<?xml version='1.0'?> <!--*-nxml-*-->

<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"

"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<refentry id="journalctl"

xmlns:xi="http://www.w3.org/2001/XInclude">

<refentryinfo>

<title>journalctl</title>

<productname>systemd</productname>

</refentryinfo>

<refmeta>

<refentrytitle>journalctl</refentrytitle>

<manvolnum>1</manvolnum>

</refmeta>

<refnamediv>

<refname>journalctl</refname>

<refpurpose>Query the systemd journal</refpurpose>

</refnamediv>

<refsynopsisdiv>

<cmdsynopsis>

<command>journalctl</command>

<arg choice="opt" rep="repeat">OPTIONS</arg>

<arg choice="opt" rep="repeat">MATCHES</arg>

</cmdsynopsis>

</refsynopsisdiv>

<refsect1>

<title>Description</title>

<para><command>journalctl</command> may be used to query the

contents of the

<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>

journal as written by

<citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>

<para>If called without parameters, it will show the full

contents of the journal, starting with the oldest entry

collected.</para>

<para>If one or more match arguments are passed, the output is

filtered accordingly. A match is in the format

<literal>FIELD=VALUE</literal>,

e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>, referring

to the components of a structured journal entry. See

<citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>

for a list of well-known fields. If multiple matches are

specified matching different fields, the log entries are

filtered by both, i.e. the resulting output will show only

entries matching all the specified matches of this kind. If two

matches apply to the same field, then they are automatically

matched as alternatives, i.e. the resulting output will show

entries matching any of the specified matches for the same

field. Finally, the character <literal>+</literal> may appear

as a separate word between other terms on the command line. This

causes all matches before and after to be combined in a

disjunction (i.e. logical OR).</para>

<para>It is also possible to filter the entries by specifying an

absolute file path as an argument. The file path may be a file or

a symbolic link and the file must exist at the time of the query. If a

file path refers to an executable binary, an <literal>_EXE=</literal>

match for the canonicalized binary path is added to the query. If a

file path refers to an executable script, a <literal>_COMM=</literal>

match for the script name is added to the query. If a file path

refers to a device node, <literal>_KERNEL_DEVICE=</literal> matches for

the kernel name of the device and for each of its ancestor devices is

added to the query. Symbolic links are dereferenced, kernel names are

synthesized, and parent devices are identified from the environment at

the time of the query. In general, a device node is the best proxy for

an actual device, as log entries do not usually contain fields that

identify an actual device. For the resulting log entries to be correct

for the actual device, the relevant parts of the environment at the time

the entry was logged, in particular the actual device corresponding to

the device node, must have been the same as those at the time of the

query. Because device nodes generally change their corresponding devices

across reboots, specifying a device node path causes the resulting

entries to be restricted to those from the current boot.</para>

<para>Additional constraints may be added using options

<option>--boot</option>, <option>--unit=</option>, etc., to

further limit what entries will be shown (logical AND).</para>

<para>Output is interleaved from all accessible journal files,

whether they are rotated or currently being written, and

regardless of whether they belong to the system itself or are

accessible user journals.</para>

<para>The set of journal files which will be used can be

modified using the <option>--user</option>,

<option>--system</option>, <option>--directory</option>, and

<option>--file</option> options, see below.</para>

<para>All users are granted access to their private per-user

journals. However, by default, only root and users who are

members of a few special groups are granted access to the system

journal and the journals of other users. Members of the groups

<literal>systemd-journal</literal>, <literal>adm</literal>, and

<literal>wheel</literal> can read all journal files. Note

that the two latter groups traditionally have additional

privileges specified by the distribution. Members of the

<literal>wheel</literal> group can often perform administrative

tasks.</para>

<para>The output is paged through <command>less</command> by

default, and long lines are "truncated" to screen width. The

hidden part can be viewed by using the left-arrow and

right-arrow keys. Paging can be disabled; see the

<option>--no-pager</option> option and the "Environment" section

below.</para>

<para>When outputting to a tty, lines are colored according to

priority: lines of level ERROR and higher are colored red; lines

of level NOTICE and higher are highlighted; lines of level DEBUG

are colored lighter grey; other lines are displayed normally.</para>

</refsect1>

<refsect1>

<title>Options</title>

<para>The following options are understood:</para>

<variablelist>

<varlistentry>

<term><option>--no-full</option></term>

<term><option>--full</option></term>

<term><option>-l</option></term>

<listitem><para>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.</para>

<para>The old options

<option>-l</option>/<option>--full</option> are not useful

anymore, except to undo <option>--no-full</option>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-a</option></term>

