I make client-sever app. It look like this:
client
import socket
host = '127.0.0.1'
port = 1338
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
while True:
st = input("Your message: ")
byt = st.encode()
s.send(byt)
server
import socket
host = ''
port = 1338
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host, port))
while True:
s.listen(5)
conn, addr = s.accept()
data = conn.recv(2000)
print(data.decode())
Problem is that only first message is display. How can I solve this problem?
The server receives data only once after accepting a connection from the client. In-order to receive continuously, you can have a while loop for receiving data from the client.
import socket
host = ''
port = 1338
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host, port))
while True:
s.listen(5)
conn, addr = s.accept()
condition = True
while condition:
data = conn.recv(2000)
if not data: break
print(data.decode())
So, the above code will receive data as long the user provides data. You can separate the data receiving part in a separate thread too.
As you have the client's connect outside the loop, you have to place the server's listen and accept also outside the loop, since the connection is to be established only once.
Related
This code is for sending and receiving between my PC and AWS Instance
I want to know whether the transmitted data is considered secure? or do I need something else to ensure the security of the transmitted data?
If the data is not encrypted, what is the addition to the code to make it secure?
code's client
import socket
HOST = "public ip of server"
PORT = 4444 # The port used by the server
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.connect((HOST, PORT))
s.sendall(b"Hello, world")
data = s.recv(1024)
print(f"Received {data!r}")
server's code
server code
import socket
HOST = "0.0.0.0"
PORT = 4444 #open this in your router
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind((HOST, PORT))
s.listen()
conn, addr = s.accept()
with conn:
print(f"Connected by {addr}")
while True:
data = conn.recv(1024)
if not data:
break
conn.sendall(data)
Hi guys i cant figure out why socket server sends me second message with the third one at the same time. However I want to get message one by one not together at the same time. How can i do this?
Server code:
import socket
host = socket.gethostbyname(socket.gethostname())
port = 5000
ADDR = (host, port)
s = socket.socket(socket.AF_INET,
socket.SOCK_STREAM)
s.bind(ADDR)
s.listen()
c, addr = s.accept()
c.send(b'7:S ACK:4,')
c.send(b'11:S END:kSfdy,')
c.send(b'8:S 120794,')
Client code:
import socket
HOST = '192.168.1.54' # The server's hostname or IP address
PORT = 5000
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
print(s.recv(1024))
print(s.recv(1024))
print(s.recv(1024)) #empty message
I have this code create a simple socket server Python.But it closes down each time client disconnect, how to I make it run forever?
import socket
HOST = ''
PORT = 8000
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
with conn:
print('Connected by', addr)
while True:
data = conn.recv(1024)
print(data)
conn.sendall('HelloClient'.encode())
if not data:
continue
If you want run forever just add a while True loop and accept the connections inside the loop.
See here for an example.
A simple demo of socket programming in python:
server.py
import socket
host = '127.0.0.1'
port = 8000
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host, port))
s.listen(1)
conn, addr = s.accept()
while True:
data = conn.recv(1024)
print 'Received:', data
if not data:
break
conn.sendall(data)
print 'Sent:', data
conn.close()
client.py
import socket
host = '127.0.0.1'
port = 8000
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
s.sendall('Hel')
s.sendall('lo world!')
print 'Received:', s.recv(1024)
s.close()
Now code work well. However, the client may not know if server will always send back every time. I tried symmetric code of while-loop in server.py
client_2.py
import socket
host = '127.0.0.1'
port = 8000
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((host, port))
s.sendall('Hel')
s.sendall('lo world!')
while True:
data = s.recv(1024)
if not data:
break
print 'Received:', data
s.close()
This code will block at
data = s.recv(1024)
But in server.py, if no data received, it will be blank string, and break from while-loop
Why it does not work for client? How can I do for same functionality without using timeout?
You can set a socket to non-blocking operation via socket.setblocking(false), which is equivalent to socket.settimeout(0). Solving this "without using timeout" is impossible.
Trying to create my first client-server application, I came across an error. This code is exactly the same as in the documentation, but I have problems.
Server:
import socket
HOST = 'localhost'
PORT = 9090
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print 'Connected by', addr
while True:
data = conn.recv(1024)
if not data: break
print data
conn.close()
Client:
import socket
HOST = 'localhost'
PORT = 9090
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.sendall('Hello, world')
s.close()
After execution, I don't see the message print Connected by, addr and print data in the server part.
I use Windows 7, Komodo Firewall (I tried to close the firewall, but it didn't solve the problem), Avast Antivirus, Python 2.7.
Very interesting, that there are no errors, but the output just doesn't work.
Also, my server application just freezes until the client connects to the server. Can this be solved just using threading?
Thanks in advance.
You need to accept() and print inside the loop. (or use two loops). I'm not very familiar with socket programming in Python but I'm guess it would look something like this. (completely untested!)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
while True:
conn, addr = s.accept()
print 'Connected by', addr
while True:
data = conn.recv(1024)
if not data:
break
print data
conn.close()
+1 to Cfreak. Basically what is happening with data is that it is getting assigned an empty string which causes the loop to break. So putting the print statement in the loop fixes the problem. Assuming you need to access that data after the loop terminates try something like
data = []
while True:
datum = conn.recv(1024)
data.append(datum)
if not datum: break
print " ".join(data)
Here is the code I am running and my computer, and it works
client
import socket
HOST = 'localhost'
PORT = 9090
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((HOST, PORT))
s.sendall('Hello, world')
s.close()
server
import socket
HOST = 'localhost'
PORT = 9090
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((HOST, PORT))
s.listen(1)
conn, addr = s.accept()
print 'Connected by', addr
data = []
while True:
datum = conn.recv(1024)
data.append(datum)
if not datum: break
print " ".join(data)
conn.close()
so I don't think it is a problem with your code... if you have a machine without a firewall/antivirus on it try the program on that machine.