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.
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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 <arg choice="opt" rep="repeat">OPTIONS</arg> <arg choice="opt" rep="repeat">MATCHES</arg></command>
  53                 </cmdsynopsis>
  54         </refsynopsisdiv>
  55
  56         <refsect1>
  57                 <title>Description</title>
  58
  59                 <para><command>journalctl</command> may be used to
  60                 query the contents of the
  61                 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>
  62                 journal as written by
  63                 <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>.</para>
  64
  65                 <para>If called without parameter it will show the full
  66                 contents of the journal, starting with the oldest
  67                 entry collected.</para>
  68
  69                 <para>If one or more match arguments are passed the
  70                 output is filtered accordingly. A match is in the
  71                 format <literal>FIELD=VALUE</literal>,
  72                 e.g. <literal>_SYSTEMD_UNIT=httpd.service</literal>,
  73                 referring to the components of a structured journal
  74                 entry. See
  75                 <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
  76                 for a list of well-known fields. If multiple matches
  77                 are specified matching different fields the log
  78                 entries are filtered by both, i.e. the resulting output
  79                 will show only entries matching all the specified
  80                 matches of this kind. If two matches apply to the same
  81                 field, then they are automatically matched as
  82                 alternatives, i.e. the resulting output will show
  83                 entries matching any of the specified matches for the
  84                 same field. Finally, if the character
  85                 "<literal>+</literal>" appears as separate word on the
  86                 command line all matches before and after are combined
  87                 in a disjunction (i.e. logical OR).</para>
  88
  89                 <para>As shortcuts for a few types of field/value
  90                 matches file paths may be specified. If a file path
  91                 refers to an executable file, this is equivalent to an
  92                 <literal>_EXE=</literal> match for the canonicalized
  93                 binary path. Similar, if a path refers to a device
  94                 node, this is equivalent to a
  95                 <literal>_KERNEL_DEVICE=</literal> match for the
  96                 device.</para>
  97
  98                 <para>Output is interleaved from all accessible
  99                 journal files, whether they are rotated or currently
 100                 being written, and regardless whether they belong to the
 101                 system itself or are accessible user journals.</para>
 102
 103                 <para>All users are granted access to their private
 104                 per-user journals. However, by default only root and
 105                 users who are members of the <literal>adm</literal>
 106                 group get access to the system journal and the
 107                 journals of other users.</para>
 108         </refsect1>
 109
 110         <refsect1>
 111                 <title>Options</title>
 112
 113                 <para>The following options are understood:</para>
 114
 115                 <variablelist>
 116                         <varlistentry>
 117                                 <term><option>-h</option></term>
 118                                 <term><option>--help</option></term>
 119
 120                                 <listitem><para>Prints a short help
 121                                 text and exits.</para></listitem>
 122                         </varlistentry>
 123
 124                         <varlistentry>
 125                                 <term><option>--version</option></term>
 126
 127                                 <listitem><para>Prints a short version
 128                                 string and exits.</para></listitem>
 129                         </varlistentry>
 130
 131                         <varlistentry>
 132                                 <term><option>--no-pager</option></term>
 133
 134                                 <listitem><para>Do not pipe output into a
 135                                 pager.</para></listitem>
 136                         </varlistentry>
 137
 138                         <varlistentry>
 139                                 <term><option>--full</option></term>
 140
 141                                 <listitem><para>Show all (printable) fields in
 142                                 full.</para></listitem>
 143                         </varlistentry>
 144
 145                         <varlistentry>
 146                                 <term><option>-a</option></term>
 147                                 <term><option>--all</option></term>
 148
 149                                 <listitem><para>Show all fields in
 150                                 full, even if they include unprintable
 151                                 characters or are very
 152                                 long.</para></listitem>
 153                         </varlistentry>
 154
 155                         <varlistentry>
 156                                 <term><option>-f</option></term>
 157                                 <term><option>--follow</option></term>
 158
 159                                 <listitem><para>Show only the most recent
 160                                 journal entries, and continuously print
 161                                 new entries as they are appended to
 162                                 the journal.</para></listitem>
 163                         </varlistentry>
 164
 165                         <varlistentry>
 166                                 <term><option>-e</option></term>
 167                                 <term><option>--pager-end</option></term>
 168
 169                                 <listitem><para>Immediately jump to
 170                                 the end of the journal inside the
