man/journalctl.xml

   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">
   4
   5 <!--
   6   This file is part of systemd.
   7
   8   Copyright 2012 Lennart Poettering
   9
  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.
  14
  15   systemd is distributed in the hope that it will be useful, but
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  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 -->
  23
  24 <refentry id="journalctl"
  25           xmlns:xi="http://www.w3.org/2001/XInclude">
  26
  27         <refentryinfo>
  28                 <title>journalctl</title>
  29                 <productname>systemd</productname>
  30
  31                 <authorgroup>
  32                         <author>
  33                                 <contrib>Developer</contrib>
  34                                 <firstname>Lennart</firstname>
  35                                 <surname>Poettering</surname>
  36                                 <email>lennart@poettering.net</email>
  37                         </author>
  38                 </authorgroup>
  39         </refentryinfo>
  40
  41         <refmeta>
  42                 <refentrytitle>journalctl</refentrytitle>
  43                 <manvolnum>1</manvolnum>
  44         </refmeta>
  45
  46         <refnamediv>
  47                 <refname>journalctl</refname>
  48                 <refpurpose>Query the systemd journal</refpurpose>
  49         </refnamediv>
  50
  51         <refsynopsisdiv>
  52                 <cmdsynopsis>
  53                         <command>journalctl</command>
  54                         <arg choice="opt" rep="repeat">OPTIONS</arg>
  55                         <arg choice="opt" rep="repeat">MATCHES</arg>
  56                 </cmdsynopsis>
  57         </refsynopsisdiv>
  58
  59         <refsect1>
  60                 <title>Description</title>
  61
  62                 <para><command>journalctl</command> may be used to
  63                 query the contents of the
  64                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  65                 journal as written by
  66                 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
  67
  68                 <para>If called without parameters, it will show the full
  69                 contents of the journal, starting with the oldest
  70                 entry collected.</para>
  71
  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
  77                 entry. See
  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>
  92
  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
 100                 device.</para>
 101
 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>
 106
 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>
 111
 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>
 116
 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>
 122
 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>
 130
 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.
 135                 </para>
 136         </refsect1>
 137
 138         <refsect1>
 139                 <title>Options</title>
 140
 141                 <para>The following options are understood:</para>
 142
 143                 <variablelist>
 144                         <varlistentry>
 145                                 <term><option>--no-full</option></term>
 146                                 <term><option>--full</option></term>
 147                                 <term><option>-l</option></term>
 148
 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>
 154
 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>
 159                         </varlistentry>
 160
 161                         <varlistentry>
 162                                 <term><option>-a</option></term>
 163                                 <term><option>--all</option></term>
 164
 165                                 <listitem><para>Show all fields in
 166                                 full, even if they include unprintable
 167                                 characters or are very
 168                                 long.</para></listitem>
 169                         </varlistentry>
 170
 171                         <varlistentry>
 172                                 <term><option>-f</option></term>
 173                                 <term><option>--follow</option></term>
 174
 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>
 179                         </varlistentry>
 180
 181                         <varlistentry>
 182                                 <term><option>-e</option></term>
 183                                 <term><option>--pager-end</option></term>
 184
 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>
 197                         </varlistentry>
 198
 199                         <varlistentry>
 200                                 <term><option>-n</option></term>
 201                                 <term><option>--lines=</option></term>
 202
 203                                 <listitem><para>Show the most recent
 204                                 journal events and limit the number of
 205                                 events shown. If
 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>
 211                         </varlistentry>
 212
 213                         <varlistentry>
 214                                 <term><option>--no-tail</option></term>
 215
 216                                 <listitem><para>Show all stored output
 217                                 lines, even in follow mode. Undoes the
 218                                 effect of
 219                                 <option>--lines=</option>.</para></listitem>
 220                         </varlistentry>
 221
 222                         <varlistentry>
 223                                 <term><option>-r</option></term>
 224                                 <term><option>--reverse</option></term>
 225
 226                                 <listitem><para>Reverse output so that the newest
 227                                 entries are displayed first.</para></listitem>
 228                         </varlistentry>
 229
 230                         <varlistentry>
 231                                 <term><option>-o</option></term>
 232                                 <term><option>--output=</option></term>
 233
 234                                 <listitem><para>Controls the
 235                                 formatting of the journal entries that
 236                                 are shown. Takes one of the following options:
 237                                 </para>
 238                                 <variablelist>
 239                                         <varlistentry>
 240                                                 <term>
 241                                                         <option>short</option>
 242                                                 </term>
 243                                                 <listitem>
 244                                                         <para>is the default
 245                                                         and generates an output
 246                                                         that is mostly identical
 247                                                         to the formatting of
 248                                                         classic syslog files,
 249                                                         showing one line per
 250                                                         journal entry.</para>
 251                                                 </listitem>
 252                                         </varlistentry>
 253
 254                                         <varlistentry>
 255                                                 <term>
 256                                                         <option>short-iso</option>
 257                                                 </term>
 258                                                 <listitem>
 259                                                         <para>is very similar,
 260                                                         but shows ISO 8601
 261                                                         wallclock timestamps.
