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
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  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
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  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
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  23
  24 <refentry id="journalctl">
  25
  26         <refentryinfo>
  27                 <title>journalctl</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>journalctl</refentrytitle>
  42                 <manvolnum>1</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>journalctl</refname>
  47                 <refpurpose>Query the systemd journal</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <cmdsynopsis>
  52                         <command>journalctl</command>
  53                         <arg choice="opt" rep="repeat">OPTIONS</arg>
  54                         <arg choice="opt" rep="repeat">MATCHES</arg>
  55                 </cmdsynopsis>
  56         </refsynopsisdiv>
  57
  58         <refsect1>
  59                 <title>Description</title>
  60
  61                 <para><command>journalctl</command> may be used to
  62                 query the contents of the
  63                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  64                 journal as written by
  65                 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
  66
  67                 <para>If called without parameters, it will show the full
  68                 contents of the journal, starting with the oldest
  69                 entry collected.</para>
  70
  71                 <para>If one or more match arguments are passed, the
  72                 output is filtered accordingly. A match is in the
  73                 format <literal>FIELD=VALUE</literal>,
  74                 e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>,
  75                 referring to the components of a structured journal
  76                 entry. See
  77                 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
  78                 for a list of well-known fields. If multiple matches
  79                 are specified matching different fields, the log
  80                 entries are filtered by both, i.e. the resulting output
  81                 will show only entries matching all the specified
  82                 matches of this kind. If two matches apply to the same
  83                 field, then they are automatically matched as
  84                 alternatives, i.e. the resulting output will show
  85                 entries matching any of the specified matches for the
  86                 same field. Finally, if the character
  87                 <literal>+</literal> appears as separate word on the
  88                 command line, all matches before and after are combined
  89                 in a disjunction (i.e. logical OR).</para>
  90
  91                 <para>As shortcuts for a few types of field/value
  92                 matches, file paths may be specified. If a file path
  93                 refers to an executable file, this is equivalent to an
  94                 <literal>_EXE=</literal> match for the canonicalized
  95                 binary path. Similarly, if a path refers to a device
  96                 node, this is equivalent to a
  97                 <literal>_KERNEL_DEVICE=</literal> match for the
  98                 device.</para>
  99
 100                 <para>Output is interleaved from all accessible
 101                 journal files, whether they are rotated or currently
 102                 being written, and regardless of whether they belong to the
 103                 system itself or are accessible user journals.</para>
 104
 105                 <para>All users are granted access to their private
 106                 per-user journals. However, by default, only root and
 107                 users who are members of the <literal>adm</literal>
 108                 group get access to the system journal and the
 109                 journals of other users.</para>
 110
 111                 <para>The output is paged through
 112                 <command>less</command> by default, and long lines are
 113                 "truncated" to screen width. The hidden part can be
 114                 viewed by using the left-arrow and right-arrow
 115                 keys. Paging can be disabled, see
 116                 <option>--no-pager</option> and section Environment
 117                 below.</para>
 118
 119                 <para>When outputing to a tty, lines are colored
 120                 according to priority: lines of level ERROR and higher
 121                 are colored red, lines of level NOTICE and higher are
 122                 highlighted, and other lines are displayed normally.
