<listitem><para>Controls the number of
journal lines to show, counting from
- the most recent ones. Takes a positive
- integer argument. In follow mode
- defaults to 10, otherwise is unset
- thus not limiting how many lines are
- shown.</para></listitem>
+ the most recent ones. The argument is
+ optional, and if specified is a
+ positive integer. If not specified and
+ in follow mode defaults to 10. If this
+ option is not passed and follow mode
+ is not enabled, how many lines are
+ shown is not
+ limited.</para></listitem>
</varlistentry>
<varlistentry>
<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
structures, but formats them in
multiple lines in order to make them
more readable for
- humans. <literal>cat</literal>
+ 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
<term><option>-b</option></term>
<listitem><para>Show data only from
- current boot.</para></listitem>
+ current boot. This will add a match
+ for <literal>_BOOT_ID=</literal> for
+ the current boot ID of the
+ kernel.</para></listitem>
</varlistentry>
<varlistentry>
- <term><option>--directory=</option></term>
- <term><option>-D</option></term>
-
- <listitem><para>Takes an absolute
- directory path as argument. If
- specified journalctl will operate on the
- specified journal directory instead of
- the default runtime and system journal
- paths.</para></listitem>
+ <term><option>--unit=</option></term>
+ <term><option>-u</option></term>
+
+ <listitem><para>Show data only of the
+ specified unit. This will add a match
+ for <literal>_SYSTEMD_UNIT=</literal>
+ for the specified
+ unit.</para></listitem>
</varlistentry>
<varlistentry>
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.</para></listitem>
+ value of the range. This will add
+ <literal>PRIORITY=</literal> matches
+ for the specified
+ priorities.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--cursor=</option></term>
+ <term><option>-c</option></term>
+
+ <listitem><para>Start showing entries
+ from the location in the journal
+ specified by the passed
+ cursor.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--since=</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 "2012-10-30 18:17:16". If
+ the time part is omitted, 00:00:00 is
+ assumed. If only the seconds component
+ is omitted, :00 is assumed. If the
+ date component is ommitted, 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.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><option>--field=</option></term>
+ <term><option>-F</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>--directory=</option></term>
+ <term><option>-D</option></term>
+
+ <listitem><para>Takes an absolute
+ directory path as argument. If
+ specified journalctl will operate on the
+ specified journal directory instead of
+ the default runtime and system journal
+ paths.</para></listitem>
</varlistentry>
<varlistentry>