How do I learn using both the TUI and the Web GUI?

Clone https://github.com/1nc0gn30/30-days-of-Linux-Fundamentals and run ./control-panel for the native C terminal TUI (with built-in Markdown reader, Flashcard Arena, and /tmp sandbox shells), or use the Astro Web GUI for browser command drills, XP tracking, and visual chmod/FHS calculators.

Is 30 Days of Linux Fundamentals completely free?

Yes, 100% of the 30 days, 90 study guides, C TUI drills, and web tools are open-source and unlocked by default with zero paywalls.

← Back to 30-Day Curriculum

WEEK 3 · SECURITY & WORKFLOWS · TUI: ./control-panel --day 20

Day 20: Shell Environment Customization, Aliases & Dotfiles

Configure persistent environment variables, PATH exports, productivity aliases, and custom prompts in ~/.bashrc.

XP 0

Streak 0

Command Mastery 0%

Study Music

YouTube Study Radio

Pick a track or paste any YouTube URL.

🍳 Breakfast (Syntax) Session

Type commands, build streaks, and then review the source guide.

Live Terminal Drill

Re-type the command exactly to clear each challenge.

target$ loading...

0 / 12 mastered

Command Board

Tap a command when you practiced it in your own terminal.

Command Intel

Meaning

Command explanation will appear here.

Sample Output

Output preview will appear here.

Useful Fun Fact

Fun facts about the active command will appear here.

Last Run Output

Run a command to see result feedback.

Knowledge Boost

Faster learning with topic cues, mini-missions, and external docs.

Key Topics

⚡ 60-Second Mental Model (Student Digest)📌 Review Variables and Loops📌 Conditionals in Scripts📌 Handling Input and Output📚 Resources

Mini Missions

Mission 1: Run export and explain the output in one sentence.
Mission 2: Run env and explain the output in one sentence.
Mission 3: Run alias and explain the output in one sentence.
Mission 4: Run mkdir -p /tmp/linux-dojo-day-20 && cd /tmp/linux-dojo-day-20 and explain the output in one sentence.

Useful Resources

📖 Digestible Study Guide & Visual Architecture

Source: day-20-breakfast-guide.md · Synced with ./control-panel --day 20

Day 20 · Breakfast — Shell Environment Customization, Aliases & Dotfiles

ZothOS × 1nc0gn30 Linux Dojo · Phase: Week 3 (Security & Workflows) · Session: Breakfast (Morning Foundation & Core Command Syntax)

Core Commands: export, env, alias, ~/.bashrc, ~/.profile, source

⚡ 60-Second Mental Model (Student Digest)

╔══════════════════════════════════════════════════════════════════════════════╗
║  ZOTHOS × 1NC0GN30 // DEFENSE-IN-DEPTH & STREAM PIPELINE ARCHITECTURE        ║
╠══════════════════════════════════════════════════════════════════════════════╣
║                                                                              ║
║  [ INBOUND PACKET ] ──► [ Netfilter: iptables / nftables ]                   ║
║                                │ (ACCEPT)                                    ║
║                                ▼                                             ║
║                         [ Hardened SSHD + Fail2Ban ]                         ║
║                                │                                             ║
║                                ▼                                             ║
║                         [ DAC: chmod/chown ] ──► [ MAC: SELinux / AppArmor ] ║
║                                │                                             ║
║                                ▼                                             ║
║                         [ Auditd & Log Pipelines: grep | awk | sed ]         ║
╚══════════════════════════════════════════════════════════════════════════════╝

Learning Pillar	How to Practice This Session
1. Native TUI (`./control-panel`)	Run `./control-panel` from repo root → Select Week 3 → Day 20 → Breakfast to drill interactive C lessons & quizzes.
2. Web Workstation (`astro-ui`)	Open `/day/20` → Select Breakfast tab → Type each target command in the live Mission Terminal to earn XP & streak mastery.
3. Safe Local Sandbox	Run `mkdir -p /tmp/linux-dojo-day-20 && cd /tmp/linux-dojo-day-20` to test every flag below without touching production files.

