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
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 -->
  23
  24 <refentry id="journalctl">
  25
  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><optional><replaceable>±offset</replaceable></optional></option></term>
 403                                 <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
 404
 405                                 <listitem><para>Show messages from a specific
 406                                 boot. This will add a match for
 407                                 <literal>_BOOT_ID=</literal>.</para>
 408
 409                                 <para>The argument may be empty, in which case
 410                                 logs for the current boot will be shown.</para>
 411
 412                                 <para>If the boot ID is omitted, a positive
 413                                 <replaceable>offset</replaceable> will look up
 414                                 the boots starting from the beginning of the
 415                                 journal, and a equal-or-less-than zero
 416                                 <replaceable>offset</replaceable> will look up
 417                                 boots starting from the end of the
 418                                 journal. Thus, <constant>1</constant> means the
 419                                 first boot found in the journal in the
 420                                 chronological order, <constant>2</constant> the
 421                                 second and so on; while <constant>-0</constant>
 422                                 is the last boot, <constant>-1</constant> the
 423                                 boot before that, and so on. An empty
 424                                 <replaceable>offset</replaceable> is equivalent
 425                                 to specifying <constant>-0</constant>, except
 426                                 when the current boot is not the last boot
 427                                 (e.g. because <option>--directory</option> was
 428                                 specified to look at logs from a different
 429                                 machine).</para>
 430
 431                                 <para>If the 32 character
 432                                 <replaceable>ID</replaceable> is specified, it
 433                                 may optionally be followed by
 434                                 <replaceable>offset</replaceable> which
 435                                 identifies the boot relative to the one given by
 436                                 boot <replaceable>ID</replaceable>. Negative
 437                                 values mean earlier boots and a positive values
 438                                 mean later boots. If
 439                                 <replaceable>offset</replaceable> is not
 440                                 specified, a value of zero is assumed and the
 441                                 logs for the boot given by
 442                                 <replaceable>ID</replaceable> are shown.
 443                                 </para>
 444
 445                                 </listitem>
 446                         </varlistentry>
 447
 448                         <varlistentry>
 449                                 <term><option>-k</option></term>
 450                                 <term><option>--dmesg</option></term>
 451
 452                                 <listitem><para>Show only kernel messages. This
 453                                 implies <option>-b</option> and adds the match
 454                                 <literal>_TRANSPORT=kernel</literal>.
 455                                 </para></listitem>
 456                         </varlistentry>
 457
 458                         <varlistentry>
 459                                 <term><option>-u</option></term>
 460                                 <term><option>--unit=</option></term>
 461
 462                                 <listitem><para>Show messages for the
 463                                 specified systemd unit. This will add
 464                                 a match for messages from the unit
 465                                 (<literal>_SYSTEMD_UNIT=</literal>)
 466                                 and additional matches for messages
 467                                 from systemd and messages about
 468                                 coredumps for the specified unit.</para>
 469                                 <para>This parameter can be specified multiple times.
 470                                 </para></listitem>
 471                         </varlistentry>
 472
 473                         <varlistentry>
 474                                 <term><option>--user-unit=</option></term>
 475
 476                                 <listitem><para>Show messages for the
 477                                 specified user session unit. This will
 478                                 add a match for messages from the unit
 479                                 (<literal>_SYSTEMD_USER_UNIT=</literal>
 480                                 and <literal>_UID=</literal>) and
 481                                 additional matches for messages from
 482                                 session systemd and messages about
 483                                 coredumps for the specified unit.</para>
 484                                 <para>This parameter can be specified multiple times.
