Internet Project 1 - Basic HTTP Server Project

This project implements a basic HTTP server in C, designed to practice network programming. The server listens on port 8002 and handles HTTP GET and POST requests. It serves a simple HTML webpage with a file upload form and supports static file retrieval.

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🔧 Features

• Basic HTTP Server:

  • Handles HTTP GET and POST requests.
  • Serves static files like HTML pages and images.

• Static File Serving:

  • Responds to requests for an HTML page and a static image (images.jpeg).
  • Uses sendfile() to serve files efficiently.

• File Upload Simulation:

  • Processes POST requests to extract the file name from the upload form.

• Process Management:

  • Uses fork() to handle multiple clients simultaneously.
  • Prevents zombie processes with signal handling (SIGCHLD).

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📂 Project Structure

• server.c: Main C program file implementing the server.
• images.jpeg: Image file served by the server and displayed on the webpage.

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🚀 How to Run the Server

Follow these steps to compile and run the server:

Step 1: Compile the Program

Use the following command to compile the server program:
gcc -o server server.c

Step 2: Start the Server

Run the compiled server program:
./server

Step 3: Access the Server

Open a web browser and navigate to:
http://<server-ip>:8002
Replace <server-ip> with the actual IP address of the server machine.

Step 4: Test the Features

• View the HTML Page:
  The server responds with a simple HTML page containing a title, an image, and a file upload form.
• Upload a File:
  Use the upload form on the webpage to send a file. The server extracts the file name and prints it in the terminal:
  receive filename: <uploaded-file-name>
• Access the Image:
  The image (images.jpeg) can be accessed directly by visiting:
  http://<server-ip>:8002/images.jpeg

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💻 How It Works

Server Initialization

1. Creates a socket and binds it to port 8002.
2. Configures the server to listen for incoming connections.
3. Uses fork() to spawn child processes for handling individual client connections.
4. Manages signals (SIGCHLD) to prevent zombie processes.

Request Handling

• GET /:
  Responds with a pre-defined HTML webpage.
• GET /images.jpeg:
  Serves the image file using sendfile().
• POST /:
  Parses the HTTP request body to extract the file name of the uploaded file.

HTML Page

The HTML page served by the server includes:

• A title: "Network Programming Homework 1".
• An image: images.jpeg.
• A file upload form that supports POST requests.

Process Management

• Each client connection is handled in a separate process created using fork().
• Signals are used to clean up zombie processes (SIGCHLD).

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📋 Example Outputs

Server Startup

When the server starts, it prints:
Server listen address: 0.0.0.0:8002

File Upload

When a file is uploaded using the form, the server prints:
receive filename: example.txt

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⚠️ Limitations

• The POST request processing only extracts the file name and does not store the uploaded file.
• Minimal error handling for malformed HTTP requests.
• Not optimized for high-concurrency environments or large-scale applications.

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📈 Future Improvements

• Implement functionality to save uploaded files.
• Enhance request parsing and error handling.
• Support additional HTTP methods and headers.
• Optimize performance for better handling of concurrent client connections.

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📝 Notes

This project is intended for learning purposes, focusing on:

• Socket programming in C.
• HTTP protocol basics.
• Client-server communication.