• Standard syslog
• journald
• multitail (for viewing multiple different files on your system)

• If you want to send logs from CLI to syslog you do it via logger

• If you want to send logs from CLI to journald you do it via systemd-cat
  • It's the equivalent of logger on syslog
  • Whatever goes to syslog is also getting logged to journald
• https://www.digitalocean.com/community/tutorials/how-to-use-journalctl-to-view-and-manipulate-systemd-logs
  • Very good crash course

I would stick with logger: it works with any standards-compliant logging system, including systemd’s journal as you’ve discovered. Using systemd-cat directly would only make your scripts systemd-specific, without adding anything; in fact, modern logger is much more flexible, and provides better support for systemd-specific features than systemd-cat itself.

Link: https://unix.stackexchange.com/a/393102/84061