The following options are understood:
--no-full, --full, -l
Ellipsize fields when they do not fit in available columns.
The default is to show full fields, allowing them to wrap or
be truncated by the pager, if one is used.
The old options -l/--full are not useful anymore, except to
undo --no-full.
-a, --all
Show all fields in full, even if they include unprintable
characters or are very long. By default, fields with
unprintable characters are abbreviated as "blob data". (Note
that the pager may escape unprintable characters again.)
-f, --follow
Show only the most recent journal entries, and continuously
print new entries as they are appended to the journal.
-e, --pager-end
Immediately jump to the end of the journal inside the implied
pager tool. This implies -n1000 to guarantee that the pager
will not buffer logs of unbounded size. This may be
overridden with an explicit -n with some other numeric value,
while -nall will disable this cap. Note that this option is
only supported for the less(1) pager.
-n, --lines=
Show the most recent journal events and limit the number of
events shown. If --follow is used, this option is implied.
The argument is a positive integer or "all" to disable line
limiting. The default value is 10 if no argument is given.
--no-tail
Show all stored output lines, even in follow mode. Undoes the
effect of --lines=.
-r, --reverse
Reverse output so that the newest entries are displayed
first.
-o, --output=
Controls the formatting of the journal entries that are
shown. Takes one of the following options:
short
is the default and generates an output that is mostly
identical to the formatting of classic syslog files,
showing one line per journal entry.
short-full
is very similar, but shows timestamps in the format the
--since= and --until= options accept. Unlike the
timestamp information shown in short output mode this
mode includes weekday, year and timezone information in
the output, and is locale-independent.
short-iso
is very similar, but shows ISO 8601 wallclock timestamps.
short-iso-precise
as for short-iso but includes full microsecond precision.
short-precise
is very similar, but shows classic syslog timestamps with
full microsecond precision.
short-monotonic
is very similar, but shows monotonic timestamps instead
of wallclock timestamps.
short-unix
is very similar, but shows seconds passed since January
1st 1970 UTC instead of wallclock timestamps ("UNIX
time"). The time is shown with microsecond accuracy.
verbose
shows the full-structured entry items with all fields.
export
serializes the journal into a binary (but mostly
text-based) stream suitable for backups and network
transfer (see Journal Export Format
json
formats entries as JSON objects, separated by newline
characters (see Journal JSON Format
1. Fields larger than 4096 bytes are encoded as null
values. (This may be turned off by passing --all, but
be aware that this may allocate overly long JSON
objects.)
2. Journal entries permit non-unique fields within the
same log entry. JSON does not allow non-unique fields
within objects. Due to this, if a non-unique field is
encountered a JSON array is used as field value,
listing all field values as elements.
3. Fields containing non-printable or non-UTF8 bytes are
encoded as arrays containing the raw bytes
individually formatted as unsigned numbers.
Note that this encoding is reversible (with the exception
of the size limit).
json-pretty
formats entries as JSON data structures, but formats them
in multiple lines in order to make them more readable by
humans.
json-sse
formats entries as JSON data structures, but wraps them
in a format suitable for Server-Sent Events
json-seq
formats entries as JSON data structures, but prefixes
them with an ASCII Record Separator character (0x1E) and
suffixes them with an ASCII Line Feed character (0x0A),
in accordance with JavaScript Object Notation (JSON) Text
Sequences
cat
generates a very terse output, only showing the actual
message of each journal entry with no metadata, not even
a timestamp. If combined with the --output-fields= option
will output the listed fields for each log record,
instead of the message.
with-unit
similar to short-full, but prefixes the unit and user
unit names instead of the traditional syslog identifier.
Useful when using templated instances, as it will include
the arguments in the unit names.
--output-fields=
A comma separated list of the fields which should be included
in the output. This has an effect only for the output modes
which would normally show all fields (verbose, export, json,
json-pretty, json-sse and json-seq), as well as on cat. For
the former, the "__CURSOR", "__REALTIME_TIMESTAMP",
"__MONOTONIC_TIMESTAMP", and "_BOOT_ID" fields are always
printed.
--utc
Express time in Coordinated Universal Time (UTC).
--no-hostname
Don't show the hostname field of log messages originating
from the local host. This switch has an effect only on the
short family of output modes (see above).
