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man: fix grammatical errors and other formatting issues
[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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16   WITHOUT ANY WARRANTY; without even the implied warranty of
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>-h</option></term>
135                                 <term><option>--help</option></term>
136
137                                 <listitem><para>Prints a short help
138                                 text and exits.</para></listitem>
139                         </varlistentry>
140
141                         <varlistentry>
142                                 <term><option>--version</option></term>
143
144                                 <listitem><para>Prints a short version
145                                 string and exits.</para></listitem>
146                         </varlistentry>
147
148                         <varlistentry>
149                                 <term><option>--no-pager</option></term>
150
151                                 <listitem><para>Do not pipe output into a
152                                 pager.</para></listitem>
153                         </varlistentry>
154
155                         <varlistentry>
156                                 <term><option>--no-full</option></term>
157                                 <term><option>--full</option></term>
158                                 <term><option>-l</option></term>
159
160                                 <listitem><para>Ellipsize fields when
161                                 they do not fit in available columns.
162                                 The default is to show full fields,
163                                 allowing them to wrap or be truncated
164                                 by the pager, if one is used.</para>
165
166                                 <para>The old options
167                                 <option>-l</option>/<option>--full</option>
168                                 are not useful anymore, except to undo
169                                 <option>--no-full</option>.</para></listitem>
170                         </varlistentry>
171
172                         <varlistentry>
173                                 <term><option>-a</option></term>
174                                 <term><option>--all</option></term>
175
176                                 <listitem><para>Show all fields in
177                                 full, even if they include unprintable
178                                 characters or are very
179                                 long.</para></listitem>
180                         </varlistentry>
181
182                         <varlistentry>
183                                 <term><option>-f</option></term>
184                                 <term><option>--follow</option></term>
185
186                                 <listitem><para>Show only the most recent
187                                 journal entries, and continuously print
188                                 new entries as they are appended to
189                                 the journal.</para></listitem>
190                         </varlistentry>
191
192                         <varlistentry>
193                                 <term><option>-e</option></term>
194                                 <term><option>--pager-end</option></term>
195
196                                 <listitem><para>Immediately jump to
197                                 the end of the journal inside the
198                                 implied pager tool. This implies
199                                 <option>-n1000</option> to guarantee
200                                 that the pager will not buffer logs of
201                                 unbounded size. This may be overridden
202                                 with an explicit <option>-n</option>
203                                 with some other numeric value on the
204                                 command line. Note that this option is
205                                 only supported for the
206                                 <citerefentry><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
207                                 pager.</para></listitem>
208                         </varlistentry>
209
210                         <varlistentry>
211                                 <term><option>-n</option></term>
212                                 <term><option>--lines=</option></term>
213
214                                 <listitem><para>Show the most recent
215                                 journal events and limit the number of
216                                 events shown. If
217                                 <option>--follow</option> is used,
218                                 this option is implied. The argument,
219                                 a positive integer, is optional, and
220                                 defaults to 10. </para></listitem>
221                         </varlistentry>
222
223                         <varlistentry>
224                                 <term><option>--no-tail</option></term>
225
226                                 <listitem><para>Show all stored output
227                                 lines, even in follow mode. Undoes the
228                                 effect of
229                                 <option>--lines=</option>.</para></listitem>
230                         </varlistentry>
231
232                         <varlistentry>
233                                 <term><option>-r</option></term>
234                                 <term><option>--reverse</option></term>
235
236                                 <listitem><para>Reverse output so that the newest
237                                 entries are displayed first.</para></listitem>
238                         </varlistentry>
239
240                         <varlistentry>
241                                 <term><option>-o</option></term>
242                                 <term><option>--output=</option></term>
243
244                                 <listitem><para>Controls the
245                                 formatting of the journal entries that
246                                 are shown. Takes one of the following options:
247                                 </para>
248                                 <variablelist>
249                                         <varlistentry>
250                                                 <term>
251                                                         <option>short</option>
252                                                 </term>
253                                                 <listitem>
254                                                         <para>is the default
255                                                         and generates an output
256                                                         that is mostly identical
257                                                         to the formatting of
258                                                         classic syslog files,
259                                                         showing one line per
260                                                         journal entry.</para>
261                                                 </listitem>
262                                         </varlistentry>
263
264                                         <varlistentry>
265                                                 <term>
266                                                         <option>short-iso</option>
267                                                 </term>
268                                                 <listitem>
269                                                         <para>is very similar,
270                                                         but shows ISO 8601
271                                                         wallclock timestamps.
