[thirdparty/systemd.git] / man / systemd.journal-fields.xml

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<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
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<refentry id="systemd.journal-fields">

        <refentryinfo>
                <title>systemd.journal-fields</title>
                <productname>systemd</productname>

                <authorgroup>
                        <author>
                                <contrib>Developer</contrib>
                                <firstname>Lennart</firstname>
                                <surname>Poettering</surname>
                                <email>lennart@poettering.net</email>
                        </author>
                </authorgroup>
        </refentryinfo>

        <refmeta>
                <refentrytitle>systemd.journal-fields</refentrytitle>
                <manvolnum>7</manvolnum>
        </refmeta>

        <refnamediv>
                <refname>systemd.journal-fields</refname>
                <refpurpose>Special journal fields</refpurpose>
        </refnamediv>

        <refsect1>
                <title>Description</title>

                <para>Entries in the journal resemble an environment
                block in their syntax, however with fields that can
                include binary data. Primarily, fields are formatted
                UTF-8 text strings, and binary formatting is used only
                where formatting as UTF-8 text strings makes little
                sense. New fields may freely be defined by
                applications, but a few fields have special
                meaning. All fields with special meanings are
                optional. In some cases fields may appear more than
                once per entry.</para>
        </refsect1>

        <refsect1>
                <title>User Journal Fields</title>

                <para>User fields are fields that are directly passed
                from clients and stored in the journal.</para>

                <variablelist class='journal-directives'>
                        <varlistentry>
                                <term><varname>MESSAGE=</varname></term>
                                <listitem>
                                        <para>The human readable
                                        message string for this
                                        entry. This is supposed to be
                                        the primary text shown to the
                                        user. It is usually not
                                        translated (but might be in
                                        some cases), and is not
                                        supposed to be parsed for meta
                                        data.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>MESSAGE_ID=</varname></term>
                                <listitem>
                                        <para>A 128bit message
                                        identifier ID for recognizing
                                        certain message types, if this
                                        is desirable. This should
                                        contain a 128bit id formatted
                                        as lower-case hexadecimal
                                        string, without any separating
                                        dashes or suchlike. This is
                                        recommended to be a UUID
                                        compatible ID, but this is not
                                        enforced, and formatted
                                        differently. Developers can
                                        generate a new ID for this
                                        purpose with
                                        <command>journalctl
                                        --new-id</command>.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>PRIORITY=</varname></term>
                                <listitem>
                                        <para>A priority value between
                                        0 (<literal>emerg</literal>)
                                        and 7
                                        (<literal>debug</literal>)
                                        formatted as decimal
                                        string. This field is
                                        compatible with syslog's
                                        priority concept.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>CODE_FILE=</varname></term>
                                <term><varname>CODE_LINE=</varname></term>
                                <term><varname>CODE_FUNC=</varname></term>
                                <listitem>
                                        <para>The code location
                                        generating this message, if
                                        known. Contains the source
                                        file name, the line number and
                                        the function name.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>ERRNO=</varname></term>
                                <listitem>
                                        <para>The low-level Unix error
                                        number causing this entry, if
                                        any. Contains the numeric
                                        value of
                                        <citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                                        formatted as decimal
                                        string.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>SYSLOG_FACILITY=</varname></term>
                                <term><varname>SYSLOG_IDENTIFIER=</varname></term>
                                <term><varname>SYSLOG_PID=</varname></term>
                                <listitem>
                                        <para>Syslog compatibility
                                        fields containing the facility
                                        (formatted as decimal string),
                                        the identifier string
                                        (i.e. "tag"), and the client
                                        PID.</para>
                                </listitem>

                        </varlistentry>
                </variablelist>
        </refsect1>

        <refsect1>
                <title>Trusted Journal Fields</title>

                <para>Fields prefixed with an underscore are trusted
                fields, i.e. fields that are implicitly added by the
                journal and cannot be altered by client code.</para>

                <variablelist class='journal-directives'>
                        <varlistentry>
                                <term><varname>_PID=</varname></term>
                                <term><varname>_UID=</varname></term>
                                <term><varname>_GID=</varname></term>
                                <listitem>
                                        <para>The process, user and
                                        group ID of the process the
                                        journal entry originates from
                                        formatted as decimal
                                        string.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>_COMM=</varname></term>
                                <term><varname>_EXE=</varname></term>
                                <term><varname>_CMDLINE=</varname></term>
                                <listitem>
                                        <para>The name, the executable
                                        path and the command line of
                                        the process the journal entry
                                        originates from.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>_AUDIT_SESSION=</varname></term>
                                <term><varname>_AUDIT_LOGINUID=</varname></term>
                                <listitem>
                                        <para>The session and login
                                        UID of the process the journal
                                        entry originates from, as
                                        maintained by the kernel audit
                                        subsystem.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>_SYSTEMD_CGROUP=</varname></term>
                                <term><varname>_SYSTEMD_SESSION=</varname></term>
                                <term><varname>_SYSTEMD_UNIT=</varname></term>
                                <term><varname>_SYSTEMD_USER_UNIT=</varname></term>
                                <term><varname>_SYSTEMD_OWNER_UID=</varname></term>

