open(down_file, 'wb') as output:
if rec:
output.write(rec)
while True:
rec = s.recv(BUF_SIZE)
if not rec:
break
output.write(rec)
print('Success!')
return None
if DOWNLOAD_DIR and not os.path.isdir(DOWNLOAD_DIR):
print('no such directory "%s"' % (DOWNLOAD_DIR,), file=sys.stderr)
sys.exit(1)
while 1:
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
sock.connect((HOST, PORT))
except Exception as e:
print("cannot connect to server:", e, file=sys.stderr)
break
file_name = input("\nFile to get: ")
if not file_name:
sock.close()
break
err = download_file(sock, file_name)
if err:
print(err, file=sys.stderr)
sock.close()
Server:
import socket
import sys
import os
HOST = ""
PORT = 8050
BUF_SIZE = 4096
def recv_dl_file(conn):
data = conn.recv(1024)
if not data:
print("Client finished")
return None, None
# Get command and filename
try:
cmd, down_file = data.decode("utf-8").split("\n")
except:
return None, "cannot parse client request"
if cmd != 'GET':
return None, "unknown command: " + cmd
print(cmd, down_file)
if not os.path.isfile(down_file):
return None, 'no such file "%s"'%(down_file,)
return down_file, None
def send_file(conn):
down_file, err = recv_dl_file(conn)
if err:
print(err, file=sys.stderr)
conn.send(bytes(err, 'utf-8'))
return True
if not down_file:
return False # client all done
# Tell client it is OK to receive file
sent = conn.send(bytes('OK', 'utf-8'))
total_sent = 0
with open(down_file,'rb') as output:
while True:
data = output.read(BUF_SIZE)
if not data:
break
conn.sendall(data)
total_sent += len(data)
print("finished sending", total_sent, "bytes")
return True
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind((HOST, PORT))
sock.listen(1)
keep_going = 1
while keep_going:
conn, addr = sock.accept()
print("Connected by", str(addr))
keep_going = send_file(conn)
conn.close() # close clien connection
print()
sock.close() # close listener

How to implement iperf module for Bandwidth monitoring in this python chatroom?

https://iperf.fr/iperf-doc.php
https://iperf.fr/
//server.py
import socket
import select
import sys
from thread import *
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
if len(sys.argv) != 3:
print "Correct usage: script, IP address, port number"
exit()
IP_address = str(sys.argv[1])
Port = int(sys.argv[2])
server.bind((IP_address, Port))
server.listen(100)
list_of_clients = []
def clientthread(conn, addr):
conn.send("Welcome to this chatroom!")
while True:
try:
message = conn.recv(2048)
if message:
print "<" + addr[0] + "> " + message
message_to_send = "<" + addr[0] + "> " + message
broadcast(message_to_send, conn)
else:
remove(conn)
except:
continue
def broadcast(message, connection):
for clients in list_of_clients:
if clients!=connection:
try:
clients.send(message)
except:
clients.close()
remove(clients)
def remove(connection):
if connection in list_of_clients:
list_of_clients.remove(connection)
while True:
conn, addr = server.accept()
list_of_clients.append(conn)
print addr[0] + " connected"
start_new_thread(clientthread,(conn,addr))
conn.close()
server.close()
The client side script will simply attempt to access the server socket created at the specified IP address and port. Once it connects, it will continuously check as to whether the input comes from the server or from the client, and accordingly redirects output. If the input is from the server, it displays the message on the terminal. If the input is from the user, it sends the message that the users enters to the server for it to be broadcasted to other users.
//client.py
import socket
import select
import sys
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
if len(sys.argv) != 3:
print "Correct usage: script, IP address, port number"
exit()
IP_address = str(sys.argv[1])
Port = int(sys.argv[2])
server.connect((IP_address, Port))
while True:
sockets_list = [sys.stdin, server]
read_sockets,write_socket, error_socket = select.select(sockets_list,[],[])
for socks in read_sockets:
if socks == server:
message = socks.recv(2048)
print message
else:
message = sys.stdin.readline()
server.send(message)
sys.stdout.write("<You>")
sys.stdout.write(message)
sys.stdout.flush()
server.close()

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)