272                                                         </para>
273                                                 </listitem>
274                                         </varlistentry>
275
276                                         <varlistentry>
277                                                 <term>
278                                                         <option>short-precise</option>
279                                                 </term>
280                                                 <listitem>
281                                                         <para>is very similar,
282                                                         but shows timestamps
283                                                         with full microsecond
284                                                         precision.
285                                                         </para>
286                                                 </listitem>
287                                         </varlistentry>
288
289                                         <varlistentry>
290                                                 <term>
291                                                         <option>short-monotonic</option>
292                                                 </term>
293                                                 <listitem>
294                                                         <para>is very similar,
295                                                         but shows monotonic
296                                                         timestamps instead of
297                                                         wallclock timestamps.
298                                                         </para>
299                                                 </listitem>
300                                         </varlistentry>
301
302                                         <varlistentry>
303                                                 <term>
304                                                         <option>verbose</option>
305                                                 </term>
306                                                 <listitem>
307                                                         <para>shows the
308                                                         full-structured entry
309                                                         items with all fields.
310                                                         </para>
311                                                 </listitem>
312                                         </varlistentry>
313
314                                         <varlistentry>
315                                                 <term>
316                                                         <option>export</option>
317                                                 </term>
318                                                 <listitem>
319                                                         <para>serializes the
320                                                         journal into a binary
321                                                         (but mostly text-based)
322                                                         stream suitable for
323                                                         backups and network
324                                                         transfer (see <ulink
325                                                         url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
326                                                         Export Format</ulink>
327                                                         for more
328                                                         information).</para>
329                                                 </listitem>
330                                         </varlistentry>
331
332                                         <varlistentry>
333                                                 <term>
334                                                         <option>json</option>
335                                                 </term>
336                                                 <listitem>
337                                                         <para>formats entries
338                                                         as JSON data structures,
339                                                         one per line (see <ulink
340                                                         url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
341                                                         JSON Format</ulink> for
342                                                         more information).</para>
343                                                 </listitem>
344                                         </varlistentry>
345
346                                         <varlistentry>
347                                                 <term>
348                                                         <option>json-pretty</option>
349                                                 </term>
350                                                 <listitem>
351                                                         <para>formats entries as
352                                                         JSON data structures,
353                                                         but formats them in
354                                                         multiple lines in order
355                                                         to make them more
356                                                         readable by humans.</para>
357                                                 </listitem>
358                                         </varlistentry>
359
360                                         <varlistentry>
361                                                 <term>
362                                                         <option>json-sse</option>
363                                                 </term>
364                                                 <listitem>
365                                                         <para>formats entries as
366                                                         JSON data structures,
367                                                         but wraps them in a
368                                                         format suitable for <ulink
369                                                         url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
370                                                         Events</ulink>.</para>
371                                                 </listitem>
372                                         </varlistentry>
373
374                                         <varlistentry>
375                                                 <term>
376                                                         <option>cat</option>
377                                                 </term>
378                                                 <listitem>
379                                                         <para>generates a very
380                                                         terse output, only
381                                                         showing the actual
382                                                         message of each journal
383                                                         entry with no meta data,
384                                                         not even a timestamp.
