I am building a simple Python server than will receive data from the client and print it on screen. This is my code so far.
SERVER CODE:
import socket
def server(interface, port):
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind((interface, port))
sock.listen(1)
print('Listening at', sock.getsockname())
while True:
sc, sockname = sock.accept()
print('We have accepted a connection from', sockname)
print(' Socket name:', sc.getsockname())
print(' Socket peer:', sc.getpeername())
if __name__ == '__main__':
server('0.0.0.0', 8000)
CLIENT CODE:
import socket
def client(host, port):
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((host, port))
print('Client has been assigned socket name', sock.getsockname())
if __name__ == '__main__':
client('localhost', 8000)
No matter how I tried to send data from the client to the server, it always errored out saying:
Transport endpoint is not connected.
Try Using 127.0.0.1 or 192.168.1.X(your private ip which you can find by using ipconfigin cmd) instead of localhost, this worked for me
Related
I have a simple echo server that echos back whatever it receives. This works well for a single client request.
# echo-server.py
import socket
HOST = "127.0.0.1"
PORT = 65432
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:
try:
data = conn.recv(1024)
except KeyboardInterrupt:
print ("KeyboardInterrupt exception captured")
exit(0)
conn.sendall(data)
# echo-client.py
import socket
HOST = "127.0.0.1" # The server's hostname or IP address
PORT = 65432 # 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}")
However, if I finish one client request, and do a second client request, the server no more echoes back. How can I solve this issue?
(base) root#40029e6c3f36:/mnt/pwd# python echo-client.py
Received b'Hello, world'
(base) root#40029e6c3f36:/mnt/pwd# python echo-client.py
On the server side, you need to accept connections in an infinite loop. This should work.
server.py
HOST = "127.0.0.1"
PORT = 65432
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind((HOST, PORT))
s.listen()
while True:
conn, addr = s.accept()
print(f"Connected by {addr}")
try:
data = conn.recv(1024)
except KeyboardInterrupt:
print ("KeyboardInterrupt exception captured")
exit(0)
conn.sendall(data)
So I was trying to figure out a way to use sockets to make a terminal-based chat application, and I managed to do it quite well. Because I could only test it on one computer, I didn't realize that it might not work on different computers. My code is as simple as this:
# Server
import socket
HOST = "0.0.0.0"
PORT = 5555
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind((HOST, PORT))
s.listen()
while True:
conn, addr = s.accept()
with conn:
print("Connected to", addr)
data = conn.recv(1024)
print("Received:", data.decode())
conn.sendall(data)
# Client
import socket
HOST = "192.168.0.14"
PORT = 5555
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.connect((HOST, PORT))
s.sendall(b"Hello this is a connection")
data = s.recv(1024)
print("Received:", data.decode())
I've tried changing the ip to 0.0.0.0, use gethostname a lot of other things, but it just doesn't work. The server is up and running, but the client can't connect. Can someone help me?
I believe that 0.0.0.0 means connect from anywhere which means that you have to allow port 5555 through your firewall.
Instead of 0.0.0.0 use localhost as the address in both the client and the server.
I just tested your code using localhost for the server and the client and your program worked.
server:
Connected to ('127.0.0.1', 53850)
Received: Hello this is a connection
client:
Received: Hello this is a connection
As you can see, all that I changed was the address on both the server and the client. If this doesn't work then there is something outside of your program that is preventing you from success. It could be a permissions issue or another program is listening on port 5555.
server.py
# Server
import socket
HOST = "0.0.0.0"
HOST = "localhost"
PORT = 5555
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.bind((HOST, PORT))
s.listen()
while True:
conn, addr = s.accept()
with conn:
print("Connected to", addr)
data = conn.recv(1024)
print("Received:", data.decode())
conn.sendall(data)
if __name__ == '__main__':
pass
client.py
# Client
import socket
HOST = "localhost"
PORT = 5555
with socket.socket(socket.AF_INET, socket.SOCK_STREAM) as s:
s.connect((HOST, PORT))
s.sendall(b"Hello this is a connection")
data = s.recv(1024)
print("Received:", data.decode())
if __name__ == '__main__':
pass
So i want to build simple Server-Client.
