🐧 Linux CLI & System Administration Mastery

A comprehensive, hands-on project demonstrating core Linux system administration, file management, process handling, and resource monitoring. This repository serves as a practical execution log of essential CLI operations required for DevOps and SysAdmin roles.

📖 Table of Contents

• 📌 Overview
• ⚙️ Prerequisites
• 🚀 Implementation Steps
  • Phase 1: File & Directory Management
  • Phase 2: Text Processing & Permissions
  • Phase 3: Archiving & Process Management
  • Phase 4: System & Network Audit
• 🎯 Conclusion

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📌 Overview

This project simulates real-world server management tasks. The challenges progress from basic file handling to intermediate system discovery, resource monitoring, and background process management.

Key Skills Demonstrated:

• Navigation & File Operations (cp, mv, rm, mkdir)
• Content Filtering & Redirection (grep, echo, >, >>)
• Permissions Management (chmod)
• Compression & Backups (tar)
• Process Control (ps, kill, background jobs)
• System Monitoring (free, du, ifconfig, uptime)

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⚙️ Prerequisites

• A Linux-based OS (Ubuntu, RHEL, CentOS, etc.) or WSL.
• Basic understanding of command-line interfaces.
• Root or Sudo privileges for system-level commands.

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🚀 Implementation Steps

Phase 1: File & Directory Management

1. Basic Directory & File Creation

Initializing the workspace by creating a project directory and an empty file.

mkdir my_project
cd my_project
touch index.html

2. Copying, Moving & Renaming

Duplicating files and organizing them into subdirectories logically.

cp -rf index.html about.html
mkdir pages
mv about.html ./pages

3. Deletion & Directory Renaming

Cleaning up the workspace and restructuring directories.

cd ..
rm index.html
mv pages assets

4. Hidden Files & Recursive Deletion

Managing hidden configuration files and safely wiping non-empty directories.

cd assets
touch .secret
ls -a
cd ..
rm -rvf assets

Phase 2: Text Processing & Permissions

5. Text Redirection & Finding Files

Writing logs directly via CLI and tracking files down using find.

mkdir network_logs && cd network_logs
echo "Destination Host Unreachable" > ping_results.txt
find . -name "ping_results.txt"

6. Appending Logs, Filtering & Permissions

Simulating application logs, filtering specific error metrics, and securing the file.

touch app.log
echo "[INFO] server is running" > app.log
echo "[ERROR] Connection Timeout" >> app.log
cat app.log | grep -F "[ERROR]"
chmod 444 app.log

Phase 3: Archiving & Process Management

7. Archiving & Extraction

Compressing the project directory into a GZIP tarball for backup simulation.

mkdir backup_dir
tar -czf Project_backup.tar.gz my_project
mv Project_backup.tar.gz backup_dir/
cd backup_dir
tar -xf Project_backup.tar.gz

8. Process Management (The "Kill" Drill)

Running dummy processes in the background, isolating their PIDs, and terminating them.

sleep 6000 &
ps | grep sleep
kill <PID>

Phase 4: System & Network Audit

9. System & Network Monitoring

Extracting real-time statistics regarding Memory (RAM), Disk Utilization, and Network Interfaces.

free -h
du -sh /var/log
ifconfig

10. System Discovery & Audit

Gathering kernel information, verifying the OS distribution, checking server uptime, and exporting the session history for documentation.

uname -a
cat /etc/os-release
uptime
history >> session_history.txt
tail -n 5 session_history.txt