chiark / gitweb /
man: mention XDG_CONFIG_HOME in systemd.unit
[elogind.git] / man / journalctl.xml
1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
4
5 <!--
6   This file is part of systemd.
7
8   Copyright 2012 Lennart Poettering
9
10   systemd is free software; you can redistribute it and/or modify it
11   under the terms of the GNU Lesser General Public License as published by
12   the Free Software Foundation; either version 2.1 of the License, or
13   (at your option) any later version.
14
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17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18   Lesser General Public License for more details.
19
20   You should have received a copy of the GNU Lesser General Public License
21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 -->
23
24 <refentry id="journalctl"
25           xmlns:xi="http://www.w3.org/2001/XInclude">
26
27         <refentryinfo>
28                 <title>journalctl</title>
29                 <productname>systemd</productname>
30
31                 <authorgroup>
32                         <author>
33                                 <contrib>Developer</contrib>
34                                 <firstname>Lennart</firstname>
35                                 <surname>Poettering</surname>
36                                 <email>lennart@poettering.net</email>
37                         </author>
38                 </authorgroup>
39         </refentryinfo>
40
41         <refmeta>
42                 <refentrytitle>journalctl</refentrytitle>
43                 <manvolnum>1</manvolnum>
44         </refmeta>
45
46         <refnamediv>
47                 <refname>journalctl</refname>
48                 <refpurpose>Query the systemd journal</refpurpose>
49         </refnamediv>
50
51         <refsynopsisdiv>
52                 <cmdsynopsis>
53                         <command>journalctl</command>
54                         <arg choice="opt" rep="repeat">OPTIONS</arg>
55                         <arg choice="opt" rep="repeat">MATCHES</arg>
56                 </cmdsynopsis>
57         </refsynopsisdiv>
58
59         <refsect1>
60                 <title>Description</title>
61
62                 <para><command>journalctl</command> may be used to
63                 query the contents of the
64                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
65                 journal as written by
66                 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
67
68                 <para>If called without parameters, it will show the full
69                 contents of the journal, starting with the oldest
70                 entry collected.</para>
71
72                 <para>If one or more match arguments are passed, the
73                 output is filtered accordingly. A match is in the
74                 format <literal>FIELD=VALUE</literal>,
75                 e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>,
76                 referring to the components of a structured journal
77                 entry. See
78                 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
79                 for a list of well-known fields. If multiple matches
80                 are specified matching different fields, the log
81                 entries are filtered by both, i.e. the resulting output
82                 will show only entries matching all the specified
83                 matches of this kind. If two matches apply to the same
84                 field, then they are automatically matched as
85                 alternatives, i.e. the resulting output will show
86                 entries matching any of the specified matches for the
87                 same field. Finally, if the character
88                 <literal>+</literal> appears as a separate word on the
89                 command line, all matches before and after are combined
90                 in a disjunction (i.e. logical OR).</para>
91
92                 <para>As shortcuts for a few types of field/value
93                 matches, file paths may be specified. If a file path
94                 refers to an executable file, this is equivalent to an
95                 <literal>_EXE=</literal> match for the canonicalized
96                 binary path. Similarly, if a path refers to a device
97                 node, this is equivalent to a
98                 <literal>_KERNEL_DEVICE=</literal> match for the
99                 device.</para>
100
101                 <para>Output is interleaved from all accessible
102                 journal files, whether they are rotated or currently
103                 being written, and regardless of whether they belong to the
104                 system itself or are accessible user journals.</para>
105
106                 <para>All users are granted access to their private
107                 per-user journals. However, by default, only root and
108                 users who are members of the <literal>systemd-journal</literal>
109                 group get access to the system journal and the
110                 journals of other users.</para>
111
112                 <para>The output is paged through
113                 <command>less</command> by default, and long lines are
114                 "truncated" to screen width. The hidden part can be
115                 viewed by using the left-arrow and right-arrow
116                 keys. Paging can be disabled; see the
117                 <option>--no-pager</option> option and the "Environment"
118                 section below.</para>
119
120                 <para>When outputing to a tty, lines are colored
121                 according to priority: lines of level ERROR and higher
122                 are colored red; lines of level NOTICE and higher are
123                 highlighted; other lines are displayed normally.
