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2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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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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16 WITHOUT ANY WARRANTY; without even the implied warranty of
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18 Lesser General Public License for more details.
20 You should have received a copy of the GNU Lesser General Public License
21 along with systemd; If not, see <http://www.gnu.org/licenses/>.
24 <refentry id="journalctl"
25 xmlns:xi="http://www.w3.org/2001/XInclude">
28 <title>journalctl</title>
29 <productname>systemd</productname>
33 <contrib>Developer</contrib>
34 <firstname>Lennart</firstname>
35 <surname>Poettering</surname>
36 <email>lennart@poettering.net</email>
42 <refentrytitle>journalctl</refentrytitle>
43 <manvolnum>1</manvolnum>
47 <refname>journalctl</refname>
48 <refpurpose>Query the systemd journal</refpurpose>
53 <command>journalctl</command>
54 <arg choice="opt" rep="repeat">OPTIONS</arg>
55 <arg choice="opt" rep="repeat">MATCHES</arg>
60 <title>Description</title>
62 <para><command>journalctl</command> may be used to
63 query the contents of the
64 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
66 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
68 <para>If called without parameters, it will show the full
69 contents of the journal, starting with the oldest
70 entry collected.</para>
72 <para>If one or more match arguments are passed, the
73 output is filtered accordingly. A match is in the
74 format <literal>FIELD=VALUE</literal>,
75 e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>,
76 referring to the components of a structured journal
78 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
79 for a list of well-known fields. If multiple matches
80 are specified matching different fields, the log
81 entries are filtered by both, i.e. the resulting output
82 will show only entries matching all the specified
83 matches of this kind. If two matches apply to the same
84 field, then they are automatically matched as
85 alternatives, i.e. the resulting output will show
86 entries matching any of the specified matches for the
87 same field. Finally, the character
88 <literal>+</literal> may appears as a separate word
89 between other terms on the command line. This causes
90 all matches before and after to be combined in a
91 disjunction (i.e. logical OR).</para>
93 <para>As shortcuts for a few types of field/value
94 matches, file paths may be specified. If a file path
95 refers to an executable file, this is equivalent to an
96 <literal>_EXE=</literal> match for the canonicalized
97 binary path. Similarly, if a path refers to a device
98 node, this is equivalent to a
99 <literal>_KERNEL_DEVICE=</literal> match for the
102 <para>Additional constraints may be added using options
103 <option>--boot</option>, <option>--unit=</option>,
104 etc, to further limit what entries will be shown
105 (logical AND).</para>
107 <para>Output is interleaved from all accessible
108 journal files, whether they are rotated or currently
109 being written, and regardless of whether they belong to the
110 system itself or are accessible user journals.</para>
112 <para>The set of journal files which will be used
113 can be modified using the <option>--user</option>,
114 <option>--system</option>, <option>--directory</option>,
115 and <option>--file</option> options, see below.</para>
117 <para>All users are granted access to their private
118 per-user journals. However, by default, only root and
119 users who are members of the <literal>systemd-journal</literal>
120 group get access to the system journal and the
121 journals of other users.</para>
123 <para>The output is paged through
124 <command>less</command> by default, and long lines are
125 "truncated" to screen width. The hidden part can be
126 viewed by using the left-arrow and right-arrow
127 keys. Paging can be disabled; see the
128 <option>--no-pager</option> option and the "Environment"
129 section below.</para>
131 <para>When outputting to a tty, lines are colored
132 according to priority: lines of level ERROR and higher
133 are colored red; lines of level NOTICE and higher are
134 highlighted; other lines are displayed normally.
139 <title>Options</title>
141 <para>The following options are understood:</para>
145 <term><option>--no-full</option></term>
146 <term><option>--full</option></term>
147 <term><option>-l</option></term>
149 <listitem><para>Ellipsize fields when
150 they do not fit in available columns.
