summaryrefslogtreecommitdiff
path: root/man/journalctl.xml
blob: e10918a9c682e0e2cf033cfafccac1d9c8ccc10a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
<?xml version='1.0'?> <!--*-nxml-*-->
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
        "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">

<!--
  This file is part of systemd.

  Copyright 2012 Lennart Poettering

  systemd is free software; you can redistribute it and/or modify it
  under the terms of the GNU Lesser General Public License as published by
  the Free Software Foundation; either version 2.1 of the License, or
  (at your option) any later version.

  systemd is distributed in the hope that it will be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public License
  along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->

<refentry id="journalctl"
          xmlns:xi="http://www.w3.org/2001/XInclude">

        <refentryinfo>
                <title>journalctl</title>
                <productname>systemd</productname>

                <authorgroup>
                        <author>
                                <contrib>Developer</contrib>
                                <firstname>Lennart</firstname>
                                <surname>Poettering</surname>
                                <email>lennart@poettering.net</email>
                        </author>
                </authorgroup>
        </refentryinfo>

        <refmeta>
                <refentrytitle>journalctl</refentrytitle>
                <manvolnum>1</manvolnum>
        </refmeta>

        <refnamediv>
                <refname>journalctl</refname>
                <refpurpose>Query the systemd journal</refpurpose>
        </refnamediv>

        <refsynopsisdiv>
                <cmdsynopsis>
                        <command>journalctl</command>
                        <arg choice="opt" rep="repeat">OPTIONS</arg>
                        <arg choice="opt" rep="repeat">MATCHES</arg>
                </cmdsynopsis>
        </refsynopsisdiv>

        <refsect1>
                <title>Description</title>

                <para><command>journalctl</command> may be used to
                query the contents of the
                <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                journal as written by
                <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>

                <para>If called without parameters, it will show the full
                contents of the journal, starting with the oldest
                entry collected.</para>

                <para>If one or more match arguments are passed, the
                output is filtered accordingly. A match is in the
                format <literal>FIELD=VALUE</literal>,
                e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>,
                referring to the components of a structured journal
                entry. See
                <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
                for a list of well-known fields. If multiple matches
                are specified matching different fields, the log
                entries are filtered by both, i.e. the resulting output
                will show only entries matching all the specified
                matches of this kind. If two matches apply to the same
                field, then they are automatically matched as
                alternatives, i.e. the resulting output will show
                entries matching any of the specified matches for the
                same field. Finally, the character
                <literal>+</literal> may appears as a separate word
                between other terms on the command line. This causes
                all matches before and after to be combined in a
                disjunction (i.e. logical OR).</para>

                <para>As shortcuts for a few types of field/value
                matches, file paths may be specified. If a file path
                refers to an executable file, this is equivalent to an
                <literal>_EXE=</literal> match for the canonicalized
                binary path. Similarly, if a path refers to a device
                node, this is equivalent to a
                <literal>_KERNEL_DEVICE=</literal> match for the
                device.</para>

                <para>Additional constraints may be added using options
                <option>--boot</option>, <option>--unit=</option>,
                etc, to further limit what entries will be shown
                (logical AND).</para>

                <para>Output is interleaved from all accessible
                journal files, whether they are rotated or currently
                being written, and regardless of whether they belong to the
                system itself or are accessible user journals.</para>

                <para>The set of journal files which will be used
                can be modified using the <option>--user</option>,
                <option>--system</option>, <option>--directory</option>,
                and <option>--file</option> options, see below.</para>

                <para>All users are granted access to their private
                per-user journals. However, by default, only root and
                users who are members of the <literal>systemd-journal</literal>
                group get access to the system journal and the
                journals of other users.</para>

                <para>The output is paged through
                <command>less</command> by default, and long lines are
                "truncated" to screen width. The hidden part can be
                viewed by using the left-arrow and right-arrow
                keys. Paging can be disabled; see the
                <option>--no-pager</option> option and the "Environment"
                section below.</para>

