Linux Shell

Format

Hands-on: terminal tasks. No trivia — you do real tasks.

Domains

Navigation · Text processing · Pipelines · Scripting

Duration

about 20 minutes

Levels examinable

L1–L5

AI policy

AI-free

Scoring

Correctness first; efficiency (time, keystrokes, steps vs an expert reference) adds a bounded bonus. Graders check outcomes, so any valid approach passes.

Credential

Module badge, valid 24 months. $39 per certification attempt; practice is free.

• L1Foundation. Navigate and read files (cd, ls, cp, mv, cat, grep)
• L2Proficient. Pipes, redirects, find, chmod, env vars
• L3Advanced. sed/awk/jq, xargs, scripting, cron
• L4Expert. Process control, ssh, tmux, regex fluency
• L5Master. Complex pipelines under time pressure, robust scripts

• Standard mode (L1–L3 on your public certificate): email verification, focus/tab detection, keystroke timing telemetry, randomized parameterized tasks, server-side timer.
• Proctored mode (required for public L4–L5): government ID and selfie check, webcam snapshots and optional screen share, reviewed only if a session is flagged. Recordings are deleted after 90 days.
• Unproctored results are capped at L3 on the public certificate; you can book a proctored retake to confirm L4 or L5. Every certificate shows whether it was proctored.
• Retakes: wait 14 days per module, maximum 3 attempts per quarter. Your highest valid level shows on your profile.
• We never show raw keystrokes or video to employers. You own your results. Data notice

Create a free account to take exams and keep your results.

• Systems Administrator / SRE · 6.21%