 171                                 implied pager tool. This implies
 172                                 <option>-n1000</option> to guarantee
 173                                 that the pager won't buffer logs of
 174                                 unbounded size. This may be overridden
 175                                 with an explicit <option>-n</option>
 176                                 with some other numeric value on the
 177                                 command line. Note that this option is
 178                                 only supported for the
 179                                 <citerefentry><refentrytitle>less</refentrytitle><manvolnum>1</manvolnum></citerefentry>
 180                                 pager.</para></listitem>
 181                         </varlistentry>
 182
 183                         <varlistentry>
 184                                 <term><option>-n</option></term>
 185                                 <term><option>--lines=</option></term>
 186
 187                                 <listitem><para>Show the most recent
 188                                 journal events and limit the number of
 189                                 events shown. If
 190                                 <option>--follow</option> is used,
 191                                 this option is implied. The argument,
 192                                 a positive integer, is optional, and
 193                                 defaults to 10. </para></listitem>
 194                         </varlistentry>
 195
 196                         <varlistentry>
 197                                 <term><option>--no-tail</option></term>
 198
 199                                 <listitem><para>Show all stored output
 200                                 lines, even in follow mode. Undoes the
 201                                 effect of
 202                                 <option>--lines=</option>.</para></listitem>
 203                         </varlistentry>
 204
 205                         <varlistentry>
 206                                 <term><option>-r</option></term>
 207                                 <term><option>--reverse</option></term>
 208
 209                                 <listitem><para>Reverse output, so the newest
 210                                 entries are displayed first.</para></listitem>
 211                         </varlistentry>
 212
 213                         <varlistentry>
 214                                 <term><option>-o</option></term>
 215                                 <term><option>--output=</option></term>
 216
 217                                 <listitem><para>Controls the
 218                                 formatting of the journal entries that
 219                                 are shown. Takes one of
 220                                 <literal>short</literal>,
 221                                 <literal>short-monotonic</literal>,
 222                                 <literal>verbose</literal>,
 223                                 <literal>export</literal>,
 224                                 <literal>json</literal>,
 225                                 <literal>json-pretty</literal>,
 226                                 <literal>json-sse</literal>,
 227                                 <literal>cat</literal>. <literal>short</literal>
 228                                 is the default and generates an output
 229                                 that is mostly identical to the
 230                                 formatting of classic syslog log
 231                                 files, showing one line per journal
 232                                 entry. <literal>short-monotonic</literal>
 233                                 is very similar but shows monotonic
 234                                 timestamps instead of wallclock
 235                                 timestamps. <literal>verbose</literal>
 236                                 shows the full structured entry items
 237                                 with all
 238                                 fields. <literal>export</literal>
 239                                 serializes the journal into a binary
 240                                 (but mostly text-based) stream
 241                                 suitable for backups and network
 242                                 transfer (see <ulink
 243                                 url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
 244                                 Export Format</ulink> for more
 245                                 information). <literal>json</literal>
 246                                 formats entries as JSON data
 247                                 structures, one per
 248                                 line (see <ulink
 249                                 url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
 250                                 JSON Format</ulink> for more
 251                                 information). <literal>json-pretty</literal>
 252                                 also formats entries as JSON data
 253                                 structures, but formats them in
 254                                 multiple lines in order to make them
 255                                 more readable for
 256                                 humans. <literal>json-sse</literal>
 257                                 also formats entries as JSON data
 258                                 structures, but wraps them in a format
 259                                 suitable for <ulink
 260                                 url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
 261                                 Events</ulink>. <literal>cat</literal>
 262                                 generates a very terse output only
 263                                 showing the actual message of each
 264                                 journal entry with no meta data, not
 265                                 even a timestamp.</para></listitem>
 266                         </varlistentry>
 267
 268                         <varlistentry>
 269                                 <term><option>-x</option></term>
 270                                 <term><option>--catalog</option></term>
 271
 272                                 <listitem><para>Augment log lines with
