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6 This file is part of systemd.
8 Copyright 2012 Lennart Poettering
10 systemd is free software; you can redistribute it and/or modify it
11 under the terms of the GNU Lesser General Public License as published by
12 the Free Software Foundation; either version 2.1 of the License, or
13 (at your option) any later version.
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24 <refentry id="journalctl">
27 <title>journalctl</title>
28 <productname>systemd</productname>
32 <contrib>Developer</contrib>
33 <firstname>Lennart</firstname>
34 <surname>Poettering</surname>
35 <email>lennart@poettering.net</email>
41 <refentrytitle>journalctl</refentrytitle>
42 <manvolnum>1</manvolnum>
46 <refname>journalctl</refname>
47 <refpurpose>Query the systemd journal</refpurpose>
52 <command>journalctl</command>
53 <arg choice="opt" rep="repeat">OPTIONS</arg>
54 <arg choice="opt" rep="repeat">MATCHES</arg>
59 <title>Description</title>
61 <para><command>journalctl</command> may be used to
62 query the contents of the
63 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
65 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
67 <para>If called without parameters, it will show the full
68 contents of the journal, starting with the oldest
69 entry collected.</para>
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
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 a separate word on the
88 command line, all matches before and after are combined
89 in a disjunction (i.e. logical OR).</para>
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
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>
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>systemd-journal</literal>
108 group get access to the system journal and the
109 journals of other users.</para>
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 the
116 <option>--no-pager</option> option and the "Environment"
117 section below.</para>
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; other lines are displayed normally.
127 <title>Options</title>
129 <para>The following options are understood:</para>
133 <term><option>-h</option></term>
134 <term><option>--help</option></term>
136 <listitem><para>Prints a short help
137 text and exits.</para></listitem>
141 <term><option>--version</option></term>
143 <listitem><para>Prints a short version
144 string and exits.</para></listitem>
148 <term><option>--no-pager</option></term>
150 <listitem><para>Do not pipe output into a
151 pager.</para></listitem>
155 <term><option>--no-full</option></term>
156 <term><option>--full</option></term>
157 <term><option>-l</option></term>
159 <listitem><para>Ellipsize fields when
160 they do not fit in available columns.
161 The default is to show full fields,
162 allowing them to wrap or be truncated
163 by the pager, if one is used.</para>
165 <para>The old options
166 <option>-l</option>/<option>--full</option>
167 are not useful anymore, except to undo
168 <option>--no-full</option>.</para></listitem>
172 <term><option>-a</option></term>
173 <term><option>--all</option></term>
175 <listitem><para>Show all fields in
176 full, even if they include unprintable
177 characters or are very
178 long.</para></listitem>
182 <term><option>-f</option></term>
183 <term><option>--follow</option></term>
185 <listitem><para>Show only the most recent
186 journal entries, and continuously print
187 new entries as they are appended to
188 the journal.</para></listitem>
192 <term><option>-e</option></term>
193 <term><option>--pager-end</option></term>
195 <listitem><para>Immediately jump to
196 the end of the journal inside the
197 implied pager tool. This implies
198 <option>-n1000</option> to guarantee
199 that the pager will not buffer logs of
200 unbounded size. This may be overridden
201 with an explicit <option>-n</option>
202 with some other numeric value on the
203 command line. Note that this option is
204 only supported for the
205 <citerefentry><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
206 pager.</para></listitem>
210 <term><option>-n</option></term>
211 <term><option>--lines=</option></term>
213 <listitem><para>Show the most recent
214 journal events and limit the number of
216 <option>--follow</option> is used,
217 this option is implied. The argument,
218 a positive integer, is optional, and
219 defaults to 10. </para></listitem>
223 <term><option>--no-tail</option></term>
225 <listitem><para>Show all stored output
226 lines, even in follow mode. Undoes the
228 <option>--lines=</option>.</para></listitem>
232 <term><option>-r</option></term>
233 <term><option>--reverse</option></term>
235 <listitem><para>Reverse output so that the newest
236 entries are displayed first.</para></listitem>
240 <term><option>-o</option></term>
241 <term><option>--output=</option></term>
243 <listitem><para>Controls the
244 formatting of the journal entries that
245 are shown. Takes one of the following options:
250 <option>short</option>
254 and generates an output
255 that is mostly identical
257 classic syslog files,
259 journal entry.</para>
265 <option>short-iso</option>
268 <para>is very similar,
270 wallclock timestamps.
277 <option>short-precise</option>
280 <para>is very similar,
282 with full microsecond
290 <option>short-monotonic</option>
293 <para>is very similar,
295 timestamps instead of
296 wallclock timestamps.
303 <option>verbose</option>
307 full-structured entry
308 items with all fields.