124                 </para>
125         </refsect1>
126
127         <refsect1>
128                 <title>Options</title>
129
130                 <para>The following options are understood:</para>
131
132                 <variablelist>
133                         <varlistentry>
134                                 <term><option>--no-full</option></term>
135                                 <term><option>--full</option></term>
136                                 <term><option>-l</option></term>
137
138                                 <listitem><para>Ellipsize fields when
139                                 they do not fit in available columns.
140                                 The default is to show full fields,
141                                 allowing them to wrap or be truncated
142                                 by the pager, if one is used.</para>
143
144                                 <para>The old options
145                                 <option>-l</option>/<option>--full</option>
146                                 are not useful anymore, except to undo
147                                 <option>--no-full</option>.</para></listitem>
148                         </varlistentry>
149
150                         <varlistentry>
151                                 <term><option>-a</option></term>
152                                 <term><option>--all</option></term>
153
154                                 <listitem><para>Show all fields in
155                                 full, even if they include unprintable
156                                 characters or are very
157                                 long.</para></listitem>
158                         </varlistentry>
159
160                         <varlistentry>
161                                 <term><option>-f</option></term>
162                                 <term><option>--follow</option></term>
163
164                                 <listitem><para>Show only the most recent
165                                 journal entries, and continuously print
166                                 new entries as they are appended to
167                                 the journal.</para></listitem>
168                         </varlistentry>
169
170                         <varlistentry>
171                                 <term><option>-e</option></term>
172                                 <term><option>--pager-end</option></term>
173
174                                 <listitem><para>Immediately jump to
175                                 the end of the journal inside the
176                                 implied pager tool. This implies
177                                 <option>-n1000</option> to guarantee
178                                 that the pager will not buffer logs of
179                                 unbounded size. This may be overridden
180                                 with an explicit <option>-n</option>
181                                 with some other numeric value on the
182                                 command line. Note that this option is
183                                 only supported for the
184                                 <citerefentry><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
185                                 pager.</para></listitem>
186                         </varlistentry>
187
188                         <varlistentry>
189                                 <term><option>-n</option></term>
190                                 <term><option>--lines=</option></term>
191
192                                 <listitem><para>Show the most recent
193                                 journal events and limit the number of
194                                 events shown. If
195                                 <option>--follow</option> is used,
196                                 this option is implied. The argument,
197                                 a positive integer, is optional, and
198                                 defaults to 10. </para></listitem>
199                         </varlistentry>
200
201                         <varlistentry>
202                                 <term><option>--no-tail</option></term>
203
204                                 <listitem><para>Show all stored output
205                                 lines, even in follow mode. Undoes the
206                                 effect of
207                                 <option>--lines=</option>.</para></listitem>
208                         </varlistentry>
209
210                         <varlistentry>
211                                 <term><option>-r</option></term>
212                                 <term><option>--reverse</option></term>
213
214                                 <listitem><para>Reverse output so that the newest
215                                 entries are displayed first.</para></listitem>
216                         </varlistentry>
217
218                         <varlistentry>
219                                 <term><option>-o</option></term>
220                                 <term><option>--output=</option></term>
221
222                                 <listitem><para>Controls the
223                                 formatting of the journal entries that
224                                 are shown. Takes one of the following options:
225                                 </para>
226                                 <variablelist>
227                                         <varlistentry>
228                                                 <term>
229                                                         <option>short</option>
230                                                 </term>
231                                                 <listitem>
232                                                         <para>is the default
233                                                         and generates an output
234                                                         that is mostly identical
235                                                         to the formatting of
236                                                         classic syslog files,
237                                                         showing one line per
238                                                         journal entry.</para>
239                                                 </listitem>
240                                         </varlistentry>
241
242                                         <varlistentry>
243                                                 <term>
244                                                         <option>short-iso</option>
245                                                 </term>
246                                                 <listitem>
247                                                         <para>is very similar,
248                                                         but shows ISO 8601
249                                                         wallclock timestamps.
250                                                         </para>
251                                                 </listitem>
252                                         </varlistentry>
253
254                                         <varlistentry>
255                                                 <term>
256                                                         <option>short-precise</option>
257                                                 </term>
258                                                 <listitem>
259                                                         <para>is very similar,
260                                                         but shows timestamps
261                                                         with full microsecond
262                                                         precision.
