Systemd journald

Systemd's builtin journaling system is called journald.
It is managed using the journalctl executable.

Cookbook

journalctl \
  # target
  /usr/bin/program    # for specific executable
  -u foo.service      # for specific service
  -b                  # boot messages

  # functions
  -f                  # tail logs
  -e                  # jump to bottom of page

  # filters
  -p 7                # set loglevel 0-7 (priority)
  -g '.*foo$'         # grep logs
  -S,-U '2012-12-30'  # since/until (optional time '2012-12-30 18:00:00')