chiark / gitweb /
man: explain journalctl --flush correctly
[elogind.git] / man / journalctl.xml
index b8b29b4cb5da2e6f74c9dd5193e3fbc61b356a0f..0ed3ca3bc8750b23930ba12575a48d031a9d685d 100644 (file)
@@ -21,7 +21,8 @@
   along with systemd; If not, see <http://www.gnu.org/licenses/>.
 -->
 
-<refentry id="journalctl">
+<refentry id="journalctl"
+          xmlns:xi="http://www.w3.org/2001/XInclude">
 
         <refentryinfo>
                 <title>journalctl</title>
                 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, if the character
-                <literal>+</literal> appears as separate word on the
-                command line, all matches before and after are combined
-                in a disjunction (i.e. logical OR).</para>
+                same field. Finally, the character
+                <literal>+</literal> may appears 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>As shortcuts for a few types of field/value
                 matches, file paths may be specified. If a file path
                 <literal>_KERNEL_DEVICE=</literal> match for the
                 device.</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 the <literal>adm</literal>
+                users who are members of the <literal>systemd-journal</literal>
                 group get access to the system journal and the
                 journals of other users.</para>
 
                 <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
-                <option>--no-pager</option> and section Environment
-                below.</para>
+                keys. Paging can be disabled; see the
+                <option>--no-pager</option> option and the "Environment"
+                section below.</para>
 
-                <para>When outputing to a tty, lines are colored
+                <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, and other lines are displayed normally.
+                are colored red; lines of level NOTICE and higher are
+                highlighted; other lines are displayed normally.
                 </para>
         </refsect1>
 
 
                 <variablelist>
                         <varlistentry>
-                                <term><option>-h</option></term>
-                                <term><option>--help</option></term>
-
-                                <listitem><para>Prints a short help
-                                text and exits.</para></listitem>
-                        </varlistentry>
-
-                        <varlistentry>
-                                <term><option>--version</option></term>
-
-                                <listitem><para>Prints a short version
-                                string and exits.</para></listitem>
-                        </varlistentry>
-
-                        <varlistentry>
-                                <term><option>--no-pager</option></term>
-
-                                <listitem><para>Do not pipe output into a
-                                pager.</para></listitem>
-                        </varlistentry>
-
-                        <varlistentry>
-                                <term><option>-l</option></term>
+                                <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>
 
-                                <listitem><para>Show all (printable) fields in
-                                full.</para></listitem>
+                                <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>
                                 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 on the
-                                command line. Note that this option is
-                                only supported for the
-                                <citerefentry><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+                                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>
 
                                 journal events and limit the number of
                                 events shown. If
                                 <option>--follow</option> is used,
-                                this option is implied. The argument,
-                                a positive integer, is optional, and
-                                defaults to 10. </para></listitem>
+                                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>-r</option></term>
                                 <term><option>--reverse</option></term>
 
-                                <listitem><para>Reverse output, so the newest
+                                <listitem><para>Reverse output so that the newest
                                 entries are displayed first.</para></listitem>
                         </varlistentry>
 
 
                                 <listitem><para>Controls the
                                 formatting of the journal entries that
-                                are shown. Takes one of
-                                <literal>short</literal>,
-                                <literal>short-monotonic</literal>,
-                                <literal>verbose</literal>,
-                                <literal>export</literal>,
-                                <literal>json</literal>,
-                                <literal>json-pretty</literal>,
-                                <literal>json-sse</literal>,
-                                <literal>cat</literal>. <literal>short</literal>
-                                is the default and generates an output
-                                that is mostly identical to the
-                                formatting of classic syslog
-                                files, showing one line per journal
-                                entry. <literal>short-monotonic</literal>
-                                is very similar but shows monotonic
-                                timestamps instead of wallclock
-                                timestamps. <literal>verbose</literal>
-                                shows the full structured entry items
-                                with all
-                                fields. <literal>export</literal>
-                                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). <literal>json</literal>
-                                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). <literal>json-pretty</literal>
-                                also formats entries as JSON data
-                                structures, but formats them in
-                                multiple lines in order to make them
-                                more readable for
-                                humans. <literal>json-sse</literal>
-                                also 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>. <literal>cat</literal>
-                                generates a very terse output only
-                                showing the actual message of each
-                                journal entry with no meta data, not
-                                even a timestamp.</para></listitem>
+                                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>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>
                                 context of an error or log event,
                                 possible solutions, as well as
                                 pointers to support forums, developer
-                                documentation and any other relevant
+                                documentation, and any other relevant
                                 manuals. Note that help texts are not
                                 available for all messages, but only
                                 for selected ones. For more
                                 please refer to the <ulink
                                 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
                                 Catalog Developer
-                                Documentation</ulink>.</para></listitem>
+                                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>--quiet</option></term>
 
                                 <listitem><para>Suppresses any warning
-                                message regarding inaccessible system
-                                journals when run as normal
+                                messages regarding inaccessible system
+                                journals when run as normal
                                 user.</para></listitem>
                         </varlistentry>
 
