1 <?xml version='
1.0'
?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
6 SPDX-License-Identifier: LGPL-2.1+
8 This file is part of systemd.
10 Copyright 2012 Lennart Poettering
13 <refentry id=
"journalctl"
14 xmlns:
xi=
"http://www.w3.org/2001/XInclude">
17 <title>journalctl
</title>
18 <productname>systemd
</productname>
22 <contrib>Developer
</contrib>
23 <firstname>Lennart
</firstname>
24 <surname>Poettering
</surname>
25 <email>lennart@poettering.net
</email>
31 <refentrytitle>journalctl
</refentrytitle>
32 <manvolnum>1</manvolnum>
36 <refname>journalctl
</refname>
37 <refpurpose>Query the systemd journal
</refpurpose>
42 <command>journalctl
</command>
43 <arg choice=
"opt" rep=
"repeat">OPTIONS
</arg>
44 <arg choice=
"opt" rep=
"repeat">MATCHES
</arg>
49 <title>Description
</title>
51 <para><command>journalctl
</command> may be used to query the
53 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>
55 <citerefentry><refentrytitle>systemd-journald.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
57 <para>If called without parameters, it will show the full
58 contents of the journal, starting with the oldest entry
61 <para>If one or more match arguments are passed, the output is
62 filtered accordingly. A match is in the format
63 <literal>FIELD=VALUE
</literal>,
64 e.g.
<literal>_SYSTEMD_UNIT=httpd.service
</literal>, referring
65 to the components of a structured journal entry. See
66 <citerefentry><refentrytitle>systemd.journal-fields
</refentrytitle><manvolnum>7</manvolnum></citerefentry>
67 for a list of well-known fields. If multiple matches are
68 specified matching different fields, the log entries are
69 filtered by both, i.e. the resulting output will show only
70 entries matching all the specified matches of this kind. If two
71 matches apply to the same field, then they are automatically
72 matched as alternatives, i.e. the resulting output will show
73 entries matching any of the specified matches for the same
74 field. Finally, the character
<literal>+
</literal> may appear
75 as a separate word between other terms on the command line. This
76 causes all matches before and after to be combined in a
77 disjunction (i.e. logical OR).
</para>
79 <para>It is also possible to filter the entries by specifying an
80 absolute file path as an argument. The file path may be a file or
81 a symbolic link and the file must exist at the time of the query. If a
82 file path refers to an executable binary, an
<literal>_EXE=
</literal>
83 match for the canonicalized binary path is added to the query. If a
84 file path refers to an executable script, a
<literal>_COMM=
</literal>
85 match for the script name is added to the query. If a file path
86 refers to a device node,
<literal>_KERNEL_DEVICE=
</literal> matches for
87 the kernel name of the device and for each of its ancestor devices is
88 added to the query. Symbolic links are dereferenced, kernel names are
89 synthesized, and parent devices are identified from the environment at
90 the time of the query. In general, a device node is the best proxy for
91 an actual device, as log entries do not usually contain fields that
92 identify an actual device. For the resulting log entries to be correct
93 for the actual device, the relevant parts of the environment at the time
94 the entry was logged, in particular the actual device corresponding to
95 the device node, must have been the same as those at the time of the
96 query. Because device nodes generally change their corresponding devices
97 across reboots, specifying a device node path causes the resulting
98 entries to be restricted to those from the current boot.
</para>
100 <para>Additional constraints may be added using options
101 <option>--boot
</option>,
<option>--unit=
</option>, etc., to
102 further limit what entries will be shown (logical AND).
</para>
104 <para>Output is interleaved from all accessible journal files,
105 whether they are rotated or currently being written, and
106 regardless of whether they belong to the system itself or are
107 accessible user journals.
</para>
109 <para>The set of journal files which will be used can be
110 modified using the
<option>--user
</option>,
111 <option>--system
</option>,
<option>--directory
</option>, and
112 <option>--file
</option> options, see below.
