I wanted to communicate between processes (one process does something, sends results to other process which does something with it).
So I used this code:
Server:
from multiprocessing.connection import Listener
address = ('localhost', 6000) # family is deduced to be 'AF_INET'
listener = Listener(address, authkey='secret password')
conn = listener.accept()
print 'connection accepted from', listener.last_accepted
while True:
msg = conn.recv()
# do something with msg
if msg == 'close':
conn.close()
break
listener.close()
Client:
from multiprocessing.connection import Client
address = ('localhost', 6000)
conn = Client(address, authkey='secret password')
conn.send('close')
conn.close()
(source: interprocess communication in python)
And it works like a charm. But I wanted to run these two programs from another computer. On Comp. A I have these 2 programs. I connect to Comp A from Comp B by Wifi Lan (using ssh connection) and I run these 2 programs (which means they're running on Comp A), but they don't connect with each other. I've tried using wifi lan address (192.168.x.x) instead of "localhost" but it didn't work neither. What parameter do I have to use instead of "localhost" so that these 2 programs can connect. Or what is the easiest way to do this.
Cheers!
Go to command prompt and type ipconfig on the other computer. You need to use the IPv4 address. You also need to make sure the ports are open and ssh enabled. replace the 'localhost' with the IPv4 address.
Related
I'm developing on a remote server which I login using ssh and develop using vi. I however need to send Terminal notification commands osascript -e "display notification {} {} {}" and such commands back to my local terminal so I can get sound/mac notifications on my system. How do I achieve this?
I know I can use import os; os.sytem('command') for the script on server to send terminal commands on the machine its running in i.e., the server itself, but is there a similar command to send commands back to my local ? Ideally, I need this to be done from the scripts itself- because I have multiple triggers for notifications to be done.
You need to use some sockets
On your server machine you need something like this:
import socket
IP = "0.0.0.0" # Your Local Machine IP
PORT = 5200 # Your Local Machine Listening Port
def send_message(msg):
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((IP, PORT))
s.send(bytes(msg, 'UTF-8'))
data = s.recv(4096)
s.close()
print(data)
You can use the method where ever you need, the only argument it takes is msg, simply it's the command you need to send to your local machine
On your local machine this script should do what you need:
import socket
import os
IP = "0.0.0.0" # 0.0.0.0 Means every available IP to assign, but you need to use your external IP on the script that u will use on server
PORT = 5200 # The port you want to listen on
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.bind((IP, PORT))
s.listen(1)
while True:
conn, addr = s.accept()
print("Command from {}".format(addr))
data = conn.recv(4096)
if not data: continue
if data == b'stop': break # This line just defines a word that will make your local machine stop listening.
print(data)
command = data.decode('UTF-8')
os.system(command)
conn.send(data)
conn.close()
You need to run The local machine script first
I am trying to setup a very simply sockets app. My server code is:
import socket
s = socket.socket()
host = socket.gethostname()
port = 1234
s.bind((host,port))
s.listen(5) #Here we wait for a client connection
while True:
c, addr = s.accept()
print "Got a connection from: ", addr
c.send("Thanks for connecting")
c.close()
I placed this file on my remote Linode server and run it using python server.py. I have checked that the port is open using nap:
PORT STATE SERVICE
22/tcp open ssh
80/tcp open http
1234/tcp open hotline
I now run the client.py on my local machine:
import socket # Import socket module
s = socket.socket() # Create a socket object
port = 1234 # Reserve a port for your service.
s.connect(("139.xxx.xx.xx", port))
print s.recv(1024)
s.close # Close the socket when done
However I am not getting any kind of activity or report of connection. Could someone give me some pointers to what I might have to do? Do I need to include the hostname in the IP address I specify in the client.py? Any help would be really appreciated!
I've just summarize our comments, so your problem is this:
When you trying to using the client program connect to the server via the Internet, not LAN.
You should configure the
port mapping on your router.
And however, you just need configure the
port mapping for your server machine.
After you did that, then you can use the client program connect to your server prigram.
I must preface this with a full disclaimer that i'm very early in my python development days
I've made a simple python program that waits for a socket connection to the local ip address over port 20000. When it gets a connection, it pops up a message alert using the win32api.
#tcpintercomserver.py
import socket
import sys
import win32api
ip = socket.gethostbyname(socket.gethostname())
#socket creation
sock=socket.socket(socket.AF_INET, socket.SOCK_STREAM)
#Binding
server_address = (ip, 20000)
sock.bind(server_address)
print server_address
#Listen
sock.listen(1)
while True:
# Wait for a connection
connection, client_address = sock.accept()
win32api.MessageBox(0,'MessageText','Titletext', 0x00001000)
# Close Connection
connection.close()
I also have a mated client program that simply connects to the socket. The script takes an argument of the host you're trying to reach (DNS name or ip address)
#tcpintercomcli.py
import socket
import sys
# Create a TCP/IP socket
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
# Connect the socket to the port where the server is listening
server_address = (sys.argv[1], 20000)
sock.connect(server_address)
This all runs fine as scripts. I then used CX_Freeze to turn them into executables. Both run just like they did when they were scripts.
