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[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
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13   (at your option) any later version.
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18   Lesser General Public License for more details.
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21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 -->
23
24 <refentry id="journalctl">
25
26         <refentryinfo>
27                 <title>journalctl</title>
28                 <productname>systemd</productname>
29
30                 <authorgroup>
31                         <author>
32                                 <contrib>Developer</contrib>
33                                 <firstname>Lennart</firstname>
34                                 <surname>Poettering</surname>
35                                 <email>lennart@poettering.net</email>
36                         </author>
37                 </authorgroup>
38         </refentryinfo>
39
40         <refmeta>
41                 <refentrytitle>journalctl</refentrytitle>
42                 <manvolnum>1</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>journalctl</refname>
47                 <refpurpose>Query the systemd journal</refpurpose>
48         </refnamediv>
49
50         <refsynopsisdiv>
51                 <cmdsynopsis>
52                         <command>journalctl</command>
53                         <arg choice="opt" rep="repeat">OPTIONS</arg>
54                         <arg choice="opt" rep="repeat">MATCHES</arg>
55                 </cmdsynopsis>
56         </refsynopsisdiv>
57
58         <refsect1>
59                 <title>Description</title>
60
61                 <para><command>journalctl</command> may be used to
62                 query the contents of the
63                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
64                 journal as written by
65                 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
66
67                 <para>If called without parameters, it will show the full
68                 contents of the journal, starting with the oldest
69                 entry collected.</para>
70
71                 <para>If one or more match arguments are passed, the
72                 output is filtered accordingly. A match is in the
73                 format <literal>FIELD=VALUE</literal>,
74                 e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>,
75                 referring to the components of a structured journal
76                 entry. See
77                 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
78                 for a list of well-known fields. If multiple matches
79                 are specified matching different fields, the log
80                 entries are filtered by both, i.e. the resulting output
81                 will show only entries matching all the specified
82                 matches of this kind. If two matches apply to the same
83                 field, then they are automatically matched as
84                 alternatives, i.e. the resulting output will show
85                 entries matching any of the specified matches for the
86                 same field. Finally, if the character
87                 <literal>+</literal> appears as separate word on the
88                 command line, all matches before and after are combined
89                 in a disjunction (i.e. logical OR).</para>
90
91                 <para>As shortcuts for a few types of field/value
92                 matches, file paths may be specified. If a file path
93                 refers to an executable file, this is equivalent to an
94                 <literal>_EXE=</literal> match for the canonicalized
95                 binary path. Similarly, if a path refers to a device
96                 node, this is equivalent to a
97                 <literal>_KERNEL_DEVICE=</literal> match for the
98                 device.</para>
99
100                 <para>Output is interleaved from all accessible
101                 journal files, whether they are rotated or currently
102                 being written, and regardless of whether they belong to the
103                 system itself or are accessible user journals.</para>
104
105                 <para>All users are granted access to their private
106                 per-user journals. However, by default, only root and
107                 users who are members of the <literal>adm</literal>
108                 group get access to the system journal and the
109                 journals of other users.</para>
110
111                 <para>The output is paged through
112                 <command>less</command> by default, and long lines are
113                 "truncated" to screen width. The hidden part can be
114                 viewed by using the left-arrow and right-arrow
115                 keys. Paging can be disabled, see
116                 <option>--no-pager</option> and section Environment
117                 below.</para>
118
119                 <para>When outputing to a tty, lines are colored
120                 according to priority: lines of level ERROR and higher
121                 are colored red, lines of level NOTICE and higher are
122                 highlighted, and other lines are displayed normally.