 485                                 </para></listitem>
 486                         </varlistentry>
 487
 488                         <varlistentry>
 489                                 <term><option>-p</option></term>
 490                                 <term><option>--priority=</option></term>
 491
 492                                 <listitem><para>Filter output by
 493                                 message priorities or priority
 494                                 ranges. Takes either a single numeric
 495                                 or textual log level (i.e. between
 496                                 0/<literal>emerg</literal> and
 497                                 7/<literal>debug</literal>), or a
 498                                 range of numeric/text log levels in
 499                                 the form FROM..TO. The log levels are
 500                                 the usual syslog log levels as
 501                                 documented in
 502                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 503                                 i.e. <literal>emerg</literal> (0),
 504                                 <literal>alert</literal> (1),
 505                                 <literal>crit</literal> (2),
 506                                 <literal>err</literal> (3),
 507                                 <literal>warning</literal> (4),
 508                                 <literal>notice</literal> (5),
 509                                 <literal>info</literal> (6),
 510                                 <literal>debug</literal> (7). If a
 511                                 single log level is specified, all
 512                                 messages with this log level or a
 513                                 lower (hence more important) log level
 514                                 are shown. If a range is specified, all
 515                                 messages within the range are shown,
 516                                 including both the start and the end
 517                                 value of the range. This will add
 518                                 <literal>PRIORITY=</literal> matches
 519                                 for the specified
 520                                 priorities.</para></listitem>
 521                         </varlistentry>
 522
 523                         <varlistentry>
 524                                 <term><option>-c</option></term>
 525                                 <term><option>--cursor=</option></term>
 526
 527                                 <listitem><para>Start showing entries
 528                                 from the location in the journal
 529                                 specified by the passed
 530                                 cursor.</para></listitem>
 531                         </varlistentry>
 532
 533                         <varlistentry>
 534                                 <term><option>--after-cursor=</option></term>
 535
 536                                 <listitem><para>Start showing entries from the
 537                                 location in the journal
 538                                 <emphasis>after</emphasis> the location
 539                                 specified by the this cursor.
 540                                 </para></listitem>
 541                         </varlistentry>
 542
 543                         <varlistentry>
 544                                 <term><option>--since=</option></term>
 545                                 <term><option>--until=</option></term>
 546
 547                                 <listitem><para>Start showing entries
 548                                 on or newer than the specified date,
 549                                 or on or older than the specified
 550                                 date, respectively. Date specifications
 551                                 should be of the format
 552                                 <literal>2012-10-30 18:17:16</literal>.
 553                                 If the time part is omitted,
 554                                 <literal>00:00:00</literal> is assumed.
 555                                 If only the seconds component is omitted,
 556                                 <literal>:00</literal> is assumed. If the
 557                                 date component is omitted, the current
 558                                 day is assumed. Alternatively the strings
 559                                 <literal>yesterday</literal>,
 560                                 <literal>today</literal>,
 561                                 <literal>tomorrow</literal> are
 562                                 understood, which refer to 00:00:00 of
 563                                 the day before the current day, the
 564                                 current day, or the day after the
 565                                 current day, respectively. <literal>now</literal>
 566                                 refers to the current time. Finally,
 567                                 relative times may be specified,
 568                                 prefixed with <literal>-</literal> or
 569                                 <literal>+</literal>, referring to
 570                                 times before or after the current
 571                                 time, respectively.</para></listitem>
 572                         </varlistentry>
 573
 574                         <varlistentry>
 575                                 <term><option>-F</option></term>
 576                                 <term><option>--field=</option></term>
 577
 578                                 <listitem><para>Print all possible
 579                                 data values the specified field can
 580                                 take in all entries of the
 581                                 journal.</para></listitem>
 582                         </varlistentry>
 583
 584                         <varlistentry>
 585                                 <term><option>--system</option></term>
 586                                 <term><option>--user</option></term>
 587
 588                                 <listitem><para>Show messages from
 589                                 system services and the kernel (with
 590                                 <option>--system</option>).  Show
 591                                 messages from service of current user
 592                                 (with <option>--user</option>).
 593                                 If neither is specified, show all
 594                                 messages that the user can see.