Now i've taken the server script and connected it to a service with srvany.exe and use of the SC command in windows.
I set up the service using SC create "intercom" binPath= "C:\dist\srvany.exe"
Under the intercom service key in the registry, i've added the Parameter's key, and under there set Application to a string value c:\dist\tcpintercomserver.exe
I then perform a "net start intercom" and the service launches successfully, and the tcpintercomserver.exe is listed as a running process. However, when i run the tcpintercomcli.py or tcpintercomcli.exe, no alert comes up.
I'm baffled...is there something with the CX_Freeze process that may be messing this up?
Service process cannot show messagebox, they don't have access to UI, they usually run as SYSTEM user. if you are running from service, proper way of debugging and showing messages are using EventLog.
See:
http://msdn.microsoft.com/en-us/library/system.diagnostics.eventlog%28VS.71%29.aspx
If you are on Windows Vista or later, your script is running headlong into Session 0 Isolation -- where GUI elements from a Windows service are not shown on an interactive user's desktop.
You will probably see your message box if you switch to session 0...
I'm new to Sockets, please excuse my complete lack of understanding.
I have a server script(server.py):
#!/usr/bin/python
import socket #import the socket module
s = socket.socket() #Create a socket object
host = socket.gethostname() #Get the local machine name
port = 12397 # Reserve a port for your service
s.bind((host,port)) #Bind to the port
s.listen(5) #Wait for the client connection
while True:
c,addr = s.accept() #Establish a connection with the client
print "Got connection from", addr
c.send("Thank you for connecting!")
c.close()
and client script (client.py):
#!/usr/bin/python
import socket #import socket module
s = socket.socket() #create a socket object
host = '192.168.1.94' #Host i.p
port = 12397 #Reserve a port for your service
s.connect((host,port))
print s.recv(1024)
s.close
I go to my desktop terminal and start the script by typing:
python server.py
after which, I go to my laptop terminal and start the client script:
python client.py
but I get the following error:
File "client.py", line 9, in
s.connect((host,port))
File "/usr/lib/python2.7/socket.py", line 224, in meth
return getattr(self._sock,name)(*args)
socket.error: [Errno 111] Connection refused
I've tried using different port numbers to no avail. However, I was able to get the host name using the same ip and the gethostname() method in the client script and I can ping the desktop (server).
Instead of
host = socket.gethostname() #Get the local machine name
port = 12397 # Reserve a port for your service
s.bind((host,port)) #Bind to the port
you should try
port = 12397 # Reserve a port for your service
s.bind(('', port)) #Bind to the port
so that the listening socket isn't too restricted. Maybe otherwise the listening only occurs on one interface which, in turn, isn't related with the local network.
One example could be that it only listens to 127.0.0.1, which makes connecting from a different host impossible.
This error means that for whatever reason the client cannot connect to the port on the computer running server script. This can be caused by few things, like lack of routing to the destination, but since you can ping the server, it should not be the case. The other reason might be that you have a firewall somewhere between your client and the server - it could be on server itself or on the client. Given your network addressing, I assume both server and client are on the same LAN, so there shouldn't be any router/firewall involved that could block the traffic. In this case, I'd try the following:
check if you really have that port listening on the server (this should tell you if your code does what you think it should): based on your OS, but on linux you could do something like netstat -ntulp
check from the server, if you're accepting the connections to the server: again based on your OS, but telnet LISTENING_IP LISTENING_PORT should do the job
check if you can access the port of the server from the client, but not using the code: just us the telnet (or appropriate command for your OS) from the client
and then let us know the findings.
Assume s = socket.socket()
The server can be bound by following methods:
Method 1:
host = socket.gethostname()
s.bind((host, port))
Method 2:
host = socket.gethostbyname("localhost") #Note the extra letters "by"
s.bind((host, port))
Method 3:
host = socket.gethostbyname("192.168.1.48")
s.bind((host, port))
If you do not exactly use same method on the client side, you will get the error: socket.error errno 111 connection refused.
So, you have to use on the client side exactly same method to get the host, as you do on the server. For example, in case of client, you will correspondingly use following methods:
Method 1:
host = socket.gethostname()
s.connect((host, port))
Method 2:
host = socket.gethostbyname("localhost") # Get local machine name
s.connect((host, port))
Method 3:
host = socket.gethostbyname("192.168.1.48") # Get local machine name
s.connect((host, port))
Hope that resolves the problem.
host = socket.gethostname() # Get the local machine name
port = 12397 # Reserve a port for your service
s.bind((host,port)) # Bind to the port
I think this error may related to the DNS resolution.