123                 </para>
124         </refsect1>
125
126         <refsect1>
127                 <title>Options</title>
128
129                 <para>The following options are understood:</para>
130
131                 <variablelist>
132                         <varlistentry>
133                                 <term><option>-h</option></term>
134                                 <term><option>--help</option></term>
135
136                                 <listitem><para>Prints a short help
137                                 text and exits.</para></listitem>
138                         </varlistentry>
139
140                         <varlistentry>
141                                 <term><option>--version</option></term>
142
143                                 <listitem><para>Prints a short version
144                                 string and exits.</para></listitem>
145                         </varlistentry>
146
147                         <varlistentry>
148                                 <term><option>--no-pager</option></term>
149
150                                 <listitem><para>Do not pipe output into a
151                                 pager.</para></listitem>
152                         </varlistentry>
153
154                         <varlistentry>
155                                 <term><option>-l</option></term>
156                                 <term><option>--full</option></term>
157
158                                 <listitem><para>Show all (printable) fields in
159                                 full.</para></listitem>
160                         </varlistentry>
161
162                         <varlistentry>
163                                 <term><option>-a</option></term>
164                                 <term><option>--all</option></term>
165
166                                 <listitem><para>Show all fields in
167                                 full, even if they include unprintable
168                                 characters or are very
169                                 long.</para></listitem>
170                         </varlistentry>
171
172                         <varlistentry>
173                                 <term><option>-f</option></term>
174                                 <term><option>--follow</option></term>
175
176                                 <listitem><para>Show only the most recent
177                                 journal entries, and continuously print
178                                 new entries as they are appended to
179                                 the journal.</para></listitem>
180                         </varlistentry>
181
182                         <varlistentry>
183                                 <term><option>-e</option></term>
184                                 <term><option>--pager-end</option></term>
185
186                                 <listitem><para>Immediately jump to
187                                 the end of the journal inside the
188                                 implied pager tool. This implies
189                                 <option>-n1000</option> to guarantee
190                                 that the pager will not buffer logs of
191                                 unbounded size. This may be overridden
192                                 with an explicit <option>-n</option>
193                                 with some other numeric value on the
194                                 command line. Note that this option is
195                                 only supported for the
196                                 <citerefentry><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
197                                 pager.</para></listitem>
198                         </varlistentry>
199
200                         <varlistentry>
201                                 <term><option>-n</option></term>
202                                 <term><option>--lines=</option></term>
203
204                                 <listitem><para>Show the most recent
205                                 journal events and limit the number of
206                                 events shown. If
207                                 <option>--follow</option> is used,
208                                 this option is implied. The argument,
209                                 a positive integer, is optional, and
210                                 defaults to 10. </para></listitem>
211                         </varlistentry>
212
213                         <varlistentry>
214                                 <term><option>--no-tail</option></term>
215
216                                 <listitem><para>Show all stored output
217                                 lines, even in follow mode. Undoes the
218                                 effect of
219                                 <option>--lines=</option>.</para></listitem>
220                         </varlistentry>
221
222                         <varlistentry>
223                                 <term><option>-r</option></term>
224                                 <term><option>--reverse</option></term>
225
226                                 <listitem><para>Reverse output, so the newest
227                                 entries are displayed first.</para></listitem>
228                         </varlistentry>
229
230                         <varlistentry>
231                                 <term><option>-o</option></term>
232                                 <term><option>--output=</option></term>
233
234                                 <listitem><para>Controls the
235                                 formatting of the journal entries that
236                                 are shown. Takes one of the following options:
237                                 </para>
238                                 <variablelist>
239                                         <varlistentry>
240                                                 <term>
241                                                         <option>short</option>
242                                                 </term>
243                                                 <listitem>
244                                                         <para>is the default
245                                                         and generates an output
246                                                         that is mostly identical
247                                                         to the formatting of
248                                                         classic syslog files,
249                                                         showing one line per
250                                                         journal entry.</para>
251                                                 </listitem>
252                                         </varlistentry>
253
254                                         <varlistentry>
255                                                 <term>
256                                                         <option>short-monotonic</option>
257                                                 </term>
258                                                 <listitem>
259                                                         <para>is very similar
260                                                         but shows monotonic
261                                                         timestamps instead of
262                                                         wallclock timestamps.
263                                                         </para>
264                                                 </listitem>
265                                         </varlistentry>
266
267                                         <varlistentry>
268                                                 <term>
269                                                         <option>verbose</option>
270                                                 </term>
271                                                 <listitem>
272                                                         <para>shows the
273                                                         full-structured entry
274                                                         items with all fields.