151 The default is to show full fields,
152 allowing them to wrap or be truncated
153 by the pager, if one is used.</para>
155 <para>The old options
156 <option>-l</option>/<option>--full</option>
157 are not useful anymore, except to undo
158 <option>--no-full</option>.</para></listitem>
162 <term><option>-a</option></term>
163 <term><option>--all</option></term>
165 <listitem><para>Show all fields in
166 full, even if they include unprintable
167 characters or are very
168 long.</para></listitem>
172 <term><option>-f</option></term>
173 <term><option>--follow</option></term>
175 <listitem><para>Show only the most recent
176 journal entries, and continuously print
177 new entries as they are appended to
178 the journal.</para></listitem>
182 <term><option>-e</option></term>
183 <term><option>--pager-end</option></term>
185 <listitem><para>Immediately jump to
186 the end of the journal inside the
187 implied pager tool. This implies
188 <option>-n1000</option> to guarantee
189 that the pager will not buffer logs of
190 unbounded size. This may be overridden
191 with an explicit <option>-n</option>
192 with some other numeric value while
193 <option>-nall</option> will disable this cap.
194 Note that this option is only supported for the
195 <citerefentry project='man-pages'><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
196 pager.</para></listitem>
200 <term><option>-n</option></term>
201 <term><option>--lines=</option></term>
203 <listitem><para>Show the most recent
204 journal events and limit the number of
206 <option>--follow</option> is used,
207 this option is implied. The argument is
208 a positive integer or <literal>all</literal>
209 to disable line limiting. The default value is
210 10 if no argument is given.</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 that 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 by 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 metadata,
374 not even a timestamp.
383 <term><option>--utc</option></term>
385 <listitem><para>Express time in Coordinated Universal
386 Time (UTC).</para></listitem>
390 <term><option>-x</option></term>
391 <term><option>--catalog</option></term>
393 <listitem><para>Augment log lines with
394 explanation texts from the message
395 catalog. This will add explanatory
396 help texts to log messages in the
397 output where this is available. These
398 short help texts will explain the
399 context of an error or log event,
400 possible solutions, as well as
401 pointers to support forums, developer
402 documentation, and any other relevant
403 manuals. Note that help texts are not
404 available for all messages, but only
405 for selected ones. For more
406 information on the message catalog,
407 please refer to the <ulink
408 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
410 Documentation</ulink>.</para>
412 <para>Note: when attaching
413 <command>journalctl</command> output
414 to bug reports, please do
415 <emphasis>not</emphasis> use
416 <option>-x</option>.</para>
421 <term><option>-q</option></term>
422 <term><option>--quiet</option></term>
424 <listitem><para>Suppresses any warning
425 messages regarding inaccessible system
426 journals when run as a normal
427 user.</para></listitem>
431 <term><option>-m</option></term>
432 <term><option>--merge</option></term>
434 <listitem><para>Show entries
435 interleaved from all available
436 journals, including remote
437 ones.</para></listitem>
441 <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
442 <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
444 <listitem><para>Show messages from a specific
445 boot. This will add a match for
446 <literal>_BOOT_ID=</literal>.</para>
448 <para>The argument may be empty, in which case
449 logs for the current boot will be shown.</para>
451 <para>If the boot ID is omitted, a positive
452 <replaceable>offset</replaceable> will look up
453 the boots starting from the beginning of the
454 journal, and a equal-or-less-than zero
455 <replaceable>offset</replaceable> will look up
456 boots starting from the end of the
457 journal. Thus, <constant>1</constant> means the
458 first boot found in the journal in
459 chronological order, <constant>2</constant> the
460 second and so on; while <constant>-0</constant>
461 is the last boot, <constant>-1</constant> the
462 boot before last, and so on. An empty
463 <replaceable>offset</replaceable> is equivalent
464 to specifying <constant>-0</constant>, except
465 when the current boot is not the last boot
466 (e.g. because <option>--directory</option> was
467 specified to look at logs from a different
470 <para>If the 32-character
471 <replaceable>ID</replaceable> is specified, it
472 may optionally be followed by
473 <replaceable>offset</replaceable> which
474 identifies the boot relative to the one given by
475 boot <replaceable>ID</replaceable>. Negative
476 values mean earlier boots and a positive values
478 <replaceable>offset</replaceable> is not
479 specified, a value of zero is assumed, and the
480 logs for the boot given by
481 <replaceable>ID</replaceable> are shown.
