Journalctl

Journalctl examples:
 * 1) journalctl -n 2 - two recent logs
 * 2) journalctl -o verbose -n 2 - some detailed information
 * 3) journalctl -f - to view log messages in real time as they are being generated and collected
 * 4) journalctl --since="6 days ago" - logs since 6days ago
 * 5) journallctl --since="2014-12-20"
 * 6) journalctl --since="2014-12-20 13:00" until="2014-12-21 14:00 -p warning" - logs between timestamps with priority warning
 * 7) journalctl _UID=1000 - log messages associated with UID =1000
 * 8) journalctl _UID=1000 PRIORITY=6
 * 9) journalctl -u dbus
 * 10) journalctl /dev/sda
 * 11) journalctl -p info - log messages with priority of info
 * 12) journalctl -n = /var/log/secure