275                                                         </para>
276                                                 </listitem>
277                                         </varlistentry>
278
279                                         <varlistentry>
280                                                 <term>
281                                                         <option>export</option>
282                                                 </term>
283                                                 <listitem>
284                                                         <para>serializes the
285                                                         journal into a binary
286                                                         (but mostly text-based)
287                                                         stream suitable for
288                                                         backups and network
289                                                         transfer (see <ulink
290                                                         url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
291                                                         Export Format</ulink>
292                                                         for more
293                                                         information).</para>
294                                                 </listitem>
295                                         </varlistentry>
296
297                                         <varlistentry>
298                                                 <term>
299                                                         <option>json</option>
300                                                 </term>
301                                                 <listitem>
302                                                         <para>formats entries
303                                                         as JSON data structures,
304                                                         one per line (see <ulink
305                                                         url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
306                                                         JSON Format</ulink> for
307                                                         more information).</para>
308                                                 </listitem>
309                                         </varlistentry>
310
311                                         <varlistentry>
312                                                 <term>
313                                                         <option>json-pretty</option>
314                                                 </term>
315                                                 <listitem>
316                                                         <para>formats entries as
317                                                         JSON data structures,
318                                                         but formats them in
319                                                         multiple lines in order
320                                                         to make them more
321                                                         readable for humans.</para>
322                                                 </listitem>
323                                         </varlistentry>
324
325                                         <varlistentry>
326                                                 <term>
327                                                         <option>json-sse</option>
328                                                 </term>
329                                                 <listitem>
330                                                         <para>formats entries as
331                                                         JSON data structures,
332                                                         but wraps them in a
333                                                         format suitable for <ulink
334                                                         url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
335                                                         Events</ulink>.</para>
336                                                 </listitem>
337                                         </varlistentry>
338
339                                         <varlistentry>
340                                                 <term>
341                                                         <option>cat</option>
342                                                 </term>
343                                                 <listitem>
344                                                         <para>generates a very
345                                                         terse output only
346                                                         showing the actual
347                                                         message of each journal
348                                                         entry with no meta data,
349                                                         not even a timestamp.
350                                                         </para>
351                                                 </listitem>
352                                         </varlistentry>
353                                 </variablelist>
354                                 </listitem>
355                         </varlistentry>
356
357                         <varlistentry>
358                                 <term><option>-x</option></term>
359                                 <term><option>--catalog</option></term>
360
361                                 <listitem><para>Augment log lines with
362                                 explanation texts from the message
363                                 catalog. This will add explanatory
364                                 help texts to log messages in the
365                                 output where this is available. These
366                                 short help texts will explain the
367                                 context of an error or log event,
368                                 possible solutions, as well as
369                                 pointers to support forums, developer
370                                 documentation and any other relevant
371                                 manuals. Note that help texts are not
372                                 available for all messages, but only
373                                 for selected ones. For more
374                                 information on the message catalog,
375                                 please refer to the <ulink
376                                 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
377                                 Catalog Developer
378                                 Documentation</ulink>.</para></listitem>
379                         </varlistentry>
380
381                         <varlistentry>
382                                 <term><option>-q</option></term>
383                                 <term><option>--quiet</option></term>
384
385                                 <listitem><para>Suppresses any warning
386                                 message regarding inaccessible system
387                                 journals when run as normal
388                                 user.</para></listitem>
389                         </varlistentry>
390
391                         <varlistentry>
392                                 <term><option>-m</option></term>
393                                 <term><option>--merge</option></term>
394
395                                 <listitem><para>Show entries
396                                 interleaved from all available
397                                 journals, including remote
398                                 ones.</para></listitem>
399                         </varlistentry>
400
401                         <varlistentry>
402                                 <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>┬▒offset</replaceable></optional></option></term>
403                                 <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>┬▒offset</replaceable></optional></option></term>
404
405                                 <listitem><para>Show messages from a specific
406                                 boot. This will add a match for
407                                 <literal>_BOOT_ID=</literal>.</para>
408
409                                 <para>The argument may be empty, in which case
410                                 logs for the current boot will be shown.</para>
411
412                                 <para>If the boot ID is omitted, a positive
413                                 <replaceable>offset</replaceable> will look up
414                                 the boots starting from the beginning of the
415                                 journal, and a equal-or-less-than zero
416                                 <replaceable>offset</replaceable> will look up
417                                 boots starting from the end of the
418                                 journal. Thus, <constant>1</constant> means the
419                                 first boot found in the journal in the
420                                 chronological order, <constant>2</constant> the
421                                 second and so on; while <constant>-0</constant>
422                                 is the last boot, <constant>-1</constant> the
423                                 boot before that, and so on. An empty
424                                 <replaceable>offset</replaceable> is equivalent
425                                 to specifying <constant>-0</constant>, except
426                                 when the current boot is not the last boot
427                                 (e.g. because <option>--directory</option> was
428                                 specified to look at logs from a different
429                                 machine).</para>
430
431                                 <para>If the 32 character
432                                 <replaceable>ID</replaceable> is specified, it
433                                 may optionally be followed by
434                                 <replaceable>offset</replaceable> which
435                                 identifies the boot relative to the one given by
436                                 boot <replaceable>ID</replaceable>. Negative
437                                 values mean earlier boots and a positive values
438                                 mean later boots. If
439                                 <replaceable>offset</replaceable> is not
440                                 specified, a value of zero is assumed and the
441                                 logs for the boot given by
442                                 <replaceable>ID</replaceable> are shown.
