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zsh_completion: Split out zsh _systemd-analyze
[elogind.git] / man / systemd.journal-fields.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 2010 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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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="systemd.journal-fields">
25
26         <refentryinfo>
27                 <title>systemd.journal-fields</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>systemd.journal-fields</refentrytitle>
42                 <manvolnum>7</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>systemd.journal-fields</refname>
47                 <refpurpose>Special journal fields</refpurpose>
48         </refnamediv>
49
50         <refsect1>
51                 <title>Description</title>
52
53                 <para>Entries in the journal resemble an environment
54                 block in their syntax, however with fields that can
55                 include binary data. Primarily, fields are formatted
56                 UTF-8 text strings, and binary formatting is used only
57                 where formatting as UTF-8 text strings makes little
58                 sense. New fields may freely be defined by
59                 applications, but a few fields have special
60                 meaning. All fields with special meanings are
61                 optional. In some cases fields may appear more than
62                 once per entry.</para>
63         </refsect1>
64
65         <refsect1>
66                 <title>User Journal Fields</title>
67
68                 <para>User fields are fields that are directly passed
69                 from clients and stored in the journal.</para>
70
71                 <variablelist class='journal-directives'>
72                         <varlistentry>
73                                 <term><varname>MESSAGE=</varname></term>
74                                 <listitem>
75                                         <para>The human-readable
76                                         message string for this
77                                         entry. This is supposed to be
78                                         the primary text shown to the
79                                         user. It is usually not
80                                         translated (but might be in
81                                         some cases), and is not
82                                         supposed to be parsed for meta
83                                         data.</para>
84                                 </listitem>
85                         </varlistentry>
86
87                         <varlistentry>
88                                 <term><varname>MESSAGE_ID=</varname></term>
89                                 <listitem>
90                                         <para>A 128-bit message
91                                         identifier ID for recognizing
92                                         certain message types, if this
93                                         is desirable. This should
94                                         contain a 128-bit ID formatted
95                                         as a lower-case hexadecimal
96                                         string, without any separating
97                                         dashes or suchlike. This is
98                                         recommended to be a
99                                         UUID-compatible ID, but this is not
100                                         enforced, and formatted
101                                         differently. Developers can
102                                         generate a new ID for this
103                                         purpose with <command>journalctl
104                                         <option>--new-id</option></command>.
105                                         </para>
106                                 </listitem>
107                         </varlistentry>
108
109                         <varlistentry>
110                                 <term><varname>PRIORITY=</varname></term>
111                                 <listitem>
112                                         <para>A priority value between
113                                         0 (<literal>emerg</literal>)
114                                         and 7
115                                         (<literal>debug</literal>)
116                                         formatted as a decimal
117                                         string. This field is
118                                         compatible with syslog's
119                                         priority concept.</para>
120                                 </listitem>
121                         </varlistentry>
122
123                         <varlistentry>
124                                 <term><varname>CODE_FILE=</varname></term>
125                                 <term><varname>CODE_LINE=</varname></term>
126                                 <term><varname>CODE_FUNC=</varname></term>
127                                 <listitem>
128                                         <para>The code location
129                                         generating this message, if
130                                         known. Contains the source
131                                         filename, the line number and
132                                         the function name.</para>
133                                 </listitem>
134                         </varlistentry>
135
136                         <varlistentry>
137                                 <term><varname>ERRNO=</varname></term>
138                                 <listitem>
139                                         <para>The low-level Unix error
140                                         number causing this entry, if
141                                         any. Contains the numeric
142                                         value of
143                                         <citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>
144                                         formatted as a decimal
145                                         string.</para>
146                                 </listitem>
147                         </varlistentry>
148
149                         <varlistentry>
150                                 <term><varname>SYSLOG_FACILITY=</varname></term>
151                                 <term><varname>SYSLOG_IDENTIFIER=</varname></term>
152                                 <term><varname>SYSLOG_PID=</varname></term>
153                                 <listitem>
154                                         <para>Syslog compatibility