<term><option>--all</option></term>

<listitem><para>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.)</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-f</option></term>

<term><option>--follow</option></term>

<listitem><para>Show only the most recent journal entries,

and continuously print new entries as they are appended to

the journal.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-e</option></term>

<term><option>--pager-end</option></term>

<listitem><para>Immediately jump to the end of the journal

inside the implied pager tool. This implies

<option>-n1000</option> to guarantee that the pager will not

buffer logs of unbounded size. This may be overridden with

an explicit <option>-n</option> with some other numeric

value, while <option>-nall</option> will disable this cap.

Note that this option is only supported for the

<citerefentry project='man-pages'><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>

pager.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-n</option></term>

<term><option>--lines=</option></term>

<listitem><para>Show the most recent journal events and

limit the number of events shown. If

<option>--follow</option> is used, this option is

implied. The argument is a positive integer or

<literal>all</literal> to disable line limiting. The default

value is 10 if no argument is given.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--no-tail</option></term>

<listitem><para>Show all stored output lines, even in follow

mode. Undoes the effect of <option>--lines=</option>.

</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-r</option></term>

<term><option>--reverse</option></term>

<listitem><para>Reverse output so that the newest entries

are displayed first.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-o</option></term>

<term><option>--output=</option></term>

<listitem><para>Controls the formatting of the journal

entries that are shown. Takes one of the following

options:</para>

<variablelist>

<varlistentry>

<term>

<option>short</option>

</term>

<listitem>

<para>is the default and generates an output that is

mostly identical to the formatting of classic syslog

files, showing one line per journal entry.</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>short-full</option>

</term>

<listitem>

<para>is very similar, but shows timestamps in the format the <option>--since=</option> and

<option>--until=</option> options accept. Unlike the timestamp information shown in

<option>short</option> output mode this mode includes weekday, year and timezone information in the

output, and is locale-independent.</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>short-iso</option>

</term>

<listitem>

<para>is very similar, but shows ISO 8601 wallclock

timestamps.</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>short-iso-precise</option>

</term>

<listitem>

<para>as for <option>short-iso</option> but includes full

microsecond precision.</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>short-precise</option>

</term>

<listitem>

<para>is very similar, but shows classic syslog timestamps

with full microsecond precision.</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>short-monotonic</option>

</term>

<listitem>

<para>is very similar, but shows monotonic timestamps

instead of wallclock timestamps.</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>short-unix</option>

</term>

<listitem>

<para>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.</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>verbose</option>

</term>

<listitem>

<para>shows the full-structured entry items with all

fields.</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>export</option>

</term>

<listitem>

<para>serializes the journal into a binary (but mostly

text-based) stream suitable for backups and network

transfer (see

<ulink url="https://www.freedesktop.org/wiki/Software/systemd/export">Journal Export Format</ulink>

for more information). To import the binary stream back

into native journald format use

<citerefentry><refentrytitle>systemd-journal-remote</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>json</option>

</term>

<listitem>

<para>formats entries as JSON objects, separated by newline characters (see <ulink

url="https://www.freedesktop.org/wiki/Software/systemd/json">Journal JSON Format</ulink> for more

information). Field values are generally encoded as JSON strings, with three exceptions:

<orderedlist>

<listitem><para>Fields larger than 4096 bytes are encoded as <constant>null</constant> values. (This

may be turned off by passing <option>--all</option>, but be aware that this may allocate overly long

JSON objects.) </para></listitem>

<listitem><para>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.</para></listitem>

<listitem><para>Fields containing non-printable or non-UTF8 bytes are encoded as arrays containing

the raw bytes individually formatted as unsigned numbers.</para></listitem>

</orderedlist>

Note that this encoding is reversible (with the exception of the size limit).</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>json-pretty</option>

</term>

<listitem>

<para>formats entries as JSON data structures, but

formats them in multiple lines in order to make them

more readable by humans.</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>json-sse</option>

</term>

<listitem>

<para>formats entries as JSON data structures, but wraps

them in a format suitable for

<ulink url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent Events</ulink>.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>json-seq</option>

</term>

<listitem>

<para>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 <ulink

url="https://tools.ietf.org/html/rfc7464">JavaScript Object Notation (JSON) Text Sequences </ulink>

(<literal>application/json-seq</literal>).