443                                 </para>
444
445                                 </listitem>
446                         </varlistentry>
447
448                         <varlistentry>
449                                 <term><option>-k</option></term>
450                                 <term><option>--dmesg</option></term>
451
452                                 <listitem><para>Show only kernel messages. This
453                                 implies <option>-b</option> and adds the match
454                                 <literal>_TRANSPORT=kernel</literal>.
455                                 </para></listitem>
456                         </varlistentry>
457
458                         <varlistentry>
459                                 <term><option>-u</option></term>
460                                 <term><option>--unit=</option></term>
461
462                                 <listitem><para>Show messages for the
463                                 specified systemd unit. This will add
464                                 a match for messages from the unit
465                                 (<literal>_SYSTEMD_UNIT=</literal>)
466                                 and additional matches for messages
467                                 from systemd and messages about
468                                 coredumps for the specified unit.</para>
469                                 <para>This parameter can be specified multiple times.
470                                 </para></listitem>
471                         </varlistentry>
472
473                         <varlistentry>
474                                 <term><option>--user-unit=</option></term>
475
476                                 <listitem><para>Show messages for the
477                                 specified user session unit. This will
478                                 add a match for messages from the unit
479                                 (<literal>_SYSTEMD_USER_UNIT=</literal>
480                                 and <literal>_UID=</literal>) and
481                                 additional matches for messages from
482                                 session systemd and messages about
483                                 coredumps for the specified unit.</para>
484                                 <para>This parameter can be specified multiple times.
485                                 </para></listitem>
486                         </varlistentry>
487
488                         <varlistentry>
489                                 <term><option>-p</option></term>
490                                 <term><option>--priority=</option></term>
491
492                                 <listitem><para>Filter output by
493                                 message priorities or priority
494                                 ranges. Takes either a single numeric
495                                 or textual log level (i.e. between
496                                 0/<literal>emerg</literal> and
497                                 7/<literal>debug</literal>), or a
498                                 range of numeric/text log levels in
499                                 the form FROM..TO. The log levels are
500                                 the usual syslog log levels as
501                                 documented in
502                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
503                                 i.e. <literal>emerg</literal> (0),
504                                 <literal>alert</literal> (1),
505                                 <literal>crit</literal> (2),
506                                 <literal>err</literal> (3),
507                                 <literal>warning</literal> (4),
508                                 <literal>notice</literal> (5),
509                                 <literal>info</literal> (6),
510                                 <literal>debug</literal> (7). If a
511                                 single log level is specified, all
512                                 messages with this log level or a
513                                 lower (hence more important) log level
514                                 are shown. If a range is specified, all
515                                 messages within the range are shown,
516                                 including both the start and the end
517                                 value of the range. This will add
518                                 <literal>PRIORITY=</literal> matches
519                                 for the specified
520                                 priorities.</para></listitem>
521                         </varlistentry>
522
523                         <varlistentry>
524                                 <term><option>-c</option></term>
525                                 <term><option>--cursor=</option></term>
526
527                                 <listitem><para>Start showing entries
528                                 from the location in the journal
529                                 specified by the passed
530                                 cursor.</para></listitem>
531                         </varlistentry>
532
533                         <varlistentry>
534                                 <term><option>--after-cursor=</option></term>
535
536                                 <listitem><para>Start showing entries from the
537                                 location in the journal
538                                 <emphasis>after</emphasis> the location
539                                 specified by the this cursor.
540                                 </para></listitem>
541                         </varlistentry>
542
543                         <varlistentry>
544                                 <term><option>--since=</option></term>
545                                 <term><option>--until=</option></term>
546
547                                 <listitem><para>Start showing entries
548                                 on or newer than the specified date,
549                                 or on or older than the specified
550                                 date, respectively. Date specifications
551                                 should be of the format
552                                 <literal>2012-10-30 18:17:16</literal>.
553                                 If the time part is omitted,
554                                 <literal>00:00:00</literal> is assumed.