Note: this option does not remove occurrences of the hostname
from log entries themselves, so it does not prevent the
hostname from being visible in the logs.
-x, --catalog
Augment log lines with explanation texts from the message
catalog. This will add explanatory help texts to log messages
in the output where this is available. These short help texts
will explain the context of an error or log event, possible
solutions, as well as pointers to support forums, developer
documentation, and any other relevant manuals. Note that help
texts are not available for all messages, but only for
selected ones. For more information on the message catalog,
please refer to the Message Catalog Developer
Documentation
Note: when attaching journalctl output to bug reports, please
do not use -x.
-q, --quiet
Suppresses all informational messages (i.e. "-- Journal
begins at ...", "-- Reboot --"), any warning messages
regarding inaccessible system journals when run as a normal
user.
-m, --merge
Show entries interleaved from all available journals,
including remote ones.
-b [[ID][±offset]|all], --boot[=[ID][±offset]|all]
Show messages from a specific boot. This will add a match for
"_BOOT_ID=".
The argument may be empty, in which case logs for the current
boot will be shown.
If the boot ID is omitted, a positive offset will look up the
boots starting from the beginning of the journal, and an
equal-or-less-than zero offset will look up boots starting
from the end of the journal. Thus, 1 means the first boot
found in the journal in chronological order, 2 the second and
so on; while -0 is the last boot, -1 the boot before last,
and so on. An empty offset is equivalent to specifying -0,
except when the current boot is not the last boot (e.g.
because --directory was specified to look at logs from a
different machine).
If the 32-character ID is specified, it may optionally be
followed by offset which identifies the boot relative to the
one given by boot ID. Negative values mean earlier boots and
positive values mean later boots. If offset is not specified,
a value of zero is assumed, and the logs for the boot given
by ID are shown.
The special argument all can be used to negate the effect of
an earlier use of -b.
--list-boots
Show a tabular list of boot numbers (relative to the current
boot), their IDs, and the timestamps of the first and last
message pertaining to the boot.
-k, --dmesg
Show only kernel messages. This implies -b and adds the match
"_TRANSPORT=kernel".
-t, --identifier=SYSLOG_IDENTIFIER
Show messages for the specified syslog identifier
SYSLOG_IDENTIFIER.
This parameter can be specified multiple times.
-u, --unit=UNIT|PATTERN
Show messages for the specified systemd unit UNIT (such as a
service unit), or for any of the units matched by PATTERN. If
a pattern is specified, a list of unit names found in the
journal is compared with the specified pattern and all that
match are used. For each unit name, a match is added for
messages from the unit ("_SYSTEMD_UNIT=UNIT"), along with
additional matches for messages from systemd and messages
about coredumps for the specified unit. A match is also added
for "_SYSTEMD_SLICE=UNIT", such that if the provided UNIT is
a systemd.slice(5) unit, all logs of children of the slice
will be shown.
This parameter can be specified multiple times.
--user-unit=
Show messages for the specified user session unit. This will
add a match for messages from the unit ("_SYSTEMD_USER_UNIT="
and "_UID=") and additional matches for messages from session
systemd and messages about coredumps for the specified unit.
A match is also added for "_SYSTEMD_USER_SLICE=UNIT", such
that if the provided UNIT is a systemd.slice(5) unit, all
logs of children of the unit will be shown.
This parameter can be specified multiple times.
-p, --priority=
Filter output by message priorities or priority ranges. Takes
either a single numeric or textual log level (i.e. between
0/"emerg" and 7/"debug"), or a range of numeric/text log
levels in the form FROM..TO. The log levels are the usual
syslog log levels as documented in syslog(3), i.e.
"emerg" (0), "alert" (1), "crit" (2), "err" (3),
"warning" (4), "notice" (5), "info" (6), "debug" (7). If a
single log level is specified, all messages with this log
level or a lower (hence more important) log level are shown.
If a range is specified, all messages within the range are
shown, including both the start and the end value of the
range. This will add "PRIORITY=" matches for the specified
priorities.
--facility=
Filter output by syslog facility. Takes a comma-separated
list of numbers or facility names. The names are the usual
syslog facilities as documented in syslog(3).
