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
  15   systemd is distributed in the hope that it will be useful, but
  16   WITHOUT ANY WARRANTY; without even the implied warranty of
  17   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  18   Lesser General Public License for more details.
  19
  20   You should have received a copy of the GNU Lesser General Public License
  21   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  22 -->
  23
  24 <refentry id="journalctl">
  25
  26         <refentryinfo>
  27                 <title>journalctl</title>
  28                 <productname>systemd</productname>
  29
  30                 <authorgroup>
  31                         <author>
  32                                 <contrib>Developer</contrib>
  33                                 <firstname>Lennart</firstname>
  34                                 <surname>Poettering</surname>
  35                                 <email>lennart@poettering.net</email>
  36                         </author>
  37                 </authorgroup>
  38         </refentryinfo>
  39
  40         <refmeta>
  41                 <refentrytitle>journalctl</refentrytitle>
  42                 <manvolnum>1</manvolnum>
  43         </refmeta>
  44
  45         <refnamediv>
  46                 <refname>journalctl</refname>
  47                 <refpurpose>Query the systemd journal</refpurpose>
  48         </refnamediv>
  49
  50         <refsynopsisdiv>
  51                 <cmdsynopsis>
  52                         <command>journalctl <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>--help</option></term>
 118                                 <term><option>-h</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>--all</option></term>
 140                                 <term><option>-a</option></term>
 141
 142                                 <listitem><para>Show all fields in
 143                                 full, even if they include unprintable
 144                                 characters or are very
 145                                 long.</para></listitem>
 146                         </varlistentry>
 147
 148                         <varlistentry>
 149                                 <term><option>--follow</option></term>
 150                                 <term><option>-f</option></term>
 151
 152                                 <listitem><para>Show only the most recent
 153                                 journal entries, and continuously print
 154                                 new entries as they are appended to
 155                                 the journal.</para></listitem>
 156                         </varlistentry>
 157
 158                         <varlistentry>
 159                                 <term><option>--lines=</option></term>
 160                                 <term><option>-n</option></term>
 161
 162                                 <listitem><para>Show the most recent
 163                                 journal events and limit the number of
 164                                 events shown. If
 165                                 <option>--follow</option> is used,
 166                                 this option is implied. The argument,
 167                                 a positive integer, is optional, and
 168                                 defaults to 10. </para></listitem>
 169                         </varlistentry>
 170
 171                         <varlistentry>
 172                                 <term><option>--no-tail</option></term>
 173
 174                                 <listitem><para>Show all stored output
 175                                 lines, even in follow mode. Undoes the
 176                                 effect of
 177                                 <option>--lines=</option>.</para></listitem>
 178                         </varlistentry>
 179
 180                         <varlistentry>
 181                                 <term><option>--output=</option></term>
 182                                 <term><option>-o</option></term>
 183
 184                                 <listitem><para>Controls the
 185                                 formatting of the journal entries that
 186                                 are shown. Takes one of
 187                                 <literal>short</literal>,
 188                                 <literal>short-monotonic</literal>,
 189                                 <literal>verbose</literal>,
 190                                 <literal>export</literal>,
 191                                 <literal>json</literal>,
 192                                 <literal>json-pretty</literal>,
 193                                 <literal>json-sse</literal>,
 194                                 <literal>cat</literal>. <literal>short</literal>
 195                                 is the default and generates an output
 196                                 that is mostly identical to the
 197                                 formatting of classic syslog log
 198                                 files, showing one line per journal
 199                                 entry. <literal>short-monotonic</literal>
 200                                 is very similar but shows monotonic
 201                                 timestamps instead of wallclock
 202                                 timestamps. <literal>verbose</literal>
 203                                 shows the full structured entry items
 204                                 with all
 205                                 fields. <literal>export</literal>
 206                                 serializes the journal into a binary
 207                                 (but mostly text-based) stream
 208                                 suitable for backups and network
 209                                 transfer (see <ulink
 210                                 url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
 211                                 Export Format</ulink> for more
 212                                 information). <literal>json</literal>
 213                                 formats entries as JSON data
 214                                 structures, one per
 215                                 line (see <ulink
 216                                 url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
 217                                 JSON Format</ulink> for more
 218                                 information). <literal>json-pretty</literal>
 219                                 also formats entries as JSON data
