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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>adm</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-monotonic</option>
259 <para>is very similar
261 timestamps instead of
262 wallclock timestamps.
269 <option>short-iso</option>
272 <para>is very similar,
274 wallclock timestamps.
281 <option>verbose</option>
285 full-structured entry
286 items with all fields.
293 <option>export</option>
297 journal into a binary
298 (but mostly text-based)
302 url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
303 Export Format</ulink>
311 <option>json</option>
314 <para>formats entries
315 as JSON data structures,
316 one per line (see <ulink
317 url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
318 JSON Format</ulink> for
319 more information).</para>
325 <option>json-pretty</option>
328 <para>formats entries as
329 JSON data structures,
331 multiple lines in order
333 readable for humans.</para>
339 <option>json-sse</option>
342 <para>formats entries as
343 JSON data structures,
345 format suitable for <ulink
346 url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
347 Events</ulink>.</para>
356 <para>generates a very
359 message of each journal
360 entry with no meta data,
361 not even a timestamp.
370 <term><option>-x</option></term>
371 <term><option>--catalog</option></term>
373 <listitem><para>Augment log lines with
374 explanation texts from the message
375 catalog. This will add explanatory
376 help texts to log messages in the
377 output where this is available. These
378 short help texts will explain the
379 context of an error or log event,
380 possible solutions, as well as
381 pointers to support forums, developer
382 documentation and any other relevant
383 manuals. Note that help texts are not
384 available for all messages, but only
385 for selected ones. For more
386 information on the message catalog,
387 please refer to the <ulink
388 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
390 Documentation</ulink>.</para></listitem>
394 <term><option>-q</option></term>
395 <term><option>--quiet</option></term>
397 <listitem><para>Suppresses any warning
398 message regarding inaccessible system
399 journals when run as normal
400 user.</para></listitem>
404 <term><option>-m</option></term>
405 <term><option>--merge</option></term>
407 <listitem><para>Show entries
408 interleaved from all available
409 journals, including remote
410 ones.</para></listitem>
414 <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
415 <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
417 <listitem><para>Show messages from a specific
418 boot. This will add a match for
419 <literal>_BOOT_ID=</literal>.</para>
421 <para>The argument may be empty, in which case
422 logs for the current boot will be shown.</para>
424 <para>If the boot ID is omitted, a positive
425 <replaceable>offset</replaceable> will look up
426 the boots starting from the beginning of the
427 journal, and a equal-or-less-than zero
428 <replaceable>offset</replaceable> will look up
429 boots starting from the end of the
430 journal. Thus, <constant>1</constant> means the
431 first boot found in the journal in the
432 chronological order, <constant>2</constant> the
433 second and so on; while <constant>-0</constant>
434 is the last boot, <constant>-1</constant> the
435 boot before that, and so on. An empty
436 <replaceable>offset</replaceable> is equivalent
437 to specifying <constant>-0</constant>, except
438 when the current boot is not the last boot
439 (e.g. because <option>--directory</option> was
440 specified to look at logs from a different
443 <para>If the 32 character
444 <replaceable>ID</replaceable> is specified, it
445 may optionally be followed by
446 <replaceable>offset</replaceable> which
447 identifies the boot relative to the one given by
448 boot <replaceable>ID</replaceable>. Negative
449 values mean earlier boots and a positive values
451 <replaceable>offset</replaceable> is not
452 specified, a value of zero is assumed and the
453 logs for the boot given by
454 <replaceable>ID</replaceable> are shown.
461 <term><option>-k</option></term>
462 <term><option>--dmesg</option></term>
464 <listitem><para>Show only kernel messages. This
465 implies <option>-b</option> and adds the match
466 <literal>_TRANSPORT=kernel</literal>.
471 <term><option>-u</option></term>
472 <term><option>--unit=</option></term>
474 <listitem><para>Show messages for the
475 specified systemd unit. This will add
476 a match for messages from the unit
477 (<literal>_SYSTEMD_UNIT=</literal>)
478 and additional matches for messages
479 from systemd and messages about
480 coredumps for the specified unit.</para>
481 <para>This parameter can be specified multiple times.
