1JOURNALCTL(1)                     journalctl                     JOURNALCTL(1)
2
3
4

NAME

6       journalctl - Query the systemd journal
7

SYNOPSIS

9       journalctl [OPTIONS...] [MATCHES...]
10

DESCRIPTION

12       journalctl may be used to query the contents of the systemd(1) journal
13       as written by systemd-journald.service(8).
14
15       If called without parameters, it will show the full contents of the
16       journal, starting with the oldest entry collected.
17
18       If one or more match arguments are passed, the output is filtered
19       accordingly. A match is in the format "FIELD=VALUE", e.g.
20       "_SYSTEMD_UNIT=httpd.service", referring to the components of a
21       structured journal entry. See systemd.journal-fields(7) for a list of
22       well-known fields. If multiple matches are specified matching different
23       fields, the log entries are filtered by both, i.e. the resulting output
24       will show only entries matching all the specified matches of this kind.
25       If two matches apply to the same field, then they are automatically
26       matched as alternatives, i.e. the resulting output will show entries
27       matching any of the specified matches for the same field. Finally, the
28       character "+" may appears as a separate word between other terms on the
29       command line. This causes all matches before and after to be combined
30       in a disjunction (i.e. logical OR).
31
32       As shortcuts for a few types of field/value matches, file paths may be
33       specified. If a file path refers to an executable file, this is
34       equivalent to an "_EXE=" match for the canonicalized binary path.
35       Similarly, if a path refers to a device node then match is added for
36       the kernel name of the device ("_KERNEL_DEVICE="). Also, matches for
37       the kernel names of all the parent devices are added automatically.
38       Device node paths are not stable across reboots, therefore match for
39       the current boot id ("_BOOT_ID=") is always added as well. Note that
40       only the log entries for the existing device nodes maybe queried by
41       providing path to the device node.
42
43       Additional constraints may be added using options --boot, --unit=, etc,
44       to further limit what entries will be shown (logical AND).
45
46       Output is interleaved from all accessible journal files, whether they
47       are rotated or currently being written, and regardless of whether they
48       belong to the system itself or are accessible user journals.
49
50       The set of journal files which will be used can be modified using the
51       --user, --system, --directory, and --file options, see below.
52
53       All users are granted access to their private per-user journals.
54       However, by default, only root and users who are members of a few
55       special groups are granted access to the system journal and the
56       journals of other users. Members of the the "systemd-journal", "adm",
57       and "wheel" groups can read all journal files. Note that the two latter
58       groups traditionally have additional privileges specified by the
59       distribution. Members of the "wheel" group can often perform
60       administrative tasks.
61
62       The output is paged through less by default, and long lines are
63       "truncated" to screen width. The hidden part can be viewed by using the
64       left-arrow and right-arrow keys. Paging can be disabled; see the
65       --no-pager option and the "Environment" section below.
66
67       When outputting to a tty, lines are colored according to priority:
68       lines of level ERROR and higher are colored red; lines of level NOTICE
69       and higher are highlighted; other lines are displayed normally.
70