555                                 If only the seconds component is omitted,
556                                 <literal>:00</literal> is assumed. If the
557                                 date component is omitted, the current
558                                 day is assumed. Alternatively the strings
559                                 <literal>yesterday</literal>,
560                                 <literal>today</literal>,
561                                 <literal>tomorrow</literal> are
562                                 understood, which refer to 00:00:00 of
563                                 the day before the current day, the
564                                 current day, or the day after the
565                                 current day, respectively. <literal>now</literal>
566                                 refers to the current time. Finally,
567                                 relative times may be specified,
568                                 prefixed with <literal>-</literal> or
569                                 <literal>+</literal>, referring to
570                                 times before or after the current
571                                 time, respectively.</para></listitem>
572                         </varlistentry>
573
574                         <varlistentry>
575                                 <term><option>-F</option></term>
576                                 <term><option>--field=</option></term>
577
578                                 <listitem><para>Print all possible
579                                 data values the specified field can
580                                 take in all entries of the
581                                 journal.</para></listitem>
582                         </varlistentry>
583
584                         <varlistentry>
585                                 <term><option>--system</option></term>
586                                 <term><option>--user</option></term>
587
588                                 <listitem><para>Show messages from
589                                 system services and the kernel (with
590                                 <option>--system</option>).  Show
591                                 messages from service of current user
592                                 (with <option>--user</option>).
593                                 If neither is specified, show all
594                                 messages that the user can see.
595                                 </para></listitem>
596                         </varlistentry>
597
598                         <varlistentry>
599                                 <term><option>-D <replaceable>DIR</replaceable></option></term>
600                                 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
601
602                                 <listitem><para>Takes a directory path
603                                 as argument. If specified, journalctl
604                                 will operate on the specified journal
605                                 directory
606                                 <replaceable>DIR</replaceable> instead
607                                 of the default runtime and system
608                                 journal paths.</para></listitem>
609                         </varlistentry>
610
611                         <varlistentry>
612                                 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
613
614                                 <listitem><para>Takes a file glob as
615                                 argument. If specified, journalctl will
616                                 operate on the specified journal files
617                                 matching <replaceable>GLOB</replaceable>
618                                 instead of the default runtime and
619                                 system journal paths. May be specified
620                                 multiple times, in which case files will
621                                 be suitably interleaved.</para></listitem>
622                         </varlistentry>
623
624                         <varlistentry>
625                                 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
626
627                                 <listitem><para>Takes a directory path
628                                 as argument. If specified, journalctl
629                                 will operate on catalog file hierarchy
630                                 underneath the specified directory
631                                 instead of the root directory
632                                 (e.g. <option>--update-catalog</option>
633                                 will create
634                                 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
635                                 </para></listitem>
636                         </varlistentry>
637
638                         <varlistentry>
639                                 <term><option>--new-id128</option></term>
640
641                                 <listitem><para>Instead of showing
642                                 journal contents, generate a new 128
643                                 bit ID suitable for identifying
644                                 messages. This is intended for usage
645                                 by developers who need a new
646                                 identifier for a new message they
647                                 introduce and want to make
648                                 recognizable. This will print the new ID in
649                                 three different formats which can be
650                                 copied into source code or
651                                 similar.</para></listitem>
652                         </varlistentry>
653
654                         <varlistentry>
655                                 <term><option>--header</option></term>
656
657                                 <listitem><para>Instead of showing
658                                 journal contents, show internal header
659                                 information of the journal fields
660                                 accessed.</para></listitem>
661                         </varlistentry>
662
663                         <varlistentry>
664                                 <term><option>--disk-usage</option></term>
665
666                                 <listitem><para>Shows the current disk
667                                 usage of all
668                                 journal files.</para></listitem>
669                         </varlistentry>
670
671                         <varlistentry>
672                                 <term><option>--list-catalog
673                                 <optional><replaceable>ID128...</replaceable></optional>
674                                 </option></term>
675
676                                 <listitem><para>List the contents of
677                                 the message catalog, as table of
678                                 message IDs plus their short
679                                 description strings.</para>
680
681                                 <para>If any
682                                 <replaceable>ID128</replaceable>s are
683                                 specified, only those entries are shown.
684                                 </para>
685                                 </listitem>
686                         </varlistentry>
687
688                         <varlistentry>
689                                 <term><option>--dump-catalog
690                                 <optional><replaceable>ID128...</replaceable></optional>
691                                 </option></term>
692
693                                 <listitem><para>Show the contents of
694                                 the message catalog, with entries
695                                 separated by a line consisting of two
696                                 dashes and the id (the format is the
697                                 same as <filename>.catalog</filename>
698                                 files.</para>
699
700                                 <para>If any
701                                 <replaceable>ID128</replaceable>s are
702                                 specified, only those entries are shown.