385                                                         </para>
386                                                 </listitem>
387                                         </varlistentry>
388                                 </variablelist>
389                                 </listitem>
390                         </varlistentry>
391
392                         <varlistentry>
393                                 <term><option>-x</option></term>
394                                 <term><option>--catalog</option></term>
395
396                                 <listitem><para>Augment log lines with
397                                 explanation texts from the message
398                                 catalog. This will add explanatory
399                                 help texts to log messages in the
400                                 output where this is available. These
401                                 short help texts will explain the
402                                 context of an error or log event,
403                                 possible solutions, as well as
404                                 pointers to support forums, developer
405                                 documentation, and any other relevant
406                                 manuals. Note that help texts are not
407                                 available for all messages, but only
408                                 for selected ones. For more
409                                 information on the message catalog,
410                                 please refer to the <ulink
411                                 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
412                                 Catalog Developer
413                                 Documentation</ulink>.</para>
414
415                                 <para>Note: when attaching
416                                 <command>journalctl</command> output
417                                 to bug reports, please do
418                                 <emphasis>not</emphasis> use
419                                 <option>-x</option>.</para>
420                                 </listitem>
421                         </varlistentry>
422
423                         <varlistentry>
424                                 <term><option>-q</option></term>
425                                 <term><option>--quiet</option></term>
426
427                                 <listitem><para>Suppresses any warning
428                                 messages regarding inaccessible system
429                                 journals when run as a normal
430                                 user.</para></listitem>
431                         </varlistentry>
432
433                         <varlistentry>
434                                 <term><option>-m</option></term>
435                                 <term><option>--merge</option></term>
436
437                                 <listitem><para>Show entries
438                                 interleaved from all available
439                                 journals, including remote
440                                 ones.</para></listitem>
441                         </varlistentry>
442
443                         <varlistentry>
444                                 <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>┬▒offset</replaceable></optional></option></term>
445                                 <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>┬▒offset</replaceable></optional></option></term>
446
447                                 <listitem><para>Show messages from a specific
448                                 boot. This will add a match for
449                                 <literal>_BOOT_ID=</literal>.</para>
450
451                                 <para>The argument may be empty, in which case
452                                 logs for the current boot will be shown.</para>
453
454                                 <para>If the boot ID is omitted, a positive
455                                 <replaceable>offset</replaceable> will look up
456                                 the boots starting from the beginning of the
457                                 journal, and a equal-or-less-than zero
458                                 <replaceable>offset</replaceable> will look up
459                                 boots starting from the end of the
460                                 journal. Thus, <constant>1</constant> means the
461                                 first boot found in the journal in
462                                 chronological order, <constant>2</constant> the
463                                 second and so on; while <constant>-0</constant>
464                                 is the last boot, <constant>-1</constant> the
465                                 boot before last, and so on. An empty
466                                 <replaceable>offset</replaceable> is equivalent
467                                 to specifying <constant>-0</constant>, except
468                                 when the current boot is not the last boot
469                                 (e.g. because <option>--directory</option> was
470                                 specified to look at logs from a different
471                                 machine).</para>
472
473                                 <para>If the 32-character
474                                 <replaceable>ID</replaceable> is specified, it
475                                 may optionally be followed by
476                                 <replaceable>offset</replaceable> which
477                                 identifies the boot relative to the one given by
478                                 boot <replaceable>ID</replaceable>. Negative
479                                 values mean earlier boots and a positive values
480                                 mean later boots. If
481                                 <replaceable>offset</replaceable> is not
482                                 specified, a value of zero is assumed, and the
483                                 logs for the boot given by
484                                 <replaceable>ID</replaceable> are shown.
485                                 </para>
486
487                                 </listitem>
488                         </varlistentry>
489
490                         <varlistentry>
491                                 <term><option>--list-boots</option></term>
492
493                                 <listitem><para>Show a tabular list of
494                                 boot numbers (relative to the current
495                                 boot), their IDs, and the timestamps
496                                 of the first and last message
497                                 pertaining to the boot.
498                                 </para></listitem>
499                         </varlistentry>
500
501                         <varlistentry>
502                                 <term><option>-k</option></term>
503                                 <term><option>--dmesg</option></term>
504
505                                 <listitem><para>Show only kernel messages. This
506                                 implies <option>-b</option> and adds the match
507                                 <literal>_TRANSPORT=kernel</literal>.
508                                 </para></listitem>
509                         </varlistentry>
510
511                         <varlistentry>
512                                 <term><option>-u</option></term>
513                                 <term><option>--unit=<replaceable>UNIT</replaceable>|<replaceable>PATTERN</replaceable></option></term>
514
515                                 <listitem><para>Show messages for the
516                                 specified systemd unit
517                                 <replaceable>UNIT</replaceable>, or
518                                 for any of the units matched by
519                                 <replaceable>PATTERN</replaceable>.
