tail
TextPackage: coreutils
The last lines of a file, and with -f the ones arriving as they come. For a systemd service, journalctl -f is the same thing without having to know the file's path.
What its options do in the lessons
From the same glossary the lessons render under their commands, so the two cannot disagree.
tail -n- How many lines to print from the end.
tail -f- Follows the file and prints new lines as they arrive.
Lessons that teach it
- Reading file contentsLinux Fundamentals
- Your first server blockHosting a web application with Nginx
- Reading the access log: what one line already provesHosting a web application with Nginx
- Reading the error log: why the 502 happenedHosting a web application with Nginx
- The limits that refuse: 413 and 504Hosting a web application with Nginx
- Mailboxes and DNS zones from the panelISPConfig: hosting several sites on one server
- Moving a live domain: the record change is the shortest partDNS: pointing a domain at your server
- What the fix proved, and what expired on its ownDiagnosing a failure: what each output proves
- pg_wal fills, and something is holding itAdministering PostgreSQL: access, connections and growth
- Finding the slow queries, not the slow momentAdministering PostgreSQL: access, connections and growth