Hospital Management System (TCP/UDP Sockets)

A multi-process hospital management system implemented using TCP and UDP sockets as part of EE450 socket programming assignment. Five independent python processes communicate over localhost using TCP and UDP sockets, with a central hospital server acting as the hub.

Overview

The system runs in two phases:

• Authentication: The client hashes (SHA-256) the username and password and sends them to the hospital server over TCP. The hospital server forwards them to the authentication server over UDP, which validates against users.txt and replies AUTH_SUCCESS or AUTH_FAIL. The hospital server then checks hospital.txt to classify the user as a PATIENT or DOCTOR.
• Commands: Once authenticated, users can issue commands (lookup, schedule, cancel, view_appointment, view_prescription, prescribe). All commands pass through the hospital server, which acts as the central relay. It receives each request from the client over TCP, forwards it over UDP to the relevant backend server (appointment or prescription), then relays the reply back to the client.

The hospital server uses select() to multiplex its UDP socket, TCP listener, and all active client connections at once. No threads or fork() are used.

Architecture

Process	Protocol	Port	Role
authentication_server.py	UDP	21860	Validates credentials against users.txt
prescription_server.py	UDP	22860	Reads/writes prescription records
appointment_server.py	UDP	23860	Reads/writes appointment slots
hospital_server.py	UDP / TCP	25860 / 26860	Central hub; routes all messages
client.py	TCP	dynamic	User-facing command-line client

Data Files

• users.txt - space-separated <username_hash> <password_hash> per line
• hospital.txt - [Doctors] and [Treatments] sections
• appointments.txt - per-doctor timeslots, with patient hash and illness when booked
• prescriptions.txt - saved prescription records
• original.txt - plaintext credentials that users.txt is derived from (SHA-256 hashed). For reference only; not used at runtime.

Setup

This project is meant to run inside a docker container, which provides the standard Ubuntu environment used for grading. Set up Docker and the ch container helper by following the instructions here: https://github.com/csci104/docker/

Once installed, start the container and open a shell into it:

ch start csci104
ch shell csci104

Inside the shell, navigate to this project's directory (mounted from your host machine) and run the code from there. Exit the shell with Ctrl+D, and stop the container when done:

ch stop csci104

Note: The servers read and write the data files from their own working directory, so all .txt files must sit in the same folder as the .py files. Copy the files out of data/ into the project directory before running (or run the programs from wherever the data files live).

Running

Inside the container shell, open a separate terminal for each process (ch shell csci104 in each) and start them in this order:

python3 authentication_server.py
python3 prescription_server.py
python3 appointment_server.py
python3 hospital_server.py
python3 client.py '<username>' '<password>'

Enclose the username and password in single quotes.