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6 This file is part of systemd.
8 Copyright 2012 Lennart Poettering
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11 under the terms of the GNU Lesser General Public License as published by
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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 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
116 <option>--no-pager</option> and section Environment
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.
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>-l</option></term>
156 <term><option>--full</option></term>
158 <listitem><para>Show all (printable) fields in
159 full.</para></listitem>
163 <term><option>-a</option></term>
164 <term><option>--all</option></term>
166 <listitem><para>Show all fields in
167 full, even if they include unprintable
168 characters or are very
169 long.</para></listitem>
173 <term><option>-f</option></term>
174 <term><option>--follow</option></term>
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>
183 <term><option>-e</option></term>
184 <term><option>--pager-end</option></term>
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>
201 <term><option>-n</option></term>
202 <term><option>--lines=</option></term>
204 <listitem><para>Show the most recent
205 journal events and limit the number of
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>
214 <term><option>--no-tail</option></term>
216 <listitem><para>Show all stored output
217 lines, even in follow mode. Undoes the
219 <option>--lines=</option>.</para></listitem>
223 <term><option>-r</option></term>
224 <term><option>--reverse</option></term>
226 <listitem><para>Reverse output, so the newest
227 entries are displayed first.</para></listitem>
231 <term><option>-o</option></term>
232 <term><option>--output=</option></term>
234 <listitem><para>Controls the
235 formatting of the journal entries that
236 are shown. Takes one of the following options:
241 <option>short</option>
245 and generates an output
246 that is mostly identical
248 classic syslog files,
250 journal entry.</para>
256 <option>short-iso</option>
259 <para>is very similar,
261 wallclock timestamps.
268 <option>short-precise</option>
271 <para>is very similar,
273 with full microsecond
281 <option>short-monotonic</option>
284 <para>is very similar,
286 timestamps instead of
287 wallclock timestamps.
294 <option>verbose</option>
298 full-structured entry
299 items with all fields.
306 <option>export</option>
310 journal into a binary
311 (but mostly text-based)
315 url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
316 Export Format</ulink>
324 <option>json</option>
327 <para>formats entries
328 as JSON data structures,
329 one per line (see <ulink
330 url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
331 JSON Format</ulink> for
332 more information).</para>
338 <option>json-pretty</option>
341 <para>formats entries as
342 JSON data structures,
344 multiple lines in order
346 readable for humans.</para>
352 <option>json-sse</option>
355 <para>formats entries as
356 JSON data structures,
358 format suitable for <ulink
359 url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
360 Events</ulink>.</para>
369 <para>generates a very
372 message of each journal
373 entry with no meta data,
374 not even a timestamp.
383 <term><option>-x</option></term>
384 <term><option>--catalog</option></term>
386 <listitem><para>Augment log lines with
387 explanation texts from the message
388 catalog. This will add explanatory
389 help texts to log messages in the
390 output where this is available. These
391 short help texts will explain the
392 context of an error or log event,
393 possible solutions, as well as
394 pointers to support forums, developer
395 documentation, and any other relevant
396 manuals. Note that help texts are not
397 available for all messages, but only
398 for selected ones. For more
399 information on the message catalog,
400 please refer to the <ulink
401 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
403 Documentation</ulink>.</para>
405 <para>Note: when attaching
406 <command>journalctl</command> output
407 to bug reports, please do
408 <emphasis>not</emphasis> use
409 <option>-x</option>.</para>
414 <term><option>-q</option></term>
415 <term><option>--quiet</option></term>
417 <listitem><para>Suppresses any warning
418 message regarding inaccessible system
419 journals when run as normal
420 user.</para></listitem>
424 <term><option>-m</option></term>
425 <term><option>--merge</option></term>
427 <listitem><para>Show entries
428 interleaved from all available
429 journals, including remote
430 ones.</para></listitem>
434 <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
435 <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
437 <listitem><para>Show messages from a specific
438 boot. This will add a match for
439 <literal>_BOOT_ID=</literal>.</para>
441 <para>The argument may be empty, in which case
442 logs for the current boot will be shown.</para>
444 <para>If the boot ID is omitted, a positive
445 <replaceable>offset</replaceable> will look up
446 the boots starting from the beginning of the
447 journal, and a equal-or-less-than zero
448 <replaceable>offset</replaceable> will look up
449 boots starting from the end of the
450 journal. Thus, <constant>1</constant> means the
451 first boot found in the journal in the
452 chronological order, <constant>2</constant> the
453 second and so on; while <constant>-0</constant>
454 is the last boot, <constant>-1</constant> the
455 boot before that, and so on. An empty
456 <replaceable>offset</replaceable> is equivalent
457 to specifying <constant>-0</constant>, except
458 when the current boot is not the last boot
459 (e.g. because <option>--directory</option> was
460 specified to look at logs from a different
463 <para>If the 32 character
464 <replaceable>ID</replaceable> is specified, it
465 may optionally be followed by
466 <replaceable>offset</replaceable> which
467 identifies the boot relative to the one given by
468 boot <replaceable>ID</replaceable>. Negative
469 values mean earlier boots and a positive values
471 <replaceable>offset</replaceable> is not
472 specified, a value of zero is assumed and the
473 logs for the boot given by
474 <replaceable>ID</replaceable> are shown.