</para>
114 <para>All users are granted access to their private per-user
115 journals. However, by default, only root and users who are
116 members of a few special groups are granted access to the system
117 journal and the journals of other users. Members of the groups
118 <literal>systemd-journal
</literal>,
<literal>adm
</literal>, and
119 <literal>wheel
</literal> can read all journal files. Note
120 that the two latter groups traditionally have additional
121 privileges specified by the distribution. Members of the
122 <literal>wheel
</literal> group can often perform administrative
125 <para>The output is paged through
<command>less
</command> by
126 default, and long lines are
"truncated" to screen width. The
127 hidden part can be viewed by using the left-arrow and
128 right-arrow keys. Paging can be disabled; see the
129 <option>--no-pager
</option> option and the
"Environment" section
132 <para>When outputting to a tty, lines are colored according to
133 priority: lines of level ERROR and higher are colored red; lines
134 of level NOTICE and higher are highlighted; other lines are
135 displayed normally.
</para>
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 they do not fit in
150 available columns. The default is to show full fields,
151 allowing them to wrap or be truncated by the pager, if one
154 <para>The old options
155 <option>-l
</option>/
<option>--full
</option> are not useful
156 anymore, except to undo
<option>--no-full
</option>.
</para>
161 <term><option>-a
</option></term>
162 <term><option>--all
</option></term>
164 <listitem><para>Show all fields in full, even if they
165 include unprintable characters or are very
166 long.
</para></listitem>
170 <term><option>-f
</option></term>
171 <term><option>--follow
</option></term>
173 <listitem><para>Show only the most recent journal entries,
174 and continuously print new entries as they are appended to
175 the journal.
</para></listitem>
179 <term><option>-e
</option></term>
180 <term><option>--pager-end
</option></term>
182 <listitem><para>Immediately jump to the end of the journal
183 inside the implied pager tool. This implies
184 <option>-n1000
</option> to guarantee that the pager will not
185 buffer logs of unbounded size. This may be overridden with
186 an explicit
<option>-n
</option> with some other numeric
187 value, while
<option>-nall
</option> will disable this cap.
188 Note that this option is only supported for the
189 <citerefentry project='man-pages'
><refentrytitle>less
</refentrytitle><manvolnum>1</manvolnum></citerefentry>
190 pager.
</para></listitem>
194 <term><option>-n
</option></term>
195 <term><option>--lines=
</option></term>
197 <listitem><para>Show the most recent journal events and
198 limit the number of events shown. If
199 <option>--follow
</option> is used, this option is
200 implied. The argument is a positive integer or
201 <literal>all
</literal> to disable line limiting. The default
202 value is
10 if no argument is given.
</para></listitem>
206 <term><option>--no-tail
</option></term>
208 <listitem><para>Show all stored output lines, even in follow
209 mode. Undoes the effect of
<option>--lines=
</option>.
214 <term><option>-r
</option></term>
215 <term><option>--reverse
</option></term>
217 <listitem><para>Reverse output so that the newest entries
218 are displayed first.
</para></listitem>
222 <term><option>-o
</option></term>
223 <term><option>--output=
</option></term>
225 <listitem><para>Controls the formatting of the journal
226 entries that are shown. Takes one of the following
231 <option>short
</option>
234 <para>is the default and generates an output that is
235 mostly identical to the formatting of classic syslog
236 files, showing one line per journal entry.
</para>
242 <option>short-full
</option>
245 <para>is very similar, but shows timestamps in the format the
<option>--since=
</option> and
246 <option>--until=
</option> options accept. Unlike the timestamp information shown in
247 <option>short
</option> output mode this mode includes weekday, year and timezone information in the
248 output, and is locale-independent.
</para>
254 <option>short-iso
</option>
257 <para>is very similar, but shows ISO
8601 wallclock
264 <option>short-iso-precise
</option>
267 <para>as for
<option>short-iso
</option> but includes full
268 microsecond precision.