📌 Review Variables and Loops

for i in {1..5}; do echo "Number: $i"; done

Declare variables without spaces: name=zoth

Access them with

name

Loops: for, while, until

Useful for batch automation and command sequences

📌 Conditionals in Scripts

if [ "$USER" = "root" ]; then echo "Admin"; else echo "User"; fi

Use [ or [[ for conditions

Operators: =, !=, -lt, -eq, -f, -d

Always quote variables inside conditionals

📌 Handling Input and Output

read -p "Enter your name: " name
echo "Hello $name" >> greetings.txt

read: Get user input

> overwrites files; >> appends

tee can write to file and print to screen

📚 Resources

https://linuxize.com/post/bash-if-else-statement/

https://opensource.com/article/19/9/getting-started-bash-scripting

🥪 Lunch (Workflows) Session

Type commands, build streaks, and then review the source guide.

Live Terminal Drill

Re-type the command exactly to clear each challenge.

target$ loading...

0 / 12 mastered

Command Board

Tap a command when you practiced it in your own terminal.

Command Intel

Meaning

Command explanation will appear here.

Sample Output

Output preview will appear here.

Useful Fun Fact

Fun facts about the active command will appear here.

Last Run Output

Run a command to see result feedback.

Knowledge Boost

Faster learning with topic cues, mini-missions, and external docs.

Key Topics

⚡ 60-Second Mental Model (Student Digest)🛠 Automating Tasks with Shell Scripts🧩 Using getopts for Command-Line Options🐞 Debugging Shell Scripts📚 Resources

Mini Missions

Mission 1: Run export and explain the output in one sentence.
Mission 2: Run env and explain the output in one sentence.
Mission 3: Run alias and explain the output in one sentence.
Mission 4: Run mkdir -p /tmp/linux-dojo-day-20 && cd /tmp/linux-dojo-day-20 and explain the output in one sentence.

Useful Resources

📖 Digestible Study Guide & Visual Architecture

Source: day-20-lunch-guide.md · Synced with ./control-panel --day 20

Day 20 · Lunch — Shell Environment Customization, Aliases & Dotfiles

ZothOS × 1nc0gn30 Linux Dojo · Phase: Week 3 (Security & Workflows) · Session: Lunch (Midday Operational Workflows & Flag Mastery)

Core Commands: export, env, alias, ~/.bashrc, ~/.profile, source

⚡ 60-Second Mental Model (Student Digest)

╔══════════════════════════════════════════════════════════════════════════════╗
║  ZOTHOS × 1NC0GN30 // DEFENSE-IN-DEPTH & STREAM PIPELINE ARCHITECTURE        ║
╠══════════════════════════════════════════════════════════════════════════════╣
║                                                                              ║
║  [ INBOUND PACKET ] ──► [ Netfilter: iptables / nftables ]                   ║
║                                │ (ACCEPT)                                    ║
║                                ▼                                             ║
║                         [ Hardened SSHD + Fail2Ban ]                         ║
║                                │                                             ║
║                                ▼                                             ║
║                         [ DAC: chmod/chown ] ──► [ MAC: SELinux / AppArmor ] ║
║                                │                                             ║
║                                ▼                                             ║
║                         [ Auditd & Log Pipelines: grep | awk | sed ]         ║
╚══════════════════════════════════════════════════════════════════════════════╝

Learning Pillar	How to Practice This Session
1. Native TUI (`./control-panel`)	Run `./control-panel` from repo root → Select Week 3 → Day 20 → Lunch to drill interactive C lessons & quizzes.
2. Web Workstation (`astro-ui`)	Open `/day/20` → Select Lunch tab → Type each target command in the live Mission Terminal to earn XP & streak mastery.
3. Safe Local Sandbox	Run `mkdir -p /tmp/linux-dojo-day-20 && cd /tmp/linux-dojo-day-20` to test every flag below without touching production files.

🛠 Automating Tasks with Shell Scripts

find /var/log -name "*.log" -mtime +7 -delete

Clean logs older than 7 days

Run in crontab for scheduled automation

🧩 Using getopts for Command-Line Options

while getopts "hvf:" opt; do
  case $opt in
    h) echo "Help";;
    v) echo "Verbose mode";;
    f) echo "File: $OPTARG";;
  esac
done

getopts handles CLI options like -h, -v, -f filename

OPTARG

gives the argument value passed with options

🐞 Debugging Shell Scripts

bash -x script.sh
set -e  # exits on any error
set -x  # shows each command as it executes

Use for tracing logic errors

Combine with echo statements and input logs

📚 Resources

https://linuxize.com/post/how-to-debug-bash-scripts/

https://wiki.bash-hackers.org/howto/getopts_tutorial

🍽️ Dinner (Hardening) Session

Type commands, build streaks, and then review the source guide.

