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/>.
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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-iso</option>
 257                                                 </term>
 258                                                 <listitem>
 259                                                         <para>is very similar,
 260                                                         but shows ISO 8601
 261                                                         wallclock timestamps.
 262                                                         </para>
 263                                                 </listitem>
 264                                         </varlistentry>
 265
 266                                         <varlistentry>
 267                                                 <term>
 268                                                         <option>short-precise</option>
 269                                                 </term>
 270                                                 <listitem>
 271                                                         <para>is very similar,
 272                                                         but shows timestamps
 273                                                         with full microsecond
 274                                                         precision.
 275                                                         </para>
 276                                                 </listitem>
 277                                         </varlistentry>
 278
 279                                         <varlistentry>
 280                                                 <term>
 281                                                         <option>short-monotonic</option>
 282                                                 </term>
 283                                                 <listitem>
 284                                                         <para>is very similar
 285                                                         but shows monotonic
 286                                                         timestamps instead of
 287                                                         wallclock timestamps.
 288                                                         </para>
 289                                                 </listitem>
 290                                         </varlistentry>
 291
 292                                         <varlistentry>
 293                                                 <term>
 294                                                         <option>verbose</option>
 295                                                 </term>
 296                                                 <listitem>
 297                                                         <para>shows the
 298                                                         full-structured entry
 299                                                         items with all fields.
 300                                                         </para>
 301                                                 </listitem>
 302                                         </varlistentry>
 303
 304                                         <varlistentry>
 305                                                 <term>
 306                                                         <option>export</option>
 307                                                 </term>
 308                                                 <listitem>
 309                                                         <para>serializes the
 310                                                         journal into a binary
 311                                                         (but mostly text-based)
 312                                                         stream suitable for
 313                                                         backups and network
 314                                                         transfer (see <ulink
 315                                                         url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
 316                                                         Export Format</ulink>
 317                                                         for more
 318                                                         information).</para>
 319                                                 </listitem>
 320                                         </varlistentry>
 321
 322                                         <varlistentry>
 323                                                 <term>
 324                                                         <option>json</option>
 325                                                 </term>
 326                                                 <listitem>
 327                                                         <para>formats entries
 328                                                         as JSON data structures,
 329                                                         one per line (see <ulink
 330                                                         url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
 331                                                         JSON Format</ulink> for
 332                                                         more information).</para>
 333                                                 </listitem>
 334                                         </varlistentry>
 335
 336                                         <varlistentry>
 337                                                 <term>
 338                                                         <option>json-pretty</option>
 339                                                 </term>
 340                                                 <listitem>
 341                                                         <para>formats entries as
 342                                                         JSON data structures,
 343                                                         but formats them in
 344                                                         multiple lines in order
 345                                                         to make them more
 346                                                         readable for humans.</para>
 347                                                 </listitem>
 348                                         </varlistentry>
 349
 350                                         <varlistentry>
 351                                                 <term>
 352                                                         <option>json-sse</option>
 353                                                 </term>
 354                                                 <listitem>
 355                                                         <para>formats entries as
 356                                                         JSON data structures,
 357                                                         but wraps them in a
 358                                                         format suitable for <ulink
 359                                                         url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
 360                                                         Events</ulink>.</para>
 361                                                 </listitem>
 362                                         </varlistentry>
 363
 364                                         <varlistentry>
 365                                                 <term>
 366                                                         <option>cat</option>
 367                                                 </term>
 368                                                 <listitem>
 369                                                         <para>generates a very
 370                                                         terse output only
 371                                                         showing the actual
 372                                                         message of each journal
 373                                                         entry with no meta data,
 374                                                         not even a timestamp.
