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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  18   Lesser General Public License for more details.
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  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
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  23
  24 <refentry id="journalctl">
  25
  26         <refentryinfo>
  27                 <title>journalctl</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>journalctl</refentrytitle>
  42                 <manvolnum>1</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>journalctl</refname>
  47                 <refpurpose>Query the systemd journal</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <cmdsynopsis>
  52                         <command>journalctl</command>
  53                         <arg choice="opt" rep="repeat">OPTIONS</arg>
  54                         <arg choice="opt" rep="repeat">MATCHES</arg>
  55                 </cmdsynopsis>
  56         </refsynopsisdiv>
  57
  58         <refsect1>
  59                 <title>Description</title>
  60
  61                 <para><command>journalctl</command> may be used to
  62                 query the contents of the
  63                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  64                 journal as written by
  65                 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
  66
  67                 <para>If called without parameters, it will show the full
  68                 contents of the journal, starting with the oldest
  69                 entry collected.</para>
  70
  71                 <para>If one or more match arguments are passed, the
  72                 output is filtered accordingly. A match is in the
  73                 format <literal>FIELD=VALUE</literal>,
  74                 e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>,
  75                 referring to the components of a structured journal
  76                 entry. See
  77                 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
  78                 for a list of well-known fields. If multiple matches
  79                 are specified matching different fields, the log
  80                 entries are filtered by both, i.e. the resulting output
  81                 will show only entries matching all the specified
  82                 matches of this kind. If two matches apply to the same
  83                 field, then they are automatically matched as
  84                 alternatives, i.e. the resulting output will show
  85                 entries matching any of the specified matches for the
  86                 same field. Finally, if the character
  87                 <literal>+</literal> appears as separate word on the
  88                 command line, all matches before and after are combined
  89                 in a disjunction (i.e. logical OR).</para>
  90
  91                 <para>As shortcuts for a few types of field/value
  92                 matches, file paths may be specified. If a file path
  93                 refers to an executable file, this is equivalent to an
  94                 <literal>_EXE=</literal> match for the canonicalized
  95                 binary path. Similarly, if a path refers to a device
  96                 node, this is equivalent to a
  97                 <literal>_KERNEL_DEVICE=</literal> match for the
  98                 device.</para>
  99
 100                 <para>Output is interleaved from all accessible
 101                 journal files, whether they are rotated or currently
 102                 being written, and regardless of whether they belong to the
 103                 system itself or are accessible user journals.</para>
 104
 105                 <para>All users are granted access to their private
 106                 per-user journals. However, by default, only root and
 107                 users who are members of the <literal>adm</literal>
 108                 group get access to the system journal and the
 109                 journals of other users.</para>
 110
 111                 <para>The output is paged through
 112                 <command>less</command> by default, and long lines are
 113                 "truncated" to screen width. The hidden part can be
 114                 viewed by using the left-arrow and right-arrow
 115                 keys. Paging can be disabled, see
 116                 <option>--no-pager</option> and section Environment
 117                 below.</para>
 118
 119                 <para>When outputing to a tty, lines are colored
 120                 according to priority: lines of level ERROR and higher
 121                 are colored red, lines of level NOTICE and higher are
 122                 highlighted, and other lines are displayed normally.
