Master Linux from your phone. Textbook of Linux teaches you the command line through interactive terminal demos, hands-on command challenges, and adaptive practice.
WATCH -Terminal walkthroughs show you exactly how each command works, with output appearing step by step.
TYPE - Terminal Challenges let you type real Linux commands on a custom keyboard. The app validates your input, accepts flag reordering (ls -lah = ls -alh), and gives partial credit when you get the command right but miss a flag.
PRACTISE - 760 multiple-choice questions across 76 topics test your understanding. The adaptive engine tracks what you know and focuses on your weak areas.
FOUR DOMAINS
• Command Line (FREE) - shell basics, files, pipes, grep, sed, awk, find
• System Administration - users, permissions, processes, packages, networking, systemd
• Programming & Tools - shell scripting, vi, git
• Modern Linux - containers, Docker, security, performance, eBPF
GAMIFICATION
• XP and levels (Newbie → Root)
• Daily streaks with streak freezes
• 20 achievements across streak, mastery, speed, and volume categories
• Spaced repetition for long-term retention
FREE TO START
The entire Command Line domain (16 topics, 160 questions, 16 terminal challenges) is free.
Subscribe to unlock all 4 domains.
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