Midori-Obsidian/Midori's Linux Dojo 🌸/Phase 3 - Users and Files/Exercises.md

🧰 Phase 3: Users and Files

Goal: Who can do what — users, groups, permissions, processes

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🎯 Exercise 1 — User Management

# Create users
useradd -m bob
passwd bob              # Set a password

# Check user info
id bob
cat /etc/passwd | grep bob

# Groups
groupadd developers
usermod -aG developers bob
groups bob

# Switch user
su - bob
whoami
exit

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🎯 Exercise 2 — File Ownership

# Create file as root, give to bob
touch /root/lab/team-project.txt
chown bob:developers /root/lab/team-project.txt
ls -la /root/lab/team-project.txt

# Set permissions
chmod 640 /root/lab/team-project.txt

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🎯 Exercise 3 — Sudo / Doas

# Give bob sudo access
echo "bob ALL=(ALL) ALL" >> /etc/sudoers
# OR on Alpine (doas):
echo "permit persist bob" >> /etc/doas.d/doas.conf

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🎯 Exercise 4 — Processes

# View processes
ps aux
ps -ef
top                     # Press 'q' to quit

# Background jobs
sleep 100 &
jobs
kill %1

# Service management (Alpine)
rc-service sshd status
rc-update show

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✅ Phase 3 Checklist

• Create users and groups
• File ownership and permissions
• Sudo/doas configuration
• Process management

Previous: Phase 2 - Networking | Next: Phase 4 - Security