486 <term><option>--user-unit=</option></term>
488 <listitem><para>Show messages for the
489 specified user session unit. This will
490 add a match for messages from the unit
491 (<literal>_SYSTEMD_USER_UNIT=</literal>
492 and <literal>_UID=</literal>) and
493 additional matches for messages from
494 session systemd and messages about
495 coredumps for the specified unit.</para>
496 <para>This parameter can be specified multiple times.
501 <term><option>-p</option></term>
502 <term><option>--priority=</option></term>
504 <listitem><para>Filter output by
505 message priorities or priority
506 ranges. Takes either a single numeric
507 or textual log level (i.e. between
508 0/<literal>emerg</literal> and
509 7/<literal>debug</literal>), or a
510 range of numeric/text log levels in
511 the form FROM..TO. The log levels are
512 the usual syslog log levels as
514 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
515 i.e. <literal>emerg</literal> (0),
516 <literal>alert</literal> (1),
517 <literal>crit</literal> (2),
518 <literal>err</literal> (3),
519 <literal>warning</literal> (4),
520 <literal>notice</literal> (5),
521 <literal>info</literal> (6),
522 <literal>debug</literal> (7). If a
523 single log level is specified, all
524 messages with this log level or a
525 lower (hence more important) log level
526 are shown. If a range is specified, all
527 messages within the range are shown,
528 including both the start and the end
529 value of the range. This will add
530 <literal>PRIORITY=</literal> matches
532 priorities.</para></listitem>
536 <term><option>-c</option></term>
537 <term><option>--cursor=</option></term>
539 <listitem><para>Start showing entries
540 from the location in the journal
541 specified by the passed
542 cursor.</para></listitem>
546 <term><option>--after-cursor=</option></term>
548 <listitem><para>Start showing entries from the
549 location in the journal
550 <emphasis>after</emphasis> the location
551 specified by the this cursor.
556 <term><option>--since=</option></term>
557 <term><option>--until=</option></term>
559 <listitem><para>Start showing entries
560 on or newer than the specified date,
561 or on or older than the specified
562 date, respectively. Date specifications
563 should be of the format
564 <literal>2012-10-30 18:17:16</literal>.
565 If the time part is omitted,
566 <literal>00:00:00</literal> is assumed.
567 If only the seconds component is omitted,
568 <literal>:00</literal> is assumed. If the
569 date component is omitted, the current
570 day is assumed. Alternatively the strings
571 <literal>yesterday</literal>,
572 <literal>today</literal>,
573 <literal>tomorrow</literal> are
574 understood, which refer to 00:00:00 of
575 the day before the current day, the
576 current day, or the day after the
577 current day, respectively. <literal>now</literal>
578 refers to the current time. Finally,
579 relative times may be specified,
580 prefixed with <literal>-</literal> or
581 <literal>+</literal>, referring to
582 times before or after the current
583 time, respectively.</para></listitem>
587 <term><option>-F</option></term>
588 <term><option>--field=</option></term>
590 <listitem><para>Print all possible
591 data values the specified field can
592 take in all entries of the
593 journal.</para></listitem>
597 <term><option>--system</option></term>
598 <term><option>--user</option></term>
600 <listitem><para>Show messages from
601 system services and the kernel (with
602 <option>--system</option>). Show
603 messages from service of current user
604 (with <option>--user</option>).
605 If neither is specified, show all
606 messages that the user can see.
611 <term><option>-D <replaceable>DIR</replaceable></option></term>
612 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
614 <listitem><para>Takes a directory path
615 as argument. If specified, journalctl
616 will operate on the specified journal
618 <replaceable>DIR</replaceable> instead
619 of the default runtime and system
620 journal paths.</para></listitem>
624 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
626 <listitem><para>Takes a file glob as
627 argument. If specified, journalctl will
628 operate on the specified journal files
629 matching <replaceable>GLOB</replaceable>
630 instead of the default runtime and
631 system journal paths. May be specified
632 multiple times, in which case files will
633 be suitably interleaved.</para></listitem>
637 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
639 <listitem><para>Takes a directory path
640 as argument. If specified, journalctl
641 will operate on catalog file hierarchy
642 underneath the specified directory
643 instead of the root directory
644 (e.g. <option>--update-catalog</option>
646 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
651 <term><option>--new-id128</option></term>
653 <listitem><para>Instead of showing
654 journal contents, generate a new 128
655 bit ID suitable for identifying
656 messages. This is intended for usage
657 by developers who need a new
658 identifier for a new message they
659 introduce and want to make
660 recognizable. This will print the new ID in
661 three different formats which can be
662 copied into source code or
663 similar.</para></listitem>
667 <term><option>--header</option></term>
669 <listitem><para>Instead of showing
670 journal contents, show internal header
671 information of the journal fields
672 accessed.</para></listitem>
676 <term><option>--disk-usage</option></term>
678 <listitem><para>Shows the current disk
680 journal files.</para></listitem>
684 <term><option>--list-catalog
685 <optional><replaceable>ID128...</replaceable></optional>
688 <listitem><para>List the contents of
689 the message catalog, as table of
690 message IDs plus their short
691 description strings.</para>
694 <replaceable>ID128</replaceable>s are
695 specified, only those entries are shown.