</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>cat</option>

</term>

<listitem>

<para>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

<option>--output-fields=</option> option will output the listed fields for each log record,

instead of the message.</para>

</listitem>

</varlistentry>

<varlistentry>

<term>

<option>with-unit</option>

</term>

<listitem>

<para>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.</para>

</listitem>

</varlistentry>

</variablelist>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--output-fields=</option></term>

<listitem><para>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 (<option>verbose</option>,

<option>export</option>, <option>json</option>, <option>json-pretty</option>,

<option>json-sse</option> and <option>json-seq</option>), as well as on <option>cat</option>. For the

former, the <literal>__CURSOR</literal>, <literal>__REALTIME_TIMESTAMP</literal>,

<literal>__MONOTONIC_TIMESTAMP</literal>, and <literal>_BOOT_ID</literal> fields are always

printed.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--utc</option></term>

<listitem><para>Express time in Coordinated Universal Time

(UTC).</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--no-hostname</option></term>

<listitem><para>Don't show the hostname field of log messages originating from the local host. This

switch has an effect only on the <option>short</option> family of output modes (see above).

</para>

<para>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.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-x</option></term>

<term><option>--catalog</option></term>

<listitem><para>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

<ulink url="https://www.freedesktop.org/wiki/Software/systemd/catalog">Message Catalog Developer Documentation</ulink>.</para>

<para>Note: when attaching <command>journalctl</command>

output to bug reports, please do <emphasis>not</emphasis> use

<option>-x</option>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-q</option></term>

<term><option>--quiet</option></term>

<listitem><para>Suppresses all informational messages

(i.e. "-- Journal begins at …", "-- Reboot --"),

any warning messages regarding

inaccessible system journals when run as a normal

user.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-m</option></term>

<term><option>--merge</option></term>

<listitem><para>Show entries interleaved from all available

journals, including remote ones.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-b <optional><optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional>|<constant>all</constant></optional></option></term>

<term><option>--boot<optional>=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional>|<constant>all</constant></optional></option></term>

<listitem><para>Show messages from a specific boot. This will

add a match for <literal>_BOOT_ID=</literal>.</para>

<para>The argument may be empty, in which case logs for the

current boot will be shown.</para>

<para>If the boot ID is omitted, a positive

<replaceable>offset</replaceable> will look up the boots

starting from the beginning of the journal, and an

equal-or-less-than zero <replaceable>offset</replaceable> will

look up boots starting from the end of the journal. Thus,

<constant>1</constant> means the first boot found in the

journal in chronological order, <constant>2</constant> the

second and so on; while <constant>-0</constant> is the last

boot, <constant>-1</constant> the boot before last, and so

on. An empty <replaceable>offset</replaceable> is equivalent

to specifying <constant>-0</constant>, except when the current

boot is not the last boot (e.g. because

<option>--directory</option> was specified to look at logs

from a different machine).</para>

<para>If the 32-character <replaceable>ID</replaceable> is

specified, it may optionally be followed by

<replaceable>offset</replaceable> which identifies the boot

relative to the one given by boot

<replaceable>ID</replaceable>. Negative values mean earlier

boots and positive values mean later boots. If

<replaceable>offset</replaceable> is not specified, a value of

zero is assumed, and the logs for the boot given by

<replaceable>ID</replaceable> are shown.</para>

<para>The special argument <constant>all</constant> can be

used to negate the effect of an earlier use of

<option>-b</option>.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--list-boots</option></term>

<listitem><para>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.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-k</option></term>

<term><option>--dmesg</option></term>

<listitem><para>Show only kernel messages. This implies

<option>-b</option> and adds the match

<literal>_TRANSPORT=kernel</literal>.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-t</option></term>