                <para>When outputting to a tty, lines are colored
                according to priority: lines of level ERROR and higher
                are colored red; lines of level NOTICE and higher are
                highlighted; other lines are displayed normally.
                </para>
        </refsect1>

        <refsect1>
                <title>Options</title>

                <para>The following options are understood:</para>

                <variablelist>
                        <varlistentry>
                                <term><option>--no-full</option></term>
                                <term><option>--full</option></term>
                                <term><option>-l</option></term>

                                <listitem><para>Ellipsize fields when
                                they do not fit in available columns.
                                The default is to show full fields,
                                allowing them to wrap or be truncated
                                by the pager, if one is used.</para>

                                <para>The old options
                                <option>-l</option>/<option>--full</option>
                                are not useful anymore, except to undo
                                <option>--no-full</option>.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-a</option></term>
                                <term><option>--all</option></term>

                                <listitem><para>Show all fields in
                                full, even if they include unprintable
                                characters or are very
                                long.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-f</option></term>
                                <term><option>--follow</option></term>

                                <listitem><para>Show only the most recent
                                journal entries, and continuously print
                                new entries as they are appended to
                                the journal.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-e</option></term>
                                <term><option>--pager-end</option></term>

                                <listitem><para>Immediately jump to
                                the end of the journal inside the
                                implied pager tool. This implies
                                <option>-n1000</option> to guarantee
                                that the pager will not buffer logs of
                                unbounded size. This may be overridden
                                with an explicit <option>-n</option>
                                with some other numeric value on the
                                command line. Note that this option is
                                only supported for the
                                <citerefentry project='man-pages'><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
                                pager.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-n</option></term>
                                <term><option>--lines=</option></term>

                                <listitem><para>Show the most recent
                                journal events and limit the number of
                                events shown. If
                                <option>--follow</option> is used,
                                this option is implied. The argument,
                                a positive integer, is optional, and
                                defaults to 10. </para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--no-tail</option></term>

                                <listitem><para>Show all stored output
                                lines, even in follow mode. Undoes the
                                effect of
                                <option>--lines=</option>.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-r</option></term>
                                <term><option>--reverse</option></term>

                                <listitem><para>Reverse output so that the newest
                                entries are displayed first.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-o</option></term>
                                <term><option>--output=</option></term>

                                <listitem><para>Controls the
                                formatting of the journal entries that
                                are shown. Takes one of the following options:
                                </para>
                                <variablelist>
                                        <varlistentry>
                                                <term>
                                                        <option>short</option>
                                                </term>
                                                <listitem>
                                                        <para>is the default
                                                        and generates an output
                                                        that is mostly identical
                                                        to the formatting of
                                                        classic syslog files,
                                                        showing one line per
                                                        journal entry.</para>
                                                </listitem>
                                        </varlistentry>

                                        <varlistentry>
                                                <term>
                                                        <option>short-iso</option>
                                                </term>
                                                <listitem>
                                                        <para>is very similar,
                                                        but shows ISO 8601
                                                        wallclock timestamps.
                                                        </para>
                                                </listitem>
                                        </varlistentry>

                                        <varlistentry>
                                                <term>
                                                        <option>short-precise</option>
                                                </term>
                                                <listitem>
                                                        <para>is very similar,
                                                        but shows timestamps
                                                        with full microsecond
                                                        precision.
                                                        </para>
                                                </listitem>
                                        </varlistentry>

                                        <varlistentry>
                                                <term>
                                                        <option>short-monotonic</option>
                                                </term>
                                                <listitem>
                                                        <para>is very similar,
                                                        but shows monotonic
                                                        timestamps instead of
                                                        wallclock timestamps.
                                                        </para>
                                                </listitem>
                                        </varlistentry>

