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6 This file is part of systemd.
8 Copyright 2012 Lennart Poettering
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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>--no-full</option></term>
156 <term><option>--full</option></term>
157 <term><option>-l</option></term>
159 <listitem><para>Ellipsize fields when
160 they do not fit in available columns.
161 The default is to show full fields,
162 allowing them to wrap or be truncated
163 by the pager if one is used.</para>
165 <para>The old options
166 <option>-l</option>/<option>--full</option>
167 are not useful anymore, except to undo
168 <option>--no-full</option>.</para></listitem>
172 <term><option>-a</option></term>
173 <term><option>--all</option></term>
175 <listitem><para>Show all fields in
176 full, even if they include unprintable
177 characters or are very
178 long.</para></listitem>
182 <term><option>-f</option></term>
183 <term><option>--follow</option></term>
185 <listitem><para>Show only the most recent
186 journal entries, and continuously print
187 new entries as they are appended to
188 the journal.</para></listitem>
192 <term><option>-e</option></term>
193 <term><option>--pager-end</option></term>
195 <listitem><para>Immediately jump to
196 the end of the journal inside the
197 implied pager tool. This implies
198 <option>-n1000</option> to guarantee
199 that the pager will not buffer logs of
200 unbounded size. This may be overridden
201 with an explicit <option>-n</option>
202 with some other numeric value on the
203 command line. Note that this option is
204 only supported for the
205 <citerefentry><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
206 pager.</para></listitem>
210 <term><option>-n</option></term>
211 <term><option>--lines=</option></term>
213 <listitem><para>Show the most recent
214 journal events and limit the number of
216 <option>--follow</option> is used,
217 this option is implied. The argument,
218 a positive integer, is optional, and
219 defaults to 10. </para></listitem>
223 <term><option>--no-tail</option></term>
225 <listitem><para>Show all stored output
226 lines, even in follow mode. Undoes the
228 <option>--lines=</option>.</para></listitem>
232 <term><option>-r</option></term>
233 <term><option>--reverse</option></term>
235 <listitem><para>Reverse output, so the newest
236 entries are displayed first.</para></listitem>
240 <term><option>-o</option></term>
241 <term><option>--output=</option></term>
243 <listitem><para>Controls the
244 formatting of the journal entries that
245 are shown. Takes one of the following options:
250 <option>short</option>
254 and generates an output
255 that is mostly identical
257 classic syslog files,
259 journal entry.</para>
265 <option>short-iso</option>
268 <para>is very similar,
270 wallclock timestamps.
277 <option>short-precise</option>
280 <para>is very similar,
282 with full microsecond
290 <option>short-monotonic</option>
293 <para>is very similar,
295 timestamps instead of
296 wallclock timestamps.
303 <option>verbose</option>
307 full-structured entry
308 items with all fields.
315 <option>export</option>
319 journal into a binary
320 (but mostly text-based)
324 url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
325 Export Format</ulink>
333 <option>json</option>
336 <para>formats entries
337 as JSON data structures,
338 one per line (see <ulink
339 url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
340 JSON Format</ulink> for
341 more information).</para>
347 <option>json-pretty</option>
350 <para>formats entries as
351 JSON data structures,
353 multiple lines in order
355 readable for humans.</para>
361 <option>json-sse</option>
364 <para>formats entries as
365 JSON data structures,
367 format suitable for <ulink
368 url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
369 Events</ulink>.</para>
378 <para>generates a very
381 message of each journal
382 entry with no meta data,
383 not even a timestamp.
392 <term><option>-x</option></term>
393 <term><option>--catalog</option></term>
395 <listitem><para>Augment log lines with
396 explanation texts from the message
397 catalog. This will add explanatory
398 help texts to log messages in the
399 output where this is available. These
400 short help texts will explain the
401 context of an error or log event,
402 possible solutions, as well as
403 pointers to support forums, developer
404 documentation, and any other relevant
405 manuals. Note that help texts are not
406 available for all messages, but only
407 for selected ones. For more
408 information on the message catalog,
409 please refer to the <ulink
410 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
412 Documentation</ulink>.</para>
414 <para>Note: when attaching
415 <command>journalctl</command> output
416 to bug reports, please do
417 <emphasis>not</emphasis> use
418 <option>-x</option>.</para>
423 <term><option>-q</option></term>
424 <term><option>--quiet</option></term>
426 <listitem><para>Suppresses any warning
427 message regarding inaccessible system
428 journals when run as normal
429 user.</para></listitem>
433 <term><option>-m</option></term>
434 <term><option>--merge</option></term>
436 <listitem><para>Show entries
437 interleaved from all available
438 journals, including remote
439 ones.</para></listitem>
443 <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
444 <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
446 <listitem><para>Show messages from a specific
447 boot. This will add a match for
448 <literal>_BOOT_ID=</literal>.</para>
450 <para>The argument may be empty, in which case
451 logs for the current boot will be shown.</para>
453 <para>If the boot ID is omitted, a positive
454 <replaceable>offset</replaceable> will look up
455 the boots starting from the beginning of the
456 journal, and a equal-or-less-than zero
457 <replaceable>offset</replaceable> will look up
458 boots starting from the end of the
459 journal. Thus, <constant>1</constant> means the
460 first boot found in the journal in the
461 chronological order, <constant>2</constant> the
462 second and so on; while <constant>-0</constant>
463 is the last boot, <constant>-1</constant> the
464 boot before that, and so on. An empty
465 <replaceable>offset</replaceable> is equivalent
466 to specifying <constant>-0</constant>, except
467 when the current boot is not the last boot
468 (e.g. because <option>--directory</option> was
469 specified to look at logs from a different
472 <para>If the 32 character
473 <replaceable>ID</replaceable> is specified, it
474 may optionally be followed by
475 <replaceable>offset</replaceable> which
476 identifies the boot relative to the one given by
477 boot <replaceable>ID</replaceable>. Negative
478 values mean earlier boots and a positive values
480 <replaceable>offset</replaceable> is not
481 specified, a value of zero is assumed and the
482 logs for the boot given by
483 <replaceable>ID</replaceable> are shown.
