journalctl

linux

Query the systemd journal. See also: `dmesg`.

Options (7)

-n, --linesboolean

Show the latest `n` lines and follow new messages (like `tail --follow` for traditional syslog)

Example: journalctl {{[-n|--lines]}} {{n}} {{[-f|--follow]}}

-f, --followboolean

Show the latest `n` lines and follow new messages (like `tail --follow` for traditional syslog)

Example: journalctl {{[-n|--lines]}} {{n}} {{[-f|--follow]}}

-b, --bootboolean

Show all messages with priority level 3 (errors) from the boot before last shutdown

Example: journalctl {{[-b|--boot]}} -1 {{[-p|--priority]}} 3

-p, --priorityboolean

Show all messages with priority level 3 (errors) from the boot before last shutdown

Example: journalctl {{[-b|--boot]}} -1 {{[-p|--priority]}} 3

-u, --unitboolean

Show all messages by a specific unit

Example: journalctl {{[-u|--unit]}} {{unit}}

-S, --sinceboolean

Filter messages within a time range (either timestamp or placeholders like "yesterday")

Example: journalctl {{[-S|--since]}} {{now|today|yesterday|tomorrow|...}} {{[-U|--until]}} "{{YYYY-MM-DD HH:MM:SS}}"

-U, --untilboolean

Filter messages within a time range (either timestamp or placeholders like "yesterday")

Example: journalctl {{[-S|--since]}} {{now|today|yesterday|tomorrow|...}} {{[-U|--until]}} "{{YYYY-MM-DD HH:MM:SS}}"

Show the latest `n` lines and follow new messages (like `tail --follow` for traditional syslog)

journalctl [-n|--lines] n [-f|--follow]

Show all messages with priority level 3 (errors) from the boot before last shutdown

journalctl [-b|--boot] -1 [-p|--priority] 3

Show all messages by a specific unit

journalctl [-u|--unit] unit

Show logs for a given unit since the last time it started

journalctl _SYSTEMD_INVOCATION_ID=$(systemctl show --value --property=InvocationID unit)

Filter messages within a time range (either timestamp or placeholders like "yesterday")

Show all messages by a specific process

journalctl _PID=pid

Show all messages by a specific executable

journalctl path/to/executable

Delete journal logs which are older than 2 days

journalctl --vacuum-time 2d