 262                                                         </para>
 263                                                 </listitem>
 264                                         </varlistentry>
 265
 266                                         <varlistentry>
 267                                                 <term>
 268                                                         <option>short-precise</option>
 269                                                 </term>
 270                                                 <listitem>
 271                                                         <para>is very similar,
 272                                                         but shows timestamps
 273                                                         with full microsecond
 274                                                         precision.
 275                                                         </para>
 276                                                 </listitem>
 277                                         </varlistentry>
 278
 279                                         <varlistentry>
 280                                                 <term>
 281                                                         <option>short-monotonic</option>
 282                                                 </term>
 283                                                 <listitem>
 284                                                         <para>is very similar,
 285                                                         but shows monotonic
 286                                                         timestamps instead of
 287                                                         wallclock timestamps.
 288                                                         </para>
 289                                                 </listitem>
 290                                         </varlistentry>
 291
 292                                         <varlistentry>
 293                                                 <term>
 294                                                         <option>verbose</option>
 295                                                 </term>
 296                                                 <listitem>
 297                                                         <para>shows the
 298                                                         full-structured entry
 299                                                         items with all fields.
 300                                                         </para>
 301                                                 </listitem>
 302                                         </varlistentry>
 303
 304                                         <varlistentry>
 305                                                 <term>
 306                                                         <option>export</option>
 307                                                 </term>
 308                                                 <listitem>
 309                                                         <para>serializes the
 310                                                         journal into a binary
 311                                                         (but mostly text-based)
 312                                                         stream suitable for
 313                                                         backups and network
 314                                                         transfer (see <ulink
 315                                                         url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
 316                                                         Export Format</ulink>
 317                                                         for more
 318                                                         information).</para>
 319                                                 </listitem>
 320                                         </varlistentry>
 321
 322                                         <varlistentry>
 323                                                 <term>
 324                                                         <option>json</option>
 325                                                 </term>
 326                                                 <listitem>
 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>
 333                                                 </listitem>
 334                                         </varlistentry>
 335
 336                                         <varlistentry>
 337                                                 <term>
 338                                                         <option>json-pretty</option>
 339                                                 </term>
 340                                                 <listitem>
 341                                                         <para>formats entries as
 342                                                         JSON data structures,
 343                                                         but formats them in
 344                                                         multiple lines in order
 345                                                         to make them more
 346                                                         readable by humans.</para>
 347                                                 </listitem>
 348                                         </varlistentry>
 349
 350                                         <varlistentry>
 351                                                 <term>
 352                                                         <option>json-sse</option>
 353                                                 </term>
 354                                                 <listitem>
 355                                                         <para>formats entries as
 356                                                         JSON data structures,
 357                                                         but wraps them in a
 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>
 361                                                 </listitem>
 362                                         </varlistentry>
 363
 364                                         <varlistentry>
 365                                                 <term>
 366                                                         <option>cat</option>
 367                                                 </term>
 368                                                 <listitem>
 369                                                         <para>generates a very
 370                                                         terse output, only
 371                                                         showing the actual
 372                                                         message of each journal
 373                                                         entry with no metadata,
 374                                                         not even a timestamp.
 375                                                         </para>
 376                                                 </listitem>
 377                                         </varlistentry>
 378                                 </variablelist>
 379                                 </listitem>
 380                         </varlistentry>
 381
 382                         <varlistentry>
 383                                 <term><option>-x</option></term>
 384                                 <term><option>--catalog</option></term>
 385
 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
 402                                 Catalog Developer
 403                                 Documentation</ulink>.</para>
 404
 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>
 410                                 </listitem>
 411                         </varlistentry>
 412
 413                         <varlistentry>
 414                                 <term><option>-q</option></term>
 415                                 <term><option>--quiet</option></term>
 416
 417                                 <listitem><para>Suppresses any warning
 418                                 messages regarding inaccessible system
 419                                 journals when run as a normal
 420                                 user.</para></listitem>
 421                         </varlistentry>
 422
 423                         <varlistentry>
 424                                 <term><option>-m</option></term>
 425                                 <term><option>--merge</option></term>
 426
 427                                 <listitem><para>Show entries
 428                                 interleaved from all available
 429                                 journals, including remote
 430                                 ones.</para></listitem>
 431                         </varlistentry>
 432
 433                         <varlistentry>
 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>
 436
 437                                 <listitem><para>Show messages from a specific
 438                                 boot. This will add a match for
 439                                 <literal>_BOOT_ID=</literal>.</para>
 440
 441                                 <para>The argument may be empty, in which case
 442                                 logs for the current boot will be shown.</para>
 443
 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
 461                                 machine).</para>
 462
 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
 470                                 mean later boots. If
 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.