 375                                                         </para>
 376                                                 </listitem>
 377                                         </varlistentry>
 378                                 </variablelist>
 379                                 </listitem>
 380                         </varlistentry>
 381
 382                         <varlistentry>
 383                                 <term><option>-x</option></term>
 384                                 <term><option>--catalog</option></term>
 385
 386                                 <listitem><para>Augment log lines with
 387                                 explanation texts from the message
 388                                 catalog. This will add explanatory
 389                                 help texts to log messages in the
 390                                 output where this is available. These
 391                                 short help texts will explain the
 392                                 context of an error or log event,
 393                                 possible solutions, as well as
 394                                 pointers to support forums, developer
 395                                 documentation and any other relevant
 396                                 manuals. Note that help texts are not
 397                                 available for all messages, but only
 398                                 for selected ones. For more
 399                                 information on the message catalog,
 400                                 please refer to the <ulink
 401                                 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
 402                                 Catalog Developer
 403                                 Documentation</ulink>.</para></listitem>
 404                         </varlistentry>
 405
 406                         <varlistentry>
 407                                 <term><option>-q</option></term>
 408                                 <term><option>--quiet</option></term>
 409
 410                                 <listitem><para>Suppresses any warning
 411                                 message regarding inaccessible system
 412                                 journals when run as normal
 413                                 user.</para></listitem>
 414                         </varlistentry>
 415
 416                         <varlistentry>
 417                                 <term><option>-m</option></term>
 418                                 <term><option>--merge</option></term>
 419
 420                                 <listitem><para>Show entries
 421                                 interleaved from all available
 422                                 journals, including remote
 423                                 ones.</para></listitem>
 424                         </varlistentry>
 425
 426                         <varlistentry>
 427                                 <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
 428                                 <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
 429
 430                                 <listitem><para>Show messages from a specific
 431                                 boot. This will add a match for
 432                                 <literal>_BOOT_ID=</literal>.</para>
 433
 434                                 <para>The argument may be empty, in which case
 435                                 logs for the current boot will be shown.</para>
 436
 437                                 <para>If the boot ID is omitted, a positive
 438                                 <replaceable>offset</replaceable> will look up
 439                                 the boots starting from the beginning of the
 440                                 journal, and a equal-or-less-than zero
 441                                 <replaceable>offset</replaceable> will look up
 442                                 boots starting from the end of the
 443                                 journal. Thus, <constant>1</constant> means the
 444                                 first boot found in the journal in the
 445                                 chronological order, <constant>2</constant> the
 446                                 second and so on; while <constant>-0</constant>
 447                                 is the last boot, <constant>-1</constant> the
 448                                 boot before that, and so on. An empty
 449                                 <replaceable>offset</replaceable> is equivalent
 450                                 to specifying <constant>-0</constant>, except
 451                                 when the current boot is not the last boot
 452                                 (e.g. because <option>--directory</option> was
 453                                 specified to look at logs from a different
 454                                 machine).</para>
 455
 456                                 <para>If the 32 character
 457                                 <replaceable>ID</replaceable> is specified, it
 458                                 may optionally be followed by
 459                                 <replaceable>offset</replaceable> which
 460                                 identifies the boot relative to the one given by
 461                                 boot <replaceable>ID</replaceable>. Negative
 462                                 values mean earlier boots and a positive values
 463                                 mean later boots. If
 464                                 <replaceable>offset</replaceable> is not
 465                                 specified, a value of zero is assumed and the
 466                                 logs for the boot given by
 467                                 <replaceable>ID</replaceable> are shown.
 468                                 </para>
 469
 470                                 </listitem>
 471                         </varlistentry>
 472
 473                         <varlistentry>
 474                                 <term><option>-k</option></term>
 475                                 <term><option>--dmesg</option></term>
 476
 477                                 <listitem><para>Show only kernel messages. This
 478                                 implies <option>-b</option> and adds the match
 479                                 <literal>_TRANSPORT=kernel</literal>.
 480                                 </para></listitem>
 481                         </varlistentry>
 482
 483                         <varlistentry>
 484                                 <term><option>-u</option></term>
 485                                 <term><option>--unit=</option></term>
 486
 487                                 <listitem><para>Show messages for the
 488                                 specified systemd unit. This will add
 489                                 a match for messages from the unit
 490                                 (<literal>_SYSTEMD_UNIT=</literal>)
 491                                 and additional matches for messages
 492                                 from systemd and messages about
 493                                 coredumps for the specified unit.</para>
 494                                 <para>This parameter can be specified multiple times.
 495                                 </para></listitem>
 496                         </varlistentry>
 497
 498                         <varlistentry>
 499                                 <term><option>--user-unit=</option></term>
 500
 501                                 <listitem><para>Show messages for the
 502                                 specified user session unit. This will
 503                                 add a match for messages from the unit
 504                                 (<literal>_SYSTEMD_USER_UNIT=</literal>
 505                                 and <literal>_UID=</literal>) and
 506                                 additional matches for messages from
 507                                 session systemd and messages about
 508                                 coredumps for the specified unit.</para>
 509                                 <para>This parameter can be specified multiple times.