<term><option>--identifier=<replaceable>SYSLOG_IDENTIFIER</replaceable></option></term>

<listitem><para>Show messages for the specified syslog

identifier

<replaceable>SYSLOG_IDENTIFIER</replaceable>.</para>

<para>This parameter can be specified multiple

times.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-u</option></term>

<term><option>--unit=<replaceable>UNIT</replaceable>|<replaceable>PATTERN</replaceable></option></term>

<listitem><para>Show messages for the specified systemd unit

<replaceable>UNIT</replaceable> (such as a service unit), or

for any of the units matched by

<replaceable>PATTERN</replaceable>. 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

(<literal>_SYSTEMD_UNIT=<replaceable>UNIT</replaceable></literal>),

along with additional matches for messages from systemd and

messages about coredumps for the specified unit. A match

is also added for <literal>_SYSTEMD_SLICE=<replaceable>UNIT</replaceable></literal>,

such that if the provided <replaceable>UNIT</replaceable> is a

<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>

unit, all logs of children of the slice will be shown.

</para>

<para>This parameter can be specified multiple times.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--user-unit=</option></term>

<listitem><para>Show messages for the specified user session

unit. This will add a match for messages from the unit

(<literal>_SYSTEMD_USER_UNIT=</literal> and

<literal>_UID=</literal>) and additional matches for messages

from session systemd and messages about coredumps for the

specified unit. A match

is also added for <literal>_SYSTEMD_USER_SLICE=<replaceable>UNIT</replaceable></literal>,

such that if the provided <replaceable>UNIT</replaceable> is a

<citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>

unit, all logs of children of the unit will be shown.</para>

<para>This parameter can be specified multiple times.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-p</option></term>

<term><option>--priority=</option></term>

<listitem><para>Filter output by message priorities or

priority ranges. Takes either a single numeric or textual log

level (i.e. between 0/<literal>emerg</literal> and

7/<literal>debug</literal>), 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

<citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,

i.e. <literal>emerg</literal> (0),

<literal>alert</literal> (1), <literal>crit</literal> (2),

<literal>err</literal> (3), <literal>warning</literal> (4),

<literal>notice</literal> (5), <literal>info</literal> (6),

<literal>debug</literal> (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

<literal>PRIORITY=</literal> matches for the specified

priorities.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--facility=</option></term>

<listitem><para>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

<citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>.

<option>--facility=help</option> may be used to display a list of known facility names and exit.

</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-g</option></term>

<term><option>--grep=</option></term>

<listitem><para>Filter output to entries where the <varname>MESSAGE=</varname>

field matches the specified regular expression. PERL-compatible regular expressions

are used, see

<citerefentry project='url'><refentrytitle url='http://pcre.org/current/doc/html/pcre2pattern.html'>pcre2pattern</refentrytitle><manvolnum>3</manvolnum></citerefentry>

for a detailed description of the syntax.</para>

<para>If the pattern is all lowercase, matching is case insensitive.

Otherwise, matching is case sensitive. This can be overridden with the

<option>--case-sensitive</option> option, see below.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--case-sensitive<optional>=BOOLEAN</optional></option></term>

<listitem><para>Make pattern matching case sensitive or case insensitive.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-c</option></term>

<term><option>--cursor=</option></term>

<listitem><para>Start showing entries from the location in the

journal specified by the passed cursor.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--cursor-file=<replaceable>FILE</replaceable></option></term>

<listitem><para>If <replaceable>FILE</replaceable> exists and contains a

cursor, start showing entries <emphasis>after</emphasis> this location.

Otherwise the show entries according the other given options. At the end,

write the cursor of the last entry to <replaceable>FILE</replaceable>. Use

this option to continually read the journal by sequentially calling

<command>journalctl</command>.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--after-cursor=</option></term>

<listitem><para>Start showing entries from the location in the

journal <emphasis>after</emphasis> the location specified by

the passed cursor. The cursor is shown when the

<option>--show-cursor</option> option is used.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--show-cursor</option></term>

<listitem><para>The cursor is shown after the last entry after

two dashes:</para>

<programlisting>-- cursor: s=0639…</programlisting>

<para>The format of the cursor is private

and subject to change.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-S</option></term>