520                                 If a pattern is specified, a list of
521                                 unit names found in the journal is
522                                 compared with the specified pattern
523                                 and all that match are used. For each
524                                 unit name a match is added for
525                                 messages from the unit
526                                 (<literal>_SYSTEMD_UNIT=<replaceable>UNIT</replaceable></literal>)
527                                 along with additional matches for
528                                 messages from systemd and messages
529                                 about coredumps for the specified
530                                 unit.</para>
531
532                                 <para>This parameter can be specified
533                                 multiple times. </para></listitem>
534                         </varlistentry>
535
536                         <varlistentry>
537                                 <term><option>--user-unit=</option></term>
538
539                                 <listitem><para>Show messages for the
540                                 specified user session unit. This will
541                                 add a match for messages from the unit
542                                 (<literal>_SYSTEMD_USER_UNIT=</literal>
543                                 and <literal>_UID=</literal>) and
544                                 additional matches for messages from
545                                 session systemd and messages about
546                                 coredumps for the specified unit.</para>
547                                 <para>This parameter can be specified multiple times.
548                                 </para></listitem>
549                         </varlistentry>
550
551                         <varlistentry>
552                                 <term><option>-p</option></term>
553                                 <term><option>--priority=</option></term>
554
555                                 <listitem><para>Filter output by
556                                 message priorities or priority
557                                 ranges. Takes either a single numeric
558                                 or textual log level (i.e. between
559                                 0/<literal>emerg</literal> and
560                                 7/<literal>debug</literal>), or a
561                                 range of numeric/text log levels in
562                                 the form FROM..TO. The log levels are
563                                 the usual syslog log levels as
564                                 documented in
565                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
566                                 i.e. <literal>emerg</literal> (0),
567                                 <literal>alert</literal> (1),
568                                 <literal>crit</literal> (2),
569                                 <literal>err</literal> (3),
570                                 <literal>warning</literal> (4),
571                                 <literal>notice</literal> (5),
572                                 <literal>info</literal> (6),
573                                 <literal>debug</literal> (7). If a
574                                 single log level is specified, all
575                                 messages with this log level or a
576                                 lower (hence more important) log level
577                                 are shown. If a range is specified, all
578                                 messages within the range are shown,
579                                 including both the start and the end
580                                 value of the range. This will add
581                                 <literal>PRIORITY=</literal> matches
582                                 for the specified
583                                 priorities.</para></listitem>
584                         </varlistentry>
585
586                         <varlistentry>
587                                 <term><option>-c</option></term>
588                                 <term><option>--cursor=</option></term>
589
590                                 <listitem><para>Start showing entries
591                                 from the location in the journal
592                                 specified by the passed
593                                 cursor.</para></listitem>
594                         </varlistentry>
595
596                         <varlistentry>
597                                 <term><option>--after-cursor=</option></term>
598
599                                 <listitem><para>Start showing entries
600                                 from the location in the journal
601                                 <emphasis>after</emphasis> the
602                                 location specified by the this cursor.
603                                 The cursor is shown when the
604                                 <option>--show-cursor</option> option
605                                 is used.</para></listitem>
606                         </varlistentry>
607
608                         <varlistentry>
609                                 <term><option>--show-cursor</option></term>
610
611                                 <listitem><para>The cursor is shown after the last
612                                 entry after two dashes:</para>
613                                 <programlisting>-- cursor: s=0639...</programlisting>
614                                 <para>The format of the cursor is private
615                                 and subject to change.</para></listitem>
616                         </varlistentry>
617
618                         <varlistentry>
619                                 <term><option>--since=</option></term>
620                                 <term><option>--until=</option></term>
621
622                                 <listitem><para>Start showing entries
623                                 on or newer than the specified date,
624                                 or on or older than the specified
625                                 date, respectively. Date specifications
626                                 should be of the format
627                                 <literal>2012-10-30 18:17:16</literal>.
628                                 If the time part is omitted,
629                                 <literal>00:00:00</literal> is assumed.