 220                                 structures, but formats them in
 221                                 multiple lines in order to make them
 222                                 more readable for
 223                                 humans. <literal>json-sse</literal>
 224                                 also formats entries as JSON data
 225                                 structures, but wraps them in a format
 226                                 suitable for <ulink
 227                                 url="https://developer.mozilla.org/en-US/docs/Server-sent_events/Using_server-sent_events">Server-Sent
 228                                 Events</ulink>. <literal>cat</literal>
 229                                 generates a very terse output only
 230                                 showing the actual message of each
 231                                 journal entry with no meta data, not
 232                                 even a timestamp.</para></listitem>
 233                         </varlistentry>
 234
 235                         <varlistentry>
 236                                 <term><option>--catalog</option></term>
 237                                 <term><option>-x</option></term>
 238
 239                                 <listitem><para>Augment log lines with
 240                                 explanation texts from the message
 241                                 catalog. This will add explanatory
 242                                 help texts to log messages in the
 243                                 output where this is available. These
 244                                 short help texts will explain the
 245                                 context of an error or log event,
 246                                 possible solutions, as well as
 247                                 pointers to support forums, developer
 248                                 documentation and any other relevant
 249                                 manuals. Note that help texts are not
 250                                 available for all messages but only
 251                                 for selected ones.</para></listitem>
 252                         </varlistentry>
 253
 254                         <varlistentry>
 255                                 <term><option>--quiet</option></term>
 256                                 <term><option>-q</option></term>
 257
 258                                 <listitem><para>Suppresses any warning
 259                                 message regarding inaccessible system
 260                                 journals when run as normal
 261                                 user.</para></listitem>
 262                         </varlistentry>
 263
 264                         <varlistentry>
 265                                 <term><option>--merge</option></term>
 266                                 <term><option>-m</option></term>
 267
 268                                 <listitem><para>Show entries
 269                                 interleaved from all available
 270                                 journals, including remote
 271                                 ones.</para></listitem>
 272                         </varlistentry>
 273
 274                         <varlistentry>
 275                                 <term><option>--this-boot</option></term>
 276                                 <term><option>-b</option></term>
 277
 278                                 <listitem><para>Show data only from
 279                                 current boot. This will add a match
 280                                 for <literal>_BOOT_ID=</literal> for
 281                                 the current boot ID of the
 282                                 kernel.</para></listitem>
 283                         </varlistentry>
 284
 285                         <varlistentry>
 286                                 <term><option>--unit=</option></term>
 287                                 <term><option>-u</option></term>
 288
 289                                 <listitem><para>Show data only of the
 290                                 specified unit. This will add a match
 291                                 for <literal>_SYSTEMD_UNIT=</literal>
 292                                 for the specified
 293                                 unit.</para></listitem>
 294                         </varlistentry>
 295
 296                         <varlistentry>
 297                                 <term><option>-p</option></term>
 298                                 <term><option>--priority=</option></term>
 299
 300                                 <listitem><para>Filter output by
 301                                 message priorities or priority
 302                                 ranges. Takes either a single numeric
 303                                 or textual log level (i.e. between
 304                                 0/<literal>emerg</literal> and
 305                                 7/<literal>debug</literal>), or a
 306                                 range of numeric/text log levels in
 307                                 the form FROM..TO. The log levels are
 308                                 the usual syslog log levels as
 309                                 documented in
 310                                 <citerefentry><refentrytitle>syslog</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
 311                                 i.e. <literal>emerg</literal> (0),
 312                                 <literal>alert</literal> (1),
 313                                 <literal>crit</literal> (2),
 314                                 <literal>err</literal> (3),
 315                                 <literal>warning</literal> (4),
 316                                 <literal>notice</literal> (5),
 317                                 <literal>info</literal> (6),
 318                                 <literal>debug</literal> (7). If a
 319                                 single log level is specified all
 320                                 messages with this log level or a
 321                                 lower (hence more important) log level
 322                                 are shown. If a range is specified all
 323                                 messages within the range are shown,
 324                                 including both the start and the end
 325                                 value of the range. This will add
 326                                 <literal>PRIORITY=</literal> matches
 327                                 for the specified