                                <listitem>
                                        <para>The control group path in
                                        the systemd hierarchy, the
                                        systemd session ID (if any),
                                        the systemd unit name (if any),
                                        the systemd user session unit name (if any)
                                        and the owner UID of the
                                        systemd session (if any) of
                                        the process the journal entry
                                        originates from.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>_SELINUX_CONTEXT=</varname></term>
                                <listitem>
                                        <para>The SELinux security
                                        context of the process the
                                        journal entry originates
                                        from.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>_SOURCE_REALTIME_TIMESTAMP=</varname></term>
                                <listitem>
                                        <para>The earliest trusted
                                        timestamp of the message, if
                                        any is known that is different
                                        from the reception time of the
                                        journal. This is the time in
                                        usec since the epoch UTC
                                        formatted as decimal
                                        string.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>_BOOT_ID=</varname></term>
                                <listitem>
                                        <para>The kernel boot ID for
                                        the boot the message was
                                        generated in, formatted as
                                        128bit hexadecimal
                                        string.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>_MACHINE_ID=</varname></term>
                                <listitem>
                                        <para>The machine ID of the
                                        originating host, as available
                                        in
                                        <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>_HOSTNAME=</varname></term>
                                <listitem>
                                        <para>The name of the
                                        originating host.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>_TRANSPORT=</varname></term>
                                <listitem>
                                        <para>How the entry was
                                        received by the journal
                                        service. One of
                                        <literal>driver</literal>,
                                        <literal>syslog</literal>,
                                        <literal>journal</literal>,
                                        <literal>stdout</literal>,
                                        <literal>kernel</literal> for
                                        internally generated messages,
                                        for those received via the
                                        local syslog socket with the
                                        syslog protocol, for those
                                        received via the native
                                        journal protocol, for the
                                        those read from a services'
                                        standard output or error
                                        output, or for those read
                                        from the kernel, respectively.
                                        </para>
                                </listitem>
                        </varlistentry>
                </variablelist>
        </refsect1>

        <refsect1>
                <title>Kernel Journal Fields</title>

                <para>Kernel fields are fields that are used by
                messages originating in the kernel and stored in the
                journal.</para>

                <variablelist class='journal-directives'>
                        <varlistentry>
                                <term><varname>_KERNEL_DEVICE=</varname></term>
                                <listitem>
                                        <para>The kernel device
                                        name. If the entry is
                                        associated to a block device,
                                        the major and minor of the
                                        device node, separated by ':'
                                        and prefixed by 'b'. Similar
                                        for character devices, but
                                        prefixed by 'c'. For network
                                        devices the interface index,
                                        prefixed by 'n'. For all other
                                        devices '+' followed by the
                                        subsystem name, followed by
                                        ':', followed by the kernel
                                        device name.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><varname>_KERNEL_SUBSYSTEM=</varname></term>
                                <listitem>
                                        <para>The kernel subsystem name.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><varname>_UDEV_SYSNAME=</varname></term>
                                <listitem>
                                        <para>The kernel device name
                                        as it shows up in the device
                                        tree below
                                        <filename>/sys</filename>.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><varname>_UDEV_DEVNODE=</varname></term>
                                <listitem>
                                        <para>The device node path of
                                        this device in
                                        <filename>/dev</filename>.</para>
                                </listitem>
                        </varlistentry>
                        <varlistentry>
                                <term><varname>_UDEV_DEVLINK=</varname></term>
                                <listitem>
                                        <para>Additional symlink names
                                        pointing to the device node in
                                        <filename>/dev</filename>. This
                                        field is frequently set more
                                        than once per entry.</para>
                                </listitem>
                        </varlistentry>
                </variablelist>
        </refsect1>

        <refsect1>
                <title>Special Journal Fields</title>

                <para>Fields used by the <command>systemd-coredump</command>
                coredump kernel helper.
                </para>

                <variablelist class='journal-directives'>
                        <varlistentry>
                                <term><varname>COREDUMP_UNIT=</varname></term>
                                <term><varname>COREDUMP_USER_UNIT=</varname></term>
                                <listitem>
                                        <para>Used to annotate
                                        messages containing coredumps from
                                        system and session units.
                                        See
                                        <citerefentry><refentrytitle>systemd-coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
                                        </para>
                                </listitem>
                        </varlistentry>
                </variablelist>
        </refsect1>