155                                         fields containing the facility
156                                         (formatted as decimal string),
157                                         the identifier string
158                                         (i.e. "tag"), and the client
159                                         PID.</para>
160                                 </listitem>
161
162                         </varlistentry>
163                 </variablelist>
164         </refsect1>
165
166         <refsect1>
167                 <title>Trusted Journal Fields</title>
168
169                 <para>Fields prefixed with an underscore are trusted
170                 fields, i.e. fields that are implicitly added by the
171                 journal and cannot be altered by client code.</para>
172
173                 <variablelist class='journal-directives'>
174                         <varlistentry>
175                                 <term><varname>_PID=</varname></term>
176                                 <term><varname>_UID=</varname></term>
177                                 <term><varname>_GID=</varname></term>
178                                 <listitem>
179                                         <para>The process, user and
180                                         group ID of the process the
181                                         journal entry originates from
182                                         formatted as a decimal
183                                         string.</para>
184                                 </listitem>
185                         </varlistentry>
186
187                         <varlistentry>
188                                 <term><varname>_COMM=</varname></term>
189                                 <term><varname>_EXE=</varname></term>
190                                 <term><varname>_CMDLINE=</varname></term>
191                                 <listitem>
192                                         <para>The name, the executable
193                                         path and the command line of
194                                         the process the journal entry
195                                         originates from.</para>
196                                 </listitem>
197                         </varlistentry>
198
199                         <varlistentry>
200                                 <term><varname>_CAP_EFFECTIVE=</varname></term>
201                                 <listitem>
202                                         <para>The effective <citerefentry><refentrytitle>capabilities</refentrytitle><manvolnum>7</manvolnum></citerefentry> of
203                                         the process the journal entry
204                                         originates from.</para>
205                                 </listitem>
206                         </varlistentry>
207
208                         <varlistentry>
209                                 <term><varname>_AUDIT_SESSION=</varname></term>
210                                 <term><varname>_AUDIT_LOGINUID=</varname></term>
211                                 <listitem>
212                                         <para>The session and login
213                                         UID of the process the journal
214                                         entry originates from, as
215                                         maintained by the kernel audit
216                                         subsystem.</para>
217                                 </listitem>
218                         </varlistentry>
219
220                         <varlistentry>
221                                 <term><varname>_SYSTEMD_CGROUP=</varname></term>
222                                 <term><varname>_SYSTEMD_SESSION=</varname></term>
223                                 <term><varname>_SYSTEMD_UNIT=</varname></term>
224                                 <term><varname>_SYSTEMD_USER_UNIT=</varname></term>
225                                 <term><varname>_SYSTEMD_OWNER_UID=</varname></term>
226
227                                 <listitem>
228                                         <para>The control group path in
229                                         the systemd hierarchy, the
230                                         systemd session ID (if any),
231                                         the systemd unit name (if any),
232                                         the systemd user session unit name (if any)
233                                         and the owner UID of the
234                                         systemd session (if any) of
235                                         the process the journal entry
236                                         originates from.</para>
237                                 </listitem>
238                         </varlistentry>
239
240                         <varlistentry>
241                                 <term><varname>_SELINUX_CONTEXT=</varname></term>
242                                 <listitem>
243                                         <para>The SELinux security
244                                         context of the process the
245                                         journal entry originates
246                                         from.</para>
247                                 </listitem>
248                         </varlistentry>
249
250                         <varlistentry>
251                                 <term><varname>_SOURCE_REALTIME_TIMESTAMP=</varname></term>
252                                 <listitem>
253                                         <para>The earliest trusted
254                                         timestamp of the message, if
255                                         any is known that is different
256                                         from the reception time of the
257                                         journal. This is the time in
258                                         microseconds since the epoch UTC,
259                                         formatted as a decimal
260                                         string.</para>
261                                 </listitem>
262                         </varlistentry>
263
264                         <varlistentry>
265                                 <term><varname>_BOOT_ID=</varname></term>
266                                 <listitem>
267                                         <para>The kernel boot ID for
268                                         the boot the message was
269                                         generated in, formatted as
270                                         a 128-bit hexadecimal
271                                         string.</para>
272                                 </listitem>