</para>
274 <option>short-precise
</option>
277 <para>is very similar, but shows classic syslog timestamps
278 with full microsecond precision.
</para>
284 <option>short-monotonic
</option>
287 <para>is very similar, but shows monotonic timestamps
288 instead of wallclock timestamps.
</para>
294 <option>short-unix
</option>
297 <para>is very similar, but shows seconds passed since January
1st
1970 UTC instead of wallclock
298 timestamps (
"UNIX time"). The time is shown with microsecond accuracy.
</para>
304 <option>verbose
</option>
307 <para>shows the full-structured entry items with all
314 <option>export
</option>
317 <para>serializes the journal into a binary (but mostly
318 text-based) stream suitable for backups and network
320 <ulink url=
"https://www.freedesktop.org/wiki/Software/systemd/export">Journal Export Format
</ulink>
321 for more information). To import the binary stream back
322 into native journald format use
323 <citerefentry><refentrytitle>systemd-journal-remote
</refentrytitle><manvolnum>8</manvolnum></citerefentry>.
</para>
329 <option>json
</option>
332 <para>formats entries as JSON data structures, one per
334 <ulink url=
"https://www.freedesktop.org/wiki/Software/systemd/json">Journal JSON Format
</ulink>
335 for more information).
</para>
341 <option>json-pretty
</option>
344 <para>formats entries as JSON data structures, but
345 formats them in multiple lines in order to make them
346 more readable by humans.
</para>
352 <option>json-sse
</option>
355 <para>formats entries as JSON data structures, but wraps
356 them in a format suitable for
357 <ulink url=
"https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent Events
</ulink>.
367 <para>generates a very terse output, only showing the
368 actual message of each journal entry with no metadata,
369 not even a timestamp.
</para>
377 <term><option>--output-fields=
</option></term>
379 <listitem><para>A comma separated list of the fields which should
380 be included in the output. This only has an effect for the output modes
381 which would normally show all fields (
<option>verbose
</option>,
382 <option>export
</option>,
<option>json
</option>,
383 <option>json-pretty
</option>, and
<option>json-sse
</option>). The
384 <literal>__CURSOR
</literal>,
<literal>__REALTIME_TIMESTAMP
</literal>,
385 <literal>__MONOTONIC_TIMESTAMP
</literal>, and
386 <literal>_BOOT_ID
</literal> fields are always
387 printed.
</para></listitem>
391 <term><option>--utc
</option></term>
393 <listitem><para>Express time in Coordinated Universal Time
394 (UTC).
</para></listitem>
398 <term><option>--no-hostname
</option></term>
400 <listitem><para>Don't show the hostname field of log messages originating from the local host. This switch only
401 has an effect on the
<option>short
</option> family of output modes (see above).
</para></listitem>
405 <term><option>-x
</option></term>
406 <term><option>--catalog
</option></term>
408 <listitem><para>Augment log lines with explanation texts from
409 the message catalog. This will add explanatory help texts to
410 log messages in the output where this is available. These
411 short help texts will explain the context of an error or log
412 event, possible solutions, as well as pointers to support
413 forums, developer documentation, and any other relevant
414 manuals. Note that help texts are not available for all
415 messages, but only for selected ones. For more information on
416 the message catalog, please refer to the
417 <ulink url=
"https://www.freedesktop.org/wiki/Software/systemd/catalog">Message Catalog Developer Documentation
</ulink>.
</para>
419 <para>Note: when attaching
<command>journalctl
</command>
420 output to bug reports, please do
<emphasis>not
</emphasis> use
421 <option>-x
</option>.
</para>
426 <term><option>-q
</option></term>
427 <term><option>--quiet
</option></term>
429 <listitem><para>Suppresses all informational messages
430 (i.e.
"-- Logs begin at …",
"-- Reboot --"),
431 any warning messages regarding
432 inaccessible system journals when run as a normal
433 user.
</para></listitem>
437 <term><option>-m
</option></term>
438 <term><option>--merge
</option></term>
440 <listitem><para>Show entries interleaved from all available
441 journals, including remote ones.