 510                                 </para></listitem>
 511                         </varlistentry>
 512
 513                         <varlistentry>
 514                                 <term><option>-p</option></term>
 515                                 <term><option>--priority=</option></term>
 516
 517                                 <listitem><para>Filter output by
 518                                 message priorities or priority
 519                                 ranges. Takes either a single numeric
 520                                 or textual log level (i.e. between
 521                                 0/<literal>emerg</literal> and
 522                                 7/<literal>debug</literal>), or a
 523                                 range of numeric/text log levels in
 524                                 the form FROM..TO. The log levels are
 525                                 the usual syslog log levels as
 526                                 documented in
 527                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 528                                 i.e. <literal>emerg</literal> (0),
 529                                 <literal>alert</literal> (1),
 530                                 <literal>crit</literal> (2),
 531                                 <literal>err</literal> (3),
 532                                 <literal>warning</literal> (4),
 533                                 <literal>notice</literal> (5),
 534                                 <literal>info</literal> (6),
 535                                 <literal>debug</literal> (7). If a
 536                                 single log level is specified, all
 537                                 messages with this log level or a
 538                                 lower (hence more important) log level
 539                                 are shown. If a range is specified, all
 540                                 messages within the range are shown,
 541                                 including both the start and the end
 542                                 value of the range. This will add
 543                                 <literal>PRIORITY=</literal> matches
 544                                 for the specified
 545                                 priorities.</para></listitem>
 546                         </varlistentry>
 547
 548                         <varlistentry>
 549                                 <term><option>-c</option></term>
 550                                 <term><option>--cursor=</option></term>
 551
 552                                 <listitem><para>Start showing entries
 553                                 from the location in the journal
 554                                 specified by the passed
 555                                 cursor.</para></listitem>
 556                         </varlistentry>
 557
 558                         <varlistentry>
 559                                 <term><option>--after-cursor=</option></term>
 560
 561                                 <listitem><para>Start showing entries from the
 562                                 location in the journal
 563                                 <emphasis>after</emphasis> the location
 564                                 specified by the this cursor.
 565                                 </para></listitem>
 566                         </varlistentry>
 567
 568                         <varlistentry>
 569                                 <term><option>--since=</option></term>
 570                                 <term><option>--until=</option></term>
 571
 572                                 <listitem><para>Start showing entries
 573                                 on or newer than the specified date,
 574                                 or on or older than the specified
 575                                 date, respectively. Date specifications
 576                                 should be of the format
 577                                 <literal>2012-10-30 18:17:16</literal>.
 578                                 If the time part is omitted,
 579                                 <literal>00:00:00</literal> is assumed.
 580                                 If only the seconds component is omitted,
 581                                 <literal>:00</literal> is assumed. If the
 582                                 date component is omitted, the current
 583                                 day is assumed. Alternatively the strings
 584                                 <literal>yesterday</literal>,
 585                                 <literal>today</literal>,
 586                                 <literal>tomorrow</literal> are
 587                                 understood, which refer to 00:00:00 of
 588                                 the day before the current day, the
 589                                 current day, or the day after the
 590                                 current day, respectively. <literal>now</literal>
 591                                 refers to the current time. Finally,
 592                                 relative times may be specified,
 593                                 prefixed with <literal>-</literal> or
 594                                 <literal>+</literal>, referring to
 595                                 times before or after the current
 596                                 time, respectively.</para></listitem>
 597                         </varlistentry>
 598
 599                         <varlistentry>
 600                                 <term><option>-F</option></term>
 601                                 <term><option>--field=</option></term>
 602
 603                                 <listitem><para>Print all possible
 604                                 data values the specified field can
 605                                 take in all entries of the
 606                                 journal.</para></listitem>
 607                         </varlistentry>
 608
 609                         <varlistentry>
 610                                 <term><option>--system</option></term>
 611                                 <term><option>--user</option></term>
 612
 613                                 <listitem><para>Show messages from
 614                                 system services and the kernel (with
 615                                 <option>--system</option>).  Show
 616                                 messages from service of current user
 617                                 (with <option>--user</option>).