<term><option>--since=</option></term>

<term><option>-U</option></term>

<term><option>--until=</option></term>

<listitem><para>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 <literal>2012-10-30 18:17:16</literal>. If the

time part is omitted, <literal>00:00:00</literal> is assumed. If only the seconds component is omitted,

<literal>:00</literal> is assumed. If the date component is omitted, the current day is assumed. Alternatively

the strings <literal>yesterday</literal>, <literal>today</literal>, <literal>tomorrow</literal> 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. <literal>now</literal> refers to the current time. Finally, relative times may be specified,

prefixed with <literal>-</literal> or <literal>+</literal>, referring to times before or after the current

time, respectively. For complete time and date specification, see

<citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>. Note that

<option>--output=short-full</option> prints timestamps that follow precisely this format.

</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-F</option></term>

<term><option>--field=</option></term>

<listitem><para>Print all possible data values the specified

field can take in all entries of the journal.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-N</option></term>

<term><option>--fields</option></term>

<listitem><para>Print all field names currently used in all entries of the journal.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--system</option></term>

<term><option>--user</option></term>

<listitem><para>Show messages from system services and the

kernel (with <option>--system</option>). Show messages from

service of current user (with <option>--user</option>). If

neither is specified, show all messages that the user can see.

</para></listitem>

</varlistentry>

<varlistentry>

<term><option>-M</option></term>

<term><option>--machine=</option></term>

<listitem><para>Show messages from a running, local

container. Specify a container name to connect to.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>-D <replaceable>DIR</replaceable></option></term>

<term><option>--directory=<replaceable>DIR</replaceable></option></term>

<listitem><para>Takes a directory path as argument. If

specified, journalctl will operate on the specified journal

directory <replaceable>DIR</replaceable> instead of the

default runtime and system journal paths.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--file=<replaceable>GLOB</replaceable></option></term>

<listitem><para>Takes a file glob as an argument. If

specified, journalctl will operate on the specified journal

files matching <replaceable>GLOB</replaceable> instead of the

default runtime and system journal paths. May be specified

multiple times, in which case files will be suitably

interleaved.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--root=<replaceable>ROOT</replaceable></option></term>

<listitem><para>Takes a directory path as an argument. If specified, <command>journalctl</command>

will operate on journal directories and catalog file hierarchy underneath the specified directory

instead of the root directory (e.g. <option>--update-catalog</option> will create

<filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>, and journal

files under <filename><replaceable>ROOT</replaceable>/run/journal/</filename> or

<filename><replaceable>ROOT</replaceable>/var/log/journal/</filename> will be displayed).

</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--image=<replaceable>IMAGE</replaceable></option></term>

<listitem><para>Takes a path to a disk image file or block device node. If specified,

<command>journalctl</command> will operate on the file system in the indicated disk image. This is

similar to <option>--root=</option> 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 <ulink url="https://systemd.io/DISCOVERABLE_PARTITIONS">Discoverable Partitions

Specification</ulink>. For further information on supported disk images, see

<citerefentry><refentrytitle>systemd-nspawn</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s

switch of the same name.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--namespace=<replaceable>NAMESPACE</replaceable></option></term>

<listitem><para>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 <literal>*</literal> data from all namespaces is

shown, interleaved. If the namespace identifier is prefixed with <literal>+</literal> data from the

specified namespace and the default namespace is shown, interleaved, but no other. For details about

journal namespaces see

<citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--header</option></term>

<listitem><para>Instead of showing journal contents, show

internal header information of the journal fields

accessed.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--disk-usage</option></term>

<listitem><para>Shows the current disk usage of all journal

files. This shows the sum of the disk usage of all archived

and active journal files.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--vacuum-size=</option></term>

<term><option>--vacuum-time=</option></term>

<term><option>--vacuum-files=</option></term>

<listitem><para>Removes the oldest archived journal files until the disk space they use falls below the

specified size (specified with the usual <literal>K</literal>, <literal>M</literal>, <literal>G</literal> and

<literal>T</literal> suffixes), or all archived journal files contain no data older than the specified timespan

(specified with the usual <literal>s</literal>, <literal>m</literal>, <literal>h</literal>,

