Nautilus

Purpose

Hands-on shell practice across Linux, networking, and security tooling. Not a course — no walkthroughs, minimal explanation. Assumes everyday CLI familiarity. Serves as a way to identify knowledge gaps and RTFM, rather than providing detailed instruction.

Disclaimers

• Use common sense and do not run these commands against infrastructure you do not own or have permission to test.
• This site has been vibe hacked together for my own practice as a side project, and while content has been verified as well as my skills allow, there might be broken things or imprecisions. PRs with fixes and new content are welcome at https://github.com/janschupke/nautilus (opens in a new tab)

Prerequisites

Linux CLI, Git, SSH, Docker, basic networking.

Coverage

• Linux fundamentals — kernel, boot, filesystem, permissions, I/O, packages
• Shell basics — environment, binary inspection, cut, sed, awk, sort, grep, jq, yq, logs, parallelism, scripting
• Filesystem — find, FHS, diff, archives, compression
• Processes and users — signals, permissions, systemd, cron, introspection
• Networking theory — addressing, ports, TCP/UDP, DNS, routing, protocols
• Networking — curl, wget, SSH, rsync, DNS, ping, whois, TLS, netcat, tcpdump, tshark
• Exploitation — nmap, ffuf, wordlists, hydra, masscan
• Forensics — artifact analysis, log investigation, host triage