OPTIONS

72       The following options are understood:
73
74       --no-full, --full, -l
75           Ellipsize fields when they do not fit in available columns. The
76           default is to show full fields, allowing them to wrap or be
77           truncated by the pager, if one is used.
78
79           The old options -l/--full are not useful anymore, except to undo
80           --no-full.
81
82       -a, --all
83           Show all fields in full, even if they include unprintable
84           characters or are very long.
85
86       -f, --follow
87           Show only the most recent journal entries, and continuously print
88           new entries as they are appended to the journal.
89
90       -e, --pager-end
91           Immediately jump to the end of the journal inside the implied pager
92           tool. This implies -n1000 to guarantee that the pager will not
93           buffer logs of unbounded size. This may be overridden with an
94           explicit -n with some other numeric value while -nall will disable
95           this cap. Note that this option is only supported for the less(1)
96           pager.
97
98       -n, --lines=
99           Show the most recent journal events and limit the number of events
100           shown. If --follow is used, this option is implied. The argument is
101           a positive integer or "all" to disable line limiting. The default
102           value is 10 if no argument is given.
103
104       --no-tail
105           Show all stored output lines, even in follow mode. Undoes the
106           effect of --lines=.
107
108       -r, --reverse
109           Reverse output so that the newest entries are displayed first.
110
111       -o, --output=
112           Controls the formatting of the journal entries that are shown.
113           Takes one of the following options:
114
115           short
116               is the default and generates an output that is mostly identical
117               to the formatting of classic syslog files, showing one line per
118               journal entry.
119
120           short-iso
121               is very similar, but shows ISO 8601 wallclock timestamps.
122
123           short-precise
124               is very similar, but shows timestamps with full microsecond
125               precision.
126
127           short-monotonic
128               is very similar, but shows monotonic timestamps instead of
129               wallclock timestamps.
130
131           verbose
132               shows the full-structured entry items with all fields.
133
134           export
135               serializes the journal into a binary (but mostly text-based)
136               stream suitable for backups and network transfer (see Journal
137               Export Format[1] for more information).
138
139           json
140               formats entries as JSON data structures, one per line (see
141               Journal JSON Format[2] for more information).
142
143           json-pretty
144               formats entries as JSON data structures, but formats them in
145               multiple lines in order to make them more readable by humans.
146
147           json-sse
148               formats entries as JSON data structures, but wraps them in a
149               format suitable for Server-Sent Events[3].
150
151           cat
152               generates a very terse output, only showing the actual message
153               of each journal entry with no metadata, not even a timestamp.
154
155       --utc
156           Express time in Coordinated Universal Time (UTC).
157
158       -x, --catalog
159           Augment log lines with explanation texts from the message catalog.
160           This will add explanatory help texts to log messages in the output
161           where this is available. These short help texts will explain the
162           context of an error or log event, possible solutions, as well as
163           pointers to support forums, developer documentation, and any other
164           relevant manuals. Note that help texts are not available for all
165           messages, but only for selected ones. For more information on the
166           message catalog, please refer to the Message Catalog Developer
167           Documentation[4].
168
169           Note: when attaching journalctl output to bug reports, please do
170           not use -x.
171
172       -q, --quiet
173           Suppresses any warning messages regarding inaccessible system
174           journals when run as a normal user.
175
176       -m, --merge
177           Show entries interleaved from all available journals, including
178           remote ones.
179
180       -b [ID][┬▒offset], --boot=[ID][┬▒offset]
181           Show messages from a specific boot. This will add a match for
182           "_BOOT_ID=".
183
184           The argument may be empty, in which case logs for the current boot
185           will be shown.
186
187           If the boot ID is omitted, a positive offset will look up the boots
188           starting from the beginning of the journal, and a
189           equal-or-less-than zero offset will look up boots starting from the
190           end of the journal. Thus, 1 means the first boot found in the
191           journal in chronological order, 2 the second and so on; while -0 is
192           the last boot, -1 the boot before last, and so on. An empty offset
193           is equivalent to specifying -0, except when the current boot is not
194           the last boot (e.g. because --directory was specified to look at
195           logs from a different machine).
196
197           If the 32-character ID is specified, it may optionally be followed
198           by offset which identifies the boot relative to the one given by
199           boot ID. Negative values mean earlier boots and a positive values
200           mean later boots. If offset is not specified, a value of zero is
201           assumed, and the logs for the boot given by ID are shown.
202
203       --list-boots
204           Show a tabular list of boot numbers (relative to the current boot),
205           their IDs, and the timestamps of the first and last message
206           pertaining to the boot.
207
208       -k, --dmesg
209           Show only kernel messages. This implies -b and adds the match
210           "_TRANSPORT=kernel".
211
212       -t, --identifier=SYSLOG_IDENTIFIER|PATTERN
213           Show messages for the specified syslog identifier
214           SYSLOG_IDENTIFIER, or for any of the messages with a
215           "SYSLOG_IDENTIFIER" matched by PATTERN.
216
217           This parameter can be specified multiple times.
218
219       -u, --unit=UNIT|PATTERN
220           Show messages for the specified systemd unit UNIT (such as a
221           service unit), or for any of the units matched by PATTERN. If a
222           pattern is specified, a list of unit names found in the journal is
223           compared with the specified pattern and all that match are used.
224           For each unit name, a match is added for messages from the unit
225           ("_SYSTEMD_UNIT=UNIT"), along with additional matches for messages
226           from systemd and messages about coredumps for the specified unit.
227
228           This parameter can be specified multiple times.
229
230       -p, --priority=
231           Filter output by message priorities or priority ranges. Takes
232           either a single numeric or textual log level (i.e. between
233           0/"emerg" and 7/"debug"), or a range of numeric/text log levels in
234           the form FROM..TO. The log levels are the usual syslog log levels
235           as documented in syslog(3), i.e.  "emerg" (0), "alert" (1),
236           "crit" (2), "err" (3), "warning" (4), "notice" (5), "info" (6),