                                        <varlistentry>
                                                <term>
                                                        <option>verbose</option>
                                                </term>
                                                <listitem>
                                                        <para>shows the
                                                        full-structured entry
                                                        items with all fields.
                                                        </para>
                                                </listitem>
                                        </varlistentry>

                                        <varlistentry>
                                                <term>
                                                        <option>export</option>
                                                </term>
                                                <listitem>
                                                        <para>serializes the
                                                        journal into a binary
                                                        (but mostly text-based)
                                                        stream suitable for
                                                        backups and network
                                                        transfer (see <ulink
                                                        url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
                                                        Export Format</ulink>
                                                        for more
                                                        information).</para>
                                                </listitem>
                                        </varlistentry>

                                        <varlistentry>
                                                <term>
                                                        <option>json</option>
                                                </term>
                                                <listitem>
                                                        <para>formats entries
                                                        as JSON data structures,
                                                        one per line (see <ulink
                                                        url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
                                                        JSON Format</ulink> for
                                                        more information).</para>
                                                </listitem>
                                        </varlistentry>

                                        <varlistentry>
                                                <term>
                                                        <option>json-pretty</option>
                                                </term>
                                                <listitem>
                                                        <para>formats entries as
                                                        JSON data structures,
                                                        but formats them in
                                                        multiple lines in order
                                                        to make them more
                                                        readable by humans.</para>
                                                </listitem>
                                        </varlistentry>

                                        <varlistentry>
                                                <term>
                                                        <option>json-sse</option>
                                                </term>
                                                <listitem>
                                                        <para>formats entries as
                                                        JSON data structures,
                                                        but wraps them in a
                                                        format suitable for <ulink
                                                        url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
                                                        Events</ulink>.</para>
                                                </listitem>
                                        </varlistentry>

                                        <varlistentry>
                                                <term>
                                                        <option>cat</option>
                                                </term>
                                                <listitem>
                                                        <para>generates a very
                                                        terse output, only
                                                        showing the actual
                                                        message of each journal
                                                        entry with no metadata,
                                                        not even a timestamp.
                                                        </para>
                                                </listitem>
                                        </varlistentry>
                                </variablelist>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-x</option></term>
                                <term><option>--catalog</option></term>

                                <listitem><para>Augment log lines with
                                explanation texts from the message
                                catalog. This will add explanatory
                                help texts to log messages in the
                                output where this is available. These
                                short help texts will explain the
                                context of an error or log event,
                                possible solutions, as well as
                                pointers to support forums, developer
                                documentation, and any other relevant
                                manuals. Note that help texts are not
                                available for all messages, but only
                                for selected ones. For more
                                information on the message catalog,
                                please refer to the <ulink
                                url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
                                Catalog Developer
                                Documentation</ulink>.</para>

                                <para>Note: when attaching
                                <command>journalctl</command> output
                                to bug reports, please do
                                <emphasis>not</emphasis> use
                                <option>-x</option>.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-q</option></term>
                                <term><option>--quiet</option></term>

                                <listitem><para>Suppresses any warning
                                messages regarding inaccessible system
                                journals when run as a normal
                                user.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-m</option></term>
                                <term><option>--merge</option></term>

                                <listitem><para>Show entries
                                interleaved from all available
                                journals, including remote
                                ones.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
                                <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>

                                <listitem><para>Show messages from a specific
                                boot. This will add a match for
                                <literal>_BOOT_ID=</literal>.</para>

                                <para>The argument may be empty, in which case
                                logs for the current boot will be shown.</para>

                                <para>If the boot ID is omitted, a positive
                                <replaceable>offset</replaceable> will look up
                                the boots starting from the beginning of the
                                journal, and a equal-or-less-than zero
                                <replaceable>offset</replaceable> will look up
                                boots starting from the end of the
                                journal. Thus, <constant>1</constant> means the
                                first boot found in the journal in
                                chronological order, <constant>2</constant> the
                                second and so on; while <constant>-0</constant>
                                is the last boot, <constant>-1</constant> the
                                boot before last, and so on. An empty
                                <replaceable>offset</replaceable> is equivalent
                                to specifying <constant>-0</constant>, except
                                when the current boot is not the last boot
                                (e.g. because <option>--directory</option> was
                                specified to look at logs from a different
                                machine).</para>