--facility=help may be used to display a list of known
facility names and exit.
-g, --grep=
Filter output to entries where the MESSAGE= field matches the
specified regular expression. PERL-compatible regular
expressions are used, see pcre2pattern(3) for a detailed
description of the syntax.
If the pattern is all lowercase, matching is case
insensitive. Otherwise, matching is case sensitive. This can
be overridden with the --case-sensitive option, see below.
--case-sensitive[=BOOLEAN]
Make pattern matching case sensitive or case insensitive.
-c, --cursor=
Start showing entries from the location in the journal
specified by the passed cursor.
--cursor-file=FILE
If FILE exists and contains a cursor, start showing entries
after this location. Otherwise the show entries according the
other given options. At the end, write the cursor of the last
entry to FILE. Use this option to continually read the
journal by sequentially calling journalctl.
--after-cursor=
Start showing entries from the location in the journal after
the location specified by the passed cursor. The cursor is
shown when the --show-cursor option is used.
--show-cursor
The cursor is shown after the last entry after two dashes:
-- cursor: s=0639...
The format of the cursor is private and subject to change.
-S, --since=, -U, --until=
Start showing entries on or newer than the specified date, or
on or older than the specified date, respectively. Date
specifications should be of the format "2012-10-30 18:17:16".
If the time part is omitted, "00:00:00" is assumed. If only
the seconds component is omitted, ":00" is assumed. If the
date component is omitted, the current day is assumed.
Alternatively the strings "yesterday", "today", "tomorrow"
are understood, which refer to 00:00:00 of the day before the
current day, the current day, or the day after the current
day, respectively. "now" refers to the current time.
Finally, relative times may be specified, prefixed with "-"
or "+", referring to times before or after the current time,
respectively. For complete time and date specification, see
systemd.time(7). Note that --output=short-full prints
timestamps that follow precisely this format.
-F, --field=
Print all possible data values the specified field can take
in all entries of the journal.
-N, --fields
Print all field names currently used in all entries of the
journal.
--system, --user
Show messages from system services and the kernel (with
--system). Show messages from service of current user (with
--user). If neither is specified, show all messages that the
user can see.
-M, --machine=
Show messages from a running, local container. Specify a
container name to connect to.
-D DIR, --directory=DIR
Takes a directory path as argument. If specified, journalctl
will operate on the specified journal directory DIR instead
of the default runtime and system journal paths.
--file=GLOB
Takes a file glob as an argument. If specified, journalctl
will operate on the specified journal files matching GLOB
instead of the default runtime and system journal paths. May
be specified multiple times, in which case files will be
suitably interleaved.
--root=ROOT
Takes a directory path as an argument. If specified,
journalctl will operate on journal directories and catalog
file hierarchy underneath the specified directory instead of
the root directory (e.g. --update-catalog will create
ROOT/var/lib/systemd/catalog/database, and journal files
under ROOT/run/journal/ or ROOT/var/log/journal/ will be
displayed).
--image=IMAGE
Takes a path to a disk image file or block device node. If
specified, journalctl will operate on the file system in the
indicated disk image. This is similar to --root= but operates
on file systems stored in disk images or block devices, thus
providing an easy way to extract log data from disk images.
The disk image should either contain just a file system or a
set of file systems within a GPT partition table, following
the Discoverable Partitions Specification
--namespace=NAMESPACE
Takes a journal namespace identifier string as argument. If
not specified the data collected by the default namespace is
shown. If specified shows the log data of the specified
namespace instead. If the namespace is specified as "*" data
from all namespaces is shown, interleaved. If the namespace
identifier is prefixed with "+" data from the specified
namespace and the default namespace is shown, interleaved,
but no other. For details about journal namespaces see
systemd-journald.service(8).
--header
Instead of showing journal contents, show internal header
information of the journal fields accessed.
--disk-usage
Shows the current disk usage of all journal files. This shows
the sum of the disk usage of all archived and active journal
files.