</para></listitem>
445 <term><option>-b
<optional><replaceable>ID
</replaceable></optional><optional><replaceable>±offset
</replaceable></optional></option></term>
446 <term><option>--boot=
<optional><replaceable>ID
</replaceable></optional><optional><replaceable>±offset
</replaceable></optional></option></term>
448 <listitem><para>Show messages from a specific boot. This will
449 add a match for
<literal>_BOOT_ID=
</literal>.
</para>
451 <para>The argument may be empty, in which case logs for the
452 current boot will be shown.
</para>
454 <para>If the boot ID is omitted, a positive
455 <replaceable>offset
</replaceable> will look up the boots
456 starting from the beginning of the journal, and an
457 equal-or-less-than zero
<replaceable>offset
</replaceable> will
458 look up boots starting from the end of the journal. Thus,
459 <constant>1</constant> means the first boot found in the
460 journal in chronological order,
<constant>2</constant> the
461 second and so on; while
<constant>-
0</constant> is the last
462 boot,
<constant>-
1</constant> the boot before last, and so
463 on. An empty
<replaceable>offset
</replaceable> is equivalent
464 to specifying
<constant>-
0</constant>, except when the current
465 boot is not the last boot (e.g. because
466 <option>--directory
</option> was specified to look at logs
467 from a different machine).
</para>
469 <para>If the
32-character
<replaceable>ID
</replaceable> is
470 specified, it may optionally be followed by
471 <replaceable>offset
</replaceable> which identifies the boot
472 relative to the one given by boot
473 <replaceable>ID
</replaceable>. Negative values mean earlier
474 boots and positive values mean later boots. If
475 <replaceable>offset
</replaceable> is not specified, a value of
476 zero is assumed, and the logs for the boot given by
477 <replaceable>ID
</replaceable> are shown.
</para>
482 <term><option>--list-boots
</option></term>
484 <listitem><para>Show a tabular list of boot numbers (relative to
485 the current boot), their IDs, and the timestamps of the first
486 and last message pertaining to the boot.
</para></listitem>
490 <term><option>-k
</option></term>
491 <term><option>--dmesg
</option></term>
493 <listitem><para>Show only kernel messages. This implies
494 <option>-b
</option> and adds the match
495 <literal>_TRANSPORT=kernel
</literal>.
</para></listitem>
499 <term><option>-t
</option></term>
500 <term><option>--identifier=
<replaceable>SYSLOG_IDENTIFIER
</replaceable></option></term>
502 <listitem><para>Show messages for the specified syslog
504 <replaceable>SYSLOG_IDENTIFIER
</replaceable>.
</para>
506 <para>This parameter can be specified multiple
507 times.
</para></listitem>
511 <term><option>-u
</option></term>
512 <term><option>--unit=
<replaceable>UNIT
</replaceable>|
<replaceable>PATTERN
</replaceable></option></term>
514 <listitem><para>Show messages for the specified systemd unit
515 <replaceable>UNIT
</replaceable> (such as a service unit), or
516 for any of the units matched by
517 <replaceable>PATTERN
</replaceable>. If a pattern is
518 specified, a list of unit names found in the journal is
519 compared with the specified pattern and all that match are
520 used. For each unit name, a match is added for messages from
522 (
<literal>_SYSTEMD_UNIT=
<replaceable>UNIT
</replaceable></literal>),
523 along with additional matches for messages from systemd and
524 messages about coredumps for the specified unit.
</para>
526 <para>This parameter can be specified multiple times.
</para>
531 <term><option>--user-unit=
</option></term>
533 <listitem><para>Show messages for the specified user session
534 unit. This will add a match for messages from the unit
535 (
<literal>_SYSTEMD_USER_UNIT=
</literal> and
536 <literal>_UID=
</literal>) and additional matches for messages
537 from session systemd and messages about coredumps for the
538 specified unit.