        <refsect1>
                <title>Address Fields</title>

                <para>During serialization into external formats, such
                as the <ulink
                url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
                Export Format</ulink> or the <ulink
                url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
                JSON Format</ulink>, the addresses of journal entries
                are serialized into fields prefixed with double
                underscores. Note that these aren't proper fields when
                stored in the journal, but addressing meta data of
                entries. They cannot be written as part of structured
                log entries via calls such as
                <citerefentry><refentrytitle>sd_journal_send</refentrytitle><manvolnum>3</manvolnum></citerefentry>. They
                may also not be used as matches for
                <citerefentry><refentrytitle>sd_journal_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry></para>

                <variablelist class='journal-directives'>
                        <varlistentry>
                                <term><varname>__CURSOR=</varname></term>
                                <listitem>
                                        <para>The cursor for the
                                        entry. A cursor is an opaque
                                        text string that uniquely
                                        describes the position of an
                                        entry in the journal and is
                                        portable across machines,
                                        platforms and journal
                                        files.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>__REALTIME_TIMESTAMP=</varname></term>
                                <listitem>
                                        <para>The wallclock time
                                        (CLOCK_REALTIME) at the point
                                        in time the entry was received
                                        by the journal, in usec since
                                        the epoch UTC formatted as
                                        decimal string. This has
                                        different properties from
                                        <literal>_SOURCE_REALTIME_TIMESTAMP=</literal>
                                        as it is usually a bit later
                                        but more likely to be
                                        monotonic.</para>
                                </listitem>
                        </varlistentry>

                        <varlistentry>
                                <term><varname>__MONOTONIC_TIMESTAMP=</varname></term>
                                <listitem>
                                        <para>The monotonic time
                                        (CLOCK_MONOTONIC) at the point
                                        in time the entry was received
                                        by the journal in usec
                                        formatted as decimal
                                        string. To be useful as an
                                        address for the entry this
                                        should be combined with with
                                        boot ID in
                                        <literal>_BOOT_ID=</literal>.</para>
                                </listitem>
                        </varlistentry>
                </variablelist>
        </refsect1>

        <refsect1>
                  <title>See Also</title>
                  <para>
                          <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd-coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
                          <citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
                  </para>
        </refsect1>