315 <option>export</option>
319 journal into a binary
320 (but mostly text-based)
324 url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
325 Export Format</ulink>
333 <option>json</option>
336 <para>formats entries
337 as JSON data structures,
338 one per line (see <ulink
339 url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
340 JSON Format</ulink> for
341 more information).</para>
347 <option>json-pretty</option>
350 <para>formats entries as
351 JSON data structures,
353 multiple lines in order
355 readable by humans.</para>
361 <option>json-sse</option>
364 <para>formats entries as
365 JSON data structures,
367 format suitable for <ulink
368 url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
369 Events</ulink>.</para>
378 <para>generates a very
381 message of each journal
382 entry with no meta data,
383 not even a timestamp.
392 <term><option>-x</option></term>
393 <term><option>--catalog</option></term>
395 <listitem><para>Augment log lines with
396 explanation texts from the message
397 catalog. This will add explanatory
398 help texts to log messages in the
399 output where this is available. These
400 short help texts will explain the
401 context of an error or log event,
402 possible solutions, as well as
403 pointers to support forums, developer
404 documentation, and any other relevant
405 manuals. Note that help texts are not
406 available for all messages, but only
407 for selected ones. For more
408 information on the message catalog,
409 please refer to the <ulink
410 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
412 Documentation</ulink>.</para>
414 <para>Note: when attaching
415 <command>journalctl</command> output
416 to bug reports, please do
417 <emphasis>not</emphasis> use
418 <option>-x</option>.</para>
423 <term><option>-q</option></term>
424 <term><option>--quiet</option></term>
426 <listitem><para>Suppresses any warning
427 messages regarding inaccessible system
428 journals when run as a normal
429 user.</para></listitem>
433 <term><option>-m</option></term>
434 <term><option>--merge</option></term>
436 <listitem><para>Show entries
437 interleaved from all available
438 journals, including remote
439 ones.</para></listitem>
443 <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
444 <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
446 <listitem><para>Show messages from a specific
447 boot. This will add a match for
448 <literal>_BOOT_ID=</literal>.</para>
450 <para>The argument may be empty, in which case
451 logs for the current boot will be shown.</para>
453 <para>If the boot ID is omitted, a positive
454 <replaceable>offset</replaceable> will look up
455 the boots starting from the beginning of the
456 journal, and a equal-or-less-than zero
457 <replaceable>offset</replaceable> will look up
458 boots starting from the end of the
459 journal. Thus, <constant>1</constant> means the
460 first boot found in the journal in
461 chronological order, <constant>2</constant> the
462 second and so on; while <constant>-0</constant>
463 is the last boot, <constant>-1</constant> the
464 boot before last, and so on. An empty
465 <replaceable>offset</replaceable> is equivalent
466 to specifying <constant>-0</constant>, except
467 when the current boot is not the last boot
468 (e.g. because <option>--directory</option> was
469 specified to look at logs from a different
472 <para>If the 32-character
473 <replaceable>ID</replaceable> is specified, it
474 may optionally be followed by
475 <replaceable>offset</replaceable> which
476 identifies the boot relative to the one given by
477 boot <replaceable>ID</replaceable>. Negative
478 values mean earlier boots and a positive values
480 <replaceable>offset</replaceable> is not
481 specified, a value of zero is assumed, and the
482 logs for the boot given by
483 <replaceable>ID</replaceable> are shown.
490 <term><option>--list-boots</option></term>
492 <listitem><para>Show a tabular list of
493 boot numbers (relative to the current
494 boot), their IDs, and the timestamps
495 of the first and last message
496 pertaining to the boot.
501 <term><option>-k</option></term>
502 <term><option>--dmesg</option></term>
504 <listitem><para>Show only kernel messages. This
505 implies <option>-b</option> and adds the match
506 <literal>_TRANSPORT=kernel</literal>.
511 <term><option>-u</option></term>
512 <term><option>--unit=<replaceable>UNIT</replaceable>|<replaceable>PATTERN</replaceable></option></term>
514 <listitem><para>Show messages for the
515 specified systemd unit
516 <replaceable>UNIT</replaceable>, or
517 for any of the units matched by
518 <replaceable>PATTERN</replaceable>.
519 If a pattern is specified, a list of
520 unit names found in the journal is
521 compared with the specified pattern
522 and all that match are used. For each
523 unit name a match is added for
524 messages from the unit
525 (<literal>_SYSTEMD_UNIT=<replaceable>UNIT</replaceable></literal>)
526 along with additional matches for
527 messages from systemd and messages
528 about coredumps for the specified
531 <para>This parameter can be specified
532 multiple times. </para></listitem>
536 <term><option>--user-unit=</option></term>
538 <listitem><para>Show messages for the
539 specified user session unit. This will
540 add a match for messages from the unit
541 (<literal>_SYSTEMD_USER_UNIT=</literal>
542 and <literal>_UID=</literal>) and
543 additional matches for messages from
544 session systemd and messages about
545 coredumps for the specified unit.</para>
546 <para>This parameter can be specified multiple times.