 273                                 explanation texts from the message
 274                                 catalog. This will add explanatory
 275                                 help texts to log messages in the
 276                                 output where this is available. These
 277                                 short help texts will explain the
 278                                 context of an error or log event,
 279                                 possible solutions, as well as
 280                                 pointers to support forums, developer
 281                                 documentation and any other relevant
 282                                 manuals. Note that help texts are not
 283                                 available for all messages, but only
 284                                 for selected ones. For more
 285                                 information on the message catalog
 286                                 please refer to the <ulink
 287                                 url="http://www.freedesktop.org/wiki/Software/systemd/catalog">Message
 288                                 Catalog Developer
 289                                 Documentation</ulink>.</para></listitem>
 290                         </varlistentry>
 291
 292                         <varlistentry>
 293                                 <term><option>-q</option></term>
 294                                 <term><option>--quiet</option></term>
 295
 296                                 <listitem><para>Suppresses any warning
 297                                 message regarding inaccessible system
 298                                 journals when run as normal
 299                                 user.</para></listitem>
 300                         </varlistentry>
 301
 302                         <varlistentry>
 303                                 <term><option>-m</option></term>
 304                                 <term><option>--merge</option></term>
 305
 306                                 <listitem><para>Show entries
 307                                 interleaved from all available
 308                                 journals, including remote
 309                                 ones.</para></listitem>
 310                         </varlistentry>
 311
 312                         <varlistentry>
 313                                 <term><option>-b</option></term>
 314                                 <term><option>--this-boot</option></term>
 315
 316                                 <listitem><para>Show data only from
 317                                 current boot. This will add a match
 318                                 for <literal>_BOOT_ID=</literal> for
 319                                 the current boot ID of the
 320                                 kernel.</para></listitem>
 321                         </varlistentry>
 322
 323                         <varlistentry>
 324                                 <term><option>-u</option></term>
 325                                 <term><option>--unit=</option></term>
 326
 327                                 <listitem><para>Show data only of the
 328                                 specified unit. This will add a match
 329                                 for <literal>_SYSTEMD_UNIT=</literal>
 330                                 for the specified
 331                                 unit.</para></listitem>
 332                         </varlistentry>
 333
 334                         <varlistentry>
 335                                 <term><option>--user-unit=</option></term>
 336
 337                                 <listitem><para>Show data only of the
 338                                 specified user session unit. This will
 339                                 add a match for
 340                                 <literal>_SYSTEMD_USER_UNIT=</literal>
 341                                 for the specified
 342                                 unit.</para></listitem>
 343                         </varlistentry>
 344
 345                         <varlistentry>
 346                                 <term><option>-p</option></term>
 347                                 <term><option>--priority=</option></term>
 348
 349                                 <listitem><para>Filter output by
 350                                 message priorities or priority
 351                                 ranges. Takes either a single numeric
 352                                 or textual log level (i.e. between
 353                                 0/<literal>emerg</literal> and
 354                                 7/<literal>debug</literal>), or a
 355                                 range of numeric/text log levels in
 356                                 the form FROM..TO. The log levels are
 357                                 the usual syslog log levels as
 358                                 documented in
 359                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 360                                 i.e. <literal>emerg</literal> (0),
 361                                 <literal>alert</literal> (1),
 362                                 <literal>crit</literal> (2),
 363                                 <literal>err</literal> (3),
 364                                 <literal>warning</literal> (4),
 365                                 <literal>notice</literal> (5),
 366                                 <literal>info</literal> (6),
 367                                 <literal>debug</literal> (7). If a
 368                                 single log level is specified all
 369                                 messages with this log level or a
 370                                 lower (hence more important) log level
 371                                 are shown. If a range is specified all
 372                                 messages within the range are shown,
 373                                 including both the start and the end
 374                                 value of the range. This will add
 375                                 <literal>PRIORITY=</literal> matches
 376                                 for the specified
 377                                 priorities.</para></listitem>
 378                         </varlistentry>
 379
 380                         <varlistentry>