</para>
540 <para>This parameter can be specified multiple times.
</para>
545 <term><option>-p
</option></term>
546 <term><option>--priority=
</option></term>
548 <listitem><para>Filter output by message priorities or
549 priority ranges. Takes either a single numeric or textual log
550 level (i.e. between
0/
<literal>emerg
</literal> and
551 7/
<literal>debug
</literal>), or a range of numeric/text log
552 levels in the form FROM..TO. The log levels are the usual
553 syslog log levels as documented in
554 <citerefentry project='man-pages'
><refentrytitle>syslog
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
555 i.e.
<literal>emerg
</literal> (
0),
556 <literal>alert
</literal> (
1),
<literal>crit
</literal> (
2),
557 <literal>err
</literal> (
3),
<literal>warning
</literal> (
4),
558 <literal>notice
</literal> (
5),
<literal>info
</literal> (
6),
559 <literal>debug
</literal> (
7). If a single log level is
560 specified, all messages with this log level or a lower (hence
561 more important) log level are shown. If a range is specified,
562 all messages within the range are shown, including both the
563 start and the end value of the range. This will add
564 <literal>PRIORITY=
</literal> matches for the specified
565 priorities.
</para></listitem>
569 <term><option>-g
</option></term>
570 <term><option>--grep=
</option></term>
572 <listitem><para>Filter output to entries where the
<varname>MESSAGE=
</varname>
573 field matches the specified regular expression. PERL-compatible regular expressions
575 <citerefentry><refentrytitle>pcre2pattern
</refentrytitle><manvolnum>3</manvolnum></citerefentry>
576 for a detailed description of the syntax.
</para>
578 <para>If the pattern is all lowercase, matching is case insensitive.
579 Otherwise, matching is case sensitive. This can be overridden with the
580 <option>--case-sensitive
</option> option, see below.
</para>
585 <term><option>--case-sensitive
<optional>=BOOLEAN
</optional></option></term>
587 <listitem><para>Make pattern matching case sensitive or case insenstive.
</para>
592 <term><option>-c
</option></term>
593 <term><option>--cursor=
</option></term>
595 <listitem><para>Start showing entries from the location in the
596 journal specified by the passed cursor.
</para></listitem>
600 <term><option>--after-cursor=
</option></term>
602 <listitem><para>Start showing entries from the location in the
603 journal
<emphasis>after
</emphasis> the location specified by
604 the passed cursor. The cursor is shown when the
605 <option>--show-cursor
</option> option is used.
</para>
610 <term><option>--show-cursor
</option></term>
612 <listitem><para>The cursor is shown after the last entry after
614 <programlisting>-- cursor: s=
0639…
</programlisting>
615 <para>The format of the cursor is private
616 and subject to change.
</para></listitem>
620 <term><option>-S
</option></term>
621 <term><option>--since=
</option></term>
622 <term><option>-U
</option></term>
623 <term><option>--until=
</option></term>
625 <listitem><para>Start showing entries on or newer than the specified date, or on or older than the specified
626 date, respectively. Date specifications should be of the format
<literal>2012-
10-
30 18:
17:
16</literal>. If the
627 time part is omitted,
<literal>00:
00:
00</literal> is assumed. If only the seconds component is omitted,
628 <literal>:
00</literal> is assumed. If the date component is omitted, the current day is assumed. Alternatively
629 the strings
<literal>yesterday
</literal>,
<literal>today
</literal>,
<literal>tomorrow
</literal> are understood,
630 which refer to
00:
00:
00 of the day before the current day, the current day, or the day after the current day,
631 respectively.
<literal>now
</literal> refers to the current time. Finally, relative times may be specified,
632 prefixed with
<literal>-
</literal> or
<literal>+
</literal>, referring to times before or after the current
633 time, respectively. For complete time and date specification, see
634 <citerefentry><refentrytitle>systemd.time
</refentrytitle><manvolnum>7</manvolnum></citerefentry>. Note that
635 <option>--output=short-full
</option> prints timestamps that follow precisely this format.