Live Terminal Drill

Re-type the command exactly to clear each challenge.

target$ loading...

0 / 12 mastered

Command Board

Tap a command when you practiced it in your own terminal.

Command Intel

Meaning

Command explanation will appear here.

Sample Output

Output preview will appear here.

Useful Fun Fact

Fun facts about the active command will appear here.

Last Run Output

Run a command to see result feedback.

Knowledge Boost

Faster learning with topic cues, mini-missions, and external docs.

Key Topics

⚡ 60-Second Mental Model (Student Digest)🧪 Lab 1: Automate System Monitoring💾 Lab 2: Backup Automation Script🐛 Lab 3: Script Debugging✅ Summary

Mini Missions

Mission 1: Run export and explain the output in one sentence.
Mission 2: Run env and explain the output in one sentence.
Mission 3: Run alias and explain the output in one sentence.
Mission 4: Run mkdir -p /tmp/linux-dojo-day-20 && cd /tmp/linux-dojo-day-20 and explain the output in one sentence.

Useful Resources

📖 Digestible Study Guide & Visual Architecture

Source: day-20-dinner-guide.md · Synced with ./control-panel --day 20

Day 20 · Dinner — Shell Environment Customization, Aliases & Dotfiles

ZothOS × 1nc0gn30 Linux Dojo · Phase: Week 3 (Security & Workflows) · Session: Dinner (Evening Hardening, Pipelines & Verification Lab)

Core Commands: export, env, alias, ~/.bashrc, ~/.profile, source

⚡ 60-Second Mental Model (Student Digest)

╔══════════════════════════════════════════════════════════════════════════════╗
║  ZOTHOS × 1NC0GN30 // DEFENSE-IN-DEPTH & STREAM PIPELINE ARCHITECTURE        ║
╠══════════════════════════════════════════════════════════════════════════════╣
║                                                                              ║
║  [ INBOUND PACKET ] ──► [ Netfilter: iptables / nftables ]                   ║
║                                │ (ACCEPT)                                    ║
║                                ▼                                             ║
║                         [ Hardened SSHD + Fail2Ban ]                         ║
║                                │                                             ║
║                                ▼                                             ║
║                         [ DAC: chmod/chown ] ──► [ MAC: SELinux / AppArmor ] ║
║                                │                                             ║
║                                ▼                                             ║
║                         [ Auditd & Log Pipelines: grep | awk | sed ]         ║
╚══════════════════════════════════════════════════════════════════════════════╝

Learning Pillar	How to Practice This Session
1. Native TUI (`./control-panel`)	Run `./control-panel` from repo root → Select Week 3 → Day 20 → Dinner to drill interactive C lessons & quizzes.
2. Web Workstation (`astro-ui`)	Open `/day/20` → Select Dinner tab → Type each target command in the live Mission Terminal to earn XP & streak mastery.
3. Safe Local Sandbox	Run `mkdir -p /tmp/linux-dojo-day-20 && cd /tmp/linux-dojo-day-20` to test every flag below without touching production files.

🧪 Lab 1: Automate System Monitoring

1. Create monitor_disk.sh:

THRESHOLD=80
USAGE=$(df / | grep / | awk '{print $5}' | sed 's/%//g')
if [ "$USAGE" -gt "$THRESHOLD" ]; then
  echo "Disk space high: $USAGE%" | mail -s "Disk Alert" root
fi

2. Add to crontab for automatic checks.

💾 Lab 2: Backup Automation Script

1. Create backup_logs.sh:

BACKUP_DIR="/backup/$(date +%F)"
mkdir -p "$BACKUP_DIR"
cp -r /var/log "$BACKUP_DIR"
find /backup -type d -mtime +7 -exec rm -rf {} +

2. Automate daily with cron.

🐛 Lab 3: Script Debugging

1. Create buggy script:

#!/bin/bash
for i in 1 2 3
  echo "Number $i"

2. Debug:

bash -x broken_script.sh

3. Fix: add do after for line
4. Use set -e to stop on error, and set -x to trace

✅ Summary

Created monitoring and backup automation

Debugged and hardened scripts with real-world usage