263                                                         </para>
264                                                 </listitem>
265                                         </varlistentry>
266
267                                         <varlistentry>
268                                                 <term>
269                                                         <option>short-monotonic</option>
270                                                 </term>
271                                                 <listitem>
272                                                         <para>is very similar,
273                                                         but shows monotonic
274                                                         timestamps instead of
275                                                         wallclock timestamps.
276                                                         </para>
277                                                 </listitem>
278                                         </varlistentry>
279
280                                         <varlistentry>
281                                                 <term>
282                                                         <option>verbose</option>
283                                                 </term>
284                                                 <listitem>
285                                                         <para>shows the
286                                                         full-structured entry
287                                                         items with all fields.
288                                                         </para>
289                                                 </listitem>
290                                         </varlistentry>
291
292                                         <varlistentry>
293                                                 <term>
294                                                         <option>export</option>
295                                                 </term>
296                                                 <listitem>
297                                                         <para>serializes the
298                                                         journal into a binary
299                                                         (but mostly text-based)
300                                                         stream suitable for
301                                                         backups and network
302                                                         transfer (see <ulink
303                                                         url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
304                                                         Export Format</ulink>
305                                                         for more
306                                                         information).</para>
307                                                 </listitem>
308                                         </varlistentry>
309
310                                         <varlistentry>
311                                                 <term>
312                                                         <option>json</option>
313                                                 </term>
314                                                 <listitem>
315                                                         <para>formats entries
316                                                         as JSON data structures,
317                                                         one per line (see <ulink
318                                                         url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
319                                                         JSON Format</ulink> for
320                                                         more information).</para>
321                                                 </listitem>
322                                         </varlistentry>
323
324                                         <varlistentry>
325                                                 <term>
326                                                         <option>json-pretty</option>
327                                                 </term>
328                                                 <listitem>
329                                                         <para>formats entries as
330                                                         JSON data structures,
331                                                         but formats them in
332                                                         multiple lines in order
333                                                         to make them more
334                                                         readable by humans.</para>
335                                                 </listitem>
336                                         </varlistentry>
337
338                                         <varlistentry>
339                                                 <term>
340                                                         <option>json-sse</option>
341                                                 </term>
342                                                 <listitem>
343                                                         <para>formats entries as
344                                                         JSON data structures,
345                                                         but wraps them in a
346                                                         format suitable for <ulink
347                                                         url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
348                                                         Events</ulink>.</para>
349                                                 </listitem>
350                                         </varlistentry>
351
352                                         <varlistentry>
353                                                 <term>
354                                                         <option>cat</option>
355                                                 </term>
356                                                 <listitem>
357                                                         <para>generates a very
358                                                         terse output, only
359                                                         showing the actual
360                                                         message of each journal
361                                                         entry with no metadata,
362                                                         not even a timestamp.
363                                                         </para>
364                                                 </listitem>
365                                         </varlistentry>
366                                 </variablelist>
367                                 </listitem>
368                         </varlistentry>
369
370                         <varlistentry>
371                                 <term><option>-x</option></term>
372                                 <term><option>--catalog</option></term>
373
374                                 <listitem><para>Augment log lines with
375                                 explanation texts from the message
376                                 catalog. This will add explanatory
377                                 help texts to log messages in the
378                                 output where this is available. These
379                                 short help texts will explain the
380                                 context of an error or log event,
381                                 possible solutions, as well as
382                                 pointers to support forums, developer
383                                 documentation, and any other relevant
384                                 manuals. Note that help texts are not
385                                 available for all messages, but only
386                                 for selected ones. For more
387                                 information on the message catalog,
