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