 123                 </para>
 124         </refsect1>
 125
 126         <refsect1>
 127                 <title>Options</title>
 128
 129                 <para>The following options are understood:</para>
 130
 131                 <variablelist>
 132                         <varlistentry>
 133                                 <term><option>-h</option></term>
 134                                 <term><option>--help</option></term>
 135
 136                                 <listitem><para>Prints a short help
 137                                 text and exits.</para></listitem>
 138                         </varlistentry>
 139
 140                         <varlistentry>
 141                                 <term><option>--version</option></term>
 142
 143                                 <listitem><para>Prints a short version
 144                                 string and exits.</para></listitem>
 145                         </varlistentry>
 146
 147                         <varlistentry>
 148                                 <term><option>--no-pager</option></term>
 149
 150                                 <listitem><para>Do not pipe output into a
 151                                 pager.</para></listitem>
 152                         </varlistentry>
 153
 154                         <varlistentry>
 155                                 <term><option>-l</option></term>
 156                                 <term><option>--full</option></term>
 157
 158                                 <listitem><para>Show all (printable) fields in
 159                                 full.</para></listitem>
 160                         </varlistentry>
 161
 162                         <varlistentry>
 163                                 <term><option>-a</option></term>
 164                                 <term><option>--all</option></term>
 165
 166                                 <listitem><para>Show all fields in
 167                                 full, even if they include unprintable
 168                                 characters or are very
 169                                 long.</para></listitem>
 170                         </varlistentry>
 171
 172                         <varlistentry>
 173                                 <term><option>-f</option></term>
 174                                 <term><option>--follow</option></term>
 175
 176                                 <listitem><para>Show only the most recent
 177                                 journal entries, and continuously print
 178                                 new entries as they are appended to
 179                                 the journal.</para></listitem>
 180                         </varlistentry>
 181
 182                         <varlistentry>
 183                                 <term><option>-e</option></term>
 184                                 <term><option>--pager-end</option></term>
 185
 186                                 <listitem><para>Immediately jump to
 187                                 the end of the journal inside the
 188                                 implied pager tool. This implies
 189                                 <option>-n1000</option> to guarantee
 190                                 that the pager will not buffer logs of
 191                                 unbounded size. This may be overridden
 192                                 with an explicit <option>-n</option>
 193                                 with some other numeric value on the
 194                                 command line. Note that this option is
 195                                 only supported for the
 196                                 <citerefentry><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 197                                 pager.</para></listitem>
 198                         </varlistentry>
 199
 200                         <varlistentry>
 201                                 <term><option>-n</option></term>
 202                                 <term><option>--lines=</option></term>
 203
 204                                 <listitem><para>Show the most recent
 205                                 journal events and limit the number of
 206                                 events shown. If
 207                                 <option>--follow</option> is used,
 208                                 this option is implied. The argument,
 209                                 a positive integer, is optional, and
 210                                 defaults to 10. </para></listitem>
 211                         </varlistentry>
 212
 213                         <varlistentry>
 214                                 <term><option>--no-tail</option></term>
 215
 216                                 <listitem><para>Show all stored output
 217                                 lines, even in follow mode. Undoes the
 218                                 effect of
 219                                 <option>--lines=</option>.</para></listitem>
 220                         </varlistentry>
 221
 222                         <varlistentry>
 223                                 <term><option>-r</option></term>
 224                                 <term><option>--reverse</option></term>
 225
 226                                 <listitem><para>Reverse output, so the newest
 227                                 entries are displayed first.</para></listitem>
 228                         </varlistentry>
 229
 230                         <varlistentry>
 231                                 <term><option>-o</option></term>
 232                                 <term><option>--output=</option></term>
 233
 234                                 <listitem><para>Controls the
 235                                 formatting of the journal entries that
 236                                 are shown. Takes one of the following options:
 237                                 </para>
 238                                 <variablelist>
 239                                         <varlistentry>
 240                                                 <term>
 241                                                         <option>short</option>
 242                                                 </term>
 243                                                 <listitem>
 244                                                         <para>is the default
 245                                                         and generates an output
 246                                                         that is mostly identical
 247                                                         to the formatting of
 248                                                         classic syslog files,
 249                                                         showing one line per
 250                                                         journal entry.</para>
 251                                                 </listitem>
 252                                         </varlistentry>
 253
 254                                         <varlistentry>
 255                                                 <term>
