Linuxコマンド実践ラボ

The Linux Command Practice Lab is a learning app that uses hypothetical failure scenarios to practice the "Observe → Hypothesis → Safe Verification" sequence.

Topics covered:
• Command execution environment and termination state
• Files, owner, mode, ACL
• Process state, OOM, parent-child relationships
• systemd units and dependencies
• Journal and log rotation
• Filesystem capacity, inode, open file
• DNS, route, listen, connection path
• Least privilege, check before change, rollback

In each exercise, you choose your first move from four possible actions, and after correcting, you can check the reasoning. Incorrect answers are recorded in the terminal and displayed as review candidates.

This app is for general learning of the Linux environment. It is not an official app of any specific certification body, distribution, or product. It does not replace changes in production environments or operational decisions for individual systems. Changes should be implemented with organizational approval, backups, testing environments, and rollback procedures in place.