 123                 </para>
 124         </refsect1>
 125
 126         <refsect1>
 127                 <title>Options</title>
 128
 129                 <para>The following options are understood:</para>
 130
 131                 <variablelist>
 132                         <varlistentry>
 133                                 <term><option>-h</option></term>
 134                                 <term><option>--help</option></term>
 135
 136                                 <listitem><para>Prints a short help
 137                                 text and exits.</para></listitem>
 138                         </varlistentry>
 139
 140                         <varlistentry>
 141                                 <term><option>--version</option></term>
 142
 143                                 <listitem><para>Prints a short version
 144                                 string and exits.</para></listitem>
 145                         </varlistentry>
 146
 147                         <varlistentry>
 148                                 <term><option>--no-pager</option></term>
 149
 150                                 <listitem><para>Do not pipe output into a
 151                                 pager.</para></listitem>
 152                         </varlistentry>
 153
 154                         <varlistentry>
 155                                 <term><option>-l</option></term>
 156                                 <term><option>--full</option></term>
 157
 158                                 <listitem><para>Show all (printable) fields in
 159                                 full.</para></listitem>
 160                         </varlistentry>
 161
 162                         <varlistentry>
 163                                 <term><option>-a</option></term>
 164                                 <term><option>--all</option></term>
 165
 166                                 <listitem><para>Show all fields in
 167                                 full, even if they include unprintable
 168                                 characters or are very
 169                                 long.</para></listitem>
 170                         </varlistentry>
 171
 172                         <varlistentry>
 173                                 <term><option>-f</option></term>
 174                                 <term><option>--follow</option></term>
 175
 176                                 <listitem><para>Show only the most recent
 177                                 journal entries, and continuously print
 178                                 new entries as they are appended to
 179                                 the journal.</para></listitem>
 180                         </varlistentry>
 181
 182                         <varlistentry>
 183                                 <term><option>-e</option></term>
 184                                 <term><option>--pager-end</option></term>
 185
 186                                 <listitem><para>Immediately jump to
 187                                 the end of the journal inside the
 188                                 implied pager tool. This implies
 189                                 <option>-n1000</option> to guarantee
 190                                 that the pager will not buffer logs of
 191                                 unbounded size. This may be overridden
 192                                 with an explicit <option>-n</option>
 193                                 with some other numeric value on the
 194                                 command line. Note that this option is
 195                                 only supported for the
 196                                 <citerefentry><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 197                                 pager.</para></listitem>
 198                         </varlistentry>
 199
 200                         <varlistentry>
 201                                 <term><option>-n</option></term>
 202                                 <term><option>--lines=</option></term>
 203
 204                                 <listitem><para>Show the most recent
 205                                 journal events and limit the number of
 206                                 events shown. If
 207                                 <option>--follow</option> is used,
 208                                 this option is implied. The argument,
 209                                 a positive integer, is optional, and
 210                                 defaults to 10. </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 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-monotonic</option>
 257                                                 </term>
 258                                                 <listitem>
 259                                                         <para>is very similar
 260                                                         but shows monotonic
 261                                                         timestamps instead of
 262                                                         wallclock timestamps.
 263                                                         </para>
 264                                                 </listitem>
 265                                         </varlistentry>
 266
 267                                         <varlistentry>
 268                                                 <term>
 269                                                         <option>verbose</option>
 270                                                 </term>
 271                                                 <listitem>
 272                                                         <para>shows the
 273                                                         full-structured entry
 274                                                         items with all fields.
 275                                                         </para>
 276                                                 </listitem>
 277                                         </varlistentry>
 278
 279                                         <varlistentry>
 280                                                 <term>
 281                                                         <option>export</option>
 282                                                 </term>
 283                                                 <listitem>
 284                                                         <para>serializes the
 285                                                         journal into a binary
 286                                                         (but mostly text-based)
 287                                                         stream suitable for
 288                                                         backups and network
 289                                                         transfer (see <ulink
 290                                                         url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
 291                                                         Export Format</ulink>
 292                                                         for more
 293                                                         information).</para>
 294                                                 </listitem>
 295                                         </varlistentry>
 296
 297                                         <varlistentry>
 298                                                 <term>
 299                                                         <option>json</option>
 300                                                 </term>
 301                                                 <listitem>
 302                                                         <para>formats entries
 303                                                         as JSON data structures,
 304                                                         one per line (see <ulink
 305                                                         url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
 306                                                         JSON Format</ulink> for
 307                                                         more information).</para>
 308                                                 </listitem>
 309                                         </varlistentry>
 310
 311                                         <varlistentry>
 312                                                 <term>
 313                                                         <option>json-pretty</option>
 314                                                 </term>
 315                                                 <listitem>
 316                                                         <para>formats entries as
 317                                                         JSON data structures,
 318                                                         but formats them in
 319                                                         multiple lines in order
 320                                                         to make them more
 321                                                         readable for humans.</para>
 322                                                 </listitem>
 323                                         </varlistentry>
 324
 325                                         <varlistentry>
 326                                                 <term>
 327                                                         <option>json-sse</option>
 328                                                 </term>
 329                                                 <listitem>
 330                                                         <para>formats entries as
 331                                                         JSON data structures,
 332                                                         but wraps them in a
 333                                                         format suitable for <ulink
 334                                                         url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
 335                                                         Events</ulink>.</para>
 336                                                 </listitem>
 337                                         </varlistentry>
 338
 339                                         <varlistentry>
 340                                                 <term>
 341                                                         <option>cat</option>
 342                                                 </term>
 343                                                 <listitem>
 344                                                         <para>generates a very
 345                                                         terse output only
 346                                                         showing the actual
 347                                                         message of each journal
 348                                                         entry with no meta data,
 349                                                         not even a timestamp.
