Write/Read App - Operating Systems - Homework Project

1. Introduction

This project demonstrates a file management system implemented using Bash scripts and socket programming. It provides a web interface for local interactions using a minimal HTML form and a TCP-based client-server system for remote communication.

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2. Objectives

• Provide basic file operations (create, read, list, and delete) via web and socket interfaces.
• Demonstrate Linux socket communication using Bash and Netcat.
• Integrate a minimal web server with CGI for backend processing.

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3. System Setup

Web Server

• Install nginx using:

  bash
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  sudo apt update  
  sudo apt install nginx  
  

• Enable CGI for handling Bash scripts in the /usr/lib/cgi-bin/ directory.

Directory and File Permissions

• Create a directory for files:

  bash
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  mkdir /tmp/server_files  
  chmod 777 /tmp/server_files  
  

• Ensure all scripts are executable:

  bash
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  chmod +x file_manager.sh tcp_server.sh tcp_client.sh  
  

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4. Script Descriptions

index.html

Provides a web-based interface for file management with buttons to send data via forms.

file_manager.sh

Processes commands from the web interface, supporting save, read, and clear file operations.

tcp_server.sh

Implements a TCP socket server. Listens for commands (WRITE, READ, LIST, DELETE, EXIT) and processes them.

tcp_client.sh

A client script that connects to the server, sends commands, and displays responses.

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5. How to Run

1. Start the Web Server

   bash
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   sudo systemctl start nginx  
   

2. Place Scripts
   • index.html and file_manager.sh in /usr/lib/cgi-bin/.
   • Ensure permissions with chmod +x.
3. Start the TCP Server

   bash
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   ./tcp_server.sh  
   

4. Run the TCP Client

   bash
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   ./tcp_client.sh  
   

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6. Commands

Command | Description | Example -- | -- | -- WRITE | Writes content to a file. | WRITE myfile.txt Hello, world! READ | Reads and displays file content. | READ myfile.txt LIST | Lists all files in the directory. | LIST DELETE | Deletes a specified file. | DELETE myfile.txt EXIT | Stops the server. | EXIT

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7. Conclusion

This project showcases a fully functional file management system using Linux-native tools and demonstrates the integration of Bash scripting with both web and socket communication.

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8. Future Improvements

One potential improvement for this project is implementing user authentication and access control. Currently, the system allows unrestricted access to all file operations. Adding a user login mechanism with different permission levels would enhance security and demonstrate more advanced system administration concepts.