man/journalctl.xml

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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>--since=</option></term>
 527                                 <term><option>--until=</option></term>
 528
 529                                 <listitem><para>Start showing entries
 530                                 on or newer than the specified date,
 531                                 or on or older than the specified
 532                                 date, respectively. Date specifications
 533                                 should be of the format
 534                                 <literal>2012-10-30 18:17:16</literal>.
 535                                 If the time part is omitted,
 536                                 <literal>00:00:00</literal> is assumed.
 537                                 If only the seconds component is omitted,
 538                                 <literal>:00</literal> is assumed. If the
 539                                 date component is omitted, the current
 540                                 day is assumed. Alternatively the strings
 541                                 <literal>yesterday</literal>,
 542                                 <literal>today</literal>,
 543                                 <literal>tomorrow</literal> are
 544                                 understood, which refer to 00:00:00 of
 545                                 the day before the current day, the
 546                                 current day, or the day after the
 547                                 current day, respectively. <literal>now</literal>
 548                                 refers to the current time. Finally,
 549                                 relative times may be specified,
 550                                 prefixed with <literal>-</literal> or
 551                                 <literal>+</literal>, referring to
 552                                 times before or after the current
 553                                 time, respectively.</para></listitem>
 554                         </varlistentry>
 555
 556                         <varlistentry>
 557                                 <term><option>-F</option></term>
 558                                 <term><option>--field=</option></term>
 559
 560                                 <listitem><para>Print all possible
 561                                 data values the specified field can
 562                                 take in all entries of the
 563                                 journal.</para></listitem>
 564                         </varlistentry>
 565
 566                         <varlistentry>
 567                                 <term><option>--system</option></term>
 568                                 <term><option>--user</option></term>
 569
 570                                 <listitem><para>Show messages from
 571                                 system services and the kernel (with
 572                                 <option>--system</option>).  Show
 573                                 messages from service of current user
 574                                 (with <option>--user</option>).
 575                                 If neither is specified, show all
 576                                 messages that the user can see.
 577                                 </para></listitem>
 578                         </varlistentry>
 579
 580                         <varlistentry>
 581                                 <term><option>-D <replaceable>DIR</replaceable></option></term>
 582                                 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
 583
 584                                 <listitem><para>Takes a directory path
 585                                 as argument. If specified, journalctl
 586                                 will operate on the specified journal
 587                                 directory
 588                                 <replaceable>DIR</replaceable> instead
 589                                 of the default runtime and system
 590                                 journal paths.</para></listitem>
 591                         </varlistentry>
 592
 593                         <varlistentry>
 594                                 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
 595
 596                                 <listitem><para>Takes a file glob as
 597                                 argument. If specified, journalctl will
 598                                 operate on the specified journal files
 599                                 matching <replaceable>GLOB</replaceable>
 600                                 instead of the default runtime and
 601                                 system journal paths. May be specified
 602                                 multiple times, in which case files will
 603                                 be suitably interleaved.</para></listitem>
 604                         </varlistentry>
 605
 606                         <varlistentry>
 607                                 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
 608
 609                                 <listitem><para>Takes a directory path
 610                                 as argument. If specified, journalctl
 611                                 will operate on catalog file hierarchy
 612                                 underneath the specified directory
 613                                 instead of the root directory
 614                                 (e.g. <option>--update-catalog</option>
 615                                 will create
 616                                 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
 617                                 </para></listitem>
 618                         </varlistentry>
 619
 620                         <varlistentry>
 621                                 <term><option>--new-id128</option></term>
 622
 623                                 <listitem><para>Instead of showing
 624                                 journal contents, generate a new 128
 625                                 bit ID suitable for identifying
 626                                 messages. This is intended for usage
 627                                 by developers who need a new
 628                                 identifier for a new message they
 629                                 introduce and want to make
 630                                 recognizable. This will print the new ID in
 631                                 three different formats which can be
 632                                 copied into source code or
 633                                 similar.</para></listitem>
 634                         </varlistentry>
 635
 636                         <varlistentry>
 637                                 <term><option>--header</option></term>
 638
 639                                 <listitem><para>Instead of showing
 640                                 journal contents, show internal header
 641                                 information of the journal fields
 642                                 accessed.</para></listitem>
 643                         </varlistentry>
 644
 645                         <varlistentry>
 646                                 <term><option>--disk-usage</option></term>
 647
 648                                 <listitem><para>Shows the current disk
 649                                 usage of all
 650                                 journal files.</para></listitem>
 651                         </varlistentry>
 652
 653                         <varlistentry>
 654                                 <term><option>--list-catalog
 655                                 <optional><replaceable>ID128...</replaceable></optional>
 656                                 </option></term>
 657
 658                                 <listitem><para>List the contents of
 659                                 the message catalog, as table of
 660                                 message IDs plus their short
 661                                 description strings.</para>
 662
 663                                 <para>If any
 664                                 <replaceable>ID128</replaceable>s are
 665                                 specified, only those entries are shown.