 350                                                         </para>
 351                                                 </listitem>
 352                                         </varlistentry>
 353                                 </variablelist>
 354                                 </listitem>
 355                         </varlistentry>
 356
 357                         <varlistentry>
 358                                 <term><option>-x</option></term>
 359                                 <term><option>--catalog</option></term>
 360
 361                                 <listitem><para>Augment log lines with
 362                                 explanation texts from the message
 363                                 catalog. This will add explanatory
 364                                 help texts to log messages in the
 365                                 output where this is available. These
 366                                 short help texts will explain the
 367                                 context of an error or log event,
 368                                 possible solutions, as well as
 369                                 pointers to support forums, developer
 370                                 documentation and any other relevant
 371                                 manuals. Note that help texts are not
 372                                 available for all messages, but only
 373                                 for selected ones. For more
 374                                 information on the message catalog,
 375                                 please refer to the <ulink
 376                                 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
 377                                 Catalog Developer
 378                                 Documentation</ulink>.</para></listitem>
 379                         </varlistentry>
 380
 381                         <varlistentry>
 382                                 <term><option>-q</option></term>
 383                                 <term><option>--quiet</option></term>
 384
 385                                 <listitem><para>Suppresses any warning
 386                                 message regarding inaccessible system
 387                                 journals when run as normal
 388                                 user.</para></listitem>
 389                         </varlistentry>
 390
 391                         <varlistentry>
 392                                 <term><option>-m</option></term>
 393                                 <term><option>--merge</option></term>
 394
 395                                 <listitem><para>Show entries
 396                                 interleaved from all available
 397                                 journals, including remote
 398                                 ones.</para></listitem>
 399                         </varlistentry>
 400
 401                         <varlistentry>
 402                                 <term><option>-b <optional><replaceable>ID</replaceable></optional></option></term>
 403                                 <term><option>--boot=<optional><replaceable>ID</replaceable></optional></option></term>
 404
 405                                 <listitem><para>Show messages from the specified
 406                                 boot <replaceable>ID</replaceable> or from
 407                                 current boot if no <replaceable>ID</replaceable>
 408                                 is given. This will add a match for
 409                                 <literal>_BOOT_ID=</literal>.</para>
 410
 411                                 <para>The argument is a 128 bit ID given in
 412                                 short or UUID form and optionally followed by
 413                                 <literal>:n</literal> which identifies the nth
 414                                 boot relative to the boot ID given to the left
 415                                 of <literal>:</literal>. Supplying a negative
 416                                 value for n will look for a past boot and a
 417                                 positive value for a future boot. The boot IDs
 418                                 are searched for in chronological order. If no
 419                                 number is provided after <literal>:</literal>,
 420                                 <literal>-1</literal> is assumed. A value of 0
 421                                 is valid and equivalent to omitting
 422                                 <literal>:0</literal>.</para>
 423
 424                                 <para>Alternatively, the argument may constist
 425                                 only of <literal>:n</literal>. In this case, a
 426                                 positive value will look up the nth boot
 427                                 starting from the beginning of the jouranl, a
 428                                 negative value will look up a previous boot
 429                                 relative to the current boot. <literal>:0</literal>
 430                                 will look for the current boot ID. Thus,
 431                                 <literal>:1</literal> is the first boot found in
 432                                 the journal, <literal>:2</literal> the second
 433                                 and so on; while <literal>:-1</literal> is the
 434                                 previous boot, <literal>:-2</literal> the boot
 435                                 before that and so on. Omitting a value after
 436                                 <literal>:</literal> will look for the previous
 437                                 boot.</para></listitem>
 438                         </varlistentry>
 439
 440                         <varlistentry>
 441                                 <term><option>-k</option></term>
 442                                 <term><option>--dmesg</option></term>
 443
 444                                 <listitem><para>Show only kernel messages. This
 445                                 implies <option>-b</option> and adds the match
 446                                 <literal>_TRANSPORT=kernel</literal>.
 447                                 </para></listitem>
 448                         </varlistentry>
 449
 450                         <varlistentry>
 451                                 <term><option>-u</option></term>
 452                                 <term><option>--unit=</option></term>
 453
 454                                 <listitem><para>Show messages for the
 455                                 specified systemd unit. This will add
 456                                 a match for messages from the unit
 457                                 (<literal>_SYSTEMD_UNIT=</literal>)
 458                                 and additional matches for messages
 459                                 from systemd and messages about
 460                                 coredumps for the specified unit.</para>
 461                                 <para>This parameter can be specified multiple times.