                         </varlistentry>
 
                         <varlistentry>
-                                <term><option>-b</option></term>
-                                <term><option>--this-boot</option></term>
+                                <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 a 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 a 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 data only from
-                                current boot. This will add a match
-                                for <literal>_BOOT_ID=</literal> for
-                                the current boot ID of the
-                                kernel.</para></listitem>
+                                <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 kernel messages from
-                                current boot. This implies <option>-b</option>
-                                and adds the match <literal>_TRANSPORT=kernel</literal>.
+                                <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>|<replaceable>PATTERN</replaceable></option></term>
+
+                                <listitem><para>Show messages for the
+                                specified syslog identifier
+                                <replaceable>SYSLOG_IDENTIFIER</replaceable>, or
+                                for any of the messages with a <literal>SYSLOG_IDENTIFIER</literal>
+                                matched by <replaceable>PATTERN</replaceable>.</para>
+
+                                <para>This parameter can be specified
+                                multiple times.</para></listitem>
+                        </varlistentry>
+
                         <varlistentry>
                                 <term><option>-u</option></term>
-                                <term><option>--unit=</option></term>
+                                <term><option>--unit=<replaceable>UNIT</replaceable>|<replaceable>PATTERN</replaceable></option></term>
 
                                 <listitem><para>Show messages for the
-                                specified systemd unit. This will add
-                                a match for messages from the unit
-                                (<literal>_SYSTEMD_UNIT=</literal>)
-                                and 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>
+                                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>
                                 the form FROM..TO. The log levels are
                                 the usual syslog log levels as
                                 documented in
-                                <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+                                <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),
                                 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 this 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>--since=</option></term>
                                 <term><option>--until=</option></term>
 
                                 <listitem><para>Show messages from
                                 system services and the kernel (with
-                                <option>--system</option>).  Show
+                                <option>--system</option>). Show
                                 messages from service of current user
                                 (with <option>--user</option>).
                                 If neither is specified, show all
                                 </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>
                         <varlistentry>
                                 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
 
-                                <listitem><para>Takes a file glob as
+                                <listitem><para>Takes a file glob as an
                                 argument. If specified, journalctl will
                                 operate on the specified journal files
                                 matching <replaceable>GLOB</replaceable>
                                 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
 
                                 <listitem><para>Takes a directory path
-                                as argument. If specified, journalctl
+                                as an argument. If specified, journalctl
                                 will operate on catalog file hierarchy
                                 underneath the specified directory
                                 instead of the root directory
                                 <term><option>--new-id128</option></term>
 
                                 <listitem><para>Instead of showing
-                                journal contents, generate a new 128
-                                bit ID suitable for identifying
+                                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
 
                         <varlistentry>
                                 <term><option>--list-catalog
-                                <optional><replaceable>ID128...</replaceable></optional>
+                                <optional><replaceable>128-bit-ID...</replaceable></optional>
                                 </option></term>
 
                                 <listitem><para>List the contents of
-                                the message catalog, as table of
-                                message IDs plus their short
+                                the message catalog as a table of
+                                message IDs, plus their short
                                 description strings.</para>
 
                                 <para>If any
-                                <replaceable>ID128</replaceable>s are
+                                <replaceable>128-bit-ID</replaceable>s are
                                 specified, only those entries are shown.
                                 </para>
                                 </listitem>
 
                         <varlistentry>
                                 <term><option>--dump-catalog
-                                <optional><replaceable>ID128...</replaceable></optional>
+                                <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
+                                dashes and the ID (the format is the
                                 same as <filename>.catalog</filename>
-                                files.</para>
+                                files).</para>
 
                                 <para>If any
-                                <replaceable>ID128</replaceable>s are
+                                <replaceable>128-bit-ID</replaceable>s are
                                 specified, only those entries are shown.
                                 </para>
                                 </listitem>
                                 <listitem><para>Update the message
                                 catalog index. This command needs to
                                 be executed each time new catalog
-                                files are installed, removed or
+                                files are installed, removed, or
                                 updated to rebuild the binary catalog
                                 index.</para></listitem>
                         </varlistentry>
                                 sealing key is stored in the journal
                                 data directory and shall remain on the
                                 host. The verification key should be
-                                stored externally. Also see the
+                                stored externally. Refer to the
                                 <option>Seal=</option> option in
                                 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
-                                for details.</para></listitem>
+                                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 --setup-keys is passed and
-                                Forward Secure Sealing has already been set up,
-                                recreate FSS keys.</para></listitem>
+                                <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>
                                 operation.</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.</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, a non-zero failure
-                code otherwise.</para>
+                <para>On success, 0 is returned; otherwise, a non-zero
+                failure code is returned.</para>
         </refsect1>
 
-        <refsect1>
-                <title>Environment</title>
-
-                <variablelist class='environment-variables'>
-                        <varlistentry>
-                                <term><varname>$SYSTEMD_PAGER</varname></term>
-                                <listitem><para>Pager to use when
-                                <option>--no-pager</option> is not given;
-                                overrides <varname>$PAGER</varname>.  Setting
-                                this to an empty string or the value
-                                <literal>cat</literal> is equivalent to passing
-                                <option>--no-pager</option>.</para></listitem>
-                        </varlistentry>
-                </variablelist>
-        </refsect1>
+        <xi:include href="less-variables.xml" />
 
         <refsect1>
                 <title>Examples</title>
 
                 <programlisting>journalctl /dev/sda</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>
                         <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>
                 </para>