273                         </varlistentry>
274
275                         <varlistentry>
276                                 <term><varname>_MACHINE_ID=</varname></term>
277                                 <listitem>
278                                         <para>The machine ID of the
279                                         originating host, as available
280                                         in
281                                         <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
282                                 </listitem>
283                         </varlistentry>
284
285                         <varlistentry>
286                                 <term><varname>_HOSTNAME=</varname></term>
287                                 <listitem>
288                                         <para>The name of the
289                                         originating host.</para>
290                                 </listitem>
291                         </varlistentry>
292
293                         <varlistentry>
294                                 <term><varname>_TRANSPORT=</varname></term>
295                                 <listitem>
296                                         <para>How the entry was
297                                         received by the journal
298                                         service. Valid transports are:
299                                         </para>
300                                         <variablelist>
301                                                 <varlistentry>
302                                                         <term>
303                                                                 <option>driver</option>
304                                                         </term>
305                                                         <listitem>
306                                                                 <para>for
307                                                                 internally
308                                                                 generated
309                                                                 messages
310                                                                 </para>
311                                                         </listitem>
312                                                 </varlistentry>
313
314                                                 <varlistentry>
315                                                         <term>
316                                                                 <option>syslog</option>
317                                                         </term>
318                                                         <listitem>
319                                                                 <para>for those
320                                                                 received via the
321                                                                 local syslog
322                                                                 socket with the
323                                                                 syslog protocol
324                                                                 </para>
325                                                         </listitem>
326                                                 </varlistentry>
327
328                                                 <varlistentry>
329                                                         <term>
330                                                                 <option>journal</option>
331                                                         </term>
332                                                         <listitem>
333                                                                 <para>for those
334                                                                 received via the
335                                                                 native journal
336                                                                 protocol
337                                                                 </para>
338                                                         </listitem>
339                                                 </varlistentry>
340
341                                                 <varlistentry>
342                                                         <term>
343                                                                 <option>stdout</option>
344                                                         </term>
345                                                         <listitem>
346                                                                 <para>for those
347                                                                 read from a
348                                                                 service's
349                                                                 standard output
350                                                                 or error output
351                                                                 </para>
352                                                         </listitem>
353                                                 </varlistentry>
354
355                                                 <varlistentry>
356                                                         <term>
357                                                                 <option>kernel</option>
358                                                         </term>
359                                                         <listitem>
360                                                                 <para>for those
361                                                                 read from the
362                                                                 kernel
363                                                                 </para>
364                                                         </listitem>
365                                                 </varlistentry>
366                                         </variablelist>
367                                 </listitem>
368                         </varlistentry>
369                 </variablelist>
370         </refsect1>
371
372         <refsect1>
373                 <title>Kernel Journal Fields</title>
374
375                 <para>Kernel fields are fields that are used by
376                 messages originating in the kernel and stored in the
377                 journal.</para>
378
379                 <variablelist class='journal-directives'>
380                         <varlistentry>
381                                 <term><varname>_KERNEL_DEVICE=</varname></term>
382                                 <listitem>