490 <term><option>-k</option></term>
491 <term><option>--dmesg</option></term>
493 <listitem><para>Show only kernel messages. This
494 implies <option>-b</option> and adds the match
495 <literal>_TRANSPORT=kernel</literal>.
500 <term><option>-u</option></term>
501 <term><option>--unit=</option></term>
503 <listitem><para>Show messages for the
504 specified systemd unit. This will add
505 a match for messages from the unit
506 (<literal>_SYSTEMD_UNIT=</literal>)
507 and additional matches for messages
508 from systemd and messages about
509 coredumps for the specified unit.</para>
510 <para>This parameter can be specified multiple times.
515 <term><option>--user-unit=</option></term>
517 <listitem><para>Show messages for the
518 specified user session unit. This will
519 add a match for messages from the unit
520 (<literal>_SYSTEMD_USER_UNIT=</literal>
521 and <literal>_UID=</literal>) and
522 additional matches for messages from
523 session systemd and messages about
524 coredumps for the specified unit.</para>
525 <para>This parameter can be specified multiple times.
530 <term><option>-p</option></term>
531 <term><option>--priority=</option></term>
533 <listitem><para>Filter output by
534 message priorities or priority
535 ranges. Takes either a single numeric
536 or textual log level (i.e. between
537 0/<literal>emerg</literal> and
538 7/<literal>debug</literal>), or a
539 range of numeric/text log levels in
540 the form FROM..TO. The log levels are
541 the usual syslog log levels as
543 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
544 i.e. <literal>emerg</literal> (0),
545 <literal>alert</literal> (1),
546 <literal>crit</literal> (2),
547 <literal>err</literal> (3),
548 <literal>warning</literal> (4),
549 <literal>notice</literal> (5),
550 <literal>info</literal> (6),
551 <literal>debug</literal> (7). If a
552 single log level is specified, all
553 messages with this log level or a
554 lower (hence more important) log level
555 are shown. If a range is specified, all
556 messages within the range are shown,
557 including both the start and the end
558 value of the range. This will add
559 <literal>PRIORITY=</literal> matches
561 priorities.</para></listitem>
565 <term><option>-c</option></term>
566 <term><option>--cursor=</option></term>
568 <listitem><para>Start showing entries
569 from the location in the journal
570 specified by the passed
571 cursor.</para></listitem>
575 <term><option>--after-cursor=</option></term>
577 <listitem><para>Start showing entries from the
578 location in the journal
579 <emphasis>after</emphasis> the location
580 specified by the this cursor.
585 <term><option>--since=</option></term>
586 <term><option>--until=</option></term>
588 <listitem><para>Start showing entries
589 on or newer than the specified date,
590 or on or older than the specified
591 date, respectively. Date specifications
592 should be of the format
593 <literal>2012-10-30 18:17:16</literal>.
594 If the time part is omitted,
595 <literal>00:00:00</literal> is assumed.
596 If only the seconds component is omitted,
597 <literal>:00</literal> is assumed. If the
598 date component is omitted, the current
599 day is assumed. Alternatively the strings
600 <literal>yesterday</literal>,
601 <literal>today</literal>,
602 <literal>tomorrow</literal> are
603 understood, which refer to 00:00:00 of
604 the day before the current day, the
605 current day, or the day after the
606 current day, respectively. <literal>now</literal>
607 refers to the current time. Finally,
608 relative times may be specified,
609 prefixed with <literal>-</literal> or
610 <literal>+</literal>, referring to
611 times before or after the current
612 time, respectively.</para></listitem>
616 <term><option>-F</option></term>
617 <term><option>--field=</option></term>
619 <listitem><para>Print all possible
620 data values the specified field can
621 take in all entries of the
622 journal.</para></listitem>
626 <term><option>--system</option></term>
627 <term><option>--user</option></term>
629 <listitem><para>Show messages from
630 system services and the kernel (with
631 <option>--system</option>). Show
632 messages from service of current user
633 (with <option>--user</option>).
634 If neither is specified, show all
635 messages that the user can see.