This server gets connections from clients (simple string), do my stuff, return answer, close the client connection and wait for another connections.
Client
import socket
client = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
ip = '127.0.0.1'
port = 4500
address = (ip, port)
message = 'mymessage'
client = socket.socket()
client.connect(address)
client.sendall(message.encode('utf-8'))
Server
import socket
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
name = socket.gethostname()
ip = '127.0.0.1'
port = 4500
address = (ip, port)
server.bind(address)
server.listen(1)
print('Start listening on', ip, ':', port)
client, addr = server.accept()
print('Received connection from', addr[0], ':', addr[1])
while True:
data = client.recv(1024).decode('utf-8')
print('Received', data, 'from the client')
# DO something.....
client.send('Goodbye'.encode('utf-8'))
client.close()
break
So currently after the client get back the response from the server the server is close and i want my server to continue listening for another connections.
Simple, you need to add another loop, so that the server can always listen:
Server
import socket
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
name = socket.gethostname()
ip = '127.0.0.1'
port = 4500
address = (ip, port)
server.bind(address)
server.listen(1)
while True:
client, addr = server.accept()
print('Start listening on', ip, ':', port)
print('Received connection from', addr[0], ':', addr[1])
while True:
data = client.recv(1024).decode('utf-8')
print('Received', data, 'from the client')
# DO something.....
client.send('Goodbye'.encode('utf-8'))
client.close()
break
I am attempting to connect a simple server and client from two computers on the same network. Both the client and server cannot 'find' each other, as they do not move past .connect() and .accept() respectively. What am I doing wrong?
(Windows 10)
Server:
import socket
HOST = socket.gethostname() #Returns: "WASS104983"
#I have also tried socket.gethostbyname(socket.gethostname)), returning: "25.38.252.147"
PORT = 50007
sock = socket.socket()
sock.bind((HOST, PORT))
sock.listen(5)
print("Awaiting connection... ")
(clnt, addr) = sock.accept()
print("Client connected")
…
and Client:
import socket
HOST = "WASS104983" #Or "25.38.252.147", depending on the servers setup
PORT = 50007
sock = socket.socket()
print("Attempting connection... ")
sock.connect((HOST, PORT))
print("Connected")
…
I have gotten this to work before so I am not sure why it's not now.
I know there are a few questions of this calibre, but none seem to cover my problem.
Also, a wifi extender should not interfere with local transmissions should it?
I have always seen servers setup as such:
import socket
import threading
bind_ip = '0.0.0.0'
bind_port = 9999
server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server.bind((bind_ip, bind_port))
server.listen(5)
print("[*] Listening on {}:{}".format(bind_ip, bind_port))
def handle_client(client_socket):
request = client_socket.recv(1024)
print('received: {}'.format(request))
client_socket.send(b'ACK!')
client_socket.close()
while True:
client, addr = server.accept()
print("[*] Accepted connection from: {}:{}".format(addr[0], addr[1]))
client_handler = threading.Thread(target=handle_client, args=(client,))
client_handler.start()*
Where I think an important distinction from your post may be that the server accepting connections is within an infinite loop. Have you tried this?
Im writing a simple socket program to receive some data and reverse the contents.
When I pass the reversed contents its not being sent..
Server
import socket
s = socket.socket()
host = socket.gethostname()
port = 1234
s.bind((host, port))
s.listen(5)
while True:
c, addr = s.accept()
print('Got connection from', addr)
print('Received message == ',c.recv(50))
s = c.recv(50)[::-1]
c.send(s)
c.close()
client
import socket
from time import sleep
s = socket.socket()
host = socket.gethostname()
port = 1234
s.connect((host, port))
print "Sending data"
s.sendall("Hello!! How are you")
print(s.recv(1024))
The problem is two lines in your server
Your server calls recv() inside a print statement. This empties the buffer. Then you call recv() again, but it is already emptied by the previous statement and so it then blocks.
You need to call recv() and store that in s. Then use s everywhere else.
Try this for your server:
import socket
s = socket.socket()
host = socket.gethostname()
port = 1234
s.bind((host, port))
s.listen(5)
while True:
c, addr = s.accept()
print('Got connection from', addr)
s = c.recv(50)
print('Received message == ',s)
c.send(s)
c.close()