 328                                 priorities.</para></listitem>
 329                         </varlistentry>
 330
 331                         <varlistentry>
 332                                 <term><option>--cursor=</option></term>
 333                                 <term><option>-c</option></term>
 334
 335                                 <listitem><para>Start showing entries
 336                                 from the location in the journal
 337                                 specified by the passed
 338                                 cursor.</para></listitem>
 339                         </varlistentry>
 340
 341                         <varlistentry>
 342                                 <term><option>--since=</option></term>
 343                                 <term><option>--until=</option></term>
 344
 345                                 <listitem><para>Start showing entries
 346                                 on or newer than the specified date,
 347                                 or on or older than the specified
 348                                 date, respectively. Date specifications should be of
 349                                 the format "2012-10-30 18:17:16". If
 350                                 the time part is omitted, 00:00:00 is
 351                                 assumed. If only the seconds component
 352                                 is omitted, :00 is assumed. If the
 353                                 date component is ommitted, the
 354                                 current day is assumed. Alternatively
 355                                 the strings
 356                                 <literal>yesterday</literal>,
 357                                 <literal>today</literal>,
 358                                 <literal>tomorrow</literal> are
 359                                 understood, which refer to 00:00:00 of
 360                                 the day before the current day, the
 361                                 current day, or the day after the
 362                                 current day, respectively. <literal>now</literal>
 363                                 refers to the current time. Finally,
 364                                 relative times may be specified,
 365                                 prefixed with <literal>-</literal> or
 366                                 <literal>+</literal>, referring to
 367                                 times before or after the current
 368                                 time, respectively.</para></listitem>
 369                         </varlistentry>
 370
 371                         <varlistentry>
 372                                 <term><option>--field=</option></term>
 373                                 <term><option>-F</option></term>
 374
 375                                 <listitem><para>Print all possible
 376                                 data values the specified field can
 377                                 take in all entries of the
 378                                 journal.</para></listitem>
 379                         </varlistentry>
 380
 381                         <varlistentry>
 382                                 <term><option>--directory=</option></term>
 383                                 <term><option>-D</option></term>
 384
 385                                 <listitem><para>Takes an absolute
 386                                 directory path as argument. If
 387                                 specified journalctl will operate on the
 388                                 specified journal directory instead of
 389                                 the default runtime and system journal
 390                                 paths.</para></listitem>
 391                         </varlistentry>
 392
 393                         <varlistentry>
 394                                 <term><option>--new-id128</option></term>
 395
 396                                 <listitem><para>Instead of showing
 397                                 journal contents generate a new 128
 398                                 bit ID suitable for identifying
 399                                 messages. This is intended for usage
 400                                 by developers who need a new
 401                                 identifier for a new message they
 402                                 introduce and want to make
 403                                 recognizable. Will print the new ID in
 404                                 three different formats which can be
 405                                 copied into source code or
 406                                 similar.</para></listitem>
 407                         </varlistentry>
 408
 409                         <varlistentry>
 410                                 <term><option>--header</option></term>
 411
 412                                 <listitem><para>Instead of showing
 413                                 journal contents show internal header
 414                                 information of the journal fields
 415                                 accessed.</para></listitem>
 416                         </varlistentry>
 417
 418                         <varlistentry>
 419                                 <term><option>--disk-usage</option></term>
 420
 421                                 <listitem><para>Shows the current disk
 422                                 usage of all
 423                                 journal files.</para></listitem>
 424                         </varlistentry>
 425
 426                         <varlistentry>
 427                                 <term><option>--list-catalog</option></term>
 428
 429                                 <listitem><para>List the contents of
 430                                 the message catalog, as table of
 431                                 message IDs plus their short
 432                                 description strings.</para></listitem>
 433                         </varlistentry>
 434
 435                         <varlistentry>
 436                                 <term><option>--update-catalog</option></term>
 437
 438                                 <listitem><para>Update the message
 439                                 catalog index. This command needs to
 440                                 be executed each time new catalog
 441                                 files are installed, removed or
 442                                 updated to rebuild the binary catalog
