It's my client:
#CLIENT
import socket
conne = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
conne.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)
i=0
while True:
conne.connect ( ('127.0.0.1', 3001) )
if i==0:
conne.send(b"test")
i+=1
data = conne.recv(1024)
#print(data)
if data.decode("utf-8")=="0":
name = input("Write your name:\n")
conne.send(bytes(name, "utf-8"))
else:
text = input("Write text:\n")
conne.send(bytes(text, "utf-8"))
conne.close()
It's my server:
#SERVER
import socket
counter=0
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.bind(('', 3001))
sock.listen(10)
while True:
conn, addr = sock.accept()
data = conn.recv(1024)
if len(data.decode("utf-8"))>0:
if counter==0:
conn.send(b"0")
counter+=1
else:
conn.send(b"1")
counter+=1
else:
break
print("Zero")
conn.send("Slava")
conn.close()
))
After starting Client.py i get this error:
Traceback (most recent call last): File "client.py", line 10, in
conne.connect ( ('127.0.0.1', 3001) ) OSError: [Errno 9] Bad file descriptor
Problem will be created just after first input.
This program - chat. Server is waiting for messages. Client is sending.
There are a number of problems with the code, however, to address the one related to the traceback, a socket can not be reused once the connection is closed, i.e. you can not call socket.connect() on a closed socket. Instead you need to create a new socket each time, so move the socket creation code into the loop:
import socket
i=0
while True:
conne = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
conne.connect(('127.0.0.1', 3001))
...
Setting socket option SO_BROADCAST on a stream socket has no affect so, unless you actually intended to use datagrams (UDP connection), you should remove the call to setsockopt().
At least one other problem is that the server closes the connection before the client sends the user's name to it. Probably there are other problems that you will find while debugging your code.
Check if 3001 port is still open.
You have given 'while True:' in the client script. Are you trying to connect to the server many times in an infinite loop?
Related
Simple client - server app.
#Server use decode
import socket
s = socket.socket()
host = socket.gethostname()
port = 12345
s.bind((host,port))
s.listen(5)
while True:
c,addr = s.accept()
print("Got connection from " + str(addr))
ret_val = s.send("Thank you".encode('utf-8'))
print ("ret_val={}".format(ret_val))
c.close()
Client:
#client use decode
from socket import gethostname, socket
serSocket = socket()
server = gethostname()
port = 12345
serSocket.connect((server, port))
data = serSocket.recv(1024)
msg = data.decode('utf-8')
print("Returned Msg from server: <{}>".format(msg))
serSocket.close()
when the server tries to send the following exception occurred
Traceback (most recent call last):
Got connection from ('192.168.177.1', 49755)
File "C:/Users/Oren/PycharmProjects/CientServer/ServerSide/Server2.py", line 16, in <module>
ret_val = s.send("Thank you".encode('utf-8'))
OSError: [WinError 10057] A request to send or receive data was disallowed because the socket is not connected and (when sending on a datagram socket using a sendto call) no address was supplied
Process finished with exit code 1
As can be seen the client connects the server successfully.
But send fails.
What is the problem?
The problem is that you are sending on the listening socket, not on the connected socket. connect returns a new socket which is the one you must use for data transfer. The listening socket can never be used for sending or receiving data.
Change the send to this and your program will work fine:
ret_val = c.send("Thank you".encode('utf-8'))
(Note c.send, not s.send)
I've got a simple client and server I found on an online tutorial
#server.py
import socket # Import socket module
s = socket.socket() # Create a socket object
host = 'localhost' # Get local machine name
port = 12345 # Reserve a port for your service.
s.bind((host, port)) # Bind to the port
s.listen(5) # Now wait for client connection.
while True:
c, addr = s.accept() # Establish connection with client.
print 'Got connection from', addr
c.send('Thank you for connecting')
c.close() # Close the connection
#client # This is client.py file
import socket # Import socket module
s = socket.socket() # Create a socket object
host = 'localhost'
port = 12345 # Reserve a port for your service.
s.connect((host, port))
print s.recv(1024)
s.close # Close the socket when done
When I run my client.py all it does is print an empty string when it should print ('Thank you for connecting'). When I connect localhost 12345 from telnet it sends the message fine so I don't know why my client isn't receiving the message
Any thoughts. I'm very new to socket programming and would love to find a solution so I can move on.
While running your script as is, I got this error:
Waiting connections ...
Got connection from ('127.0.0.1', 63875)
Traceback (most recent call last):
File "serv.py", line 14, in <module>
c.send('Thank you for connecting')
TypeError: a bytes-like object is required, not 'str'
Few things here:
Ensure you're sending bytes instead of str. you could do this by replacing line 14 with:
c.send(b'Thank you for connecting')
Also, it's always useful to declare your sockets s like this:
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
Further read:
Py2: https://docs.python.org/2/library/socket.html
Py3: https://docs.python.org/3/library/socket.html
Hope it works! :)
I need some help. I have a simple server:
host="localhost"
port=4447
from socket import *
import thread
def func():
while 1:
data = conn.recv(1024)
if not data:
continue
else:
print("%s said: %s")%(player, data)
conn.close()
s=socket(AF_INET, SOCK_STREAM)
s.bind((host,port))
s.listen(2)
print("Waiting for clients on localhost, port %s")%port
while 1:
conn, addr = s.accept()
player = addr[1]
print(conn)
thread.start_new_thread(func,())
And a simple client:
import socket
TCP_IP = '127.0.0.1'
TCP_PORT = 4447
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((TCP_IP, TCP_PORT))
while 1:
data = raw_input("Input: ")
s.send(data)
So when I connect to the server I can type anything and it is printed in the server's terminal. When I open another terminal and start second client I can also type anything and it is sent to the server, but when I go back to the first client's terminal and type several messages, it returns:
Traceback (most recent call last):
File "Client.py", line 18, in <module>
s.send(data)
socket.error: [Errno 32] Broken pipe
So I fixed that with adding conn as a parameter in func(), but I don't understand why this error happened? Could anyone please explain it to me?
