This project was originally hosted on GitHub and can still be accessed there:
https://github.com/Ethiwam/socket-project
This project was originally for a class of mine, CS 4390 Computer Networking. The goal
of this project was to learn how two programs can interact via the internet. I
designed both a client and a server, both written in Python using the socket module.
The client is simple, the socket created for the client uses IPv4 (IF_INET) and TCP
(SOCK_STREAM) to send and receive information. It must be run each time you want to
send information to the server, it does not stay on after receiving information from
the server. This could easily be changed with a while True loop, but I thought it
wasn’t necessary to show the sending and receiving functions of the client.
The client asks the user for an integer, then sends a message to the server including
both the user’s integer and the name of the client. In the case of this project, I
haven’t created it for different users since I was focused on the sending and receiving
between the client and server. So the message is hardcoded to send the message, “Client
of Ethan Iwama: {user integer}” after getting the user’s integer. After sending the
message, the client waits for the server response, prints it to console, then
terminates the client session.
The server is also straightforward. The socket created also uses IPv4 and TCP to send
and receive information, but the server will maintain the socket until told to
terminate. Anytime it receives a message from a client it does 3 things: (1) it prints
that the client has connected to itself (e.g. “Ethan Iwama has connected to Server of
Ethan Iwama”), (2) it takes the integer from the client and adds it to its own integer
(my server’s number is 42 and does not change) printing the client, server, and
combined numbers to terminal, and lastly (3) terminates the server socket if the
client number is less than 1 or more than 100. The server uses regex to parse the
client message for name and number, but to do so the client message must be in the
form “Client of {username}: {user number}”. The server’s name is “Server of Ethan
Iwama” and the server’s number is hardcoded as 42. When the server receives the client
number it will add it to the server number and save it as the combined number, which
will all be printed.
Below are examples of the terminals of the server and client. These were taken from
the same sessions, so each line group of lines from the client matches with the group
of lines in the server.
Client
Server
Note: I could not test with a second computer. Unfortunately at time of creation, I
lived in an on-campus apartment and the wifi routers they gave us did not allow two
computers connect directly through IP. It would require me to configure the router's
firewall, which I did not have access to.
To try out my code, you can either run the client on one computer and the server on
the other (you'd have to figure out your network yourself), or you can run it like I
did which involves running client in one environment and the server in another on the
same machine. I suppose you could do this either with Anaconda or Docker. These were
built in Python 3, though it might still work in Python 2.
client.py
server.py
Network Sockets