💡 Systemd & Services March 5, 2026 5

Linux Command: journalctl

Query and display systemd journal logs

Terminal — Systemd & Services

Command

$ journalctl -u nginx --no-pager -n 50

Output

Shows last 50 log lines for nginx.

journalctl queries and displays logs from the systemd journal. The journal captures all system logs including kernel messages, service output, and syslog messages in a structured, indexed format. journalctl provides powerful filtering by service, time range, priority, and more. It replaces reading raw log files in /var/log/ for most troubleshooting tasks. journalctl is the primary log viewer for systemd-based systems. It supports real-time following, JSON output, and persistent storage of logs.

Syntax

journalctl [OPTION]...

Common Examples

journalctl -u nginx --no-pager -n 50 — Shows last 50 log lines for nginx.
journalctl -u myapp -f — Follows log output in real time (like tail -f).
journalctl -p err -b — Shows only error-level messages from current boot.
journalctl --since "2024-01-15 02:00" --until "2024-01-15 04:00" — Shows logs from a specific time window.