641 <term><option>-F
</option></term>
642 <term><option>--field=
</option></term>
644 <listitem><para>Print all possible data values the specified
645 field can take in all entries of the journal.
</para></listitem>
649 <term><option>-N
</option></term>
650 <term><option>--fields
</option></term>
652 <listitem><para>Print all field names currently used in all entries of the journal.
</para></listitem>
656 <term><option>--system
</option></term>
657 <term><option>--user
</option></term>
659 <listitem><para>Show messages from system services and the
660 kernel (with
<option>--system
</option>). Show messages from
661 service of current user (with
<option>--user
</option>). If
662 neither is specified, show all messages that the user can see.
667 <term><option>-M
</option></term>
668 <term><option>--machine=
</option></term>
670 <listitem><para>Show messages from a running, local
671 container. Specify a container name to connect to.
</para>
676 <term><option>-D
<replaceable>DIR
</replaceable></option></term>
677 <term><option>--directory=
<replaceable>DIR
</replaceable></option></term>
679 <listitem><para>Takes a directory path as argument. If
680 specified, journalctl will operate on the specified journal
681 directory
<replaceable>DIR
</replaceable> instead of the
682 default runtime and system journal paths.
</para></listitem>
686 <term><option>--file=
<replaceable>GLOB
</replaceable></option></term>
688 <listitem><para>Takes a file glob as an argument. If
689 specified, journalctl will operate on the specified journal
690 files matching
<replaceable>GLOB
</replaceable> instead of the
691 default runtime and system journal paths. May be specified
692 multiple times, in which case files will be suitably
693 interleaved.
</para></listitem>
697 <term><option>--root=
<replaceable>ROOT
</replaceable></option></term>
699 <listitem><para>Takes a directory path as an argument. If
700 specified, journalctl will operate on journal directories and catalog file hierarchy
701 underneath the specified directory instead of the root
702 directory (e.g.
<option>--update-catalog
</option> will create
703 <filename><replaceable>ROOT
</replaceable>/var/lib/systemd/catalog/database
</filename>,
704 and journal files under
<filename><replaceable>ROOT
</replaceable>/run/journal
</filename>
705 or
<filename><replaceable>ROOT
</replaceable>/var/log/journal
</filename> will be displayed).
710 <term><option>--new-id128
</option></term>
712 <listitem><para>Instead of showing journal contents, generate
713 a new
128-bit ID suitable for identifying messages. This is
714 intended for usage by developers who need a new identifier for
715 a new message they introduce and want to make
716 recognizable. This will print the new ID in four different
717 formats which can be copied into source code or similar.
722 <term><option>--header
</option></term>
724 <listitem><para>Instead of showing journal contents, show
725 internal header information of the journal fields
726 accessed.
</para></listitem>
730 <term><option>--disk-usage
</option></term>
732 <listitem><para>Shows the current disk usage of all journal
733 files. This shows the sum of the disk usage of all archived
734 and active journal files.
</para></listitem>
738 <term><option>--vacuum-size=
</option></term>
739 <term><option>--vacuum-time=
</option></term>
740 <term><option>--vacuum-files=
</option></term>
742 <listitem><para>Removes the oldest archived journal files until the disk
743 space they use falls below the specified size (specified with
744 the usual
<literal>K
</literal>,
<literal>M
</literal>,
745 <literal>G
</literal> and
<literal>T
</literal> suffixes), or all
746 archived journal files contain no data older than the specified
747 timespan (specified with the usual
<literal>s
</literal>,
748 <literal>m
</literal>,
<literal>h
</literal>,
749 <literal>days
</literal>,
<literal>months
</literal>,
750 <literal>weeks
</literal> and
<literal>years
</literal> suffixes),
751 or no more than the specified number of separate journal files
752 remain. Note that running
<option>--vacuum-size=
</option> has
753 only an indirect effect on the output shown by
754 <option>--disk-usage
</option>, as the latter includes active
755 journal files, while the vacuuming operation only operates
756 on archived journal files. Similarly,
757 <option>--vacuum-files=
</option> might not actually reduce the
758 number of journal files to below the specified number, as it
759 will not remove active journal
760 files.