388                                 please refer to the <ulink
389                                 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
390                                 Catalog Developer
391                                 Documentation</ulink>.</para>
392
393                                 <para>Note: when attaching
394                                 <command>journalctl</command> output
395                                 to bug reports, please do
396                                 <emphasis>not</emphasis> use
397                                 <option>-x</option>.</para>
398                                 </listitem>
399                         </varlistentry>
400
401                         <varlistentry>
402                                 <term><option>-q</option></term>
403                                 <term><option>--quiet</option></term>
404
405                                 <listitem><para>Suppresses any warning
406                                 messages regarding inaccessible system
407                                 journals when run as a normal
408                                 user.</para></listitem>
409                         </varlistentry>
410
411                         <varlistentry>
412                                 <term><option>-m</option></term>
413                                 <term><option>--merge</option></term>
414
415                                 <listitem><para>Show entries
416                                 interleaved from all available
417                                 journals, including remote
418                                 ones.</para></listitem>
419                         </varlistentry>
420
421                         <varlistentry>
422                                 <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>┬▒offset</replaceable></optional></option></term>
423                                 <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>┬▒offset</replaceable></optional></option></term>
424
425                                 <listitem><para>Show messages from a specific
426                                 boot. This will add a match for
427                                 <literal>_BOOT_ID=</literal>.</para>
428
429                                 <para>The argument may be empty, in which case
430                                 logs for the current boot will be shown.</para>
431
432                                 <para>If the boot ID is omitted, a positive
433                                 <replaceable>offset</replaceable> will look up
434                                 the boots starting from the beginning of the
435                                 journal, and a equal-or-less-than zero
436                                 <replaceable>offset</replaceable> will look up
437                                 boots starting from the end of the
438                                 journal. Thus, <constant>1</constant> means the
439                                 first boot found in the journal in
440                                 chronological order, <constant>2</constant> the
441                                 second and so on; while <constant>-0</constant>
442                                 is the last boot, <constant>-1</constant> the
443                                 boot before last, and so on. An empty
444                                 <replaceable>offset</replaceable> is equivalent
445                                 to specifying <constant>-0</constant>, except
446                                 when the current boot is not the last boot
447                                 (e.g. because <option>--directory</option> was
448                                 specified to look at logs from a different
449                                 machine).</para>
450
451                                 <para>If the 32-character
452                                 <replaceable>ID</replaceable> is specified, it
453                                 may optionally be followed by
454                                 <replaceable>offset</replaceable> which
455                                 identifies the boot relative to the one given by
456                                 boot <replaceable>ID</replaceable>. Negative
457                                 values mean earlier boots and a positive values
458                                 mean later boots. If
459                                 <replaceable>offset</replaceable> is not
460                                 specified, a value of zero is assumed, and the
461                                 logs for the boot given by
462                                 <replaceable>ID</replaceable> are shown.
463                                 </para>
464
465                                 </listitem>
466                         </varlistentry>
467
468                         <varlistentry>
469                                 <term><option>--list-boots</option></term>
470
471                                 <listitem><para>Show a tabular list of
472                                 boot numbers (relative to the current
473                                 boot), their IDs, and the timestamps
474                                 of the first and last message
475                                 pertaining to the boot.
476                                 </para></listitem>
477                         </varlistentry>
478
479                         <varlistentry>
480                                 <term><option>-k</option></term>
481                                 <term><option>--dmesg</option></term>
482
483                                 <listitem><para>Show only kernel messages. This
484                                 implies <option>-b</option> and adds the match
485                                 <literal>_TRANSPORT=kernel</literal>.
486                                 </para></listitem>
487                         </varlistentry>
488
489                         <varlistentry>
490                                 <term><option>-u</option></term>
491                                 <term><option>--unit=<replaceable>UNIT</replaceable>|<replaceable>PATTERN</replaceable></option></term>
492
493                                 <listitem><para>Show messages for the
494                                 specified systemd unit
495                                 <replaceable>UNIT</replaceable>, or
496                                 for any of the units matched by
497                                 <replaceable>PATTERN</replaceable>.
498                                 If a pattern is specified, a list of
499                                 unit names found in the journal is
500                                 compared with the specified pattern
501                                 and all that match are used. For each
502                                 unit name, a match is added for
503                                 messages from the unit
504                                 (<literal>_SYSTEMD_UNIT=<replaceable>UNIT</replaceable></literal>),
505                                 along with additional matches for
506                                 messages from systemd and messages
507                                 about coredumps for the specified
508                                 unit.</para>
509
510                                 <para>This parameter can be specified
511                                 multiple times.</para></listitem>
512                         </varlistentry>
513
514                         <varlistentry>
515                                 <term><option>--user-unit=</option></term>
516
517                                 <listitem><para>Show messages for the
518                                 specified user session unit. This will
519                                 add a match for messages from the unit
520                                 (<literal>_SYSTEMD_USER_UNIT=</literal>
521                                 and <literal>_UID=</literal>) and
522                                 additional matches for messages from
523                                 session systemd and messages about
524                                 coredumps for the specified unit.</para>
525                                 <para>This parameter can be specified multiple times.
