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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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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>-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 messages regarding inaccessible system
419 journals when run as a 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
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 last, 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>--list-boots</option></term>
483 <listitem><para>Show a tabular list of
484 boot numbers (relative to the current
485 boot), their IDs, and the timestamps
486 of the first and last message
487 pertaining to the boot.
492 <term><option>-k</option></term>
493 <term><option>--dmesg</option></term>
495 <listitem><para>Show only kernel messages. This
496 implies <option>-b</option> and adds the match
497 <literal>_TRANSPORT=kernel</literal>.
502 <term><option>-t</option></term>
503 <term><option>--identifier=<replaceable>SYSLOG_IDENTIFIER</replaceable>|<replaceable>PATTERN</replaceable></option></term>
505 <listitem><para>Show messages for the
506 specified syslog identifier
507 <replaceable>SYSLOG_IDENTIFIER</replaceable>, or
508 for any of the messages with a <literal>SYSLOG_IDENTIFIER</literal>
509 matched by <replaceable>PATTERN</replaceable>.</para>
511 <para>This parameter can be specified
512 multiple times.</para></listitem>
516 <term><option>-u</option></term>
517 <term><option>--unit=<replaceable>UNIT</replaceable>|<replaceable>PATTERN</replaceable></option></term>
519 <listitem><para>Show messages for the
520 specified systemd unit
521 <replaceable>UNIT</replaceable> (such
522 as a service unit), or for any of the
524 <replaceable>PATTERN</replaceable>.
525 If a pattern is specified, a list of
526 unit names found in the journal is
527 compared with the specified pattern
528 and all that match are used. For each
529 unit name, a match is added for
530 messages from the unit
531 (<literal>_SYSTEMD_UNIT=<replaceable>UNIT</replaceable></literal>),
532 along with additional matches for
533 messages from systemd and messages
534 about coredumps for the specified
537 <para>This parameter can be specified
538 multiple times.</para></listitem>
542 <term><option>--user-unit=</option></term>
544 <listitem><para>Show messages for the
545 specified user session unit. This will
546 add a match for messages from the unit
547 (<literal>_SYSTEMD_USER_UNIT=</literal>
548 and <literal>_UID=</literal>) and
549 additional matches for messages from
550 session systemd and messages about
551 coredumps for the specified unit.</para>
552 <para>This parameter can be specified multiple times.
557 <term><option>-p</option></term>
558 <term><option>--priority=</option></term>
560 <listitem><para>Filter output by
561 message priorities or priority
562 ranges. Takes either a single numeric
563 or textual log level (i.e. between
564 0/<literal>emerg</literal> and
565 7/<literal>debug</literal>), or a
566 range of numeric/text log levels in
567 the form FROM..TO. The log levels are
568 the usual syslog log levels as
570 <citerefentry project='man-pages'><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
571 i.e. <literal>emerg</literal> (0),
572 <literal>alert</literal> (1),
573 <literal>crit</literal> (2),
574 <literal>err</literal> (3),
575 <literal>warning</literal> (4),
576 <literal>notice</literal> (5),
577 <literal>info</literal> (6),
578 <literal>debug</literal> (7). If a
579 single log level is specified, all
580 messages with this log level or a
581 lower (hence more important) log level
582 are shown. If a range is specified, all
583 messages within the range are shown,
584 including both the start and the end
585 value of the range. This will add
586 <literal>PRIORITY=</literal> matches
588 priorities.</para></listitem>
592 <term><option>-c</option></term>
593 <term><option>--cursor=</option></term>
595 <listitem><para>Start showing entries
596 from the location in the journal
597 specified by the passed
598 cursor.</para></listitem>
602 <term><option>--after-cursor=</option></term>
604 <listitem><para>Start showing entries
605 from the location in the journal
606 <emphasis>after</emphasis> the
607 location specified by the this cursor.
608 The cursor is shown when the
609 <option>--show-cursor</option> option
610 is used.</para></listitem>
614 <term><option>--show-cursor</option></term>
616 <listitem><para>The cursor is shown after the last
617 entry after two dashes:</para>
618 <programlisting>-- cursor: s=0639...</programlisting>
619 <para>The format of the cursor is private
620 and subject to change.</para></listitem>
624 <term><option>--since=</option></term>
625 <term><option>--until=</option></term>
627 <listitem><para>Start showing entries
628 on or newer than the specified date,
629 or on or older than the specified
630 date, respectively. Date specifications
631 should be of the format
632 <literal>2012-10-30 18:17:16</literal>.
633 If the time part is omitted,
634 <literal>00:00:00</literal> is assumed.
635 If only the seconds component is omitted,
636 <literal>:00</literal> is assumed. If the
637 date component is omitted, the current
638 day is assumed. Alternatively the strings
639 <literal>yesterday</literal>,
640 <literal>today</literal>,
641 <literal>tomorrow</literal> are
642 understood, which refer to 00:00:00 of
643 the day before the current day, the
644 current day, or the day after the
645 current day, respectively. <literal>now</literal>
646 refers to the current time. Finally,
647 relative times may be specified,
648 prefixed with <literal>-</literal> or
649 <literal>+</literal>, referring to
650 times before or after the current
651 time, respectively.</para></listitem>
655 <term><option>-F</option></term>
656 <term><option>--field=</option></term>
658 <listitem><para>Print all possible
659 data values the specified field can
660 take in all entries of the
661 journal.</para></listitem>
665 <term><option>--system</option></term>
666 <term><option>--user</option></term>
668 <listitem><para>Show messages from
669 system services and the kernel (with
670 <option>--system</option>). Show
671 messages from service of current user
672 (with <option>--user</option>).
673 If neither is specified, show all
674 messages that the user can see.