<option>--vacuum-size=
</option>,
761 <option>--vacuum-time=
</option> and
762 <option>--vacuum-files=
</option> may be combined in a single
763 invocation to enforce any combination of a size, a time and a
764 number of files limit on the archived journal
765 files. Specifying any of these three parameters as zero is
766 equivalent to not enforcing the specific limit, and is thus
767 redundant.
</para></listitem>
771 <term><option>--list-catalog
772 <optional><replaceable>128-bit-ID…
</replaceable></optional>
775 <listitem><para>List the contents of the message catalog as a
776 table of message IDs, plus their short description strings.
779 <para>If any
<replaceable>128-bit-ID
</replaceable>s are
780 specified, only those entries are shown.
</para>
785 <term><option>--dump-catalog
786 <optional><replaceable>128-bit-ID…
</replaceable></optional>
789 <listitem><para>Show the contents of the message catalog, with
790 entries separated by a line consisting of two dashes and the
791 ID (the format is the same as
<filename>.catalog
</filename>
794 <para>If any
<replaceable>128-bit-ID
</replaceable>s are
795 specified, only those entries are shown.
</para>
800 <term><option>--update-catalog
</option></term>
802 <listitem><para>Update the message catalog index. This command
803 needs to be executed each time new catalog files are
804 installed, removed, or updated to rebuild the binary catalog
805 index.
</para></listitem>
809 <term><option>--setup-keys
</option></term>
811 <listitem><para>Instead of showing journal contents, generate
812 a new key pair for Forward Secure Sealing (FSS). This will
813 generate a sealing key and a verification key. The sealing key
814 is stored in the journal data directory and shall remain on
815 the host. The verification key should be stored
816 externally. Refer to the
<option>Seal=
</option> option in
817 <citerefentry><refentrytitle>journald.conf
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
818 for information on Forward Secure Sealing and for a link to a
819 refereed scholarly paper detailing the cryptographic theory it
820 is based on.
</para></listitem>
824 <term><option>--force
</option></term>
826 <listitem><para>When
<option>--setup-keys
</option> is passed
827 and Forward Secure Sealing (FSS) has already been configured,
828 recreate FSS keys.
</para></listitem>
832 <term><option>--interval=
</option></term>
834 <listitem><para>Specifies the change interval for the sealing
835 key when generating an FSS key pair with
836 <option>--setup-keys
</option>. Shorter intervals increase CPU
837 consumption but shorten the time range of undetectable journal
838 alterations. Defaults to
15min.
</para></listitem>
842 <term><option>--verify
</option></term>
844 <listitem><para>Check the journal file for internal
845 consistency. If the file has been generated with FSS enabled and
846 the FSS verification key has been specified with
847 <option>--verify-key=
</option>, authenticity of the journal file
848 is verified.
</para></listitem>
852 <term><option>--verify-key=
</option></term>
854 <listitem><para>Specifies the FSS verification key to use for
855 the
<option>--verify
</option> operation.
</para></listitem>
859 <term><option>--sync
</option></term>
861 <listitem><para>Asks the journal daemon to write all yet
862 unwritten journal data to the backing file system and
863 synchronize all journals. This call does not return until the
864 synchronization operation is complete. This command guarantees
865 that any log messages written before its invocation are safely
866 stored on disk at the time it returns.
</para></listitem>
870 <term><option>--flush
</option></term>
872 <listitem><para>Asks the journal daemon to flush any log data
873 stored in
<filename>/run/log/journal
</filename> into
874 <filename>/var/log/journal
</filename>, if persistent storage
875 is enabled. This call does not return until the operation is
876 complete. Note that this call is idempotent: the data is only
877 flushed from
<filename>/run/log/journal
</filename> into
878 <filename>/var/log/journal
</filename> once during system
879 runtime, and this command exits cleanly without executing any
880 operation if this has already happened. This command
881 effectively guarantees that all data is flushed to
882 <filename>/var/log/journal
</filename> at the time it
883 returns.