Thanks!
Your func, apart from needing a better name, uses global state in your program to communicate with a client. No matter how many threads you start to handle client connections, there's still only one global conn variable. Each time a new client connects, your main thread loop rebinds conn to the new connection. The old socket is thrown away and automatically closed by the Python runtime.
You can fix this by removing the use of global variables to track per-connection state. A better route to explore, though, is Twisted.
My socket program hangs at clientsocket, address) = serversocket.accept() and doesn't spit our an error or anything.
I followed directions on https://docs.python.org/3/howto/sockets.html
I've been trying to figure it out for an hour now, but to no avail. I'm using python3 btw. What am i doing wrong? EDIT: My intedentation is all screwed up because I pasted it wrong, but other than that my code is as I have it in my file.
#import socket module
import socket
#creates an inet streaming socket.
serversocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
print('socket created')
#binds socket to a public host, and a well known port
serversocket.bind(('127.0.0.1', 1024))
#print(socket.gethostname())# on desktop prints 'myname-PC')
#become a server socket
serversocket.listen(5) # listens for up to 5 requests
while True:
#accept connections from outside
#print('In while true loop') This works, but we never get to the next print statement. Why the hell is it catching at line 20?
(clientsocket, address) = serversocket.accept()
#clientsocket = serversocket.accept()
print('Ready to serve')
#now we do something with client socket...
try:
message = clientsocket.recv(1024)
filename = message.split()[1]
f = open(filename[1:])
outputdata = f.read()
#send an http header line
clientsocket.send('HTTP/1.1 200 OK\nContent-Type: text/html\n\n')
for i in range(0, len(outputdata)):
clientsocket.send(outputdata[i])
clientsocket.close()
except IOERROR:
clientsocket.send('HTTP/1.1 404 File not found!')
clientsocket.close()
If you haven't written a client script / program to connect to the socket and send it data, it's also going to hang on serversocket.accept() due to there being nothing to accept. But assuming you have...
while True:
#accept connections from outside
#print('In while true loop') This works, but we never get to the next print statement. Why the hell is it catching at line 20?
(clientsocket, address) = serversocket.accept()
#clientsocket = serversocket.accept()
It hangs because the loop never exits due to True always being True. In the example provided, once a connection is accepted they pretend that the server is threaded and the idea is to create a separate thread to begin reading and processing data received allowing the socket to continue to listen for more connections.
while True:
# accept connections from outside
(clientsocket, address) = serversocket.accept()
# now do something with the clientsocket
# in this case, we'll pretend this is a threaded server
ct = client_thread(clientsocket)
ct.run()
I'm working on a bit of a project in python. I have a client and a server. The server listens for connections and once a connection is received it waits for input from the client. The idea is that the client can connect to the server and execute system commands such as ls and cat. This is my server code:
import sys, os, socket
host = ''
port = 50105
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((host, port))
print("Server started on port: ", port)
s.listen(5)
print("Server listening\n")
conn, addr = s.accept()
print 'New connection from ', addr
while (1):
rc = conn.recv(5)
pipe = os.popen(rc)
rl = pipe.readlines()
file = conn.makefile('w', 0)
file.writelines(rl[:-1])
file.close()
conn.close()
And this is my client code:
import sys, socket
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = 'localhost'
port = input('Port: ')
s.connect((host, port))
cmd = raw_input('$ ')
s.send(cmd)
file = s.makefile('r', 0)
sys.stdout.writelines(file.readlines())
When I start the server I get the right output, saying the server is listening. But when I connect with my client and type a command the server exits with this error:
Traceback (most recent call last):
File "server.py", line 21, in <module>
rc = conn.recv(2)
File "/usr/lib/python2.6/socket.py", line 165, in _dummy
raise error(EBADF, 'Bad file descriptor')
socket.error: [Errno 9] Bad file descriptor
On the client side, I get the output of ls but the server gets screwed up.
Your code calls conn.close() and then loops back around to conn.recv(), but conn is already closed.
If you want your client to repeat what it's doing, just add a loop in there ;)
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
host = 'localhost'
port = input('Port: ')
s.connect((host, port))
while True:
cmd = raw_input('$ ')
s.send(cmd)
file = s.makefile('r', 0)
sys.stdout.writelines(file.readlines())
Should probably be closer to what you want.
Other comments:
s.listen(1)
This statement should probably be moved outside of the while loop. You only need to call listen once.
pipe = os.popen(rc)
os.popen has been deprecated, use the subprocess module instead.
file = s.makefile('r', 0)
You're opening a file, yet you never close the file. You should probably add a file.close() after your sys.stdout.writelines() call.
EDIT: to answer below comment; done here due to length and formatting
As it stands, you read from the socket once, and then immediately close it. Thus, when the client goes to send the next command, it sees that the server closed the socket and indicates an error.
The solution is to change your server code so that it can handle receiving multiple commands. Note that this is solved by introducing another loop.
You need to wrap
rc = conn.recv(2)
pipe = os.popen(rc)
rl = pipe.readlines()
fl = conn.makefile('w', 0)
fl.writelines(rl[:-1])
in another while True: loop so that it repeats until the client disconnects, and then wrap that in a try-except block that catches the IOError that is thrown by conn.recv() when the client disconnects.
the try-except block should look like
try:
# the described above loop goes here
except IOError:
conn.close()
# execution continues on...