679 <term><option>-M</option></term>
680 <term><option>--machine=</option></term>
682 <listitem><para>Show messages from a
683 running, local container. Specify a
684 container name to connect
685 to.</para></listitem>
689 <term><option>-D <replaceable>DIR</replaceable></option></term>
690 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
692 <listitem><para>Takes a directory path
693 as argument. If specified, journalctl
694 will operate on the specified journal
696 <replaceable>DIR</replaceable> instead
697 of the default runtime and system
698 journal paths.</para></listitem>
702 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
704 <listitem><para>Takes a file glob as an
705 argument. If specified, journalctl will
706 operate on the specified journal files
707 matching <replaceable>GLOB</replaceable>
708 instead of the default runtime and
709 system journal paths. May be specified
710 multiple times, in which case files will
711 be suitably interleaved.</para></listitem>
715 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
717 <listitem><para>Takes a directory path
718 as an argument. If specified, journalctl
719 will operate on catalog file hierarchy
720 underneath the specified directory
721 instead of the root directory
722 (e.g. <option>--update-catalog</option>
724 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
729 <term><option>--new-id128</option></term>
731 <listitem><para>Instead of showing
732 journal contents, generate a new 128-bit
733 ID suitable for identifying
734 messages. This is intended for usage
735 by developers who need a new
736 identifier for a new message they
737 introduce and want to make
738 recognizable. This will print the new ID in
739 three different formats which can be
740 copied into source code or
741 similar.</para></listitem>
745 <term><option>--header</option></term>
747 <listitem><para>Instead of showing
748 journal contents, show internal header
749 information of the journal fields
750 accessed.</para></listitem>
754 <term><option>--disk-usage</option></term>
756 <listitem><para>Shows the current disk
758 journal files.</para></listitem>
762 <term><option>--list-catalog
763 <optional><replaceable>128-bit-ID...</replaceable></optional>
766 <listitem><para>List the contents of
767 the message catalog as a table of
768 message IDs, plus their short
769 description strings.</para>
772 <replaceable>128-bit-ID</replaceable>s are
773 specified, only those entries are shown.
779 <term><option>--dump-catalog
780 <optional><replaceable>128-bit-ID...</replaceable></optional>
783 <listitem><para>Show the contents of
784 the message catalog, with entries
785 separated by a line consisting of two
786 dashes and the ID (the format is the
787 same as <filename>.catalog</filename>
791 <replaceable>128-bit-ID</replaceable>s are
792 specified, only those entries are shown.
798 <term><option>--update-catalog</option></term>
800 <listitem><para>Update the message
801 catalog index. This command needs to
802 be executed each time new catalog
803 files are installed, removed, or
804 updated to rebuild the binary catalog
805 index.</para></listitem>
809 <term><option>--setup-keys</option></term>
811 <listitem><para>Instead of showing
812 journal contents, generate a new key
813 pair for Forward Secure Sealing
814 (FSS). This will generate a sealing
815 key and a verification key. The
816 sealing key is stored in the journal
817 data directory and shall remain on the
818 host. The verification key should be
819 stored externally. Refer to the
820 <option>Seal=</option> option in
821 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
822 for information on Forward Secure
823 Sealing and for a link to a refereed
824 scholarly paper detailing the
825 cryptographic theory it is based on.
830 <term><option>--force</option></term>
833 <option>--setup-keys</option> is passed and
834 Forward Secure Sealing (FSS) has already been
835 configured, recreate FSS keys.</para></listitem>
839 <term><option>--interval=</option></term>
841 <listitem><para>Specifies the change
842 interval for the sealing key when
843 generating an FSS key pair with
844 <option>--setup-keys</option>. Shorter
845 intervals increase CPU consumption but
846 shorten the time range of
848 alterations. Defaults to
849 15min.</para></listitem>
853 <term><option>--verify</option></term>
855 <listitem><para>Check the journal file
856 for internal consistency. If the
857 file has been generated with FSS
858 enabled and the FSS verification key
859 has been specified with
860 <option>--verify-key=</option>,
861 authenticity of the journal file is
862 verified.</para></listitem>
866 <term><option>--verify-key=</option></term>
868 <listitem><para>Specifies the FSS
869 verification key to use for the
870 <option>--verify</option>
871 operation.</para></listitem>
874 <xi:include href="standard-options.xml" xpointer="help" />
875 <xi:include href="standard-options.xml" xpointer="version" />
876 <xi:include href="standard-options.xml" xpointer="no-pager" />
881 <title>Exit status</title>
883 <para>On success, 0 is returned; otherwise, a non-zero
884 failure code is returned.</para>
887 <xi:include href="less-variables.xml" />
890 <title>Examples</title>
892 <para>Without arguments, all collected logs are shown
895 <programlisting>journalctl</programlisting>
897 <para>With one match specified, all entries with a field matching the expression are shown:</para>
899 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
901 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
903 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
905 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
907 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
909 <para>If the separator <literal>+</literal> is used,
910 two expressions may be combined in a logical OR. The
911 following will show all messages from the Avahi
912 service process with the PID 28097 plus all messages
913 from the D-Bus service (from any of its
916 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
918 <para>Show all logs generated by the D-Bus executable:</para>
920 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
922 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
924 <programlisting>journalctl /dev/sda</programlisting>
926 <para>Show all kernel logs from previous boot:</para>
928 <programlisting>journalctl -k -b -1</programlisting>
930 <para>Show a live log display from a system service <filename>apache.service</filename>:</para>
932 <programlisting>journalctl -f -u apache</programlisting>
937 <title>See Also</title>
939 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
940 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
941 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
942 <citerefentry><refentrytitle>coredumpctl</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>