                                <para>If the 32-character
                                <replaceable>ID</replaceable> is specified, it
                                may optionally be followed by
                                <replaceable>offset</replaceable> which
                                identifies the boot relative to the one given by
                                boot <replaceable>ID</replaceable>. Negative
                                values mean earlier boots and a positive values
                                mean later boots. If
                                <replaceable>offset</replaceable> is not
                                specified, a value of zero is assumed, and the
                                logs for the boot given by
                                <replaceable>ID</replaceable> are shown.
                                </para>

                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--list-boots</option></term>

                                <listitem><para>Show a tabular list of
                                boot numbers (relative to the current
                                boot), their IDs, and the timestamps
                                of the first and last message
                                pertaining to the boot.
                                </para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-k</option></term>
                                <term><option>--dmesg</option></term>

                                <listitem><para>Show only kernel messages. This
                                implies <option>-b</option> and adds the match
                                <literal>_TRANSPORT=kernel</literal>.
                                </para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-u</option></term>
                                <term><option>--unit=<replaceable>UNIT</replaceable>|<replaceable>PATTERN</replaceable></option></term>

                                <listitem><para>Show messages for the
                                specified systemd unit
                                <replaceable>UNIT</replaceable> (such
                                as a service unit), or for any of the
                                units matched by
                                <replaceable>PATTERN</replaceable>.
                                If a pattern is specified, a list of
                                unit names found in the journal is
                                compared with the specified pattern
                                and all that match are used. For each
                                unit name, a match is added for
                                messages from the unit
                                (<literal>_SYSTEMD_UNIT=<replaceable>UNIT</replaceable></literal>),
                                along with additional matches for
                                messages from systemd and messages
                                about coredumps for the specified
                                unit.</para>

                                <para>This parameter can be specified
                                multiple times.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--user-unit=</option></term>

                                <listitem><para>Show messages for the
                                specified user session unit. This will
                                add a match for messages from the unit
                                (<literal>_SYSTEMD_USER_UNIT=</literal>
                                and <literal>_UID=</literal>) and
                                additional matches for messages from
                                session systemd and messages about
                                coredumps for the specified unit.</para>
                                <para>This parameter can be specified multiple times.
                                </para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-p</option></term>
                                <term><option>--priority=</option></term>

                                <listitem><para>Filter output by
                                message priorities or priority
                                ranges. Takes either a single numeric
                                or textual log level (i.e. between
                                0/<literal>emerg</literal> and
                                7/<literal>debug</literal>), or a
                                range of numeric/text log levels in
                                the form FROM..TO. The log levels are
                                the usual syslog log levels as
                                documented in
                                <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                                i.e. <literal>emerg</literal> (0),
                                <literal>alert</literal> (1),
                                <literal>crit</literal> (2),
                                <literal>err</literal> (3),
                                <literal>warning</literal> (4),
                                <literal>notice</literal> (5),
                                <literal>info</literal> (6),
                                <literal>debug</literal> (7). If a
                                single log level is specified, all
                                messages with this log level or a
                                lower (hence more important) log level
                                are shown. If a range is specified, all
                                messages within the range are shown,
                                including both the start and the end
                                value of the range. This will add
                                <literal>PRIORITY=</literal> matches
                                for the specified
                                priorities.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-c</option></term>
                                <term><option>--cursor=</option></term>

                                <listitem><para>Start showing entries
                                from the location in the journal
                                specified by the passed
                                cursor.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--after-cursor=</option></term>