This sentence host = socket.gethostname() get the host name, but if the operating system can not resolve the host name to local address, you would get the error.
Linux operating system can modify the /etc/hosts file, add one line in it. It looks like below( 'hostname' is which socket.gethostname() got).
127.0.0.1 hostname
in your server.py file make : host ='192.168.1.94' instead of host = socket.gethostname()
Pay attention to change the port number. Sometimes, you need just to change the port number. I experienced that when i made changes over changes over syntax and functions.
I was being able to ping my connection but was STILL getting the 'connection refused' error. Turns out I was pinging myself! That's what the problem was.
I was getting the same problem in my code, and after thow days of search i finally found the solution, and the problem is the function socket.gethostbyname(socket.gethostname) doesnt work in linux so instead of that you have to use socket.gethostbyname('put the hostname manually') not socket.gethostbyname('localhost'), use socket.gethostbyname('host') looking with ifconfig.
try this command in terminal:
sudo ufw enable
ufw allow 12397
I am trying to set up a local server so that other PCs on the same local network can connect to it. When trying to do so, on the client side, I get the following error:
[Errno 10061] No connection could be made because the target machine actively refused it
I have been searching around for hours and still couldn't resolve this issue. I tried turning off my Firewall too, but nothing.
These are my server and client codes:
Server Code:
import socket
import threading
import SocketServer
import datetime
ver_codes = []
class ThreadedTCPRequestHandler(SocketServer.BaseRequestHandler):
def handle(self):
print threading.current_thread().isDaemon()
data = self.request.recv(1024)
command = data.split()[0]
if(command=="login"):
if(logged_in(data.split()[1])==False):
self.request.sendall(login(data.split()[1], data.split()[2]))
else:
self.request.sendall("already in")
class ThreadedTCPServer(SocketServer.ThreadingMixIn, SocketServer.TCPServer):
pass
def client(ip, port, message):
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.connect((ip, port))
try:
sock.sendall(message)
response = sock.recv(1024)
print "Received: {}".format(response)
finally:
sock.close()
def logged_in(id_num):
for i in ver_codes:
if(i[0]==id_num):
return True
return False
def login(username, password):
login_file = open("Login.txt", "r")
match = login_file.readline()
while(match!="*"):
if(match.split()[0]==username):
if(match.split()[1]==password):
ver_codes.append([match.split()[0], encryption_code(match.split()[2])])
login_file.close()
return "{} {}".format(match.split()[2], encryption_code(match.split()[2]))
print "And Here"
match = login_file.readline()
return "Denied"
login_file.close()
def encryption_code(to_encrypt):
now = datetime.datetime.now()
return int(str(now.microsecond)) * int(to_encrypt)
if __name__ == "__main__":
HOST, PORT = "localhost", 7274
server = ThreadedTCPServer((HOST, PORT), ThreadedTCPRequestHandler)
ip, port = server.server_address
print server.server_address
server_thread = threading.Thread(target=server.serve_forever)
server_thread.daemon = False
server_thread.start()
print "Server loop running in thread:", server_thread.name
Client Code:
import socket
import sys
HOST, PORT = "localhost", 7274
data = " ".join(sys.argv[1:])
sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
try:
sock.connect((HOST, PORT))
sock.sendall("login mahdiNolan m1373")
received = sock.recv(1024)
finally:
sock.close()
I really appreciate any help you could give me!
Thanks A LOT beforehand!
Your issue is because you're listening on localhost - this will only accept connections from the local machine.
If you want to accept connections from anywhere, instead of "localhost" just pass the empty string "". This is equivalent to specifying INADDR_ANY to the C sockets API - see the ip man page for more information, or this page also looks like it has some useful explanation. In short, this means "accept connections on any local interface".
Instead of the empty string you can instead specify an IP address of a local interface to only accept connections on that interface - it's unlikely you need to do this unless you machine has multiple network cards inside it (e.g. acting as a gateway) and you only want to serve requests on one of the networks.
Also, on the client side you should use the actual address of the machine - replace "localhost" with the IP address or hostname of the server machine. For example, something like "192.168.0.99". If you want to find the IP address of the server under Windows, open a DOS window and run the ipconfig command, look for the line with IPv4 Address (assuming you've got an IPv4 network which is very likely).
The Windows firewall will also block the server from accepting connections as you've already found, but you shouldn't need to disable it - as soon as you run your server you should see a popup window where you can instruct it to accept connections (that was on Windows 7, it might be different on other versions). In any case, turning the software firewall off should allow everything to work, although whether that's a security risk is a matter outside of the scope of this question.