526                                 </para></listitem>
527                         </varlistentry>
528
529                         <varlistentry>
530                                 <term><option>-p</option></term>
531                                 <term><option>--priority=</option></term>
532
533                                 <listitem><para>Filter output by
534                                 message priorities or priority
535                                 ranges. Takes either a single numeric
536                                 or textual log level (i.e. between
537                                 0/<literal>emerg</literal> and
538                                 7/<literal>debug</literal>), or a
539                                 range of numeric/text log levels in
540                                 the form FROM..TO. The log levels are
541                                 the usual syslog log levels as
542                                 documented in
543                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
544                                 i.e. <literal>emerg</literal> (0),
545                                 <literal>alert</literal> (1),
546                                 <literal>crit</literal> (2),
547                                 <literal>err</literal> (3),
548                                 <literal>warning</literal> (4),
549                                 <literal>notice</literal> (5),
550                                 <literal>info</literal> (6),
551                                 <literal>debug</literal> (7). If a
552                                 single log level is specified, all
553                                 messages with this log level or a
554                                 lower (hence more important) log level
555                                 are shown. If a range is specified, all
556                                 messages within the range are shown,
557                                 including both the start and the end
558                                 value of the range. This will add
559                                 <literal>PRIORITY=</literal> matches
560                                 for the specified
561                                 priorities.</para></listitem>
562                         </varlistentry>
563
564                         <varlistentry>
565                                 <term><option>-c</option></term>
566                                 <term><option>--cursor=</option></term>
567
568                                 <listitem><para>Start showing entries
569                                 from the location in the journal
570                                 specified by the passed
571                                 cursor.</para></listitem>
572                         </varlistentry>
573
574                         <varlistentry>
575                                 <term><option>--after-cursor=</option></term>
576
577                                 <listitem><para>Start showing entries
578                                 from the location in the journal
579                                 <emphasis>after</emphasis> the
580                                 location specified by the this cursor.
581                                 The cursor is shown when the
582                                 <option>--show-cursor</option> option
583                                 is used.</para></listitem>
584                         </varlistentry>
585
586                         <varlistentry>
587                                 <term><option>--show-cursor</option></term>
588
589                                 <listitem><para>The cursor is shown after the last
590                                 entry after two dashes:</para>
591                                 <programlisting>-- cursor: s=0639...</programlisting>
592                                 <para>The format of the cursor is private
593                                 and subject to change.</para></listitem>
594                         </varlistentry>
595
596                         <varlistentry>
597                                 <term><option>--since=</option></term>
598                                 <term><option>--until=</option></term>
599
600                                 <listitem><para>Start showing entries
601                                 on or newer than the specified date,
602                                 or on or older than the specified
603                                 date, respectively. Date specifications
604                                 should be of the format
605                                 <literal>2012-10-30 18:17:16</literal>.
606                                 If the time part is omitted,
607                                 <literal>00:00:00</literal> is assumed.
608                                 If only the seconds component is omitted,
609                                 <literal>:00</literal> is assumed. If the
610                                 date component is omitted, the current
611                                 day is assumed. Alternatively the strings
612                                 <literal>yesterday</literal>,
613                                 <literal>today</literal>,
614                                 <literal>tomorrow</literal> are
615                                 understood, which refer to 00:00:00 of
616                                 the day before the current day, the
617                                 current day, or the day after the
618                                 current day, respectively. <literal>now</literal>
619                                 refers to the current time. Finally,
620                                 relative times may be specified,
621                                 prefixed with <literal>-</literal> or
622                                 <literal>+</literal>, referring to
623                                 times before or after the current
624                                 time, respectively.</para></listitem>
625                         </varlistentry>
626
627                         <varlistentry>
628                                 <term><option>-F</option></term>
629                                 <term><option>--field=</option></term>
630
631                                 <listitem><para>Print all possible
632                                 data values the specified field can
633                                 take in all entries of the
634                                 journal.</para></listitem>
635                         </varlistentry>
636
637                         <varlistentry>
638                                 <term><option>--system</option></term>
639                                 <term><option>--user</option></term>
640
641                                 <listitem><para>Show messages from
642                                 system services and the kernel (with
643                                 <option>--system</option>). Show
644                                 messages from service of current user
645                                 (with <option>--user</option>).