</para></listitem>
887 <term><option>--rotate
</option></term>
889 <listitem><para>Asks the journal daemon to rotate journal
890 files. This call does not return until the rotation operation
891 is complete.
</para></listitem>
894 <xi:include href=
"standard-options.xml" xpointer=
"help" />
895 <xi:include href=
"standard-options.xml" xpointer=
"version" />
896 <xi:include href=
"standard-options.xml" xpointer=
"no-pager" />
901 <title>Exit status
</title>
903 <para>On success,
0 is returned; otherwise, a non-zero failure
904 code is returned.
</para>
907 <xi:include href=
"less-variables.xml" />
910 <title>Examples
</title>
912 <para>Without arguments, all collected logs are shown
915 <programlisting>journalctl
</programlisting>
917 <para>With one match specified, all entries with a field matching
918 the expression are shown:
</para>
920 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service
921 journalctl _SYSTEMD_CGROUP=/user.slice/user-
42.slice/session-c1.scope
</programlisting>
923 <para>If two different fields are matched, only entries matching
924 both expressions at the same time are shown:
</para>
926 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=
28097</programlisting>
928 <para>If two matches refer to the same field, all entries matching
929 either expression are shown:
</para>
931 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service
</programlisting>
933 <para>If the separator
<literal>+
</literal> is used, two
934 expressions may be combined in a logical OR. The following will
935 show all messages from the Avahi service process with the PID
936 28097 plus all messages from the D-Bus service (from any of its
939 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=
28097 + _SYSTEMD_UNIT=dbus.service
</programlisting>
941 <para>To show all fields emited
<emphasis>by
</emphasis> a unit and
<emphasis>about
</emphasis>
942 the unit, option
<option>-u
</option>/
<option>--unit=
</option> should be used.
943 <command>journalctl -u
<replaceable>name
</replaceable></command>
944 expands to a complex filter similar to
945 <programlisting>_SYSTEMD_UNIT=
<replaceable>name
</replaceable>.service
946 + UNIT=
<replaceable>name
</replaceable>.service _PID=
1
947 + OBJECT_SYSTEMD_UNIT=
<replaceable>name
</replaceable>.service _UID=
0
948 + COREDUMP_UNIT=
<replaceable>name
</replaceable>.service _UID=
0 MESSAGE_ID=fc2e22bc6ee647b6b90729ab34a250b1
950 (see
<citerefentry><refentrytitle>systemd.journal-fields
</refentrytitle><manvolnum>5</manvolnum></citerefentry>
951 for an explanation of those patterns).
954 <para>Show all logs generated by the D-Bus executable:
</para>
956 <programlisting>journalctl /usr/bin/dbus-daemon
</programlisting>
958 <para>Show all kernel logs from previous boot:
</para>
960 <programlisting>journalctl -k -b -
1</programlisting>
962 <para>Show a live log display from a system service
963 <filename>apache.service
</filename>:
</para>
965 <programlisting>journalctl -f -u apache
</programlisting>
970 <title>See Also
</title>
972 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
973 <citerefentry><refentrytitle>systemd-journald.service
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
974 <citerefentry><refentrytitle>systemctl
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
975 <citerefentry><refentrytitle>coredumpctl
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
976 <citerefentry><refentrytitle>systemd.journal-fields
</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
977 <citerefentry><refentrytitle>journald.conf
</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
978 <citerefentry><refentrytitle>systemd.time
</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
979 <citerefentry><refentrytitle>systemd-journal-remote
</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
980 <citerefentry><refentrytitle>systemd-journal-upload
</refentrytitle><manvolnum>8</manvolnum></citerefentry>