Clairos Learn A safe command line training game for Linux and Mac basics
Unix ops lab

Security administration

Identity, sudo boundaries, SSH hardening, firewall rules, and review notes.

0/25 lessons 0/7 missions
01 Security administration Security admin

Practice safe security habits: identity, logs, firewall rules, and fake sudo.

12 minutes · whoami, id, groups, ufw, sudo, grep 02 Security administration SSH hardening

Read fake SSH settings and confirm safer defaults without connecting anywhere.

9 minutes · grep, cat, journalctl 03 Security administration Firewall and incident review

Inspect firewall state, add a fake rule, and write a short incident note.

10 minutes · ufw, grep, echo, cat
Command coverage

Commands you will practice here.

echo <text>

Print text or write safe lab notes with >.

cat <file>

Print text file contents.

grep [-i] <text> <file>

Find literal text inside a file.

whoami|id|groups

Inspect the fake learner account.

journalctl -u <service>

Read fake service journal entries.

ufw status

Inspect fake firewall rules.