646                                 If neither is specified, show all
647                                 messages that the user can see.
648                                 </para></listitem>
649                         </varlistentry>
650
651                         <varlistentry>
652                                 <term><option>-M</option></term>
653                                 <term><option>--machine=</option></term>
654
655                                 <listitem><para>Show messages from a
656                                 running, local container. Specify a
657                                 container name to connect
658                                 to.</para></listitem>
659                         </varlistentry>
660
661                         <varlistentry>
662                                 <term><option>-D <replaceable>DIR</replaceable></option></term>
663                                 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
664
665                                 <listitem><para>Takes a directory path
666                                 as argument. If specified, journalctl
667                                 will operate on the specified journal
668                                 directory
669                                 <replaceable>DIR</replaceable> instead
670                                 of the default runtime and system
671                                 journal paths.</para></listitem>
672                         </varlistentry>
673
674                         <varlistentry>
675                                 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
676
677                                 <listitem><para>Takes a file glob as an
678                                 argument. If specified, journalctl will
679                                 operate on the specified journal files
680                                 matching <replaceable>GLOB</replaceable>
681                                 instead of the default runtime and
682                                 system journal paths. May be specified
683                                 multiple times, in which case files will
684                                 be suitably interleaved.</para></listitem>
685                         </varlistentry>
686
687                         <varlistentry>
688                                 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
689
690                                 <listitem><para>Takes a directory path
691                                 as an argument. If specified, journalctl
692                                 will operate on catalog file hierarchy
693                                 underneath the specified directory
694                                 instead of the root directory
695                                 (e.g. <option>--update-catalog</option>
696                                 will create
697                                 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
698                                 </para></listitem>
699                         </varlistentry>
700
701                         <varlistentry>
702                                 <term><option>--new-id128</option></term>
703
704                                 <listitem><para>Instead of showing
705                                 journal contents, generate a new 128-bit
706                                 ID suitable for identifying
707                                 messages. This is intended for usage
708                                 by developers who need a new
709                                 identifier for a new message they
710                                 introduce and want to make
711                                 recognizable. This will print the new ID in
712                                 three different formats which can be
713                                 copied into source code or
714                                 similar.</para></listitem>
715                         </varlistentry>
716
717                         <varlistentry>
718                                 <term><option>--header</option></term>
719
720                                 <listitem><para>Instead of showing
721                                 journal contents, show internal header
722                                 information of the journal fields
723                                 accessed.</para></listitem>
724                         </varlistentry>
725
726                         <varlistentry>
727                                 <term><option>--disk-usage</option></term>
728
729                                 <listitem><para>Shows the current disk
730                                 usage of all
731                                 journal files.</para></listitem>
732                         </varlistentry>
733
734                         <varlistentry>
735                                 <term><option>--list-catalog
736                                 <optional><replaceable>128-bit-ID...</replaceable></optional>
737                                 </option></term>
738
739                                 <listitem><para>List the contents of
740                                 the message catalog as a table of
741                                 message IDs, plus their short
742                                 description strings.</para>
743
744                                 <para>If any
745                                 <replaceable>128-bit-ID</replaceable>s are
746                                 specified, only those entries are shown.
747                                 </para>
748                                 </listitem>
749                         </varlistentry>
750
751                         <varlistentry>
752                                 <term><option>--dump-catalog
753                                 <optional><replaceable>128-bit-ID...</replaceable></optional>
754                                 </option></term>
755
756                                 <listitem><para>Show the contents of
757                                 the message catalog, with entries
758                                 separated by a line consisting of two
759                                 dashes and the ID (the format is the
760                                 same as <filename>.catalog</filename>
761                                 files).</para>
762
763                                 <para>If any
764                                 <replaceable>128-bit-ID</replaceable>s are
765                                 specified, only those entries are shown.
