两台计算机之间的套接字编程

Question

I am trying to communicate between two computers and one is Mac and other one is Linux.

The code I have at server side:

import os
from socket import *

host = "192.168.1.47"
port = 10000
buf = 1024

address = (host, port)
UDPSock = socket(AF_INET, SOCK_DGRAM)
UDPSock.bind(address)

print ("Waiting to receive messages...")

while True:
    (data, address) = UDPSock.recvfrom(buf)
    print("Received message: " + data)
    if data == "exit":
        break

UDPSock.close()
os._exit(0)

At client side I have:

import os
from socket import *

host = "192.168.1.47" # set to IP address of target computer
port = 10000
addr = (host, port)

UDPSock = socket(AF_INET, SOCK_DGRAM)

while True:
    data = raw_input("Enter message to send or type 'exit': ")
    UDPSock.sendto(data, addr)
    if data == "exit":
        break

UDPSock.close()
os._exit(0)

The server keeps waiting for the request and though I send some message typed in client side server is unable to receive it. The host address is my mac ip address and asking the other computer to connect to this ip. Could anyone help me understand where I went wrong. I referred to the other posts related to this topic but there were no appropriate solution for this. Thanks

Answer 1

First : use the same port :)

And you are sending a message on the client with the localhost address. Use the server address for the client.

For the server :

ip = "localhost" or "server ip"

port = 10000

For the client :

ip = "server ip"

port = 10000

Answer 2

It worked for me on the same host. When there is a "b" before a string it is because I change the string in bytes.

< string >.encode() change the string in bytes

< bytes >.decode() change the bytes in string

You need to understand if you use UDP there is no connection between your 2 computers. So the firewall will block the link, if you want to change that use TCP socket.

I recommand you to use python 3 if you can and to print this syntax is cool :

print("{}".format(msg_recv))

You add the variables in the format(..), and they will replace the " {} ".

Client :

import os
from socket import *

host = "127.0.0.1" # set to IP address of target computer
port = 10000
addr = (host, port)

UDPSock = socket(AF_INET, SOCK_DGRAM)

while True:
    data = input("Enter message to send or type 'exit': ")
    UDPSock.sendto(data.encode(), addr)
    if data == "exit":
        break

UDPSock.close()
os._exit(0)

Server :

import os
from socket import *

host = "127.0.0.1"
port = 10000
buf = 1024

address = (host, port)
UDPSock = socket(AF_INET, SOCK_DGRAM)
UDPSock.bind(address)

print ("Waiting to receive messages...")

while True:
    (data, address) = UDPSock.recvfrom(buf)
    print("Received message: " + data.decode())
    if data == b"exit":
        break

UDPSock.close()
os._exit(0)