 475                                 </para>
 476
 477                                 </listitem>
 478                         </varlistentry>
 479
 480                         <varlistentry>
 481                                 <term><option>--list-boots</option></term>
 482
 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.
 488                                 </para></listitem>
 489                         </varlistentry>
 490
 491                         <varlistentry>
 492                                 <term><option>-k</option></term>
 493                                 <term><option>--dmesg</option></term>
 494
 495                                 <listitem><para>Show only kernel messages. This
 496                                 implies <option>-b</option> and adds the match
 497                                 <literal>_TRANSPORT=kernel</literal>.
 498                                 </para></listitem>
 499                         </varlistentry>
 500
 501                         <varlistentry>
 502                                 <term><option>-t</option></term>
 503                                 <term><option>--identifier=<replaceable>SYSLOG_IDENTIFIER</replaceable>|<replaceable>PATTERN</replaceable></option></term>
 504
 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>
 510
 511                                 <para>This parameter can be specified
 512                                 multiple times.</para></listitem>
 513                         </varlistentry>
 514
 515                         <varlistentry>
 516                                 <term><option>-u</option></term>
 517                                 <term><option>--unit=<replaceable>UNIT</replaceable>|<replaceable>PATTERN</replaceable></option></term>
 518
 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
 523                                 units matched by
 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
 535                                 unit.</para>
 536
 537                                 <para>This parameter can be specified
 538                                 multiple times.</para></listitem>
 539                         </varlistentry>
 540
 541                         <varlistentry>
 542                                 <term><option>--user-unit=</option></term>
 543
 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.
 553                                 </para></listitem>
 554                         </varlistentry>
 555
 556                         <varlistentry>
 557                                 <term><option>-p</option></term>
 558                                 <term><option>--priority=</option></term>
 559
 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
 569                                 documented in
 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
 587                                 for the specified
 588                                 priorities.</para></listitem>
 589                         </varlistentry>
 590
 591                         <varlistentry>
 592                                 <term><option>-c</option></term>
 593                                 <term><option>--cursor=</option></term>
 594
 595                                 <listitem><para>Start showing entries
 596                                 from the location in the journal
 597                                 specified by the passed
 598                                 cursor.</para></listitem>
 599                         </varlistentry>
 600
 601                         <varlistentry>
 602                                 <term><option>--after-cursor=</option></term>
 603
 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>
 611                         </varlistentry>
 612
 613                         <varlistentry>
 614                                 <term><option>--show-cursor</option></term>
 615
 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>
 621                         </varlistentry>
 622
 623                         <varlistentry>
 624                                 <term><option>--since=</option></term>
 625                                 <term><option>--until=</option></term>
 626
 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>
 652                         </varlistentry>
 653
 654                         <varlistentry>
 655                                 <term><option>-F</option></term>
 656                                 <term><option>--field=</option></term>
 657
 658                                 <listitem><para>Print all possible
 659                                 data values the specified field can
 660                                 take in all entries of the
 661                                 journal.</para></listitem>
 662                         </varlistentry>
 663
 664                         <varlistentry>
 665                                 <term><option>--system</option></term>
 666                                 <term><option>--user</option></term>
 667
 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.
