Linux Commands and Scripts

This repository serves as a centralized collection for all of my small Linux projects, utility scripts, and commands. Each project is organized in its own subdirectory and contains its own detailed documentation.

Table of Contents (TOC)

Directory Layout

graph TD
    root["Root"]
    root --> assets["assets/"]
    root --> bash_basics["bash-basics/"]
    root --> ipv6_validation["ipv6-validation/"]
    root --> regex_task_manager["regex-task-manager/"]
    root --> user_login_data["user-login-data-script/"]
    root --> autoconfig_router["Auto-config_router/"]
    root --> context[".context/"]

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• User Login Data Script - Bash script for automated user creation from a CSV file, supporting various Linux distributions.
• Bash Basics - Introductory exercises showing basic greeting statements and parameter printing.
• IPv6 Validation - Tool for validating IPv6 formats using regular expressions, supporting both command-line arguments and interactive prompts.
• Regex Task Manager - A central terminal-based dashboard that guides users through 10 different Regex extraction and filtering tasks.
• Auto-config Router - Distro-aware automation script for configuring systems as a Router or Client using a central JSON file and dynamic MAC address mapping.

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Project Catalog

1. User Login Data Script

• Path: user-login-data-script/
• Description: Reads a CSV file containing first names, last names, and birth dates, and creates corresponding Linux system users.
• Key Features:
  • Automatically detects the active Linux distribution (e.g., Debian/Ubuntu, RHEL/Fedora, Alpine, Arch) and applies the correct user-creation commands.
  • Normalizes names to generate valid Unix usernames (converts to lowercase, cleans German umlauts like ä -> ae, and strips invalid characters).
  • Assigns standard passwords following the pattern Firstname.Lastname.Birthdate.
  • Automatically cleans Windows carriage returns (\r\n).

2. Bash Basics

• Path: bash-basics/
• Description: Basic shell programming examples.
• Key Features:
  • Greeting output with self-name resolution ($0).
  • Positional argument printer supporting arguments 1 to 10 (${10}).

3. IPv6 Validation

• Path: ipv6-validation/
• Description: Validates IPv6 addresses (standard/compressed/mapped).
• Key Features:
  • Runs in CLI-argument mode or interactive prompt mode.
  • Applies a comprehensive regular expression to check validity.

4. Regex Task Manager

• Path: regex-task-manager/
• Description: Interactive terminal dashboard executing 10 regex filtration assignments.
• Key Features:
  • Colorful TUI dashboard with safe input loops.
  • Network logs parser (IPv4, IPv6, interfaces).
  • User database parser (UID/GID filtering).
  • Protocol database column extraction and counting (ports, protocol unique counts).

5. Auto-config Router

• Path: Auto-config_router/
• Description: Distro-aware automation script for configuring systems as a Router or Client using a central JSON file.
• Key Features:
  • Distro-aware automated installation of required packages (dnsmasq, iptables, and JSON parser jq).
  • Automatically scans local network interfaces and dynamically maps/records their MAC addresses into the configuration JSON file (Config.json).
  • Sets up routing logic (enabling IPv4 forwarding and NAT iptables rules) or default gateway settings depending on host role.
  • Configures DHCP service ranges automatically using dnsmasq.