Python Problem With sockets

Question

Hy, i'm try to create a simple Telnet Server in python, but the server receve just one command send by Client... Code:

from socket import *
server = socket(AF_INET, SOCK_STREAM)
server.bind((gethostname(), 23))
server.listen(5)
while 1:
 (connection, address) = server.accept()
 data = connection.recv(1024)
 print data
 if data=='X':
 break 
connection.close()

Answer 1

Taking the server.accept outside the while loop will allow your client to send in more commands:

from socket import *
server = socket(AF_INET, SOCK_STREAM)
server.bind((gethostname(), 23))
server.listen(5)
(connection, address) = server.accept()
while 1:
 data = connection.recv(1024)
 print data
 if data=='X':
 break 
connection.close()

There are a couple more problems with this: your server will only allow one client. As long as that one client is connected, no other client can connect. You can solve this by using threads (which can be tricky to get right), or using the select module.

And telnet sends newlines, so data will never be 'X'. You can check with if data.strip() == 'X':

Also, if your client disconnects, data will be an empty string. So you may want to add the additional check too:

if not data:
 break

Answer 2

After receiving a bunch of data you print it out and then accept a new client. So the old client's socket is not used anymore.

Answer 3

Once you read data into data variable, you print it then, if data is different from 'X', connection goes out of scope and it is closed.

You need to store that connection somewhere and close it when you really need to (I guess when client sends in 'exit'...).

• The Psicopath: yes, but if the Client send "aaa" the Server get the message and print it and the server dont close the connection!! after the client send "www" the Server dont print any message!! but the connection remains active!!