Added Journalctl commands

cheat/cheatsheets/journalctl

@@ -19,3 +19,14 @@ journalctl /usr/bin/dbus-daemon
 # Filter by PID
 journalctl _PID=123
 
+# Filter by Command, e.g., sshd
+journalctl _COMM=sshd
+
+# Filter by Command and time period
+journalctl _COMM=crond --since '10:00' --until '11:00'
+
+# List all available boots 
+journalctl --list-boots
+
+# Filter by specific User ID e.g., user id 1000 
+journalctl _UID=1000