                                <listitem><para>Start showing entries
                                from the location in the journal
                                <emphasis>after</emphasis> the
                                location specified by the this cursor.
                                The cursor is shown when the
                                <option>--show-cursor</option> option
                                is used.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--show-cursor</option></term>

                                <listitem><para>The cursor is shown after the last
                                entry after two dashes:</para>
                                <programlisting>-- cursor: s=0639...</programlisting>
                                <para>The format of the cursor is private
                                and subject to change.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--since=</option></term>
                                <term><option>--until=</option></term>

                                <listitem><para>Start showing entries
                                on or newer than the specified date,
                                or on or older than the specified
                                date, respectively. Date specifications
                                should be of the format
                                <literal>2012-10-30 18:17:16</literal>.
                                If the time part is omitted,
                                <literal>00:00:00</literal> is assumed.
                                If only the seconds component is omitted,
                                <literal>:00</literal> is assumed. If the
                                date component is omitted, the current
                                day is assumed. Alternatively the strings
                                <literal>yesterday</literal>,
                                <literal>today</literal>,
                                <literal>tomorrow</literal> are
                                understood, which refer to 00:00:00 of
                                the day before the current day, the
                                current day, or the day after the
                                current day, respectively. <literal>now</literal>
                                refers to the current time. Finally,
                                relative times may be specified,
                                prefixed with <literal>-</literal> or
                                <literal>+</literal>, referring to
                                times before or after the current
                                time, respectively.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-F</option></term>
                                <term><option>--field=</option></term>

                                <listitem><para>Print all possible
                                data values the specified field can
                                take in all entries of the
                                journal.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--system</option></term>
                                <term><option>--user</option></term>

                                <listitem><para>Show messages from
                                system services and the kernel (with
                                <option>--system</option>). Show
                                messages from service of current user
                                (with <option>--user</option>).
                                If neither is specified, show all
                                messages that the user can see.
                                </para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-M</option></term>
                                <term><option>--machine=</option></term>

                                <listitem><para>Show messages from a
                                running, local container. Specify a
                                container name to connect
                                to.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>-D <replaceable>DIR</replaceable></option></term>
                                <term><option>--directory=<replaceable>DIR</replaceable></option></term>

                                <listitem><para>Takes a directory path
                                as argument. If specified, journalctl
                                will operate on the specified journal
                                directory
                                <replaceable>DIR</replaceable> instead
                                of the default runtime and system
                                journal paths.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--file=<replaceable>GLOB</replaceable></option></term>

                                <listitem><para>Takes a file glob as an
                                argument. If specified, journalctl will
                                operate on the specified journal files
                                matching <replaceable>GLOB</replaceable>
                                instead of the default runtime and
                                system journal paths. May be specified
                                multiple times, in which case files will
                                be suitably interleaved.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--root=<replaceable>ROOT</replaceable></option></term>

                                <listitem><para>Takes a directory path
                                as an argument. If specified, journalctl
                                will operate on catalog file hierarchy
                                underneath the specified directory
                                instead of the root directory
                                (e.g. <option>--update-catalog</option>
                                will create
                                <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
                                </para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--new-id128</option></term>

                                <listitem><para>Instead of showing
                                journal contents, generate a new 128-bit
                                ID suitable for identifying
                                messages. This is intended for usage
                                by developers who need a new
                                identifier for a new message they
                                introduce and want to make
                                recognizable. This will print the new ID in
                                three different formats which can be
                                copied into source code or
                                similar.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--header</option></term>

                                <listitem><para>Instead of showing
                                journal contents, show internal header
                                information of the journal fields
                                accessed.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--disk-usage</option></term>

                                <listitem><para>Shows the current disk
                                usage of all
                                journal files.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--list-catalog
                                <optional><replaceable>128-bit-ID...</replaceable></optional>
                                </option></term>

                                <listitem><para>List the contents of
                                the message catalog as a table of
                                message IDs, plus their short
                                description strings.</para>