630                                 If only the seconds component is omitted,
631                                 <literal>:00</literal> is assumed. If the
632                                 date component is omitted, the current
633                                 day is assumed. Alternatively the strings
634                                 <literal>yesterday</literal>,
635                                 <literal>today</literal>,
636                                 <literal>tomorrow</literal> are
637                                 understood, which refer to 00:00:00 of
638                                 the day before the current day, the
639                                 current day, or the day after the
640                                 current day, respectively. <literal>now</literal>
641                                 refers to the current time. Finally,
642                                 relative times may be specified,
643                                 prefixed with <literal>-</literal> or
644                                 <literal>+</literal>, referring to
645                                 times before or after the current
646                                 time, respectively.</para></listitem>
647                         </varlistentry>
648
649                         <varlistentry>
650                                 <term><option>-F</option></term>
651                                 <term><option>--field=</option></term>
652
653                                 <listitem><para>Print all possible
654                                 data values the specified field can
655                                 take in all entries of the
656                                 journal.</para></listitem>
657                         </varlistentry>
658
659                         <varlistentry>
660                                 <term><option>--system</option></term>
661                                 <term><option>--user</option></term>
662
663                                 <listitem><para>Show messages from
664                                 system services and the kernel (with
665                                 <option>--system</option>). Show
666                                 messages from service of current user
667                                 (with <option>--user</option>).
668                                 If neither is specified, show all
669                                 messages that the user can see.
670                                 </para></listitem>
671                         </varlistentry>
672
673                         <varlistentry>
674                                 <term><option>-M</option></term>
675                                 <term><option>--machine=</option></term>
676
677                                 <listitem><para>Show messages from a
678                                 running, local container. Specify a
679                                 container name to connect
680                                 to.</para></listitem>
681                         </varlistentry>
682
683                         <varlistentry>
684                                 <term><option>-D <replaceable>DIR</replaceable></option></term>
685                                 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
686
687                                 <listitem><para>Takes a directory path
688                                 as argument. If specified, journalctl
689                                 will operate on the specified journal
690                                 directory
691                                 <replaceable>DIR</replaceable> instead
692                                 of the default runtime and system
693                                 journal paths.</para></listitem>
694                         </varlistentry>
695
696                         <varlistentry>
697                                 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
698
699                                 <listitem><para>Takes a file glob as an
700                                 argument. If specified, journalctl will
701                                 operate on the specified journal files
702                                 matching <replaceable>GLOB</replaceable>
703                                 instead of the default runtime and
704                                 system journal paths. May be specified
705                                 multiple times, in which case files will
706                                 be suitably interleaved.</para></listitem>
707                         </varlistentry>
708
709                         <varlistentry>
710                                 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
711
712                                 <listitem><para>Takes a directory path
713                                 as an argument. If specified, journalctl
714                                 will operate on catalog file hierarchy
715                                 underneath the specified directory
716                                 instead of the root directory
717                                 (e.g. <option>--update-catalog</option>
718                                 will create
719                                 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
720                                 </para></listitem>
721                         </varlistentry>
722
723                         <varlistentry>
724                                 <term><option>--new-id128</option></term>
725
726                                 <listitem><para>Instead of showing
727                                 journal contents, generate a new 128-bit
728                                 ID suitable for identifying
729                                 messages. This is intended for usage
730                                 by developers who need a new
731                                 identifier for a new message they
732                                 introduce and want to make
733                                 recognizable. This will print the new ID in
734                                 three different formats which can be
735                                 copied into source code or
736                                 similar.</para></listitem>
737                         </varlistentry>
738
739                         <varlistentry>
740                                 <term><option>--header</option></term>
741
742                                 <listitem><para>Instead of showing
743                                 journal contents, show internal header
744                                 information of the journal fields
745                                 accessed.</para></listitem>
746                         </varlistentry>
747
748                         <varlistentry>
749                                 <term><option>--disk-usage</option></term>
750
751                                 <listitem><para>Shows the current disk
752                                 usage of all
753                                 journal files.</para></listitem>
754                         </varlistentry>
755
756                         <varlistentry>
757                                 <term><option>--list-catalog
758                                 <optional><replaceable>128-bit-ID...</replaceable></optional>
759                                 </option></term>
760
761                                 <listitem><para>List the contents of
762                                 the message catalog as a table of
763                                 message IDs, plus their short
764                                 description strings.</para>
765
766                                 <para>If any
767                                 <replaceable>128-bit-ID</replaceable>s are
768                                 specified, only those entries are shown.
769                                 </para>
770                                 </listitem>
771                         </varlistentry>
772
773                         <varlistentry>
774                                 <term><option>--dump-catalog
775                                 <optional><replaceable>128-bit-ID...</replaceable></optional>
776                                 </option></term>
777
778                                 <listitem><para>Show the contents of
779                                 the message catalog, with entries
780                                 separated by a line consisting of two
781                                 dashes and the ID (the format is the
782                                 same as <filename>.catalog</filename>
783                                 files).</para>
784
785                                 <para>If any
786                                 <replaceable>128-bit-ID</replaceable>s are
787                                 specified, only those entries are shown.