 462                                 </para></listitem>
 463                         </varlistentry>
 464
 465                         <varlistentry>
 466                                 <term><option>--user-unit=</option></term>
 467
 468                                 <listitem><para>Show messages for the
 469                                 specified user session unit. This will
 470                                 add a match for messages from the unit
 471                                 (<literal>_SYSTEMD_USER_UNIT=</literal>
 472                                 and <literal>_UID=</literal>) and
 473                                 additional matches for messages from
 474                                 session systemd and messages about
 475                                 coredumps for the specified unit.</para>
 476                                 <para>This parameter can be specified multiple times.
 477                                 </para></listitem>
 478                         </varlistentry>
 479
 480                         <varlistentry>
 481                                 <term><option>-p</option></term>
 482                                 <term><option>--priority=</option></term>
 483
 484                                 <listitem><para>Filter output by
 485                                 message priorities or priority
 486                                 ranges. Takes either a single numeric
 487                                 or textual log level (i.e. between
 488                                 0/<literal>emerg</literal> and
 489                                 7/<literal>debug</literal>), or a
 490                                 range of numeric/text log levels in
 491                                 the form FROM..TO. The log levels are
 492                                 the usual syslog log levels as
 493                                 documented in
 494                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 495                                 i.e. <literal>emerg</literal> (0),
 496                                 <literal>alert</literal> (1),
 497                                 <literal>crit</literal> (2),
 498                                 <literal>err</literal> (3),
 499                                 <literal>warning</literal> (4),
 500                                 <literal>notice</literal> (5),
 501                                 <literal>info</literal> (6),
 502                                 <literal>debug</literal> (7). If a
 503                                 single log level is specified, all
 504                                 messages with this log level or a
 505                                 lower (hence more important) log level
 506                                 are shown. If a range is specified, all
 507                                 messages within the range are shown,
 508                                 including both the start and the end
 509                                 value of the range. This will add
 510                                 <literal>PRIORITY=</literal> matches
 511                                 for the specified
 512                                 priorities.</para></listitem>
 513                         </varlistentry>
 514
 515                         <varlistentry>
 516                                 <term><option>-c</option></term>
 517                                 <term><option>--cursor=</option></term>
 518
 519                                 <listitem><para>Start showing entries
 520                                 from the location in the journal
 521                                 specified by the passed
 522                                 cursor.</para></listitem>
 523                         </varlistentry>
 524
 525                         <varlistentry>
 526                                 <term><option>--after-cursor=</option></term>
 527
 528                                 <listitem><para>Start showing entries from the
 529                                 location in the journal
 530                                 <emphasis>after</emphasis> the location
 531                                 specified by the this cursor.
 532                                 </para></listitem>
 533                         </varlistentry>
 534
 535                         <varlistentry>
 536                                 <term><option>--since=</option></term>
 537                                 <term><option>--until=</option></term>
 538
 539                                 <listitem><para>Start showing entries
 540                                 on or newer than the specified date,
 541                                 or on or older than the specified
 542                                 date, respectively. Date specifications
 543                                 should be of the format
 544                                 <literal>2012-10-30 18:17:16</literal>.
 545                                 If the time part is omitted,
 546                                 <literal>00:00:00</literal> is assumed.
 547                                 If only the seconds component is omitted,
 548                                 <literal>:00</literal> is assumed. If the
 549                                 date component is omitted, the current
 550                                 day is assumed. Alternatively the strings
 551                                 <literal>yesterday</literal>,
 552                                 <literal>today</literal>,
 553                                 <literal>tomorrow</literal> are
 554                                 understood, which refer to 00:00:00 of
 555                                 the day before the current day, the
 556                                 current day, or the day after the
 557                                 current day, respectively. <literal>now</literal>
 558                                 refers to the current time. Finally,
 559                                 relative times may be specified,
 560                                 prefixed with <literal>-</literal> or
 561                                 <literal>+</literal>, referring to
 562                                 times before or after the current
 563                                 time, respectively.</para></listitem>
 564                         </varlistentry>
 565
 566                         <varlistentry>
 567                                 <term><option>-F</option></term>
 568                                 <term><option>--field=</option></term>
 569
 570                                 <listitem><para>Print all possible
 571                                 data values the specified field can
 572                                 take in all entries of the
 573                                 journal.</para></listitem>
 574                         </varlistentry>
 575
 576                         <varlistentry>
 577                                 <term><option>--system</option></term>
 578                                 <term><option>--user</option></term>
 579
 580                                 <listitem><para>Show messages from
 581                                 system services and the kernel (with
 582                                 <option>--system</option>).  Show
 583                                 messages from service of current user
 584                                 (with <option>--user</option>).