 381                                 <term><option>-c</option></term>
 382                                 <term><option>--cursor=</option></term>
 383
 384                                 <listitem><para>Start showing entries
 385                                 from the location in the journal
 386                                 specified by the passed
 387                                 cursor.</para></listitem>
 388                         </varlistentry>
 389
 390                         <varlistentry>
 391                                 <term><option>--since=</option></term>
 392                                 <term><option>--until=</option></term>
 393
 394                                 <listitem><para>Start showing entries
 395                                 on or newer than the specified date,
 396                                 or on or older than the specified
 397                                 date, respectively. Date specifications should be of
 398                                 the format "2012-10-30 18:17:16". If
 399                                 the time part is omitted, 00:00:00 is
 400                                 assumed. If only the seconds component
 401                                 is omitted, :00 is assumed. If the
 402                                 date component is omitted, the
 403                                 current day is assumed. Alternatively
 404                                 the strings
 405                                 <literal>yesterday</literal>,
 406                                 <literal>today</literal>,
 407                                 <literal>tomorrow</literal> are
 408                                 understood, which refer to 00:00:00 of
 409                                 the day before the current day, the
 410                                 current day, or the day after the
 411                                 current day, respectively. <literal>now</literal>
 412                                 refers to the current time. Finally,
 413                                 relative times may be specified,
 414                                 prefixed with <literal>-</literal> or
 415                                 <literal>+</literal>, referring to
 416                                 times before or after the current
 417                                 time, respectively.</para></listitem>
 418                         </varlistentry>
 419
 420                         <varlistentry>
 421                                 <term><option>-F</option></term>
 422                                 <term><option>--field=</option></term>
 423
 424                                 <listitem><para>Print all possible
 425                                 data values the specified field can
 426                                 take in all entries of the
 427                                 journal.</para></listitem>
 428                         </varlistentry>
 429
 430                         <varlistentry>
 431                                 <term><option>-D</option></term>
 432                                 <term><option>--directory=</option></term>
 433
 434                                 <listitem><para>Takes an absolute
 435                                 directory path as argument. If
 436                                 specified journalctl will operate on the
 437                                 specified journal directory instead of
 438                                 the default runtime and system journal
 439                                 paths.</para></listitem>
 440                         </varlistentry>
 441
 442                         <varlistentry>
 443                                 <term><option>--new-id128</option></term>
 444
 445                                 <listitem><para>Instead of showing
 446                                 journal contents generate a new 128
 447                                 bit ID suitable for identifying
 448                                 messages. This is intended for usage
 449                                 by developers who need a new
 450                                 identifier for a new message they
 451                                 introduce and want to make
 452                                 recognizable. Will print the new ID in
 453                                 three different formats which can be
 454                                 copied into source code or
 455                                 similar.</para></listitem>
 456                         </varlistentry>
 457
 458                         <varlistentry>
 459                                 <term><option>--header</option></term>
 460
 461                                 <listitem><para>Instead of showing
 462                                 journal contents show internal header
 463                                 information of the journal fields
 464                                 accessed.</para></listitem>
 465                         </varlistentry>
 466
 467                         <varlistentry>
 468                                 <term><option>--disk-usage</option></term>
 469
 470                                 <listitem><para>Shows the current disk
 471                                 usage of all
 472                                 journal files.</para></listitem>
 473                         </varlistentry>
 474
 475                         <varlistentry>
 476                                 <term><option>--list-catalog</option></term>
 477
 478                                 <listitem><para>List the contents of
 479                                 the message catalog, as table of
 480                                 message IDs plus their short
 481                                 description strings.</para></listitem>
 482                         </varlistentry>
 483
 484                         <varlistentry>
 485                                 <term><option>--update-catalog</option></term>
 486
 487                                 <listitem><para>Update the message
 488                                 catalog index. This command needs to
 489                                 be executed each time new catalog
 490                                 files are installed, removed or
 491                                 updated to rebuild the binary catalog