 256                                                         <option>short-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>
 404
 405                                 <para>Note: when attaching
 406                                 <command>journalctl</command> output
 407                                 to bug reports, please do
 408                                 <emphasis>not</emphasis> use
 409                                 <option>-x</option>.</para>
 410                                 </listitem>
 411                         </varlistentry>
 412
 413                         <varlistentry>
 414                                 <term><option>-q</option></term>
 415                                 <term><option>--quiet</option></term>
 416
 417                                 <listitem><para>Suppresses any warning
 418                                 message regarding inaccessible system
 419                                 journals when run as normal
 420                                 user.</para></listitem>
 421                         </varlistentry>
 422
 423                         <varlistentry>
 424                                 <term><option>-m</option></term>
 425                                 <term><option>--merge</option></term>
 426
 427                                 <listitem><para>Show entries
 428                                 interleaved from all available
 429                                 journals, including remote
 430                                 ones.</para></listitem>
 431                         </varlistentry>
 432
 433                         <varlistentry>
 434                                 <term><option>-b <optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
 435                                 <term><option>--boot=<optional><replaceable>ID</replaceable></optional><optional><replaceable>±offset</replaceable></optional></option></term>
 436
 437                                 <listitem><para>Show messages from a specific
 438                                 boot. This will add a match for
 439                                 <literal>_BOOT_ID=</literal>.</para>
 440
 441                                 <para>The argument may be empty, in which case
 442                                 logs for the current boot will be shown.</para>
 443
 444                                 <para>If the boot ID is omitted, a positive
 445                                 <replaceable>offset</replaceable> will look up
 446                                 the boots starting from the beginning of the
 447                                 journal, and a equal-or-less-than zero
 448                                 <replaceable>offset</replaceable> will look up
 449                                 boots starting from the end of the
 450                                 journal. Thus, <constant>1</constant> means the
 451                                 first boot found in the journal in the
 452                                 chronological order, <constant>2</constant> the
 453                                 second and so on; while <constant>-0</constant>
 454                                 is the last boot, <constant>-1</constant> the
 455                                 boot before that, and so on. An empty
 456                                 <replaceable>offset</replaceable> is equivalent
 457                                 to specifying <constant>-0</constant>, except
 458                                 when the current boot is not the last boot
 459                                 (e.g. because <option>--directory</option> was
 460                                 specified to look at logs from a different
 461                                 machine).</para>
 462
 463                                 <para>If the 32 character
 464                                 <replaceable>ID</replaceable> is specified, it
 465                                 may optionally be followed by
 466                                 <replaceable>offset</replaceable> which
 467                                 identifies the boot relative to the one given by
 468                                 boot <replaceable>ID</replaceable>. Negative
 469                                 values mean earlier boots and a positive values
 470                                 mean later boots. If
 471                                 <replaceable>offset</replaceable> is not
 472                                 specified, a value of zero is assumed and the
 473                                 logs for the boot given by
 474                                 <replaceable>ID</replaceable> are shown.
 475                                 </para>
 476
 477                                 </listitem>
 478                         </varlistentry>
 479
 480                         <varlistentry>
 481                                 <term><option>-k</option></term>
 482                                 <term><option>--dmesg</option></term>
 483
 484                                 <listitem><para>Show only kernel messages. This
 485                                 implies <option>-b</option> and adds the match
 486                                 <literal>_TRANSPORT=kernel</literal>.
 487                                 </para></listitem>
 488                         </varlistentry>
 489
 490                         <varlistentry>
 491                                 <term><option>-u</option></term>
 492                                 <term><option>--unit=</option></term>
 493
 494                                 <listitem><para>Show messages for the
 495                                 specified systemd unit. This will add
 496                                 a match for messages from the unit
 497                                 (<literal>_SYSTEMD_UNIT=</literal>)
 498                                 and additional matches for messages
 499                                 from systemd and messages about
 500                                 coredumps for the specified unit.</para>
 501                                 <para>This parameter can be specified multiple times.
 502                                 </para></listitem>
 503                         </varlistentry>
 504
 505                         <varlistentry>
 506                                 <term><option>--user-unit=</option></term>
 507
 508                                 <listitem><para>Show messages for the
 509                                 specified user session unit. This will
 510                                 add a match for messages from the unit
 511                                 (<literal>_SYSTEMD_USER_UNIT=</literal>
 512                                 and <literal>_UID=</literal>) and
 513                                 additional matches for messages from
 514                                 session systemd and messages about
 515                                 coredumps for the specified unit.</para>
 516                                 <para>This parameter can be specified multiple times.