551 <term><option>-p</option></term>
552 <term><option>--priority=</option></term>
554 <listitem><para>Filter output by
555 message priorities or priority
556 ranges. Takes either a single numeric
557 or textual log level (i.e. between
558 0/<literal>emerg</literal> and
559 7/<literal>debug</literal>), or a
560 range of numeric/text log levels in
561 the form FROM..TO. The log levels are
562 the usual syslog log levels as
564 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
565 i.e. <literal>emerg</literal> (0),
566 <literal>alert</literal> (1),
567 <literal>crit</literal> (2),
568 <literal>err</literal> (3),
569 <literal>warning</literal> (4),
570 <literal>notice</literal> (5),
571 <literal>info</literal> (6),
572 <literal>debug</literal> (7). If a
573 single log level is specified, all
574 messages with this log level or a
575 lower (hence more important) log level
576 are shown. If a range is specified, all
577 messages within the range are shown,
578 including both the start and the end
579 value of the range. This will add
580 <literal>PRIORITY=</literal> matches
582 priorities.</para></listitem>
586 <term><option>-c</option></term>
587 <term><option>--cursor=</option></term>
589 <listitem><para>Start showing entries
590 from the location in the journal
591 specified by the passed
592 cursor.</para></listitem>
596 <term><option>--after-cursor=</option></term>
598 <listitem><para>Start showing entries
599 from the location in the journal
600 <emphasis>after</emphasis> the
601 location specified by the this cursor.
602 The cursor is shown when the
603 <option>--show-cursor</option> option
604 is used.</para></listitem>
608 <term><option>--show-cursor</option></term>
610 <listitem><para>The cursor is shown after the last
611 entry after two dashes:</para>
612 <programlisting>-- cursor: s=0639...</programlisting>
613 <para>The format of the cursor is private
614 and subject to change.</para></listitem>
618 <term><option>--since=</option></term>
619 <term><option>--until=</option></term>
621 <listitem><para>Start showing entries
622 on or newer than the specified date,
623 or on or older than the specified
624 date, respectively. Date specifications
625 should be of the format
626 <literal>2012-10-30 18:17:16</literal>.
627 If the time part is omitted,
628 <literal>00:00:00</literal> is assumed.
629 If only the seconds component is omitted,
630 <literal>:00</literal> is assumed. If the
631 date component is omitted, the current
632 day is assumed. Alternatively the strings
633 <literal>yesterday</literal>,
634 <literal>today</literal>,
635 <literal>tomorrow</literal> are
636 understood, which refer to 00:00:00 of
637 the day before the current day, the
638 current day, or the day after the
639 current day, respectively. <literal>now</literal>
640 refers to the current time. Finally,
641 relative times may be specified,
642 prefixed with <literal>-</literal> or
643 <literal>+</literal>, referring to
644 times before or after the current
645 time, respectively.</para></listitem>
649 <term><option>-F</option></term>
650 <term><option>--field=</option></term>
652 <listitem><para>Print all possible
653 data values the specified field can
654 take in all entries of the
655 journal.</para></listitem>
659 <term><option>--system</option></term>
660 <term><option>--user</option></term>
662 <listitem><para>Show messages from
663 system services and the kernel (with
664 <option>--system</option>). Show
665 messages from service of current user
666 (with <option>--user</option>).
667 If neither is specified, show all
668 messages that the user can see.