640 <term><option>-D <replaceable>DIR</replaceable></option></term>
641 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
643 <listitem><para>Takes a directory path
644 as argument. If specified, journalctl
645 will operate on the specified journal
647 <replaceable>DIR</replaceable> instead
648 of the default runtime and system
649 journal paths.</para></listitem>
653 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
655 <listitem><para>Takes a file glob as
656 argument. If specified, journalctl will
657 operate on the specified journal files
658 matching <replaceable>GLOB</replaceable>
659 instead of the default runtime and
660 system journal paths. May be specified
661 multiple times, in which case files will
662 be suitably interleaved.</para></listitem>
666 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
668 <listitem><para>Takes a directory path
669 as argument. If specified, journalctl
670 will operate on catalog file hierarchy
671 underneath the specified directory
672 instead of the root directory
673 (e.g. <option>--update-catalog</option>
675 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
680 <term><option>--new-id128</option></term>
682 <listitem><para>Instead of showing
683 journal contents, generate a new 128
684 bit ID suitable for identifying
685 messages. This is intended for usage
686 by developers who need a new
687 identifier for a new message they
688 introduce and want to make
689 recognizable. This will print the new ID in
690 three different formats which can be
691 copied into source code or
692 similar.</para></listitem>
696 <term><option>--header</option></term>
698 <listitem><para>Instead of showing
699 journal contents, show internal header
700 information of the journal fields
701 accessed.</para></listitem>
705 <term><option>--disk-usage</option></term>
707 <listitem><para>Shows the current disk
709 journal files.</para></listitem>
713 <term><option>--list-catalog
714 <optional><replaceable>ID128...</replaceable></optional>
717 <listitem><para>List the contents of
718 the message catalog, as table of
719 message IDs plus their short
720 description strings.</para>
723 <replaceable>ID128</replaceable>s are
724 specified, only those entries are shown.
730 <term><option>--dump-catalog
731 <optional><replaceable>ID128...</replaceable></optional>
734 <listitem><para>Show the contents of
735 the message catalog, with entries
736 separated by a line consisting of two
737 dashes and the id (the format is the
738 same as <filename>.catalog</filename>
742 <replaceable>ID128</replaceable>s are
743 specified, only those entries are shown.
749 <term><option>--update-catalog</option></term>
751 <listitem><para>Update the message
752 catalog index. This command needs to
753 be executed each time new catalog
754 files are installed, removed or
755 updated to rebuild the binary catalog
756 index.</para></listitem>
760 <term><option>--setup-keys</option></term>
762 <listitem><para>Instead of showing
763 journal contents, generate a new key
764 pair for Forward Secure Sealing
765 (FSS). This will generate a sealing
766 key and a verification key. The
767 sealing key is stored in the journal
768 data directory and shall remain on the
769 host. The verification key should be
770 stored externally. Also see the
771 <option>Seal=</option> option in
772 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
773 for details.</para></listitem>
777 <term><option>--force</option></term>
779 <listitem><para>When --setup-keys is passed and
780 Forward Secure Sealing has already been set up,
781 recreate FSS keys.</para></listitem>
785 <term><option>--interval=</option></term>
787 <listitem><para>Specifies the change
788 interval for the sealing key when
789 generating an FSS key pair with
790 <option>--setup-keys</option>. Shorter
791 intervals increase CPU consumption but
792 shorten the time range of
794 alterations. Defaults to
795 15min.</para></listitem>
799 <term><option>--verify</option></term>
801 <listitem><para>Check the journal file
802 for internal consistency. If the
803 file has been generated with FSS
804 enabled and the FSS verification key
805 has been specified with
806 <option>--verify-key=</option>,
807 authenticity of the journal file is
808 verified.</para></listitem>
812 <term><option>--verify-key=</option></term>
814 <listitem><para>Specifies the FSS
815 verification key to use for the
816 <option>--verify</option>
817 operation.</para></listitem>
824 <title>Exit status</title>
826 <para>On success, 0 is returned, a non-zero failure
827 code otherwise.</para>
831 <title>Environment</title>
833 <variablelist class='environment-variables'>
835 <term><varname>$SYSTEMD_PAGER</varname></term>
836 <listitem><para>Pager to use when
837 <option>--no-pager</option> is not given;
838 overrides <varname>$PAGER</varname>. Setting
839 this to an empty string or the value
840 <literal>cat</literal> is equivalent to passing
841 <option>--no-pager</option>.</para></listitem>
847 <title>Examples</title>
849 <para>Without arguments, all collected logs are shown
852 <programlisting>journalctl</programlisting>
854 <para>With one match specified, all entries with a field matching the expression are shown:</para>
856 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
858 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
860 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
862 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
864 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
866 <para>If the separator <literal>+</literal> is used,
867 two expressions may be combined in a logical OR. The
868 following will show all messages from the Avahi
869 service process with the PID 28097 plus all messages
870 from the D-Bus service (from any of its
873 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
875 <para>Show all logs generated by the D-Bus executable:</para>
877 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
879 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
881 <programlisting>journalctl /dev/sda</programlisting>
883 <para>Show all kernel logs from previous boot:</para>
885 <programlisting>journalctl -k -b -1</programlisting>
890 <title>See Also</title>
892 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
893 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
894 <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
895 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
896 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>