 618                                 If neither is specified, show all
 619                                 messages that the user can see.
 620                                 </para></listitem>
 621                         </varlistentry>
 622
 623                         <varlistentry>
 624                                 <term><option>-D <replaceable>DIR</replaceable></option></term>
 625                                 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
 626
 627                                 <listitem><para>Takes a directory path
 628                                 as argument. If specified, journalctl
 629                                 will operate on the specified journal
 630                                 directory
 631                                 <replaceable>DIR</replaceable> instead
 632                                 of the default runtime and system
 633                                 journal paths.</para></listitem>
 634                         </varlistentry>
 635
 636                         <varlistentry>
 637                                 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
 638
 639                                 <listitem><para>Takes a file glob as
 640                                 argument. If specified, journalctl will
 641                                 operate on the specified journal files
 642                                 matching <replaceable>GLOB</replaceable>
 643                                 instead of the default runtime and
 644                                 system journal paths. May be specified
 645                                 multiple times, in which case files will
 646                                 be suitably interleaved.</para></listitem>
 647                         </varlistentry>
 648
 649                         <varlistentry>
 650                                 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
 651
 652                                 <listitem><para>Takes a directory path
 653                                 as argument. If specified, journalctl
 654                                 will operate on catalog file hierarchy
 655                                 underneath the specified directory
 656                                 instead of the root directory
 657                                 (e.g. <option>--update-catalog</option>
 658                                 will create
 659                                 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
 660                                 </para></listitem>
 661                         </varlistentry>
 662
 663                         <varlistentry>
 664                                 <term><option>--new-id128</option></term>
 665
 666                                 <listitem><para>Instead of showing
 667                                 journal contents, generate a new 128
 668                                 bit ID suitable for identifying
 669                                 messages. This is intended for usage
 670                                 by developers who need a new
 671                                 identifier for a new message they
 672                                 introduce and want to make
 673                                 recognizable. This will print the new ID in
 674                                 three different formats which can be
 675                                 copied into source code or
 676                                 similar.</para></listitem>
 677                         </varlistentry>
 678
 679                         <varlistentry>
 680                                 <term><option>--header</option></term>
 681
 682                                 <listitem><para>Instead of showing
 683                                 journal contents, show internal header
 684                                 information of the journal fields
 685                                 accessed.</para></listitem>
 686                         </varlistentry>
 687
 688                         <varlistentry>
 689                                 <term><option>--disk-usage</option></term>
 690
 691                                 <listitem><para>Shows the current disk
 692                                 usage of all
 693                                 journal files.</para></listitem>
 694                         </varlistentry>
 695
 696                         <varlistentry>
 697                                 <term><option>--list-catalog
 698                                 <optional><replaceable>ID128...</replaceable></optional>
 699                                 </option></term>
 700
 701                                 <listitem><para>List the contents of
 702                                 the message catalog, as table of
 703                                 message IDs plus their short
 704                                 description strings.</para>
 705
 706                                 <para>If any
 707                                 <replaceable>ID128</replaceable>s are
 708                                 specified, only those entries are shown.
 709                                 </para>
 710                                 </listitem>
 711                         </varlistentry>
 712
 713                         <varlistentry>
 714                                 <term><option>--dump-catalog
 715                                 <optional><replaceable>ID128...</replaceable></optional>
 716                                 </option></term>
 717
 718                                 <listitem><para>Show the contents of
 719                                 the message catalog, with entries
 720                                 separated by a line consisting of two
 721                                 dashes and the id (the format is the
 722                                 same as <filename>.catalog</filename>
 723                                 files.</para>
 724
 725                                 <para>If any
 726                                 <replaceable>ID128</replaceable>s are
 727                                 specified, only those entries are shown.