481 <term><option>-k</option></term>
482 <term><option>--dmesg</option></term>
484 <listitem><para>Show only kernel messages. This
485 implies <option>-b</option> and adds the match
486 <literal>_TRANSPORT=kernel</literal>.
491 <term><option>-u</option></term>
492 <term><option>--unit=</option></term>
494 <listitem><para>Show messages for the
495 specified systemd unit. This will add
496 a match for messages from the unit
497 (<literal>_SYSTEMD_UNIT=</literal>)
498 and additional matches for messages
499 from systemd and messages about
500 coredumps for the specified unit.</para>
501 <para>This parameter can be specified multiple times.
506 <term><option>--user-unit=</option></term>
508 <listitem><para>Show messages for the
509 specified user session unit. This will
510 add a match for messages from the unit
511 (<literal>_SYSTEMD_USER_UNIT=</literal>
512 and <literal>_UID=</literal>) and
513 additional matches for messages from
514 session systemd and messages about
515 coredumps for the specified unit.</para>
516 <para>This parameter can be specified multiple times.
521 <term><option>-p</option></term>
522 <term><option>--priority=</option></term>
524 <listitem><para>Filter output by
525 message priorities or priority
526 ranges. Takes either a single numeric
527 or textual log level (i.e. between
528 0/<literal>emerg</literal> and
529 7/<literal>debug</literal>), or a
530 range of numeric/text log levels in
531 the form FROM..TO. The log levels are
532 the usual syslog log levels as
534 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
535 i.e. <literal>emerg</literal> (0),
536 <literal>alert</literal> (1),
537 <literal>crit</literal> (2),
538 <literal>err</literal> (3),
539 <literal>warning</literal> (4),
540 <literal>notice</literal> (5),
541 <literal>info</literal> (6),
542 <literal>debug</literal> (7). If a
543 single log level is specified, all
544 messages with this log level or a
545 lower (hence more important) log level
546 are shown. If a range is specified, all
547 messages within the range are shown,
548 including both the start and the end
549 value of the range. This will add
550 <literal>PRIORITY=</literal> matches
552 priorities.</para></listitem>
556 <term><option>-c</option></term>
557 <term><option>--cursor=</option></term>
559 <listitem><para>Start showing entries
560 from the location in the journal
561 specified by the passed
562 cursor.</para></listitem>
566 <term><option>--after-cursor=</option></term>
568 <listitem><para>Start showing entries from the
569 location in the journal
570 <emphasis>after</emphasis> the location
571 specified by the this cursor.
576 <term><option>--since=</option></term>
577 <term><option>--until=</option></term>
579 <listitem><para>Start showing entries
580 on or newer than the specified date,
581 or on or older than the specified
582 date, respectively. Date specifications
583 should be of the format
584 <literal>2012-10-30 18:17:16</literal>.
585 If the time part is omitted,
586 <literal>00:00:00</literal> is assumed.
587 If only the seconds component is omitted,
588 <literal>:00</literal> is assumed. If the
589 date component is omitted, the current
590 day is assumed. Alternatively the strings
591 <literal>yesterday</literal>,
592 <literal>today</literal>,
593 <literal>tomorrow</literal> are
594 understood, which refer to 00:00:00 of
595 the day before the current day, the
596 current day, or the day after the
597 current day, respectively. <literal>now</literal>
598 refers to the current time. Finally,
599 relative times may be specified,
600 prefixed with <literal>-</literal> or
601 <literal>+</literal>, referring to
602 times before or after the current
603 time, respectively.</para></listitem>
607 <term><option>-F</option></term>
608 <term><option>--field=</option></term>
610 <listitem><para>Print all possible
611 data values the specified field can
612 take in all entries of the
613 journal.</para></listitem>
617 <term><option>--system</option></term>
618 <term><option>--user</option></term>
620 <listitem><para>Show messages from
621 system services and the kernel (with
622 <option>--system</option>). Show
623 messages from service of current user
624 (with <option>--user</option>).
625 If neither is specified, show all
626 messages that the user can see.