701 <term><option>--dump-catalog
702 <optional><replaceable>ID128...</replaceable></optional>
705 <listitem><para>Show the contents of
706 the message catalog, with entries
707 separated by a line consisting of two
708 dashes and the id (the format is the
709 same as <filename>.catalog</filename>
713 <replaceable>ID128</replaceable>s are
714 specified, only those entries are shown.
720 <term><option>--update-catalog</option></term>
722 <listitem><para>Update the message
723 catalog index. This command needs to
724 be executed each time new catalog
725 files are installed, removed or
726 updated to rebuild the binary catalog
727 index.</para></listitem>
731 <term><option>--setup-keys</option></term>
733 <listitem><para>Instead of showing
734 journal contents, generate a new key
735 pair for Forward Secure Sealing
736 (FSS). This will generate a sealing
737 key and a verification key. The
738 sealing key is stored in the journal
739 data directory and shall remain on the
740 host. The verification key should be
741 stored externally. Also see the
742 <option>Seal=</option> option in
743 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
744 for details.</para></listitem>
748 <term><option>--force</option></term>
750 <listitem><para>When --setup-keys is passed and
751 Forward Secure Sealing has already been set up,
752 recreate FSS keys.</para></listitem>
756 <term><option>--interval=</option></term>
758 <listitem><para>Specifies the change
759 interval for the sealing key when
760 generating an FSS key pair with
761 <option>--setup-keys</option>. Shorter
762 intervals increase CPU consumption but
763 shorten the time range of
765 alterations. Defaults to
766 15min.</para></listitem>
770 <term><option>--verify</option></term>
772 <listitem><para>Check the journal file
773 for internal consistency. If the
774 file has been generated with FSS
775 enabled and the FSS verification key
776 has been specified with
777 <option>--verify-key=</option>,
778 authenticity of the journal file is
779 verified.</para></listitem>
783 <term><option>--verify-key=</option></term>
785 <listitem><para>Specifies the FSS
786 verification key to use for the
787 <option>--verify</option>
788 operation.</para></listitem>
795 <title>Exit status</title>
797 <para>On success, 0 is returned, a non-zero failure
798 code otherwise.</para>
802 <title>Environment</title>
804 <variablelist class='environment-variables'>
806 <term><varname>$SYSTEMD_PAGER</varname></term>
807 <listitem><para>Pager to use when
808 <option>--no-pager</option> is not given;
809 overrides <varname>$PAGER</varname>. Setting
810 this to an empty string or the value
811 <literal>cat</literal> is equivalent to passing
812 <option>--no-pager</option>.</para></listitem>
818 <title>Examples</title>
820 <para>Without arguments, all collected logs are shown
823 <programlisting>journalctl</programlisting>
825 <para>With one match specified, all entries with a field matching the expression are shown:</para>
827 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
829 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
831 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
833 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
835 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
837 <para>If the separator <literal>+</literal> is used,
838 two expressions may be combined in a logical OR. The
839 following will show all messages from the Avahi
840 service process with the PID 28097 plus all messages
841 from the D-Bus service (from any of its
844 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
846 <para>Show all logs generated by the D-Bus executable:</para>
848 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
850 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
852 <programlisting>journalctl /dev/sda</programlisting>
854 <para>Show all kernel logs from previous boot:</para>
856 <programlisting>journalctl -k -b -1</programlisting>
861 <title>See Also</title>
863 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
864 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
865 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
866 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
867 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>