 517                                 </para></listitem>
 518                         </varlistentry>
 519
 520                         <varlistentry>
 521                                 <term><option>-p</option></term>
 522                                 <term><option>--priority=</option></term>
 523
 524                                 <listitem><para>Filter output by
 525                                 message priorities or priority
 526                                 ranges. Takes either a single numeric
 527                                 or textual log level (i.e. between
 528                                 0/<literal>emerg</literal> and
 529                                 7/<literal>debug</literal>), or a
 530                                 range of numeric/text log levels in
 531                                 the form FROM..TO. The log levels are
 532                                 the usual syslog log levels as
 533                                 documented in
 534                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 535                                 i.e. <literal>emerg</literal> (0),
 536                                 <literal>alert</literal> (1),
 537                                 <literal>crit</literal> (2),
 538                                 <literal>err</literal> (3),
 539                                 <literal>warning</literal> (4),
 540                                 <literal>notice</literal> (5),
 541                                 <literal>info</literal> (6),
 542                                 <literal>debug</literal> (7). If a
 543                                 single log level is specified, all
 544                                 messages with this log level or a
 545                                 lower (hence more important) log level
 546                                 are shown. If a range is specified, all
 547                                 messages within the range are shown,
 548                                 including both the start and the end
 549                                 value of the range. This will add
 550                                 <literal>PRIORITY=</literal> matches
 551                                 for the specified
 552                                 priorities.</para></listitem>
 553                         </varlistentry>
 554
 555                         <varlistentry>
 556                                 <term><option>-c</option></term>
 557                                 <term><option>--cursor=</option></term>
 558
 559                                 <listitem><para>Start showing entries
 560                                 from the location in the journal
 561                                 specified by the passed
 562                                 cursor.</para></listitem>
 563                         </varlistentry>
 564
 565                         <varlistentry>
 566                                 <term><option>--after-cursor=</option></term>
 567
 568                                 <listitem><para>Start showing entries from the
 569                                 location in the journal
 570                                 <emphasis>after</emphasis> the location
 571                                 specified by the this cursor.
 572                                 </para></listitem>
 573                         </varlistentry>
 574
 575                         <varlistentry>
 576                                 <term><option>--since=</option></term>
 577                                 <term><option>--until=</option></term>
 578
 579                                 <listitem><para>Start showing entries
 580                                 on or newer than the specified date,
 581                                 or on or older than the specified
 582                                 date, respectively. Date specifications
 583                                 should be of the format
 584                                 <literal>2012-10-30 18:17:16</literal>.
 585                                 If the time part is omitted,
 586                                 <literal>00:00:00</literal> is assumed.
 587                                 If only the seconds component is omitted,
 588                                 <literal>:00</literal> is assumed. If the
 589                                 date component is omitted, the current
 590                                 day is assumed. Alternatively the strings
 591                                 <literal>yesterday</literal>,
 592                                 <literal>today</literal>,
 593                                 <literal>tomorrow</literal> are
 594                                 understood, which refer to 00:00:00 of
 595                                 the day before the current day, the
 596                                 current day, or the day after the
 597                                 current day, respectively. <literal>now</literal>
 598                                 refers to the current time. Finally,
 599                                 relative times may be specified,
 600                                 prefixed with <literal>-</literal> or
 601                                 <literal>+</literal>, referring to
 602                                 times before or after the current
 603                                 time, respectively.</para></listitem>
 604                         </varlistentry>
 605
 606                         <varlistentry>
 607                                 <term><option>-F</option></term>
 608                                 <term><option>--field=</option></term>
 609
 610                                 <listitem><para>Print all possible
 611                                 data values the specified field can
 612                                 take in all entries of the
 613                                 journal.</para></listitem>
 614                         </varlistentry>
 615
 616                         <varlistentry>
 617                                 <term><option>--system</option></term>
 618                                 <term><option>--user</option></term>
 619
 620                                 <listitem><para>Show messages from
 621                                 system services and the kernel (with
 622                                 <option>--system</option>).  Show
 623                                 messages from service of current user
 624                                 (with <option>--user</option>).
 625                                 If neither is specified, show all
 626                                 messages that the user can see.