237           "debug" (7). If a single log level is specified, all messages with
238           this log level or a lower (hence more important) log level are
239           shown. If a range is specified, all messages within the range are
240           shown, including both the start and the end value of the range.
241           This will add "PRIORITY=" matches for the specified priorities.
242
243       -c, --cursor=
244           Start showing entries from the location in the journal specified by
245           the passed cursor.
246
247       --after-cursor=
248           Start showing entries from the location in the journal after the
249           location specified by the this cursor. The cursor is shown when the
250           --show-cursor option is used.
251
252       --show-cursor
253           The cursor is shown after the last entry after two dashes:
254
255               -- cursor: s=0639...
256
257           The format of the cursor is private and subject to change.
258
259       -S, --since=, -U, --until=
260           Start showing entries on or newer than the specified date, or on or
261           older than the specified date, respectively. Date specifications
262           should be of the format "2012-10-30 18:17:16". If the time part is
263           omitted, "00:00:00" is assumed. If only the seconds component is
264           omitted, ":00" is assumed. If the date component is omitted, the
265           current day is assumed. Alternatively the strings "yesterday",
266           "today", "tomorrow" are understood, which refer to 00:00:00 of the
267           day before the current day, the current day, or the day after the
268           current day, respectively.  "now" refers to the current time.
269           Finally, relative times may be specified, prefixed with "-" or "+",
270           referring to times before or after the current time, respectively.
271
272       -F, --field=
273           Print all possible data values the specified field can take in all
274           entries of the journal.
275
276       --system, --user
277           Show messages from system services and the kernel (with --system).
278           Show messages from service of current user (with --user). If
279           neither is specified, show all messages that the user can see.
280
281       -M, --machine=
282           Show messages from a running, local container. Specify a container
283           name to connect to.
284
285       -D DIR, --directory=DIR
286           Takes a directory path as argument. If specified, journalctl will
287           operate on the specified journal directory DIR instead of the
288           default runtime and system journal paths.
289
290       --file=GLOB
291           Takes a file glob as an argument. If specified, journalctl will
292           operate on the specified journal files matching GLOB instead of the
293           default runtime and system journal paths. May be specified multiple
294           times, in which case files will be suitably interleaved.
295
296       --root=ROOT
297           Takes a directory path as an argument. If specified, journalctl
298           will operate on catalog file hierarchy underneath the specified
299           directory instead of the root directory (e.g.  --update-catalog
300           will create ROOT/var/lib/systemd/catalog/database).
301
302       --new-id128
303           Instead of showing journal contents, generate a new 128-bit ID
304           suitable for identifying messages. This is intended for usage by
305           developers who need a new identifier for a new message they
306           introduce and want to make recognizable. This will print the new ID
307           in three different formats which can be copied into source code or
308           similar.
309
310       --header
311           Instead of showing journal contents, show internal header
312           information of the journal fields accessed.
313
314       --disk-usage
315           Shows the current disk usage of all journal files. This shows the
316           sum of the disk usage of all archived and active journal files.
317
318       --vacuum-size=, --vacuum-time=
319           Removes archived journal files until the disk space they use falls
320           below the specified size (specified with the usual "K", "M", "G",
321           "T" suffixes), or all journal files contain no data older than the
322           specified timespan (specified with the usual "s", "min", "h",
323           "days", "months", "weeks", "years" suffixes). Note that running
324           --vacuum-size= has only indirect effect on the output shown by
325           --disk-usage as the latter includes active journal files, while the
326           former only operates on archived journal files.  --vacuum-size= and
327           --vacuum-time= may be combined in a single invocation to enforce
328           both a size and time limit on the archived journal files.
329
330       --list-catalog [128-bit-ID...]
331           List the contents of the message catalog as a table of message IDs,
332           plus their short description strings.
333
334           If any 128-bit-IDs are specified, only those entries are shown.
335
336       --dump-catalog [128-bit-ID...]
337           Show the contents of the message catalog, with entries separated by
338           a line consisting of two dashes and the ID (the format is the same
339           as .catalog files).
340
341           If any 128-bit-IDs are specified, only those entries are shown.
342
343       --update-catalog
344           Update the message catalog index. This command needs to be executed
345           each time new catalog files are installed, removed, or updated to
346           rebuild the binary catalog index.
347
348       --setup-keys
349           Instead of showing journal contents, generate a new key pair for
350           Forward Secure Sealing (FSS). This will generate a sealing key and
351           a verification key. The sealing key is stored in the journal data
352           directory and shall remain on the host. The verification key should
353           be stored externally. Refer to the Seal= option in journald.conf(5)
354           for information on Forward Secure Sealing and for a link to a
355           refereed scholarly paper detailing the cryptographic theory it is
356           based on.
357
358       --force
359           When --setup-keys is passed and Forward Secure Sealing (FSS) has
360           already been configured, recreate FSS keys.
361
362       --interval=
363           Specifies the change interval for the sealing key when generating
364           an FSS key pair with --setup-keys. Shorter intervals increase CPU
365           consumption but shorten the time range of undetectable journal
366           alterations. Defaults to 15min.
367
368       --verify
369           Check the journal file for internal consistency. If the file has
370           been generated with FSS enabled and the FSS verification key has
371           been specified with --verify-key=, authenticity of the journal file
372           is verified.
373
374       --verify-key=
375           Specifies the FSS verification key to use for the --verify
376           operation.
377
378       --flush
379           Asks the Journal daemon to flush any log data stored in
380           /run/log/journal into /var/log/journal, if persistent storage is
381           enabled. This call does not return until the operation is complete.
382
383       -h, --help
384           Print a short help text and exit.
385
386       --version
387           Print a short version string and exit.
388
389       --no-pager
390           Do not pipe output into a pager.
391

