ShellPer: Linux Commands & Lab

Karatas

In-app purchases

About this app

Most command references stop at telling you what a command does. ShellPer lets you run it.
Read it, try it in a real shell, prove you can do it under pressure. The whole app is built on that idea.
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FREE, ALWAYS
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📚 358 Linux commands across 13 categories — files, text processing, networking, system, processes, users, disk, packages, developer tools, security, monitoring and the shell itself. Every command has its flags explained and real usage examples.
🔍 Search that understands what you meant. Make a typo, describe the symptom, type half a word — it still finds the command.
🧩 Daily Puzzle — one terminal task a day, the same one for everybody. Solve it, build a streak, share your result.
📋 One-tap copy, favourites, level filtering, works offline, dark theme. No account, no tracking.
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PRO — ONE PAYMENT, YOURS FOR GOOD
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🧪 THE LAB — a real shell in your pocket
Ten scripted missions on a simulated Linux box: a disk at 96%, an SSH key the daemon refuses, a backup script eating the CPU, a 3 GB log a service holds open. Real commands, real output, real error messages.
You cannot break anything. And a mission is judged by whether the machine actually ended up fixed, not by what you typed — memorising the answer will not get you through.
Three levels of hint when you are stuck, and a "why that worked" at the end.
🔎 PASTE & UNDERSTAND
Paste any command you found on the internet. ShellPer takes it apart, explains every flag, splits the pipeline into stages and tells you what each connector does.
Danger Radar checks it against 31 rules before you run it — from rm -rf and mkfs to curl | sh. It also spots passwords and API keys that would land in your shell history.
📕 26 PLAYBOOKS
Search by symptom, not by command. Type "disk full" and get the ordered steps: which command, what to look for in its output, and the classic trap that costs people hours.
🧰 THE TOOLKIT
• Permission converter — 755 ⇄ rwxr-xr-x, including setuid, setgid and sticky
• Cron translator — plain language, plus the next five run times as real dates
• Distro translator — 15 package operations across apt, dnf, pacman, zypper and apk
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Everything works offline. Nothing is sent anywhere.
For sysadmins, developers, students, and anyone who has ever pasted a command they did not understand.

What’s new

This release turns ShellPer from a dictionary into a practice app.

• THE LAB — 10 scripted missions on a simulated Linux box. Real shell, real error messages.

• DAILY PUZZLE — one task a day, the same for everyone. Free.

• PASTE & UNDERSTAND — takes a command apart and checks it against 31 danger rules.

• 26 PLAYBOOKS — from symptom to fix, step by step.

• Permission, cron and distro converters.

• The command library grew from 90 to 358.

• Search now handles typos and partial words.