788                                 </para>
789                                 </listitem>
790                         </varlistentry>
791
792                         <varlistentry>
793                                 <term><option>--update-catalog</option></term>
794
795                                 <listitem><para>Update the message
796                                 catalog index. This command needs to
797                                 be executed each time new catalog
798                                 files are installed, removed, or
799                                 updated to rebuild the binary catalog
800                                 index.</para></listitem>
801                         </varlistentry>
802
803                         <varlistentry>
804                                 <term><option>--setup-keys</option></term>
805
806                                 <listitem><para>Instead of showing
807                                 journal contents, generate a new key
808                                 pair for Forward Secure Sealing
809                                 (FSS). This will generate a sealing
810                                 key and a verification key. The
811                                 sealing key is stored in the journal
812                                 data directory and shall remain on the
813                                 host. The verification key should be
814                                 stored externally. Refer to the
815                                 <option>Seal=</option> option in
816                                 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
817                                 for information on Forward Secure
818                                 Sealing and for a link to a refereed
819                                 scholarly paper detailing the
820                                 cryptographic theory it is based on.
821                                 </para></listitem>
822                         </varlistentry>
823
824                         <varlistentry>
825                                 <term><option>--force</option></term>
826
827                                 <listitem><para>When
828                                 <option>--setup-keys</option> is passed and
829                                 Forward Secure Sealing (FSS) has already been
830                                 configured, recreate FSS keys.</para></listitem>
831                         </varlistentry>
832
833                         <varlistentry>
834                                 <term><option>--interval=</option></term>
835
836                                 <listitem><para>Specifies the change
837                                 interval for the sealing key when
838                                 generating an FSS key pair with
839                                 <option>--setup-keys</option>. Shorter
840                                 intervals increase CPU consumption but
841                                 shorten the time range of
842                                 undetectable journal
843                                 alterations. Defaults to
844                                 15min.</para></listitem>
845                         </varlistentry>
846
847                         <varlistentry>
848                                 <term><option>--verify</option></term>
849
850                                 <listitem><para>Check the journal file
851                                 for internal consistency. If the
852                                 file has been generated with FSS
853                                 enabled and the FSS verification key
854                                 has been specified with
855                                 <option>--verify-key=</option>,
856                                 authenticity of the journal file is
857                                 verified.</para></listitem>
858                         </varlistentry>
859
860                         <varlistentry>
861                                 <term><option>--verify-key=</option></term>
862
863                                 <listitem><para>Specifies the FSS
864                                 verification key to use for the
865                                 <option>--verify</option>
866                                 operation.</para></listitem>
867                         </varlistentry>
868
869                 </variablelist>
870         </refsect1>
871
872         <refsect1>
873                 <title>Exit status</title>
874
875                 <para>On success, 0 is returned; otherwise, a non-zero
876                 failure code is returned.</para>
877         </refsect1>
878
879         <xi:include href="less-variables.xml" />
880
881         <refsect1>
882                 <title>Examples</title>
883
884                 <para>Without arguments, all collected logs are shown
885                 unfiltered:</para>
886
887                 <programlisting>journalctl</programlisting>
888
889                 <para>With one match specified, all entries with a field matching the expression are shown:</para>
890
891                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
892
893                 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
894
895                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
896
897                 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
898
899                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
900
901                 <para>If the separator <literal>+</literal> is used,
902                 two expressions may be combined in a logical OR. The
903                 following will show all messages from the Avahi
904                 service process with the PID 28097 plus all messages
905                 from the D-Bus service (from any of its
906                 processes):</para>
907
908                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
909
910                 <para>Show all logs generated by the D-Bus executable:</para>
911
912                 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
913
914                 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
915
916                 <programlisting>journalctl /dev/sda</programlisting>
917
918                 <para>Show all kernel logs from previous boot:</para>
919
920                 <programlisting>journalctl -k -b -1</programlisting>
921
922         </refsect1>
923
924         <refsect1>
925                 <title>See Also</title>
926                 <para>
927                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
928                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
929                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
930                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
931                         <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
932                 </para>
933         </refsect1>
934
935 </refentry>