EXIT STATUS

393       On success, 0 is returned; otherwise, a non-zero failure code is
394       returned.
395

ENVIRONMENT

397       $SYSTEMD_PAGER
398           Pager to use when --no-pager is not given; overrides $PAGER.
399           Setting this to an empty string or the value "cat" is equivalent to
400           passing --no-pager.
401
402       $SYSTEMD_LESS
403           Override the default options passed to less ("FRSXMK").
404

EXAMPLES

406       Without arguments, all collected logs are shown unfiltered:
407
408           journalctl
409
410       With one match specified, all entries with a field matching the
411       expression are shown:
412
413           journalctl _SYSTEMD_UNIT=avahi-daemon.service
414
415       If two different fields are matched, only entries matching both
416       expressions at the same time are shown:
417
418           journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097
419
420       If two matches refer to the same field, all entries matching either
421       expression are shown:
422
423           journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service
424
425       If the separator "+" is used, two expressions may be combined in a
426       logical OR. The following will show all messages from the Avahi service
427       process with the PID 28097 plus all messages from the D-Bus service
428       (from any of its processes):
429
430           journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service
431
432       Show all logs generated by the D-Bus executable:
433
434           journalctl /usr/bin/dbus-daemon
435
436       Show all kernel logs from previous boot:
437
438           journalctl -k -b -1
439
440       Show a live log display from a system service apache.service:
441
442           journalctl -f -u apache
443

SEE ALSO

445       systemd(1), systemd-journald.service(8), systemctl(1), coredumpctl(1),
446       systemd.journal-fields(7), journald.conf(5)
447

NOTES

449        1. Journal Export Format
450           http://www.freedesktop.org/wiki/Software/systemd/export
451
452        2. Journal JSON Format
453           http://www.freedesktop.org/wiki/Software/systemd/json
454
455        3. Server-Sent Events
456           https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events
457
458        4. Message Catalog Developer Documentation
459           http://www.freedesktop.org/wiki/Software/systemd/catalog
460
461
462
463systemd 219                                                      JOURNALCTL(1)
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