 666                                 </para>
 667                                 </listitem>
 668                         </varlistentry>
 669
 670                         <varlistentry>
 671                                 <term><option>--dump-catalog
 672                                 <optional><replaceable>ID128...</replaceable></optional>
 673                                 </option></term>
 674
 675                                 <listitem><para>Show the contents of
 676                                 the message catalog, with entries
 677                                 separated by a line consisting of two
 678                                 dashes and the id (the format is the
 679                                 same as <filename>.catalog</filename>
 680                                 files.</para>
 681
 682                                 <para>If any
 683                                 <replaceable>ID128</replaceable>s are
 684                                 specified, only those entries are shown.
 685                                 </para>
 686                                 </listitem>
 687                         </varlistentry>
 688
 689                         <varlistentry>
 690                                 <term><option>--update-catalog</option></term>
 691
 692                                 <listitem><para>Update the message
 693                                 catalog index. This command needs to
 694                                 be executed each time new catalog
 695                                 files are installed, removed or
 696                                 updated to rebuild the binary catalog
 697                                 index.</para></listitem>
 698                         </varlistentry>
 699
 700                         <varlistentry>
 701                                 <term><option>--setup-keys</option></term>
 702
 703                                 <listitem><para>Instead of showing
 704                                 journal contents, generate a new key
 705                                 pair for Forward Secure Sealing
 706                                 (FSS). This will generate a sealing
 707                                 key and a verification key. The
 708                                 sealing key is stored in the journal
 709                                 data directory and shall remain on the
 710                                 host. The verification key should be
 711                                 stored externally. Also see the
 712                                 <option>Seal=</option> option in
 713                                 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 714                                 for details.</para></listitem>
 715                         </varlistentry>
 716
 717                         <varlistentry>
 718                                 <term><option>--force</option></term>
 719
 720                                 <listitem><para>When --setup-keys is passed and
 721                                 Forward Secure Sealing has already been set up,
 722                                 recreate FSS keys.</para></listitem>
 723                         </varlistentry>
 724
 725                         <varlistentry>
 726                                 <term><option>--interval=</option></term>
 727
 728                                 <listitem><para>Specifies the change
 729                                 interval for the sealing key when
 730                                 generating an FSS key pair with
 731                                 <option>--setup-keys</option>. Shorter
 732                                 intervals increase CPU consumption but
 733                                 shorten the time range of
 734                                 undetectable journal
 735                                 alterations. Defaults to
 736                                 15min.</para></listitem>
 737                         </varlistentry>
 738
 739                         <varlistentry>
 740                                 <term><option>--verify</option></term>
 741
 742                                 <listitem><para>Check the journal file
 743                                 for internal consistency. If the
 744                                 file has been generated with FSS
 745                                 enabled and the FSS verification key
 746                                 has been specified with
 747                                 <option>--verify-key=</option>,
 748                                 authenticity of the journal file is
 749                                 verified.</para></listitem>
 750                         </varlistentry>
 751
 752                         <varlistentry>
 753                                 <term><option>--verify-key=</option></term>
 754
 755                                 <listitem><para>Specifies the FSS
 756                                 verification key to use for the
 757                                 <option>--verify</option>
 758                                 operation.</para></listitem>
 759                         </varlistentry>
 760
 761                 </variablelist>
 762         </refsect1>
 763
 764         <refsect1>
 765                 <title>Exit status</title>
 766
 767                 <para>On success, 0 is returned, a non-zero failure
 768                 code otherwise.</para>
 769         </refsect1>
 770
 771         <refsect1>
 772                 <title>Environment</title>
 773
 774                 <variablelist class='environment-variables'>
 775                         <varlistentry>
 776                                 <term><varname>$SYSTEMD_PAGER</varname></term>
 777                                 <listitem><para>Pager to use when
 778                                 <option>--no-pager</option> is not given;
 779                                 overrides <varname>$PAGER</varname>.  Setting
 780                                 this to an empty string or the value
 781                                 <literal>cat</literal> is equivalent to passing
 782                                 <option>--no-pager</option>.</para></listitem>
 783                         </varlistentry>
 784                 </variablelist>
 785         </refsect1>
 786
 787         <refsect1>
 788                 <title>Examples</title>
 789
 790                 <para>Without arguments, all collected logs are shown
 791                 unfiltered:</para>
 792
 793                 <programlisting>journalctl</programlisting>
 794
 795                 <para>With one match specified, all entries with a field matching the expression are shown:</para>
 796
 797                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
 798
 799                 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
 800
 801                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
 802
 803                 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
 804
 805                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
 806
 807                 <para>If the separator <literal>+</literal> is used,
 808                 two expressions may be combined in a logical OR. The
 809                 following will show all messages from the Avahi
 810                 service process with the PID 28097 plus all messages
 811                 from the D-Bus service (from any of its
 812                 processes):</para>
 813
 814                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
 815
 816                 <para>Show all logs generated by the D-Bus executable:</para>
 817
 818                 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
 819
 820                 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
 821
 822                 <programlisting>journalctl /dev/sda</programlisting>
 823
 824                 <para>Show all kernel logs from last boot:</para>
 825
 826                 <programlisting>journalctl -k -b :</programlisting>
 827
 828         </refsect1>
 829
 830         <refsect1>
 831                 <title>See Also</title>
 832                 <para>
 833                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 834                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 835                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 836                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 837                         <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 838                 </para>
 839         </refsect1>
 840
 841 </refentry>