 728                                 </para>
 729                                 </listitem>
 730                         </varlistentry>
 731
 732                         <varlistentry>
 733                                 <term><option>--update-catalog</option></term>
 734
 735                                 <listitem><para>Update the message
 736                                 catalog index. This command needs to
 737                                 be executed each time new catalog
 738                                 files are installed, removed or
 739                                 updated to rebuild the binary catalog
 740                                 index.</para></listitem>
 741                         </varlistentry>
 742
 743                         <varlistentry>
 744                                 <term><option>--setup-keys</option></term>
 745
 746                                 <listitem><para>Instead of showing
 747                                 journal contents, generate a new key
 748                                 pair for Forward Secure Sealing
 749                                 (FSS). This will generate a sealing
 750                                 key and a verification key. The
 751                                 sealing key is stored in the journal
 752                                 data directory and shall remain on the
 753                                 host. The verification key should be
 754                                 stored externally. Also see the
 755                                 <option>Seal=</option> option in
 756                                 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 757                                 for details.</para></listitem>
 758                         </varlistentry>
 759
 760                         <varlistentry>
 761                                 <term><option>--force</option></term>
 762
 763                                 <listitem><para>When --setup-keys is passed and
 764                                 Forward Secure Sealing has already been set up,
 765                                 recreate FSS keys.</para></listitem>
 766                         </varlistentry>
 767
 768                         <varlistentry>
 769                                 <term><option>--interval=</option></term>
 770
 771                                 <listitem><para>Specifies the change
 772                                 interval for the sealing key when
 773                                 generating an FSS key pair with
 774                                 <option>--setup-keys</option>. Shorter
 775                                 intervals increase CPU consumption but
 776                                 shorten the time range of
 777                                 undetectable journal
 778                                 alterations. Defaults to
 779                                 15min.</para></listitem>
 780                         </varlistentry>
 781
 782                         <varlistentry>
 783                                 <term><option>--verify</option></term>
 784
 785                                 <listitem><para>Check the journal file
 786                                 for internal consistency. If the
 787                                 file has been generated with FSS
 788                                 enabled and the FSS verification key
 789                                 has been specified with
 790                                 <option>--verify-key=</option>,
 791                                 authenticity of the journal file is
 792                                 verified.</para></listitem>
 793                         </varlistentry>
 794
 795                         <varlistentry>
 796                                 <term><option>--verify-key=</option></term>
 797
 798                                 <listitem><para>Specifies the FSS
 799                                 verification key to use for the
 800                                 <option>--verify</option>
 801                                 operation.</para></listitem>
 802                         </varlistentry>
 803
 804                 </variablelist>
 805         </refsect1>
 806
 807         <refsect1>
 808                 <title>Exit status</title>
 809
 810                 <para>On success, 0 is returned, a non-zero failure
 811                 code otherwise.</para>
 812         </refsect1>
 813
 814         <refsect1>
 815                 <title>Environment</title>
 816
 817                 <variablelist class='environment-variables'>
 818                         <varlistentry>
 819                                 <term><varname>$SYSTEMD_PAGER</varname></term>
 820                                 <listitem><para>Pager to use when
 821                                 <option>--no-pager</option> is not given;
 822                                 overrides <varname>$PAGER</varname>.  Setting
 823                                 this to an empty string or the value
 824                                 <literal>cat</literal> is equivalent to passing
 825                                 <option>--no-pager</option>.</para></listitem>
 826                         </varlistentry>
 827                 </variablelist>
 828         </refsect1>
 829
 830         <refsect1>
 831                 <title>Examples</title>
 832
 833                 <para>Without arguments, all collected logs are shown
 834                 unfiltered:</para>
 835
 836                 <programlisting>journalctl</programlisting>
 837
 838                 <para>With one match specified, all entries with a field matching the expression are shown:</para>
 839
 840                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
 841
 842                 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
 843
 844                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
 845
 846                 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
 847
 848                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
 849
 850                 <para>If the separator <literal>+</literal> is used,
 851                 two expressions may be combined in a logical OR. The
 852                 following will show all messages from the Avahi
 853                 service process with the PID 28097 plus all messages
 854                 from the D-Bus service (from any of its
 855                 processes):</para>
 856
 857                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
 858
 859                 <para>Show all logs generated by the D-Bus executable:</para>
 860
 861                 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
 862
 863                 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
 864
 865                 <programlisting>journalctl /dev/sda</programlisting>
 866
 867                 <para>Show all kernel logs from previous boot:</para>
 868
 869                 <programlisting>journalctl -k -b -1</programlisting>
 870
 871         </refsect1>
 872
 873         <refsect1>
 874                 <title>See Also</title>
 875                 <para>
 876                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 877                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 878                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 879                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 880                         <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 881                 </para>
 882         </refsect1>
 883
 884 </refentry>