488 <term><option>--list-boots</option></term>
490 <listitem><para>Show a tabular list of
491 boot numbers (relative to the current
492 boot), their IDs, and the timestamps
493 of the first and last message
494 pertaining to the boot.
499 <term><option>-k</option></term>
500 <term><option>--dmesg</option></term>
502 <listitem><para>Show only kernel messages. This
503 implies <option>-b</option> and adds the match
504 <literal>_TRANSPORT=kernel</literal>.
509 <term><option>-t</option></term>
510 <term><option>--identifier=<replaceable>SYSLOG_IDENTIFIER</replaceable>|<replaceable>PATTERN</replaceable></option></term>
512 <listitem><para>Show messages for the
513 specified syslog identifier
514 <replaceable>SYSLOG_IDENTIFIER</replaceable>, or
515 for any of the messages with a <literal>SYSLOG_IDENTIFIER</literal>
516 matched by <replaceable>PATTERN</replaceable>.</para>
518 <para>This parameter can be specified
519 multiple times.</para></listitem>
523 <term><option>-u</option></term>
524 <term><option>--unit=<replaceable>UNIT</replaceable>|<replaceable>PATTERN</replaceable></option></term>
526 <listitem><para>Show messages for the
527 specified systemd unit
528 <replaceable>UNIT</replaceable> (such
529 as a service unit), or for any of the
531 <replaceable>PATTERN</replaceable>.
532 If a pattern is specified, a list of
533 unit names found in the journal is
534 compared with the specified pattern
535 and all that match are used. For each
536 unit name, a match is added for
537 messages from the unit
538 (<literal>_SYSTEMD_UNIT=<replaceable>UNIT</replaceable></literal>),
539 along with additional matches for
540 messages from systemd and messages
541 about coredumps for the specified
544 <para>This parameter can be specified
545 multiple times.</para></listitem>
549 <term><option>--user-unit=</option></term>
551 <listitem><para>Show messages for the
552 specified user session unit. This will
553 add a match for messages from the unit
554 (<literal>_SYSTEMD_USER_UNIT=</literal>
555 and <literal>_UID=</literal>) and
556 additional matches for messages from
557 session systemd and messages about
558 coredumps for the specified unit.</para>
559 <para>This parameter can be specified multiple times.
564 <term><option>-p</option></term>
565 <term><option>--priority=</option></term>
567 <listitem><para>Filter output by
568 message priorities or priority
569 ranges. Takes either a single numeric
570 or textual log level (i.e. between
571 0/<literal>emerg</literal> and
572 7/<literal>debug</literal>), or a
573 range of numeric/text log levels in
574 the form FROM..TO. The log levels are
575 the usual syslog log levels as
577 <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
578 i.e. <literal>emerg</literal> (0),
579 <literal>alert</literal> (1),
580 <literal>crit</literal> (2),
581 <literal>err</literal> (3),
582 <literal>warning</literal> (4),
583 <literal>notice</literal> (5),
584 <literal>info</literal> (6),
585 <literal>debug</literal> (7). If a
586 single log level is specified, all
587 messages with this log level or a
588 lower (hence more important) log level
589 are shown. If a range is specified, all
590 messages within the range are shown,
591 including both the start and the end
592 value of the range. This will add
593 <literal>PRIORITY=</literal> matches
595 priorities.</para></listitem>
599 <term><option>-c</option></term>
600 <term><option>--cursor=</option></term>
602 <listitem><para>Start showing entries
603 from the location in the journal
604 specified by the passed
605 cursor.</para></listitem>
609 <term><option>--after-cursor=</option></term>
611 <listitem><para>Start showing entries
612 from the location in the journal
613 <emphasis>after</emphasis> the
614 location specified by the this cursor.