 595                                 </para></listitem>
 596                         </varlistentry>
 597
 598                         <varlistentry>
 599                                 <term><option>-D <replaceable>DIR</replaceable></option></term>
 600                                 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
 601
 602                                 <listitem><para>Takes a directory path
 603                                 as argument. If specified, journalctl
 604                                 will operate on the specified journal
 605                                 directory
 606                                 <replaceable>DIR</replaceable> instead
 607                                 of the default runtime and system
 608                                 journal paths.</para></listitem>
 609                         </varlistentry>
 610
 611                         <varlistentry>
 612                                 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
 613
 614                                 <listitem><para>Takes a file glob as
 615                                 argument. If specified, journalctl will
 616                                 operate on the specified journal files
 617                                 matching <replaceable>GLOB</replaceable>
 618                                 instead of the default runtime and
 619                                 system journal paths. May be specified
 620                                 multiple times, in which case files will
 621                                 be suitably interleaved.</para></listitem>
 622                         </varlistentry>
 623
 624                         <varlistentry>
 625                                 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
 626
 627                                 <listitem><para>Takes a directory path
 628                                 as argument. If specified, journalctl
 629                                 will operate on catalog file hierarchy
 630                                 underneath the specified directory
 631                                 instead of the root directory
 632                                 (e.g. <option>--update-catalog</option>
 633                                 will create
 634                                 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
 635                                 </para></listitem>
 636                         </varlistentry>
 637
 638                         <varlistentry>
 639                                 <term><option>--new-id128</option></term>
 640
 641                                 <listitem><para>Instead of showing
 642                                 journal contents, generate a new 128
 643                                 bit ID suitable for identifying
 644                                 messages. This is intended for usage
 645                                 by developers who need a new
 646                                 identifier for a new message they
 647                                 introduce and want to make
 648                                 recognizable. This will print the new ID in
 649                                 three different formats which can be
 650                                 copied into source code or
 651                                 similar.</para></listitem>
 652                         </varlistentry>
 653
 654                         <varlistentry>
 655                                 <term><option>--header</option></term>
 656
 657                                 <listitem><para>Instead of showing
 658                                 journal contents, show internal header
 659                                 information of the journal fields
 660                                 accessed.</para></listitem>
 661                         </varlistentry>
 662
 663                         <varlistentry>
 664                                 <term><option>--disk-usage</option></term>
 665
 666                                 <listitem><para>Shows the current disk
 667                                 usage of all
 668                                 journal files.</para></listitem>
 669                         </varlistentry>
 670
 671                         <varlistentry>
 672                                 <term><option>--list-catalog
 673                                 <optional><replaceable>ID128...</replaceable></optional>
 674                                 </option></term>
 675
 676                                 <listitem><para>List the contents of
 677                                 the message catalog, as table of
 678                                 message IDs plus their short
 679                                 description strings.</para>
 680
 681                                 <para>If any
 682                                 <replaceable>ID128</replaceable>s are
 683                                 specified, only those entries are shown.
 684                                 </para>
 685                                 </listitem>
 686                         </varlistentry>
 687
 688                         <varlistentry>
 689                                 <term><option>--dump-catalog
 690                                 <optional><replaceable>ID128...</replaceable></optional>
 691                                 </option></term>
 692
 693                                 <listitem><para>Show the contents of
 694                                 the message catalog, with entries
 695                                 separated by a line consisting of two
 696                                 dashes and the id (the format is the
 697                                 same as <filename>.catalog</filename>
 698                                 files.</para>
 699
 700                                 <para>If any
 701                                 <replaceable>ID128</replaceable>s are
 702                                 specified, only those entries are shown.