 443                                 index.</para></listitem>
 444                         </varlistentry>
 445
 446                         <varlistentry>
 447                                 <term><option>--setup-keys</option></term>
 448
 449                                 <listitem><para>Instead of showing
 450                                 journal contents generate a new key
 451                                 pair for Forward Secure Sealing
 452                                 (FSS). This will generate a sealing
 453                                 key and a verification key. The
 454                                 sealing key is stored in the journal
 455                                 data directory and shall remain on the
 456                                 host. The verification key should be
 457                                 stored externally.</para></listitem>
 458                         </varlistentry>
 459
 460                         <varlistentry>
 461                                 <term><option>--interval=</option></term>
 462
 463                                 <listitem><para>Specifies the change
 464                                 interval for the sealing key, when
 465                                 generating an FSS key pair with
 466                                 <option>--setup-keys</option>. Shorter
 467                                 intervals increase CPU consumption but
 468                                 shorten the time range of
 469                                 undetectable journal
 470                                 alterations. Defaults to
 471                                 15min.</para></listitem>
 472                         </varlistentry>
 473
 474                         <varlistentry>
 475                                 <term><option>--verify</option></term>
 476
 477                                 <listitem><para>Check the journal file
 478                                 for internal consistency. If the
 479                                 file has been generated with FSS
 480                                 enabled, and the FSS verification key
 481                                 has been specified with
 482                                 <option>--verify-key=</option>
 483                                 authenticity of the journal file is
 484                                 verified.</para></listitem>
 485                         </varlistentry>
 486
 487                         <varlistentry>
 488                                 <term><option>--verify-key=</option></term>
 489
 490                                 <listitem><para>Specifies the FSS
 491                                 verification key to use for the
 492                                 <option>--verify</option>
 493                                 operation.</para></listitem>
 494                         </varlistentry>
 495
 496                 </variablelist>
 497         </refsect1>
 498
 499         <refsect1>
 500                 <title>Exit status</title>
 501
 502                 <para>On success 0 is returned, a non-zero failure
 503                 code otherwise.</para>
 504         </refsect1>
 505
 506         <refsect1>
 507                 <title>Environment</title>
 508
 509                 <variablelist>
 510                         <varlistentry>
 511                                 <term><varname>$SYSTEMD_PAGER</varname></term>
 512                                 <listitem><para>Pager to use when
 513                                 <option>--no-pager</option> is not given;
 514                                 overrides <varname>$PAGER</varname>.  Setting
 515                                 this to an empty string or the value
 516                                 <literal>cat</literal> is equivalent to passing
 517                                 <option>--no-pager</option>.</para></listitem>
 518                         </varlistentry>
 519                 </variablelist>
 520         </refsect1>
 521
 522         <refsect1>
 523                 <title>Examples</title>
 524
 525                 <para>Without arguments all collected logs are shown
 526                 unfiltered:</para>
 527
 528                 <programlisting>journalctl</programlisting>
 529
 530                 <para>With one match specified all entries with a field matching the expression are shown:</para>
 531
 532                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service</programlisting>
 533
 534                 <para>If two different fields are matched only entries matching both expressions at the same time are shown:</para>
 535
 536                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097</programlisting>
 537
 538                 <para>If two matches refer to the same field all entries matching either expression are shown:</para>
 539
 540                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _SYSTEMD_UNIT=dbus.service</programlisting>
 541
 542                 <para>If the separator "<literal>+</literal>" is used
 543                 two expressions may be combined in a logical OR. The
 544                 following will show all messages from the Avahi
 545                 service process with the PID 28097 plus all messages
 546                 from the D-Bus service (from any of its
 547                 processes):</para>
 548
 549                 <programlisting>journalctl _SYSTEMD_UNIT=avahi-daemon.service _PID=28097 + _SYSTEMD_UNIT=dbus.service</programlisting>
 550
 551                 <para>Show all logs generated by the D-Bus executable:</para>
 552
 553                 <programlisting>journalctl /usr/bin/dbus-daemon</programlisting>
 554
 555                 <para>Show all logs of the kernel device node <filename>/dev/sda</filename>:</para>
 556
 557                 <programlisting>journalctl /dev/sda</programlisting>
 558
 559         </refsect1>
 560
 561         <refsect1>
 562                 <title>See Also</title>
 563                 <para>
 564                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 565                         <citerefentry><refentrytitle>systemd-journald.service</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
 566                         <citerefentry><refentrytitle>systemctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
 567                         <citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
 568                         <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>
 569                 </para>
 570         </refsect1>
 571
 572 </refentry>