<literal>days</literal>, <literal>months</literal>, <literal>weeks</literal> and <literal>years</literal>

suffixes), or no more than the specified number of separate journal files remain. Note that running

<option>--vacuum-size=</option> has only an indirect effect on the output shown by

<option>--disk-usage</option>, as the latter includes active journal files, while the vacuuming operation only

operates on archived journal files. Similarly, <option>--vacuum-files=</option> might not actually reduce the

number of journal files to below the specified number, as it will not remove active journal

files.</para>

<para><option>--vacuum-size=</option>, <option>--vacuum-time=</option> and <option>--vacuum-files=</option>

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.</para>

<para>These three switches may also be combined with <option>--rotate</option> 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.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--list-catalog

<optional><replaceable>128-bit-ID…</replaceable></optional>

</option></term>

<listitem><para>List the contents of the message catalog as a

table of message IDs, plus their short description strings.

</para>

<para>If any <replaceable>128-bit-ID</replaceable>s are

specified, only those entries are shown.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--dump-catalog

<optional><replaceable>128-bit-ID…</replaceable></optional>

</option></term>

<listitem><para>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 <filename>.catalog</filename>

files).</para>

<para>If any <replaceable>128-bit-ID</replaceable>s are

specified, only those entries are shown.</para>

</listitem>

</varlistentry>

<varlistentry>

<term><option>--update-catalog</option></term>

<listitem><para>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.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--setup-keys</option></term>

<listitem><para>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 <option>Seal=</option> option in

<citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>

for information on Forward Secure Sealing and for a link to a

refereed scholarly paper detailing the cryptographic theory it

is based on.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--force</option></term>

<listitem><para>When <option>--setup-keys</option> is passed

and Forward Secure Sealing (FSS) has already been configured,

recreate FSS keys.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--interval=</option></term>

<listitem><para>Specifies the change interval for the sealing

key when generating an FSS key pair with

<option>--setup-keys</option>. Shorter intervals increase CPU

consumption but shorten the time range of undetectable journal

alterations. Defaults to 15min.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--verify</option></term>

<listitem><para>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

<option>--verify-key=</option>, authenticity of the journal file

is verified.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--verify-key=</option></term>

<listitem><para>Specifies the FSS verification key to use for

the <option>--verify</option> operation.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--sync</option></term>

<listitem><para>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.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--flush</option></term>

<listitem><para>Asks the journal daemon to flush any log data stored in

<filename>/run/log/journal/</filename> into <filename>/var/log/journal/</filename>, 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 <filename>/run/log/journal/</filename> into

<filename>/var/log/journal/</filename> once during system runtime (but see

<option>--relinquish-var</option> 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 <filename>/var/log/journal/</filename> at the time it returns.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--relinquish-var</option></term>

<listitem><para>Asks the journal daemon for the reverse operation to <option>--flush</option>: if

requested the daemon will write further log data to <filename>/run/log/journal/</filename> and stops

writing to <filename>/var/log/journal/</filename>. A subsequent call to <option>--flush</option>

causes the log output to switch back to <filename>/var/log/journal/</filename>, see

above.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--smart-relinquish-var</option></term>

<listitem><para>Similar to <option>--relinquish-var</option> but executes no operation if the root file

system and <filename>/var/lib/journal/</filename> reside on the same mount point. This operation is

used during system shutdown in order to make the journal daemon stop writing data to

<filename>/var/log/journal/</filename> in case that directory is located on a mount point that needs

to be unmounted.</para></listitem>

</varlistentry>

<varlistentry>

<term><option>--rotate</option></term>

<listitem><para>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 <option>--vacuum-size=</option>,

<option>--vacuum-time=</option> and <option>--vacuum-file=</option> into a single command, see

above.</para></listitem>

</varlistentry>

<xi:include href="standard-options.xml" xpointer="help" />

<xi:include href="standard-options.xml" xpointer="version" />

<xi:include href="standard-options.xml" xpointer="no-pager" />

</variablelist>

</refsect1>

<refsect1>

<title>Exit status</title>

<para>On success, 0 is returned; otherwise, a non-zero failure

code is returned.</para>

</refsect1>

<xi:include href="common-variables.xml" />

<refsect1>

<title>Examples</title>

<para>Without arguments, all collected logs are shown