703                                 </para>
704                                 </listitem>
705                         </varlistentry>
706
707                         <varlistentry>
708                                 <term><option>--update-catalog</option></term>
709
710                                 <listitem><para>Update the message
711                                 catalog index. This command needs to
712                                 be executed each time new catalog
713                                 files are installed, removed or
714                                 updated to rebuild the binary catalog
715                                 index.</para></listitem>
716                         </varlistentry>
717
718                         <varlistentry>
719                                 <term><option>--setup-keys</option></term>
720
721                                 <listitem><para>Instead of showing
722                                 journal contents, generate a new key
723                                 pair for Forward Secure Sealing
724                                 (FSS). This will generate a sealing
725                                 key and a verification key. The
726                                 sealing key is stored in the journal
727                                 data directory and shall remain on the
728                                 host. The verification key should be
729                                 stored externally. Also see the
730                                 <option>Seal=</option> option in
731                                 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
732                                 for details.</para></listitem>
733                         </varlistentry>
734
735                         <varlistentry>
736                                 <term><option>--force</option></term>
737
738                                 <listitem><para>When --setup-keys is passed and
739                                 Forward Secure Sealing has already been set up,
740                                 recreate FSS keys.</para></listitem>
741                         </varlistentry>
742
743                         <varlistentry>
744                                 <term><option>--interval=</option></term>
745
746                                 <listitem><para>Specifies the change
747                                 interval for the sealing key when
748                                 generating an FSS key pair with
749                                 <option>--setup-keys</option>. Shorter
750                                 intervals increase CPU consumption but
751                                 shorten the time range of
752                                 undetectable journal
753                                 alterations. Defaults to
754                                 15min.</para></listitem>
755                         </varlistentry>
756
757                         <varlistentry>
758                                 <term><option>--verify</option></term>
759
760                                 <listitem><para>Check the journal file
761                                 for internal consistency. If the
762                                 file has been generated with FSS
763                                 enabled and the FSS verification key
764                                 has been specified with
765                                 <option>--verify-key=</option>,
766                                 authenticity of the journal file is
767                                 verified.</para></listitem>
768                         </varlistentry>
769
770                         <varlistentry>
771                                 <term><option>--verify-key=</option></term>
772
773                                 <listitem><para>Specifies the FSS
774                                 verification key to use for the
775                                 <option>--verify</option>
776                                 operation.</para></listitem>
777                         </varlistentry>
778
779                 </variablelist>
780         </refsect1>
781
782         <refsect1>
783                 <title>Exit status</title>
784
785                 <para>On success, 0 is returned, a non-zero failure
786                 code otherwise.</para>
787         </refsect1>
788
789         <refsect1>
790                 <title>Environment</title>
791
792                 <variablelist class='environment-variables'>
793                         <varlistentry>
794                                 <term><varname>$SYSTEMD_PAGER</varname></term>
795                                 <listitem><para>Pager to use when
796                                 <option>--no-pager</option> is not given;
797                                 overrides <varname>$PAGER</varname>.  Setting
798                                 this to an empty string or the value
799                                 <literal>cat</literal> is equivalent to passing
800                                 <option>--no-pager</option>.</para></listitem>
801                         </varlistentry>
802                 </variablelist>
803         </refsect1>
804
805         <refsect1>
806                 <title>Examples</title>
807
808                 <para>Without arguments, all collected logs are shown
809                 unfiltered:</para>
810
811                 <programlisting>journalctl</programlisting>
812
813                 <para>With one match specified, all entries with a field matching the expression are shown:</para>
814
815                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
816
817                 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
818
819                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
820
821                 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
822
823                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
824
825                 <para>If the separator <literal>+</literal> is used,
826                 two expressions may be combined in a logical OR. The
827                 following will show all messages from the Avahi
828                 service process with the PID 28097 plus all messages
829                 from the D-Bus service (from any of its
830                 processes):</para>
831
832                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
833
834                 <para>Show all logs generated by the D-Bus executable:</para>
835
836                 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
837
838                 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
839
840                 <programlisting>journalctl /dev/sda</programlisting>
841
842                 <para>Show all kernel logs from last boot:</para>
843
844                 <programlisting>journalctl -k -b :</programlisting>
845
846         </refsect1>
847
848         <refsect1>
849                 <title>See Also</title>
850                 <para>
851                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
852                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
853                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
854                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
855                         <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
856                 </para>
857         </refsect1>
858
859 </refentry>