631 <term><option>-D <replaceable>DIR</replaceable></option></term>
632 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
634 <listitem><para>Takes a directory path
635 as argument. If specified, journalctl
636 will operate on the specified journal
638 <replaceable>DIR</replaceable> instead
639 of the default runtime and system
640 journal paths.</para></listitem>
644 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
646 <listitem><para>Takes a file glob as
647 argument. If specified, journalctl will
648 operate on the specified journal files
649 matching <replaceable>GLOB</replaceable>
650 instead of the default runtime and
651 system journal paths. May be specified
652 multiple times, in which case files will
653 be suitably interleaved.</para></listitem>
657 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
659 <listitem><para>Takes a directory path
660 as argument. If specified, journalctl
661 will operate on catalog file hierarchy
662 underneath the specified directory
663 instead of the root directory
664 (e.g. <option>--update-catalog</option>
666 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
671 <term><option>--new-id128</option></term>
673 <listitem><para>Instead of showing
674 journal contents, generate a new 128
675 bit ID suitable for identifying
676 messages. This is intended for usage
677 by developers who need a new
678 identifier for a new message they
679 introduce and want to make
680 recognizable. This will print the new ID in
681 three different formats which can be
682 copied into source code or
683 similar.</para></listitem>
687 <term><option>--header</option></term>
689 <listitem><para>Instead of showing
690 journal contents, show internal header
691 information of the journal fields
692 accessed.</para></listitem>
696 <term><option>--disk-usage</option></term>
698 <listitem><para>Shows the current disk
700 journal files.</para></listitem>
704 <term><option>--list-catalog
705 <optional><replaceable>ID128...</replaceable></optional>
708 <listitem><para>List the contents of
709 the message catalog, as table of
710 message IDs plus their short
711 description strings.</para>
714 <replaceable>ID128</replaceable>s are
715 specified, only those entries are shown.
721 <term><option>--dump-catalog
722 <optional><replaceable>ID128...</replaceable></optional>
725 <listitem><para>Show the contents of
726 the message catalog, with entries
727 separated by a line consisting of two
728 dashes and the id (the format is the
729 same as <filename>.catalog</filename>
733 <replaceable>ID128</replaceable>s are
734 specified, only those entries are shown.
740 <term><option>--update-catalog</option></term>
742 <listitem><para>Update the message
743 catalog index. This command needs to
744 be executed each time new catalog
745 files are installed, removed or
746 updated to rebuild the binary catalog
747 index.</para></listitem>
751 <term><option>--setup-keys</option></term>
753 <listitem><para>Instead of showing
754 journal contents, generate a new key
755 pair for Forward Secure Sealing
756 (FSS). This will generate a sealing
757 key and a verification key. The
758 sealing key is stored in the journal
759 data directory and shall remain on the
760 host. The verification key should be
761 stored externally. Also see the
762 <option>Seal=</option> option in
763 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
764 for details.</para></listitem>
768 <term><option>--force</option></term>
770 <listitem><para>When --setup-keys is passed and
771 Forward Secure Sealing has already been set up,
772 recreate FSS keys.</para></listitem>
776 <term><option>--interval=</option></term>
778 <listitem><para>Specifies the change
779 interval for the sealing key when
780 generating an FSS key pair with
781 <option>--setup-keys</option>. Shorter
782 intervals increase CPU consumption but
783 shorten the time range of
785 alterations. Defaults to
786 15min.</para></listitem>
790 <term><option>--verify</option></term>
792 <listitem><para>Check the journal file
793 for internal consistency. If the
794 file has been generated with FSS
795 enabled and the FSS verification key
796 has been specified with
797 <option>--verify-key=</option>,
798 authenticity of the journal file is
799 verified.</para></listitem>
803 <term><option>--verify-key=</option></term>
805 <listitem><para>Specifies the FSS
806 verification key to use for the
807 <option>--verify</option>
808 operation.</para></listitem>
815 <title>Exit status</title>
817 <para>On success, 0 is returned, a non-zero failure
818 code otherwise.</para>
822 <title>Environment</title>
824 <variablelist class='environment-variables'>
826 <term><varname>$SYSTEMD_PAGER</varname></term>
827 <listitem><para>Pager to use when
828 <option>--no-pager</option> is not given;
829 overrides <varname>$PAGER</varname>. Setting
830 this to an empty string or the value
831 <literal>cat</literal> is equivalent to passing
832 <option>--no-pager</option>.</para></listitem>
838 <title>Examples</title>
840 <para>Without arguments, all collected logs are shown
843 <programlisting>journalctl</programlisting>
845 <para>With one match specified, all entries with a field matching the expression are shown:</para>
847 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
849 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
851 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
853 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
855 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
857 <para>If the separator <literal>+</literal> is used,
858 two expressions may be combined in a logical OR. The
859 following will show all messages from the Avahi
860 service process with the PID 28097 plus all messages
861 from the D-Bus service (from any of its
864 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
866 <para>Show all logs generated by the D-Bus executable:</para>
868 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
870 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
872 <programlisting>journalctl /dev/sda</programlisting>
874 <para>Show all kernel logs from previous boot:</para>
876 <programlisting>journalctl -k -b -1</programlisting>
881 <title>See Also</title>
883 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
884 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
885 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
886 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
887 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>