383                                         <para>The kernel device
384                                         name. If the entry is
385                                         associated to a block device,
386                                         the major and minor of the
387                                         device node, separated by <literal>:</literal>
388                                         and prefixed by <literal>b</literal>. Similar
389                                         for character devices, but
390                                         prefixed by <literal>c</literal>. For network
391                                         devices the interface index,
392                                         prefixed by <literal>n</literal>. For all other
393                                         devices <literal>+</literal> followed by the
394                                         subsystem name, followed by
395                                         <literal>:</literal>, followed by the kernel
396                                         device name.</para>
397                                 </listitem>
398                         </varlistentry>
399                         <varlistentry>
400                                 <term><varname>_KERNEL_SUBSYSTEM=</varname></term>
401                                 <listitem>
402                                         <para>The kernel subsystem name.</para>
403                                 </listitem>
404                         </varlistentry>
405                         <varlistentry>
406                                 <term><varname>_UDEV_SYSNAME=</varname></term>
407                                 <listitem>
408                                         <para>The kernel device name
409                                         as it shows up in the device
410                                         tree below
411                                         <filename>/sys</filename>.</para>
412                                 </listitem>
413                         </varlistentry>
414                         <varlistentry>
415                                 <term><varname>_UDEV_DEVNODE=</varname></term>
416                                 <listitem>
417                                         <para>The device node path of
418                                         this device in
419                                         <filename>/dev</filename>.</para>
420                                 </listitem>
421                         </varlistentry>
422                         <varlistentry>
423                                 <term><varname>_UDEV_DEVLINK=</varname></term>
424                                 <listitem>
425                                         <para>Additional symlink names
426                                         pointing to the device node in
427                                         <filename>/dev</filename>. This
428                                         field is frequently set more
429                                         than once per entry.</para>
430                                 </listitem>
431                         </varlistentry>
432                 </variablelist>
433         </refsect1>
434
435         <refsect1>
436                 <title>Fields to log on behalf of a different program</title>
437
438                 <para>Fields in this section are used by programs
439                 to specify that they are logging on behalf of another
440                 program or unit.
441                 </para>
442
443                 <para>Fields used by the <command>systemd-coredump</command>
444                 coredump kernel helper:
445                 </para>
446
447                 <variablelist class='journal-directives'>
448                         <varlistentry>
449                                 <term><varname>COREDUMP_UNIT=</varname></term>
450                                 <term><varname>COREDUMP_USER_UNIT=</varname></term>
451                                 <listitem>
452                                         <para>Used to annotate
453                                         messages containing coredumps from
454                                         system and session units.
455                                         See
456                                         <citerefentry><refentrytitle>systemd-coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
457                                         </para>
458                                 </listitem>
459                         </varlistentry>
460                 </variablelist>
461
462                 <para>Priviledged programs (currently UID 0) may
463                 attach <varname>OBJECT_PID=</varname> to a
464                 message. This will instruct
465                 <command>systemd-journald</command> to attach
466                 additional fields on behalf of the caller:</para>
467
468                 <variablelist class='journal-directives'>
469                         <varlistentry>
470                                 <term><varname>OBJECT_PID=<replaceable>PID</replaceable></varname></term>
471                                 <listitem>
472                                         <para>PID of the program that this
473                                         message pertains to.
474                                         </para>
475                                 </listitem>
476                         </varlistentry>
477
478                         <varlistentry>
479                                 <term><varname>OBJECT_UID=</varname></term>
480                                 <term><varname>OBJECT_GID=</varname></term>
481                                 <term><varname>OBJECT_COMM=</varname></term>
482                                 <term><varname>OBJECT_EXE=</varname></term>
483                                 <term><varname>OBJECT_CMDLINE=</varname></term>
484                                 <term><varname>OBJECT_AUDIT_SESSION=</varname></term>
485                                 <term><varname>OBJECT_AUDIT_LOGINUID=</varname></term>
486                                 <term><varname>OBJECT_SYSTEMD_CGROUP=</varname></term>
487                                 <term><varname>OBJECT_SYSTEMD_SESSION=</varname></term>
488                                 <term><varname>OBJECT_SYSTEMD_OWNER_UID=</varname></term>
489                                 <term><varname>OBJECT_SYSTEMD_UNIT=</varname></term>
490                                 <term><varname>OBJECT_SYSTEMD_USER_UNIT=</varname></term>
491                                 <listitem>
492                                         <para>These are additional fields added automatically
493                                         by <command>systemd-journald</command>.