 585                                 If neither is specified, show all
 586                                 messages that the user can see.
 587                                 </para></listitem>
 588                         </varlistentry>
 589
 590                         <varlistentry>
 591                                 <term><option>-D <replaceable>DIR</replaceable></option></term>
 592                                 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
 593
 594                                 <listitem><para>Takes a directory path
 595                                 as argument. If specified, journalctl
 596                                 will operate on the specified journal
 597                                 directory
 598                                 <replaceable>DIR</replaceable> instead
 599                                 of the default runtime and system
 600                                 journal paths.</para></listitem>
 601                         </varlistentry>
 602
 603                         <varlistentry>
 604                                 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
 605
 606                                 <listitem><para>Takes a file glob as
 607                                 argument. If specified, journalctl will
 608                                 operate on the specified journal files
 609                                 matching <replaceable>GLOB</replaceable>
 610                                 instead of the default runtime and
 611                                 system journal paths. May be specified
 612                                 multiple times, in which case files will
 613                                 be suitably interleaved.</para></listitem>
 614                         </varlistentry>
 615
 616                         <varlistentry>
 617                                 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
 618
 619                                 <listitem><para>Takes a directory path
 620                                 as argument. If specified, journalctl
 621                                 will operate on catalog file hierarchy
 622                                 underneath the specified directory
 623                                 instead of the root directory
 624                                 (e.g. <option>--update-catalog</option>
 625                                 will create
 626                                 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
 627                                 </para></listitem>
 628                         </varlistentry>
 629
 630                         <varlistentry>
 631                                 <term><option>--new-id128</option></term>
 632
 633                                 <listitem><para>Instead of showing
 634                                 journal contents, generate a new 128
 635                                 bit ID suitable for identifying
 636                                 messages. This is intended for usage
 637                                 by developers who need a new
 638                                 identifier for a new message they
 639                                 introduce and want to make
 640                                 recognizable. This will print the new ID in
 641                                 three different formats which can be
 642                                 copied into source code or
 643                                 similar.</para></listitem>
 644                         </varlistentry>
 645
 646                         <varlistentry>
 647                                 <term><option>--header</option></term>
 648
 649                                 <listitem><para>Instead of showing
 650                                 journal contents, show internal header
 651                                 information of the journal fields
 652                                 accessed.</para></listitem>
 653                         </varlistentry>
 654
 655                         <varlistentry>
 656                                 <term><option>--disk-usage</option></term>
 657
 658                                 <listitem><para>Shows the current disk
 659                                 usage of all
 660                                 journal files.</para></listitem>
 661                         </varlistentry>
 662
 663                         <varlistentry>
 664                                 <term><option>--list-catalog
 665                                 <optional><replaceable>ID128...</replaceable></optional>
 666                                 </option></term>
 667
 668                                 <listitem><para>List the contents of
 669                                 the message catalog, as table of
 670                                 message IDs plus their short
 671                                 description strings.</para>
 672
 673                                 <para>If any
 674                                 <replaceable>ID128</replaceable>s are
 675                                 specified, only those entries are shown.
 676                                 </para>
 677                                 </listitem>
 678                         </varlistentry>
 679
 680                         <varlistentry>
 681                                 <term><option>--dump-catalog
 682                                 <optional><replaceable>ID128...</replaceable></optional>
 683                                 </option></term>
 684
 685                                 <listitem><para>Show the contents of
 686                                 the message catalog, with entries
 687                                 separated by a line consisting of two
 688                                 dashes and the id (the format is the
 689                                 same as <filename>.catalog</filename>
 690                                 files.</para>
 691
 692                                 <para>If any
 693                                 <replaceable>ID128</replaceable>s are
 694                                 specified, only those entries are shown.