                                <para>If any
                                <replaceable>128-bit-ID</replaceable>s are
                                specified, only those entries are shown.
                                </para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--dump-catalog
                                <optional><replaceable>128-bit-ID...</replaceable></optional>
                                </option></term>

                                <listitem><para>Show the contents of
                                the message catalog, with entries
                                separated by a line consisting of two
                                dashes and the ID (the format is the
                                same as <filename>.catalog</filename>
                                files).</para>

                                <para>If any
                                <replaceable>128-bit-ID</replaceable>s are
                                specified, only those entries are shown.
                                </para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--update-catalog</option></term>

                                <listitem><para>Update the message
                                catalog index. This command needs to
                                be executed each time new catalog
                                files are installed, removed, or
                                updated to rebuild the binary catalog
                                index.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--setup-keys</option></term>

                                <listitem><para>Instead of showing
                                journal contents, generate a new key
                                pair for Forward Secure Sealing
                                (FSS). This will generate a sealing
                                key and a verification key. The
                                sealing key is stored in the journal
                                data directory and shall remain on the
                                host. The verification key should be
                                stored externally. Refer to the
                                <option>Seal=</option> option in
                                <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                                for information on Forward Secure
                                Sealing and for a link to a refereed
                                scholarly paper detailing the
                                cryptographic theory it is based on.
                                </para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--force</option></term>

                                <listitem><para>When
                                <option>--setup-keys</option> is passed and
                                Forward Secure Sealing (FSS) has already been
                                configured, recreate FSS keys.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--interval=</option></term>

                                <listitem><para>Specifies the change
                                interval for the sealing key when
                                generating an FSS key pair with
                                <option>--setup-keys</option>. Shorter
                                intervals increase CPU consumption but
                                shorten the time range of
                                undetectable journal
                                alterations. Defaults to
                                15min.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--verify</option></term>

                                <listitem><para>Check the journal file
                                for internal consistency. If the
                                file has been generated with FSS
                                enabled and the FSS verification key
                                has been specified with
                                <option>--verify-key=</option>,
                                authenticity of the journal file is
                                verified.</para></listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><option>--verify-key=</option></term>

                                <listitem><para>Specifies the FSS
                                verification key to use for the
                                <option>--verify</option>
                                operation.</para></listitem>
                        </varlistentry>

                        <xi:include href="standard-options.xml" xpointer="help" />
                        <xi:include href="standard-options.xml" xpointer="version" />
                        <xi:include href="standard-options.xml" xpointer="no-pager" />
                </variablelist>
        </refsect1>

        <refsect1>
                <title>Exit status</title>

                <para>On success, 0 is returned; otherwise, a non-zero
                failure code is returned.</para>
        </refsect1>

        <xi:include href="less-variables.xml" />

        <refsect1>
                <title>Examples</title>

                <para>Without arguments, all collected logs are shown
                unfiltered:</para>

                <programlisting>journalctl</programlisting>

                <para>With one match specified, all entries with a field matching the expression are shown:</para>

                <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>

                <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>

                <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>

                <para>If two matches refer to the same field, all entries matching either expression are shown:</para>

                <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>

                <para>If the separator <literal>+</literal> is used,
                two expressions may be combined in a logical OR. The
                following will show all messages from the Avahi
                service process with the PID 28097 plus all messages
                from the D-Bus service (from any of its
                processes):</para>

                <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>

                <para>Show all logs generated by the D-Bus executable:</para>

                <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>

                <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>

                <programlisting>journalctl /dev/sda</programlisting>

                <para>Show all kernel logs from previous boot:</para>

                <programlisting>journalctl -k -b -1</programlisting>

                <para>Show a live log display from a system service <filename>apache.service</filename>:</para>

                <programlisting>journalctl -f -u apache</programlisting>

        </refsect1>

        <refsect1>
                <title>See Also</title>
                <para>
                        <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
                </para>
        </refsect1>

</refentry>