 703                                 </para>
 704                                 </listitem>
 705                         </varlistentry>
 706
 707                         <varlistentry>
 708                                 <term><option>--update-catalog</option></term>
 709
 710                                 <listitem><para>Update the message
 711                                 catalog index. This command needs to
 712                                 be executed each time new catalog
 713                                 files are installed, removed or
 714                                 updated to rebuild the binary catalog
 715                                 index.</para></listitem>
 716                         </varlistentry>
 717
 718                         <varlistentry>
 719                                 <term><option>--setup-keys</option></term>
 720
 721                                 <listitem><para>Instead of showing
 722                                 journal contents, generate a new key
 723                                 pair for Forward Secure Sealing
 724                                 (FSS). This will generate a sealing
 725                                 key and a verification key. The
 726                                 sealing key is stored in the journal
 727                                 data directory and shall remain on the
 728                                 host. The verification key should be
 729                                 stored externally. Also see the
 730                                 <option>Seal=</option> option in
 731                                 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 732                                 for details.</para></listitem>
 733                         </varlistentry>
 734
 735                         <varlistentry>
 736                                 <term><option>--force</option></term>
 737
 738                                 <listitem><para>When --setup-keys is passed and
 739                                 Forward Secure Sealing has already been set up,
 740                                 recreate FSS keys.</para></listitem>
 741                         </varlistentry>
 742
 743                         <varlistentry>
 744                                 <term><option>--interval=</option></term>
 745
 746                                 <listitem><para>Specifies the change
 747                                 interval for the sealing key when
 748                                 generating an FSS key pair with
 749                                 <option>--setup-keys</option>. Shorter
 750                                 intervals increase CPU consumption but
 751                                 shorten the time range of
 752                                 undetectable journal
 753                                 alterations. Defaults to
 754                                 15min.</para></listitem>
 755                         </varlistentry>
 756
 757                         <varlistentry>
 758                                 <term><option>--verify</option></term>
 759
 760                                 <listitem><para>Check the journal file
 761                                 for internal consistency. If the
 762                                 file has been generated with FSS
 763                                 enabled and the FSS verification key
 764                                 has been specified with
 765                                 <option>--verify-key=</option>,
 766                                 authenticity of the journal file is
 767                                 verified.</para></listitem>
 768                         </varlistentry>
 769
 770                         <varlistentry>
 771                                 <term><option>--verify-key=</option></term>
 772
 773                                 <listitem><para>Specifies the FSS
 774                                 verification key to use for the
 775                                 <option>--verify</option>
 776                                 operation.</para></listitem>
 777                         </varlistentry>
 778
 779                 </variablelist>
 780         </refsect1>
 781
 782         <refsect1>
 783                 <title>Exit status</title>
 784
 785                 <para>On success, 0 is returned, a non-zero failure
 786                 code otherwise.</para>
 787         </refsect1>
 788
 789         <refsect1>
 790                 <title>Environment</title>
 791
 792                 <variablelist class='environment-variables'>
 793                         <varlistentry>
 794                                 <term><varname>$SYSTEMD_PAGER</varname></term>
 795                                 <listitem><para>Pager to use when
 796                                 <option>--no-pager</option> is not given;
 797                                 overrides <varname>$PAGER</varname>.  Setting
 798                                 this to an empty string or the value
 799                                 <literal>cat</literal> is equivalent to passing
 800                                 <option>--no-pager</option>.</para></listitem>
 801                         </varlistentry>
 802                 </variablelist>
 803         </refsect1>
 804
 805         <refsect1>
 806                 <title>Examples</title>
 807
 808                 <para>Without arguments, all collected logs are shown
 809                 unfiltered:</para>
 810
 811                 <programlisting>journalctl</programlisting>
 812
 813                 <para>With one match specified, all entries with a field matching the expression are shown:</para>
 814
 815                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
 816
 817                 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
 818
 819                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
 820
 821                 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
 822
 823                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
 824
 825                 <para>If the separator <literal>+</literal> is used,
 826                 two expressions may be combined in a logical OR. The
 827                 following will show all messages from the Avahi
 828                 service process with the PID 28097 plus all messages
 829                 from the D-Bus service (from any of its
 830                 processes):</para>
 831
 832                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
 833
 834                 <para>Show all logs generated by the D-Bus executable:</para>
 835
 836                 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
 837
 838                 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
 839
 840                 <programlisting>journalctl /dev/sda</programlisting>
 841
 842                 <para>Show all kernel logs from last boot:</para>
 843
 844                 <programlisting>journalctl -k -b :</programlisting>
 845
 846         </refsect1>
 847
 848         <refsect1>
 849                 <title>See Also</title>
 850                 <para>
 851                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 852                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 853                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 854                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 855                         <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 856                 </para>
 857         </refsect1>
 858
 859 </refentry>