 675                                 </para></listitem>
 676                         </varlistentry>
 677
 678                         <varlistentry>
 679                                 <term><option>-M</option></term>
 680                                 <term><option>--machine=</option></term>
 681
 682                                 <listitem><para>Show messages from a
 683                                 running, local container. Specify a
 684                                 container name to connect
 685                                 to.</para></listitem>
 686                         </varlistentry>
 687
 688                         <varlistentry>
 689                                 <term><option>-D <replaceable>DIR</replaceable></option></term>
 690                                 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
 691
 692                                 <listitem><para>Takes a directory path
 693                                 as argument. If specified, journalctl
 694                                 will operate on the specified journal
 695                                 directory
 696                                 <replaceable>DIR</replaceable> instead
 697                                 of the default runtime and system
 698                                 journal paths.</para></listitem>
 699                         </varlistentry>
 700
 701                         <varlistentry>
 702                                 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
 703
 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>
 712                         </varlistentry>
 713
 714                         <varlistentry>
 715                                 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
 716
 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>
 723                                 will create
 724                                 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
 725                                 </para></listitem>
 726                         </varlistentry>
 727
 728                         <varlistentry>
 729                                 <term><option>--new-id128</option></term>
 730
 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>
 742                         </varlistentry>
 743
 744                         <varlistentry>
 745                                 <term><option>--header</option></term>
 746
 747                                 <listitem><para>Instead of showing
 748                                 journal contents, show internal header
 749                                 information of the journal fields
 750                                 accessed.</para></listitem>
 751                         </varlistentry>
 752
 753                         <varlistentry>
 754                                 <term><option>--disk-usage</option></term>
 755
 756                                 <listitem><para>Shows the current disk
 757                                 usage of all
 758                                 journal files.</para></listitem>
 759                         </varlistentry>
 760
 761                         <varlistentry>
 762                                 <term><option>--list-catalog
 763                                 <optional><replaceable>128-bit-ID...</replaceable></optional>
 764                                 </option></term>
 765
 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>
 770
 771                                 <para>If any
 772                                 <replaceable>128-bit-ID</replaceable>s are
 773                                 specified, only those entries are shown.
 774                                 </para>
 775                                 </listitem>
 776                         </varlistentry>
 777
 778                         <varlistentry>
 779                                 <term><option>--dump-catalog
 780                                 <optional><replaceable>128-bit-ID...</replaceable></optional>
 781                                 </option></term>
 782
 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>
 788                                 files).</para>
 789
 790                                 <para>If any
 791                                 <replaceable>128-bit-ID</replaceable>s are
 792                                 specified, only those entries are shown.
 793                                 </para>
 794                                 </listitem>
 795                         </varlistentry>
 796
 797                         <varlistentry>
 798                                 <term><option>--update-catalog</option></term>
 799
 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>
 806                         </varlistentry>
 807
 808                         <varlistentry>
 809                                 <term><option>--setup-keys</option></term>
 810
 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.
 826                                 </para></listitem>
 827                         </varlistentry>
 828
 829                         <varlistentry>
 830                                 <term><option>--force</option></term>
 831
 832                                 <listitem><para>When
 833                                 <option>--setup-keys</option> is passed and
 834                                 Forward Secure Sealing (FSS) has already been
 835                                 configured, recreate FSS keys.</para></listitem>
 836                         </varlistentry>
 837
 838                         <varlistentry>
 839                                 <term><option>--interval=</option></term>
 840
 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
 847                                 undetectable journal
 848                                 alterations. Defaults to
 849                                 15min.</para></listitem>
 850                         </varlistentry>
 851
 852                         <varlistentry>
 853                                 <term><option>--verify</option></term>
 854
 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>
 863                         </varlistentry>
 864
 865                         <varlistentry>
 866                                 <term><option>--verify-key=</option></term>
 867
 868                                 <listitem><para>Specifies the FSS
 869                                 verification key to use for the
 870                                 <option>--verify</option>
 871                                 operation.</para></listitem>
 872                         </varlistentry>
 873
 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" />
 877                 </variablelist>
 878         </refsect1>
 879
 880         <refsect1>
 881                 <title>Exit status</title>
 882
 883                 <para>On success, 0 is returned; otherwise, a non-zero
 884                 failure code is returned.</para>
 885         </refsect1>
 886
 887         <xi:include href="less-variables.xml" />
 888
 889         <refsect1>
 890                 <title>Examples</title>
 891
 892                 <para>Without arguments, all collected logs are shown
 893                 unfiltered:</para>
 894
 895                 <programlisting>journalctl</programlisting>
 896
 897                 <para>With one match specified, all entries with a field matching the expression are shown:</para>
 898
 899                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
 900
 901                 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
 902
 903                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
 904
 905                 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
 906
 907                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
 908
 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
 914                 processes):</para>
 915
 916                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
 917
 918                 <para>Show all logs generated by the D-Bus executable:</para>
 919
 920                 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
 921
 922                 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
 923
 924                 <programlisting>journalctl /dev/sda</programlisting>
 925
 926                 <para>Show all kernel logs from previous boot:</para>
 927
 928                 <programlisting>journalctl -k -b -1</programlisting>
 929
 930                 <para>Show a live log display from a system service <filename>apache.service</filename>:</para>
 931
 932                 <programlisting>journalctl -f -u apache</programlisting>
 933
 934         </refsect1>
 935
 936         <refsect1>
 937                 <title>See Also</title>
 938                 <para>
 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>
 945                 </para>
 946         </refsect1>
 947
 948 </refentry>