 627                                 </para></listitem>
 628                         </varlistentry>
 629
 630                         <varlistentry>
 631                                 <term><option>-D <replaceable>DIR</replaceable></option></term>
 632                                 <term><option>--directory=<replaceable>DIR</replaceable></option></term>
 633
 634                                 <listitem><para>Takes a directory path
 635                                 as argument. If specified, journalctl
 636                                 will operate on the specified journal
 637                                 directory
 638                                 <replaceable>DIR</replaceable> instead
 639                                 of the default runtime and system
 640                                 journal paths.</para></listitem>
 641                         </varlistentry>
 642
 643                         <varlistentry>
 644                                 <term><option>--file=<replaceable>GLOB</replaceable></option></term>
 645
 646                                 <listitem><para>Takes a file glob as
 647                                 argument. If specified, journalctl will
 648                                 operate on the specified journal files
 649                                 matching <replaceable>GLOB</replaceable>
 650                                 instead of the default runtime and
 651                                 system journal paths. May be specified
 652                                 multiple times, in which case files will
 653                                 be suitably interleaved.</para></listitem>
 654                         </varlistentry>
 655
 656                         <varlistentry>
 657                                 <term><option>--root=<replaceable>ROOT</replaceable></option></term>
 658
 659                                 <listitem><para>Takes a directory path
 660                                 as argument. If specified, journalctl
 661                                 will operate on catalog file hierarchy
 662                                 underneath the specified directory
 663                                 instead of the root directory
 664                                 (e.g. <option>--update-catalog</option>
 665                                 will create
 666                                 <filename><replaceable>ROOT</replaceable>/var/lib/systemd/catalog/database</filename>).
 667                                 </para></listitem>
 668                         </varlistentry>
 669
 670                         <varlistentry>
 671                                 <term><option>--new-id128</option></term>
 672
 673                                 <listitem><para>Instead of showing
 674                                 journal contents, generate a new 128
 675                                 bit ID suitable for identifying
 676                                 messages. This is intended for usage
 677                                 by developers who need a new
 678                                 identifier for a new message they
 679                                 introduce and want to make
 680                                 recognizable. This will print the new ID in
 681                                 three different formats which can be
 682                                 copied into source code or
 683                                 similar.</para></listitem>
 684                         </varlistentry>
 685
 686                         <varlistentry>
 687                                 <term><option>--header</option></term>
 688
 689                                 <listitem><para>Instead of showing
 690                                 journal contents, show internal header
 691                                 information of the journal fields
 692                                 accessed.</para></listitem>
 693                         </varlistentry>
 694
 695                         <varlistentry>
 696                                 <term><option>--disk-usage</option></term>
 697
 698                                 <listitem><para>Shows the current disk
 699                                 usage of all
 700                                 journal files.</para></listitem>
 701                         </varlistentry>
 702
 703                         <varlistentry>
 704                                 <term><option>--list-catalog
 705                                 <optional><replaceable>ID128...</replaceable></optional>
 706                                 </option></term>
 707
 708                                 <listitem><para>List the contents of
 709                                 the message catalog, as table of
 710                                 message IDs plus their short
 711                                 description strings.</para>
 712
 713                                 <para>If any
 714                                 <replaceable>ID128</replaceable>s are
 715                                 specified, only those entries are shown.
 716                                 </para>
 717                                 </listitem>
 718                         </varlistentry>
 719
 720                         <varlistentry>
 721                                 <term><option>--dump-catalog
 722                                 <optional><replaceable>ID128...</replaceable></optional>
 723                                 </option></term>
 724
 725                                 <listitem><para>Show the contents of
 726                                 the message catalog, with entries
 727                                 separated by a line consisting of two
 728                                 dashes and the id (the format is the
 729                                 same as <filename>.catalog</filename>
 730                                 files.</para>
 731
 732                                 <para>If any
 733                                 <replaceable>ID128</replaceable>s are
 734                                 specified, only those entries are shown.