766                                 </para>
767                                 </listitem>
768                         </varlistentry>
769
770                         <varlistentry>
771                                 <term><option>--update-catalog</option></term>
772
773                                 <listitem><para>Update the message
774                                 catalog index. This command needs to
775                                 be executed each time new catalog
776                                 files are installed, removed, or
777                                 updated to rebuild the binary catalog
778                                 index.</para></listitem>
779                         </varlistentry>
780
781                         <varlistentry>
782                                 <term><option>--setup-keys</option></term>
783
784                                 <listitem><para>Instead of showing
785                                 journal contents, generate a new key
786                                 pair for Forward Secure Sealing
787                                 (FSS). This will generate a sealing
788                                 key and a verification key. The
789                                 sealing key is stored in the journal
790                                 data directory and shall remain on the
791                                 host. The verification key should be
792                                 stored externally. Refer to the
793                                 <option>Seal=</option> option in
794                                 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
795                                 for information on Forward Secure
796                                 Sealing and for a link to a refereed
797                                 scholarly paper detailing the
798                                 cryptographic theory it is based on.
799                                 </para></listitem>
800                         </varlistentry>
801
802                         <varlistentry>
803                                 <term><option>--force</option></term>
804
805                                 <listitem><para>When
806                                 <option>--setup-keys</option> is passed and
807                                 Forward Secure Sealing (FSS) has already been
808                                 configured, recreate FSS keys.</para></listitem>
809                         </varlistentry>
810
811                         <varlistentry>
812                                 <term><option>--interval=</option></term>
813
814                                 <listitem><para>Specifies the change
815                                 interval for the sealing key when
816                                 generating an FSS key pair with
817                                 <option>--setup-keys</option>. Shorter
818                                 intervals increase CPU consumption but
819                                 shorten the time range of
820                                 undetectable journal
821                                 alterations. Defaults to
822                                 15min.</para></listitem>
823                         </varlistentry>
824
825                         <varlistentry>
826                                 <term><option>--verify</option></term>
827
828                                 <listitem><para>Check the journal file
829                                 for internal consistency. If the
830                                 file has been generated with FSS
831                                 enabled and the FSS verification key
832                                 has been specified with
833                                 <option>--verify-key=</option>,
834                                 authenticity of the journal file is
835                                 verified.</para></listitem>
836                         </varlistentry>
837
838                         <varlistentry>
839                                 <term><option>--verify-key=</option></term>
840
841                                 <listitem><para>Specifies the FSS
842                                 verification key to use for the
843                                 <option>--verify</option>
844                                 operation.</para></listitem>
845                         </varlistentry>
846
847                         <xi:include href="standard-options.xml" xpointer="help" />
848                         <xi:include href="standard-options.xml" xpointer="version" />
849                         <xi:include href="standard-options.xml" xpointer="no-pager" />
850                 </variablelist>
851         </refsect1>
852
853         <refsect1>
854                 <title>Exit status</title>
855
856                 <para>On success, 0 is returned; otherwise, a non-zero
857                 failure code is returned.</para>
858         </refsect1>
859
860         <xi:include href="less-variables.xml" />
861
862         <refsect1>
863                 <title>Examples</title>
864
865                 <para>Without arguments, all collected logs are shown
866                 unfiltered:</para>
867
868                 <programlisting>journalctl</programlisting>
869
870                 <para>With one match specified, all entries with a field matching the expression are shown:</para>
871
872                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
873
874                 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
875
876                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
877
878                 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
879
880                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
881
882                 <para>If the separator <literal>+</literal> is used,
883                 two expressions may be combined in a logical OR. The
884                 following will show all messages from the Avahi
885                 service process with the PID 28097 plus all messages
886                 from the D-Bus service (from any of its
887                 processes):</para>
888
889                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
890
891                 <para>Show all logs generated by the D-Bus executable:</para>
892
893                 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
894
895                 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
896
897                 <programlisting>journalctl /dev/sda</programlisting>
898
899                 <para>Show all kernel logs from previous boot:</para>
900
901                 <programlisting>journalctl -k -b -1</programlisting>
902
903         </refsect1>
904
905         <refsect1>
906                 <title>See Also</title>
907                 <para>
908                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
909                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
910                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
911                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
912                         <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
913                 </para>
914         </refsect1>
915
916 </refentry>