615 The cursor is shown when the
616 <option>--show-cursor</option> option
617 is used.</para></listitem>
621 <term><option>--show-cursor</option></term>
623 <listitem><para>The cursor is shown after the last
624 entry after two dashes:</para>
625 <programlisting>-- cursor: s=0639...</programlisting>
626 <para>The format of the cursor is private
627 and subject to change.</para></listitem>
631 <term><option>--since=</option></term>
632 <term><option>--until=</option></term>
634 <listitem><para>Start showing entries
635 on or newer than the specified date,
636 or on or older than the specified
637 date, respectively. Date specifications
638 should be of the format
639 <literal>2012-10-30 18:17:16</literal>.
640 If the time part is omitted,
641 <literal>00:00:00</literal> is assumed.
642 If only the seconds component is omitted,
643 <literal>:00</literal> is assumed. If the
644 date component is omitted, the current
645 day is assumed. Alternatively the strings
646 <literal>yesterday</literal>,
647 <literal>today</literal>,
648 <literal>tomorrow</literal> are
649 understood, which refer to 00:00:00 of
650 the day before the current day, the
651 current day, or the day after the
652 current day, respectively. <literal>now</literal>
653 refers to the current time. Finally,
654 relative times may be specified,
655 prefixed with <literal>-</literal> or
656 <literal>+</literal>, referring to
657 times before or after the current
658 time, respectively.</para></listitem>
662 <term><option>-F</option></term>
663 <term><option>--field=</option></term>
665 <listitem><para>Print all possible
666 data values the specified field can
667 take in all entries of the
668 journal.</para></listitem>
672 <term><option>--system</option></term>
673 <term><option>--user</option></term>
675 <listitem><para>Show messages from
676 system services and the kernel (with
677 <option>--system</option>). Show
678 messages from service of current user
679 (with <option>--user</option>).
680 If neither is specified, show all
681 messages that the user can see.
686 <term><option>-M</option></term>
687 <term><option>--machine=</option></term>
689 <listitem><para>Show messages from a
690 running, local container. Specify a
691 container name to connect
692 to.</para></listitem>
696 <term><option>-D <replaceable>DIR</replaceable></option></term>
697 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
699 <listitem><para>Takes a directory path
700 as argument. If specified, journalctl
701 will operate on the specified journal
703 <replaceable>DIR</replaceable> instead
704 of the default runtime and system
705 journal paths.</para></listitem>
709 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
711 <listitem><para>Takes a file glob as an
712 argument. If specified, journalctl will
713 operate on the specified journal files
714 matching <replaceable>GLOB</replaceable>
715 instead of the default runtime and
716 system journal paths. May be specified
717 multiple times, in which case files will
718 be suitably interleaved.</para></listitem>
722 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
724 <listitem><para>Takes a directory path
725 as an argument. If specified, journalctl
726 will operate on catalog file hierarchy
727 underneath the specified directory
728 instead of the root directory
729 (e.g. <option>--update-catalog</option>
731 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
736 <term><option>--new-id128</option></term>
738 <listitem><para>Instead of showing
739 journal contents, generate a new 128-bit
740 ID suitable for identifying
741 messages. This is intended for usage
742 by developers who need a new
743 identifier for a new message they
744 introduce and want to make
745 recognizable. This will print the new ID in
746 three different formats which can be
747 copied into source code or
748 similar.</para></listitem>
752 <term><option>--header</option></term>
754 <listitem><para>Instead of showing
755 journal contents, show internal header
756 information of the journal fields
757 accessed.</para></listitem>
761 <term><option>--disk-usage</option></term>
763 <listitem><para>Shows the current disk
765 journal files.</para></listitem>
769 <term><option>--list-catalog
770 <optional><replaceable>128-bit-ID...</replaceable></optional>
773 <listitem><para>List the contents of
774 the message catalog as a table of
775 message IDs, plus their short
776 description strings.</para>
779 <replaceable>128-bit-ID</replaceable>s are
780 specified, only those entries are shown.