 735                                 </para>
 736                                 </listitem>
 737                         </varlistentry>
 738
 739                         <varlistentry>
 740                                 <term><option>--update-catalog</option></term>
 741
 742                                 <listitem><para>Update the message
 743                                 catalog index. This command needs to
 744                                 be executed each time new catalog
 745                                 files are installed, removed or
 746                                 updated to rebuild the binary catalog
 747                                 index.</para></listitem>
 748                         </varlistentry>
 749
 750                         <varlistentry>
 751                                 <term><option>--setup-keys</option></term>
 752
 753                                 <listitem><para>Instead of showing
 754                                 journal contents, generate a new key
 755                                 pair for Forward Secure Sealing
 756                                 (FSS). This will generate a sealing
 757                                 key and a verification key. The
 758                                 sealing key is stored in the journal
 759                                 data directory and shall remain on the
 760                                 host. The verification key should be
 761                                 stored externally. Also see the
 762                                 <option>Seal=</option> option in
 763                                 <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 764                                 for details.</para></listitem>
 765                         </varlistentry>
 766
 767                         <varlistentry>
 768                                 <term><option>--force</option></term>
 769
 770                                 <listitem><para>When --setup-keys is passed and
 771                                 Forward Secure Sealing has already been set up,
 772                                 recreate FSS keys.</para></listitem>
 773                         </varlistentry>
 774
 775                         <varlistentry>
 776                                 <term><option>--interval=</option></term>
 777
 778                                 <listitem><para>Specifies the change
 779                                 interval for the sealing key when
 780                                 generating an FSS key pair with
 781                                 <option>--setup-keys</option>. Shorter
 782                                 intervals increase CPU consumption but
 783                                 shorten the time range of
 784                                 undetectable journal
 785                                 alterations. Defaults to
 786                                 15min.</para></listitem>
 787                         </varlistentry>
 788
 789                         <varlistentry>
 790                                 <term><option>--verify</option></term>
 791
 792                                 <listitem><para>Check the journal file
 793                                 for internal consistency. If the
 794                                 file has been generated with FSS
 795                                 enabled and the FSS verification key
 796                                 has been specified with
 797                                 <option>--verify-key=</option>,
 798                                 authenticity of the journal file is
 799                                 verified.</para></listitem>
 800                         </varlistentry>
 801
 802                         <varlistentry>
 803                                 <term><option>--verify-key=</option></term>
 804
 805                                 <listitem><para>Specifies the FSS
 806                                 verification key to use for the
 807                                 <option>--verify</option>
 808                                 operation.</para></listitem>
 809                         </varlistentry>
 810
 811                 </variablelist>
 812         </refsect1>
 813
 814         <refsect1>
 815                 <title>Exit status</title>
 816
 817                 <para>On success, 0 is returned, a non-zero failure
 818                 code otherwise.</para>
 819         </refsect1>
 820
 821         <refsect1>
 822                 <title>Environment</title>
 823
 824                 <variablelist class='environment-variables'>
 825                         <varlistentry>
 826                                 <term><varname>$SYSTEMD_PAGER</varname></term>
 827                                 <listitem><para>Pager to use when
 828                                 <option>--no-pager</option> is not given;
 829                                 overrides <varname>$PAGER</varname>.  Setting
 830                                 this to an empty string or the value
 831                                 <literal>cat</literal> is equivalent to passing
 832                                 <option>--no-pager</option>.</para></listitem>
 833                         </varlistentry>
 834                 </variablelist>
 835         </refsect1>
 836
 837         <refsect1>
 838                 <title>Examples</title>
 839
 840                 <para>Without arguments, all collected logs are shown
 841                 unfiltered:</para>
 842
 843                 <programlisting>journalctl</programlisting>
 844
 845                 <para>With one match specified, all entries with a field matching the expression are shown:</para>
 846
 847                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
 848
 849                 <para>If two different fields are matched, only entries matching both expressions at the same time are shown:</para>
 850
 851                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
 852
 853                 <para>If two matches refer to the same field, all entries matching either expression are shown:</para>
 854
 855                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
 856
 857                 <para>If the separator <literal>+</literal> is used,
 858                 two expressions may be combined in a logical OR. The
 859                 following will show all messages from the Avahi
 860                 service process with the PID 28097 plus all messages
 861                 from the D-Bus service (from any of its
 862                 processes):</para>
 863
 864                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
 865
 866                 <para>Show all logs generated by the D-Bus executable:</para>
 867
 868                 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
 869
 870                 <para>Show all logs of the kernel device node <filename noindex='true'>/dev/sda</filename>:</para>
 871
 872                 <programlisting>journalctl /dev/sda</programlisting>
 873
 874                 <para>Show all kernel logs from previous boot:</para>
 875
 876                 <programlisting>journalctl -k -b -1</programlisting>
 877
 878         </refsect1>
 879
 880         <refsect1>
 881                 <title>See Also</title>
 882                 <para>
 883                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 884                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 885                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 886                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 887                         <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 888                 </para>
 889         </refsect1>
 890
 891 </refentry>