 492                                 index.</para></listitem>
 493                         </varlistentry>
 494
 495                         <varlistentry>
 496                                 <term><option>--setup-keys</option></term>
 497
 498                                 <listitem><para>Instead of showing
 499                                 journal contents generate a new key
 500                                 pair for Forward Secure Sealing
 501                                 (FSS). This will generate a sealing
 502                                 key and a verification key. The
 503                                 sealing key is stored in the journal
 504                                 data directory and shall remain on the
 505                                 host. The verification key should be
 506                                 stored externally.</para></listitem>
 507                         </varlistentry>
 508
 509                         <varlistentry>
 510                                 <term><option>--interval=</option></term>
 511
 512                                 <listitem><para>Specifies the change
 513                                 interval for the sealing key, when
 514                                 generating an FSS key pair with
 515                                 <option>--setup-keys</option>. Shorter
 516                                 intervals increase CPU consumption but
 517                                 shorten the time range of
 518                                 undetectable journal
 519                                 alterations. Defaults to
 520                                 15min.</para></listitem>
 521                         </varlistentry>
 522
 523                         <varlistentry>
 524                                 <term><option>--verify</option></term>
 525
 526                                 <listitem><para>Check the journal file
 527                                 for internal consistency. If the
 528                                 file has been generated with FSS
 529                                 enabled, and the FSS verification key
 530                                 has been specified with
 531                                 <option>--verify-key=</option>
 532                                 authenticity of the journal file is
 533                                 verified.</para></listitem>
 534                         </varlistentry>
 535
 536                         <varlistentry>
 537                                 <term><option>--verify-key=</option></term>
 538
 539                                 <listitem><para>Specifies the FSS
 540                                 verification key to use for the
 541                                 <option>--verify</option>
 542                                 operation.</para></listitem>
 543                         </varlistentry>
 544
 545                 </variablelist>
 546         </refsect1>
 547
 548         <refsect1>
 549                 <title>Exit status</title>
 550
 551                 <para>On success 0 is returned, a non-zero failure
 552                 code otherwise.</para>
 553         </refsect1>
 554
 555         <refsect1>
 556                 <title>Environment</title>
 557
 558                 <variablelist class='environment-variables'>
 559                         <varlistentry>
 560                                 <term><varname>$SYSTEMD_PAGER</varname></term>
 561                                 <listitem><para>Pager to use when
 562                                 <option>--no-pager</option> is not given;
 563                                 overrides <varname>$PAGER</varname>.  Setting
 564                                 this to an empty string or the value
 565                                 <literal>cat</literal> is equivalent to passing
 566                                 <option>--no-pager</option>.</para></listitem>
 567                         </varlistentry>
 568                 </variablelist>
 569         </refsect1>
 570
 571         <refsect1>
 572                 <title>Examples</title>
 573
 574                 <para>Without arguments all collected logs are shown
 575                 unfiltered:</para>
 576
 577                 <programlisting>journalctl</programlisting>
 578
 579                 <para>With one match specified all entries with a field matching the expression are shown:</para>
 580
 581                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
 582
 583                 <para>If two different fields are matched only entries matching both expressions at the same time are shown:</para>
 584
 585                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
 586
 587                 <para>If two matches refer to the same field all entries matching either expression are shown:</para>
 588
 589                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
 590
 591                 <para>If the separator "<literal>+</literal>" is used
 592                 two expressions may be combined in a logical OR. The
 593                 following will show all messages from the Avahi
 594                 service process with the PID 28097 plus all messages
 595                 from the D-Bus service (from any of its
 596                 processes):</para>
 597
 598                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
 599
 600                 <para>Show all logs generated by the D-Bus executable:</para>
 601
 602                 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
 603
 604                 <para>Show all logs of the kernel device node <filename>/dev/sda</filename>:</para>
 605
 606                 <programlisting>journalctl /dev/sda</programlisting>
 607
 608         </refsect1>
 609
 610         <refsect1>
 611                 <title>See Also</title>
 612                 <para>
 613                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 614                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 615                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 616                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 617                         <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 618                 </para>
 619         </refsect1>
 620
 621 </refentry>