--vacuum-size=, --vacuum-time=, --vacuum-files=
Removes the oldest archived journal files until the disk
space they use falls below the specified size (specified with
the usual "K", "M", "G" and "T" suffixes), or all archived
journal files contain no data older than the specified
timespan (specified with the usual "s", "m", "h", "days",
"months", "weeks" and "years" suffixes), or no more than the
specified number of separate journal files remain. Note that
running --vacuum-size= has only an indirect effect on the
output shown by --disk-usage, as the latter includes active
journal files, while the vacuuming operation only operates on
archived journal files. Similarly, --vacuum-files= might not
actually reduce the number of journal files to below the
specified number, as it will not remove active journal files.
--vacuum-size=, --vacuum-time= and --vacuum-files= may be
combined in a single invocation to enforce any combination of
a size, a time and a number of files limit on the archived
journal files. Specifying any of these three parameters as
zero is equivalent to not enforcing the specific limit, and
is thus redundant.
These three switches may also be combined with --rotate into
one command. If so, all active files are rotated first, and
the requested vacuuming operation is executed right after.
The rotation has the effect that all currently active files
are archived (and potentially new, empty journal files opened
as replacement), and hence the vacuuming operation has the
greatest effect as it can take all log data written so far
into account.
--list-catalog [128-bit-ID...]
List the contents of the message catalog as a table of
message IDs, plus their short description strings.
If any 128-bit-IDs are specified, only those entries are
shown.
--dump-catalog [128-bit-ID...]
Show the contents of the message catalog, with entries
separated by a line consisting of two dashes and the ID (the
format is the same as .catalog files).
If any 128-bit-IDs are specified, only those entries are
shown.
--update-catalog
Update the message catalog index. This command needs to be
executed each time new catalog files are installed, removed,
or updated to rebuild the binary catalog index.
--setup-keys
Instead of showing journal contents, generate a new key pair
for Forward Secure Sealing (FSS). This will generate a
sealing key and a verification key. The sealing key is stored
in the journal data directory and shall remain on the host.
The verification key should be stored externally. Refer to
the Seal= option in journald.conf(5) for information on
Forward Secure Sealing and for a link to a refereed scholarly
paper detailing the cryptographic theory it is based on.
--force
When --setup-keys is passed and Forward Secure Sealing (FSS)
has already been configured, recreate FSS keys.
--interval=
Specifies the change interval for the sealing key when
generating an FSS key pair with --setup-keys. Shorter
intervals increase CPU consumption but shorten the time range
of undetectable journal alterations. Defaults to 15min.
--verify
Check the journal file for internal consistency. If the file
has been generated with FSS enabled and the FSS verification
key has been specified with --verify-key=, authenticity of
the journal file is verified.
--verify-key=
Specifies the FSS verification key to use for the --verify
operation.
--sync
Asks the journal daemon to write all yet unwritten journal
data to the backing file system and synchronize all journals.
This call does not return until the synchronization operation
is complete. This command guarantees that any log messages
written before its invocation are safely stored on disk at
the time it returns.
--flush
Asks the journal daemon to flush any log data stored in
/run/log/journal/ into /var/log/journal/, if persistent
storage is enabled. This call does not return until the
operation is complete. Note that this call is idempotent: the
data is only flushed from /run/log/journal/ into
/var/log/journal/ once during system runtime (but see
--relinquish-var below), and this command exits cleanly
without executing any operation if this has already happened.
This command effectively guarantees that all data is flushed
to /var/log/journal/ at the time it returns.
--relinquish-var
Asks the journal daemon for the reverse operation to --flush:
if requested the daemon will write further log data to
/run/log/journal/ and stops writing to /var/log/journal/. A
subsequent call to --flush causes the log output to switch
back to /var/log/journal/, see above.
--smart-relinquish-var
Similar to --relinquish-var but executes no operation if the
root file system and /var/lib/journal/ reside on the same
mount point. This operation is used during system shutdown in
order to make the journal daemon stop writing data to
/var/log/journal/ in case that directory is located on a
mount point that needs to be unmounted.
--rotate
Asks the journal daemon to rotate journal files. This call
does not return until the rotation operation is complete.
Journal file rotation has the effect that all currently
active journal files are marked as archived and renamed, so
that they are never written to in future. New (empty) journal
files are then created in their place. This operation may be
combined with --vacuum-size=, --vacuum-time= and
--vacuum-file= into a single command, see above.
-h, --help
Print a short help text and exit.
--version
Print a short version string and exit.
--no-pager
Do not pipe output into a pager.