673 <term><option>-M</option></term>
674 <term><option>--machine=</option></term>
676 <listitem><para>Show messages from a
677 running, local container. Specify a
678 container name to connect
679 to.</para></listitem>
683 <term><option>-D <replaceable>DIR</replaceable></option></term>
684 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
686 <listitem><para>Takes a directory path
687 as argument. If specified, journalctl
688 will operate on the specified journal
690 <replaceable>DIR</replaceable> instead
691 of the default runtime and system
692 journal paths.</para></listitem>
696 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
698 <listitem><para>Takes a file glob as an
699 argument. If specified, journalctl will
700 operate on the specified journal files
701 matching <replaceable>GLOB</replaceable>
702 instead of the default runtime and
703 system journal paths. May be specified
704 multiple times, in which case files will
705 be suitably interleaved.</para></listitem>
709 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
711 <listitem><para>Takes a directory path
712 as an argument. If specified, journalctl
713 will operate on catalog file hierarchy
714 underneath the specified directory
715 instead of the root directory
716 (e.g. <option>--update-catalog</option>
718 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
723 <term><option>--new-id128</option></term>
725 <listitem><para>Instead of showing
726 journal contents, generate a new 128-bit
727 ID suitable for identifying
728 messages. This is intended for usage
729 by developers who need a new
730 identifier for a new message they
731 introduce and want to make
732 recognizable. This will print the new ID in
733 three different formats which can be
734 copied into source code or
735 similar.</para></listitem>
739 <term><option>--header</option></term>
741 <listitem><para>Instead of showing
742 journal contents, show internal header
743 information of the journal fields
744 accessed.</para></listitem>
748 <term><option>--disk-usage</option></term>
750 <listitem><para>Shows the current disk
752 journal files.</para></listitem>
756 <term><option>--list-catalog
757 <optional><replaceable>128-bit-ID...</replaceable></optional>
760 <listitem><para>List the contents of
761 the message catalog as a table of
762 message IDs, plus their short
763 description strings.</para>
766 <replaceable>128-bit-ID</replaceable>s are
767 specified, only those entries are shown.
773 <term><option>--dump-catalog
774 <optional><replaceable>128-bit-ID...</replaceable></optional>
777 <listitem><para>Show the contents of
778 the message catalog, with entries
779 separated by a line consisting of two
780 dashes and the ID (the format is the
781 same as <filename>.catalog</filename>
785 <replaceable>128-bit-ID</replaceable>s are
786 specified, only those entries are shown.
792 <term><option>--update-catalog</option></term>
794 <listitem><para>Update the message
795 catalog index. This command needs to
796 be executed each time new catalog
797 files are installed, removed, or
798 updated to rebuild the binary catalog
799 index.</para></listitem>
803 <term><option>--setup-keys</option></term>
805 <listitem><para>Instead of showing
806 journal contents, generate a new key
807 pair for Forward Secure Sealing
808 (FSS). This will generate a sealing
809 key and a verification key. The
810 sealing key is stored in the journal
811 data directory and shall remain on the
812 host. The verification key should be
813 stored externally. Refer to the
814 <option>Seal=</option> option in
815 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
816 for information on Forward Secure
817 Sealing and for a link to a refereed
818 scholarly paper detailing the
819 cryptographic theory it is based on.
824 <term><option>--force</option></term>
827 <option>--setup-keys</option> is passed and
828 Forward Secure Sealing (FSS) has already been
829 configured, recreate FSS keys.</para></listitem>
833 <term><option>--interval=</option></term>
835 <listitem><para>Specifies the change
836 interval for the sealing key when
837 generating an FSS key pair with
838 <option>--setup-keys</option>. Shorter
839 intervals increase CPU consumption but
840 shorten the time range of
842 alterations. Defaults to
843 15min.</para></listitem>
847 <term><option>--verify</option></term>
849 <listitem><para>Check the journal file
850 for internal consistency. If the
851 file has been generated with FSS
852 enabled and the FSS verification key
853 has been specified with
854 <option>--verify-key=</option>,
855 authenticity of the journal file is
856 verified.</para></listitem>
860 <term><option>--verify-key=</option></term>
862 <listitem><para>Specifies the FSS
863 verification key to use for the
864 <option>--verify</option>
865 operation.</para></listitem>
872 <title>Exit status</title>
874 <para>On success, 0 is returned; otherwise, a non-zero
875 failure code is returned.</para>
879 <title>Environment</title>
881 <variablelist class='environment-variables'>
883 <term><varname>$SYSTEMD_PAGER</varname></term>
884 <listitem><para>Pager to use when
885 <option>--no-pager</option> is not given;
886 overrides <varname>$PAGER</varname>. Setting
887 this to an empty string or the value
888 <literal>cat</literal> is equivalent to passing
889 <option>--no-pager</option>.</para></listitem>
895 <title>Examples</title>
897 <para>Without arguments, all collected logs are shown
900 <programlisting>journalctl</programlisting>
902 <para>With one match specified, all entries with a field matching the expression are shown:</para>
904 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
906 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
908 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
910 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
912 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
914 <para>If the separator <literal>+</literal> is used,
915 two expressions may be combined in a logical OR. The
916 following will show all messages from the Avahi
917 service process with the PID 28097 plus all messages
918 from the D-Bus service (from any of its
921 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
923 <para>Show all logs generated by the D-Bus executable:</para>
925 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
927 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
929 <programlisting>journalctl /dev/sda</programlisting>
931 <para>Show all kernel logs from previous boot:</para>
933 <programlisting>journalctl -k -b -1</programlisting>
938 <title>See Also</title>
940 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
941 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
942 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
943 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
944 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>