 695                                 </para>
 696                                 </listitem>
 697                         </varlistentry>
 698
 699                         <varlistentry>
 700                                 <term><option>--update-catalog</option></term>
 701
 702                                 <listitem><para>Update the message
 703                                 catalog index. This command needs to
 704                                 be executed each time new catalog
 705                                 files are installed, removed or
 706                                 updated to rebuild the binary catalog
 707                                 index.</para></listitem>
 708                         </varlistentry>
 709
 710                         <varlistentry>
 711                                 <term><option>--setup-keys</option></term>
 712
 713                                 <listitem><para>Instead of showing
 714                                 journal contents, generate a new key
 715                                 pair for Forward Secure Sealing
 716                                 (FSS). This will generate a sealing
 717                                 key and a verification key. The
 718                                 sealing key is stored in the journal
 719                                 data directory and shall remain on the
 720                                 host. The verification key should be
 721                                 stored externally. Also see the
 722                                 <option>Seal=</option> option in
 723                                 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 724                                 for details.</para></listitem>
 725                         </varlistentry>
 726
 727                         <varlistentry>
 728                                 <term><option>--force</option></term>
 729
 730                                 <listitem><para>When --setup-keys is passed and
 731                                 Forward Secure Sealing has already been set up,
 732                                 recreate FSS keys.</para></listitem>
 733                         </varlistentry>
 734
 735                         <varlistentry>
 736                                 <term><option>--interval=</option></term>
 737
 738                                 <listitem><para>Specifies the change
 739                                 interval for the sealing key when
 740                                 generating an FSS key pair with
 741                                 <option>--setup-keys</option>. Shorter
 742                                 intervals increase CPU consumption but
 743                                 shorten the time range of
 744                                 undetectable journal
 745                                 alterations. Defaults to
 746                                 15min.</para></listitem>
 747                         </varlistentry>
 748
 749                         <varlistentry>
 750                                 <term><option>--verify</option></term>
 751
 752                                 <listitem><para>Check the journal file
 753                                 for internal consistency. If the
 754                                 file has been generated with FSS
 755                                 enabled and the FSS verification key
 756                                 has been specified with
 757                                 <option>--verify-key=</option>,
 758                                 authenticity of the journal file is
 759                                 verified.</para></listitem>
 760                         </varlistentry>
 761
 762                         <varlistentry>
 763                                 <term><option>--verify-key=</option></term>
 764
 765                                 <listitem><para>Specifies the FSS
 766                                 verification key to use for the
 767                                 <option>--verify</option>
 768                                 operation.</para></listitem>
 769                         </varlistentry>
 770
 771                 </variablelist>
 772         </refsect1>
 773
 774         <refsect1>
 775                 <title>Exit status</title>
 776
 777                 <para>On success, 0 is returned, a non-zero failure
 778                 code otherwise.</para>
 779         </refsect1>
 780
 781         <refsect1>
 782                 <title>Environment</title>
 783
 784                 <variablelist class='environment-variables'>
 785                         <varlistentry>
 786                                 <term><varname>$SYSTEMD_PAGER</varname></term>
 787                                 <listitem><para>Pager to use when
 788                                 <option>--no-pager</option> is not given;
 789                                 overrides <varname>$PAGER</varname>.  Setting
 790                                 this to an empty string or the value
 791                                 <literal>cat</literal> is equivalent to passing
 792                                 <option>--no-pager</option>.</para></listitem>
 793                         </varlistentry>
 794                 </variablelist>
 795         </refsect1>
 796
 797         <refsect1>
 798                 <title>Examples</title>
 799
 800                 <para>Without arguments, all collected logs are shown
 801                 unfiltered:</para>
 802
 803                 <programlisting>journalctl</programlisting>
 804
 805                 <para>With one match specified, all entries with a field matching the expression are shown:</para>
 806
 807                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
 808
 809                 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
 810
 811                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
 812
 813                 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
 814
 815                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
 816
 817                 <para>If the separator <literal>+</literal> is used,
 818                 two expressions may be combined in a logical OR. The
 819                 following will show all messages from the Avahi
 820                 service process with the PID 28097 plus all messages
 821                 from the D-Bus service (from any of its
 822                 processes):</para>
 823
 824                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
 825
 826                 <para>Show all logs generated by the D-Bus executable:</para>
 827
 828                 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
 829
 830                 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
 831
 832                 <programlisting>journalctl /dev/sda</programlisting>
 833
 834                 <para>Show all kernel logs from last boot:</para>
 835
 836                 <programlisting>journalctl -k -b :</programlisting>
 837
 838         </refsect1>
 839
 840         <refsect1>
 841                 <title>See Also</title>
 842                 <para>
 843                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 844                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 845                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 846                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 847                         <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 848                 </para>
 849         </refsect1>
 850
 851 </refentry>