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+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+ "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+ This file is part of systemd.
+
+ Copyright 2012 Lennart Poettering
+
+ systemd is free software; you can redistribute it and/or modify it
+ under the terms of the GNU Lesser General Public License as published by
+ the Free Software Foundation; either version 2.1 of the License, or
+ (at your option) any later version.
+
+ systemd is distributed in the hope that it will be useful, but
+ WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public License
+ along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+
+ <refentry id="journalctl"
+ xmlns:xi="http://www.w3.org/2001/XInclude">
+
+ <refentryinfo>
+ <title>journalctl</title>
+ <productname>systemd</productname>
+
+ <authorgroup>
+ <author>
+ <contrib>Developer</contrib>
+ <firstname>Lennart</firstname>
+ <surname>Poettering</surname>
+ <email>lennart@poettering.net</email>
+ </author>
+ </authorgroup>
+ </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; 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.</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-iso</option>
+ </term>
+ <listitem>
+ <para>is very similar, but shows ISO 8601 wallclock
+ timestamps.</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>
+ <option>short-precise</option>
+ </term>
+ <listitem>
+ <para>is very similar, but shows 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="http://www.freedesktop.org/wiki/Software/systemd/export">Journal Export Format</ulink>
+ for more information).</para>
+ </listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term>
+ <option>json</option>
+ </term>
+ <listitem>
+ <para>formats entries as JSON data structures, one per
+ line (see
+ <ulink url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal JSON Format</ulink>
+ for more information).</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>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.</para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
+ </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 only
+ has an effect on the <option>short</option> family of output modes (see above).</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="http://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 info messages
+ (i.e. "-- Logs begin 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><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
+ <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></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>
+ </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.</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.</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>-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>--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>.
+ </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, journalctl will operate on 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>).
+ </para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--new-id128</option></term>
+
+ <listitem><para>Instead of showing journal contents, generate
+ a new 128-bit ID suitable for identifying messages. This is
+ intended for usage by developers who need a new identifier for
+ a new message they introduce and want to make
+ recognizable. This will print the new ID in three different
+ formats which can be copied into source code or similar.
+ </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 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. <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></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, 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>--rotate</option></term>
+
+ <listitem><para>Asks the journal daemon to rotate journal
+ files. This call does not return until the rotation operation
+ is complete.</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="less-variables.xml" />
+
+ <refsect1>
+ <title>Examples</title>
+
+ <para>Without arguments, all collected logs are shown
+ unfiltered:</para>
+
+ <programlisting>journalctl</programlisting>
+
+ <para>With one match specified, all entries with a field matching
+ the expression are shown:</para>
+
+ <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
+
+ <para>If two different fields are matched, only entries matching
+ both expressions at the same time are shown:</para>
+
+ <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
+
+ <para>If two matches refer to the same field, all entries matching
+ either expression are shown:</para>
+
+ <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
+
+ <para>If the separator <literal>+</literal> is used, two
+ expressions may be combined in a logical OR. The following will
+ show all messages from the Avahi service process with the PID
+ 28097 plus all messages from the D-Bus service (from any of its
+ processes):</para>
+
+ <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
+
+ <para>Show all logs generated by the D-Bus executable:</para>
+
+ <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
+
+ <para>Show all kernel logs from previous boot:</para>
+
+ <programlisting>journalctl -k -b -1</programlisting>
+
+ <para>Show a live log display from a system service
+ <filename>apache.service</filename>:</para>
+
+ <programlisting>journalctl -f -u apache</programlisting>
+
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+ <para>
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>systemd.time</refentrytitle><manvolnum>7</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+</refentry>