494                                         Their meaning is the same as
495                                         <varname>_UID=</varname>,
496                                         <varname>_GID=</varname>,
497                                         <varname>_COMM=</varname>,
498                                         <varname>_EXE=</varname>,
499                                         <varname>_CMDLINE=</varname>,
500                                         <varname>_AUDIT_SESSION=</varname>,
501                                         <varname>_AUDIT_LOGINUID=</varname>,
502                                         <varname>_SYSTEMD_CGROUP=</varname>,
503                                         <varname>_SYSTEMD_SESSION=</varname>,
504                                         <varname>_SYSTEMD_UNIT=</varname>,
505                                         <varname>_SYSTEMD_USER_UNIT=</varname>, and
506                                         <varname>_SYSTEMD_OWNER_UID=</varname>
507                                         as described above, except that the
508                                         process identified by <replaceable>PID</replaceable>
509                                         is described, instead of the process
510                                         which logged the message.</para>
511                                 </listitem>
512                         </varlistentry>
513                 </variablelist>
514
515
516         </refsect1>
517
518         <refsect1>
519                 <title>Address Fields</title>
520
521                 <para>During serialization into external formats, such
522                 as the <ulink
523                 url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
524                 Export Format</ulink> or the <ulink
525                 url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
526                 JSON Format</ulink>, the addresses of journal entries
527                 are serialized into fields prefixed with double
528                 underscores. Note that these aren't proper fields when
529                 stored in the journal but for addressing meta data of
530                 entries. They cannot be written as part of structured
531                 log entries via calls such as
532                 <citerefentry><refentrytitle>sd_journal_send</refentrytitle><manvolnum>3</manvolnum></citerefentry>. They
533                 may also not be used as matches for
534                 <citerefentry><refentrytitle>sd_journal_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry></para>
535
536                 <variablelist class='journal-directives'>
537                         <varlistentry>
538                                 <term><varname>__CURSOR=</varname></term>
539                                 <listitem>
540                                         <para>The cursor for the
541                                         entry. A cursor is an opaque
542                                         text string that uniquely
543                                         describes the position of an
544                                         entry in the journal and is
545                                         portable across machines,
546                                         platforms and journal files.
547                                         </para>
548                                 </listitem>
549                         </varlistentry>
550
551                         <varlistentry>
552                                 <term><varname>__REALTIME_TIMESTAMP=</varname></term>
553                                 <listitem>
554                                         <para>The wallclock time
555                                         (<constant>CLOCK_REALTIME</constant>)
556                                         at the point in time the entry
557                                         was received by the journal,
558                                         in microseconds since the epoch
559                                         UTC, formatted as a decimal
560                                         string. This has different
561                                         properties from
562                                         <literal>_SOURCE_REALTIME_TIMESTAMP=</literal>,
563                                         as it is usually a bit later
564                                         but more likely to be monotonic.
565                                         </para>
566                                 </listitem>
567                         </varlistentry>
568
569                         <varlistentry>
570                                 <term><varname>__MONOTONIC_TIMESTAMP=</varname></term>
571                                 <listitem>
572                                         <para>The monotonic time
573                                         (<constant>CLOCK_MONOTONIC</constant>)
574                                         at the point in time the entry
575                                         was received by the journal in
576                                         microseconds, formatted as a decimal
577                                         string. To be useful as an
578                                         address for the entry, this
579                                         should be combined with with the
580                                         boot ID in <literal>_BOOT_ID=</literal>.
581                                         </para>
582                                 </listitem>
583                         </varlistentry>
584                 </variablelist>
585         </refsect1>
586
587         <refsect1>
588                   <title>See Also</title>
589                   <para>
590                           <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
591                           <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
592                           <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
593                           <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
594                           <citerefentry><refentrytitle>systemd-coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
595                           <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
596                   </para>
597         </refsect1>
598
599 </refentry>