786 <term><option>--dump-catalog
787 <optional><replaceable>128-bit-ID...</replaceable></optional>
790 <listitem><para>Show the contents of
791 the message catalog, with entries
792 separated by a line consisting of two
793 dashes and the ID (the format is the
794 same as <filename>.catalog</filename>
798 <replaceable>128-bit-ID</replaceable>s are
799 specified, only those entries are shown.
805 <term><option>--update-catalog</option></term>
807 <listitem><para>Update the message
808 catalog index. This command needs to
809 be executed each time new catalog
810 files are installed, removed, or
811 updated to rebuild the binary catalog
812 index.</para></listitem>
816 <term><option>--setup-keys</option></term>
818 <listitem><para>Instead of showing
819 journal contents, generate a new key
820 pair for Forward Secure Sealing
821 (FSS). This will generate a sealing
822 key and a verification key. The
823 sealing key is stored in the journal
824 data directory and shall remain on the
825 host. The verification key should be
826 stored externally. Refer to the
827 <option>Seal=</option> option in
828 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
829 for information on Forward Secure
830 Sealing and for a link to a refereed
831 scholarly paper detailing the
832 cryptographic theory it is based on.
837 <term><option>--force</option></term>
840 <option>--setup-keys</option> is passed and
841 Forward Secure Sealing (FSS) has already been
842 configured, recreate FSS keys.</para></listitem>
846 <term><option>--interval=</option></term>
848 <listitem><para>Specifies the change
849 interval for the sealing key when
850 generating an FSS key pair with
851 <option>--setup-keys</option>. Shorter
852 intervals increase CPU consumption but
853 shorten the time range of
855 alterations. Defaults to
856 15min.</para></listitem>
860 <term><option>--verify</option></term>
862 <listitem><para>Check the journal file
863 for internal consistency. If the
864 file has been generated with FSS
865 enabled and the FSS verification key
866 has been specified with
867 <option>--verify-key=</option>,
868 authenticity of the journal file is
869 verified.</para></listitem>
873 <term><option>--verify-key=</option></term>
875 <listitem><para>Specifies the FSS
876 verification key to use for the
877 <option>--verify</option>
878 operation.</para></listitem>
881 <xi:include href="standard-options.xml" xpointer="help" />
882 <xi:include href="standard-options.xml" xpointer="version" />
883 <xi:include href="standard-options.xml" xpointer="no-pager" />
888 <title>Exit status</title>
890 <para>On success, 0 is returned; otherwise, a non-zero
891 failure code is returned.</para>
894 <xi:include href="less-variables.xml" />
897 <title>Examples</title>
899 <para>Without arguments, all collected logs are shown
902 <programlisting>journalctl</programlisting>
904 <para>With one match specified, all entries with a field matching the expression are shown:</para>
906 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
908 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
910 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
912 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
914 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
916 <para>If the separator <literal>+</literal> is used,
917 two expressions may be combined in a logical OR. The
918 following will show all messages from the Avahi
919 service process with the PID 28097 plus all messages
920 from the D-Bus service (from any of its
923 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
925 <para>Show all logs generated by the D-Bus executable:</para>
927 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
929 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
931 <programlisting>journalctl /dev/sda</programlisting>
933 <para>Show all kernel logs from previous boot:</para>
935 <programlisting>journalctl -k -b -1</programlisting>
937 <para>Show a live log display from a system service <filename>apache.service</filename>:</para>
939 <programlisting>journalctl -f -u apache</programlisting>
944 <title>See Also</title>
946 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
947 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
948 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
949 <citerefentry><refentrytitle>coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
950 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
951 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>