</refentry>
Commit	Line	Data
ffa16db0 LP	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
5430f7f2 LP	11	under the terms of the GNU Lesser General Public License as published by
5430f7f2 LP	12	the Free Software Foundation; either version 2.1 of the License, or
ffa16db0 LP	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
5430f7f2	18	Lesser General Public License for more details.
ffa16db0	19
5430f7f2	20	You should have received a copy of the GNU Lesser General Public License
ffa16db0 LP	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
a8eedf49 LP	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
bdfb9e7f LP	61	optional. In some cases fields may appear more than
bdfb9e7f LP	62	once per entry.</para>
ffa16db0 LP	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
f6c2e28b	71	<variablelist class='journal-directives'>
ffa16db0	72	<varlistentry>
f6c2e28b	73	<term><varname>MESSAGE=</varname></term>
ffa16db0 LP	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
33ba4c4b LP	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>
ffa16db0 LP	84	</listitem>
	85	</varlistentry>
	86
	87	<varlistentry>
f6c2e28b	88	<term><varname>MESSAGE_ID=</varname></term>
ffa16db0 LP	89	<listitem>
	90	<para>A 128bit message
	91	identifier ID for recognizing
	92	certain message types, if this
	93	is desirable. This should
	94	contain a 128bit id formatted
	95	as lower-case hexadecimal
	96	string, without any separating
	97	dashes or suchlike. This is
	98	recommended to be a UUID
	99	compatible ID, but this is not
	100	enforced, and formatted
	101	differently. Developers can
	102	generate a new ID for this
	103	purpose with
	104	<command>journalctl
	105	--new-id</command>.</para>
	106	</listitem>
	107	</varlistentry>
	108
	109	<varlistentry>
f6c2e28b	110	<term><varname>PRIORITY=</varname></term>
ffa16db0 LP	111	<listitem>
	112	<para>A priority value between
	113	0 (<literal>emerg</literal>)
	114	and 7
	115	(<literal>debug</literal>)
	116	formatted as decimal
	117	string. This field is
	118	compatible with syslog's
	119	priority concept.</para>
	120	</listitem>
	121	</varlistentry>
	122
	123	<varlistentry>
f6c2e28b ZJS	124	<term><varname>CODE_FILE=</varname></term>
	125	<term><varname>CODE_LINE=</varname></term>
	126	<term><varname>CODE_FUNC=</varname></term>
ffa16db0 LP	127	<listitem>
	128	<para>The code location
	129	generating this message, if
	130	known. Contains the source
	131	file name, the line number and
	132	the function name.</para>
	133	</listitem>
	134	</varlistentry>
18c7ed18 LP	135
18c7ed18 LP	136	<varlistentry>
f6c2e28b	137	<term><varname>ERRNO=</varname></term>
18c7ed18 LP	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 decimal
	145	string.</para>
	146	</listitem>
	147	</varlistentry>
ffa16db0 LP	148
ffa16db0 LP	149	<varlistentry>
f6c2e28b ZJS	150	<term><varname>SYSLOG_FACILITY=</varname></term>
	151	<term><varname>SYSLOG_IDENTIFIER=</varname></term>
	152	<term><varname>SYSLOG_PID=</varname></term>
ffa16db0 LP	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
f6c2e28b	173	<variablelist class='journal-directives'>
ffa16db0	174	<varlistentry>
f6c2e28b ZJS	175	<term><varname>_PID=</varname></term>
	176	<term><varname>_UID=</varname></term>
	177	<term><varname>_GID=</varname></term>
ffa16db0 LP	178	<listitem>
	179	<para>The process, user and
	180	group ID of the process the
	181	journal entry originates from
	182	formatted as decimal
	183	string.</para>
	184	</listitem>
	185	</varlistentry>
	186
	187	<varlistentry>
f6c2e28b ZJS	188	<term><varname>_COMM=</varname></term>
	189	<term><varname>_EXE=</varname></term>
	190	<term><varname>_CMDLINE=</varname></term>
ffa16db0 LP	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>
f6c2e28b ZJS	200	<term><varname>_AUDIT_SESSION=</varname></term>
f6c2e28b ZJS	201	<term><varname>_AUDIT_LOGINUID=</varname></term>
ffa16db0 LP	202	<listitem>
	203	<para>The session and login
	204	UID of the process the journal
	205	entry originates from, as
	206	maintained by the kernel audit
	207	subsystem.</para>
	208	</listitem>
	209	</varlistentry>
	210
	211	<varlistentry>
f6c2e28b ZJS	212	<term><varname>_SYSTEMD_CGROUP=</varname></term>
	213	<term><varname>_SYSTEMD_SESSION=</varname></term>
	214	<term><varname>_SYSTEMD_UNIT=</varname></term>
64abe9aa	215	<term><varname>_SYSTEMD_USER_UNIT=</varname></term>
f6c2e28b	216	<term><varname>_SYSTEMD_OWNER_UID=</varname></term>
ffa16db0 LP	217
ffa16db0 LP	218	<listitem>
bb31a4ac	219	<para>The control group path in
ffa16db0 LP	220	the systemd hierarchy, the
ffa16db0 LP	221	systemd session ID (if any),
64abe9aa MT	222	the systemd unit name (if any),
64abe9aa MT	223	the systemd user session unit name (if any)
ffa16db0 LP	224	and the owner UID of the
	225	systemd session (if any) of
	226	the process the journal entry
	227	originates from.</para>
	228	</listitem>
	229	</varlistentry>
	230
	231	<varlistentry>
f6c2e28b	232	<term><varname>_SELINUX_CONTEXT=</varname></term>
ffa16db0 LP	233	<listitem>
	234	<para>The SELinux security
	235	context of the process the
	236	journal entry originates
	237	from.</para>
	238	</listitem>
	239	</varlistentry>
	240
	241	<varlistentry>
f6c2e28b	242	<term><varname>_SOURCE_REALTIME_TIMESTAMP=</varname></term>
ffa16db0 LP	243	<listitem>
	244	<para>The earliest trusted
	245	timestamp of the message, if
	246	any is known that is different
	247	from the reception time of the
41048afa LP	248	journal. This is the time in
	249	usec since the epoch UTC
	250	formatted as decimal
	251	string.</para>
ffa16db0 LP	252	</listitem>
	253	</varlistentry>
	254
	255	<varlistentry>
f6c2e28b	256	<term><varname>_BOOT_ID=</varname></term>
ffa16db0 LP	257	<listitem>
	258	<para>The kernel boot ID for
	259	the boot the message was
	260	generated in, formatted as
	261	128bit hexadecimal
	262	string.</para>
	263	</listitem>
	264	</varlistentry>
	265
	266	<varlistentry>
f6c2e28b	267	<term><varname>_MACHINE_ID=</varname></term>
ffa16db0 LP	268	<listitem>
	269	<para>The machine ID of the
	270	originating host, as available
	271	in
	272	<citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
	273	</listitem>
	274	</varlistentry>
	275
	276	<varlistentry>
f6c2e28b	277	<term><varname>_HOSTNAME=</varname></term>
ffa16db0 LP	278	<listitem>
	279	<para>The name of the
	280	originating host.</para>
	281	</listitem>
	282	</varlistentry>
6bc3bf5b LP	283
6bc3bf5b LP	284	<varlistentry>
f6c2e28b	285	<term><varname>_TRANSPORT=</varname></term>
6bc3bf5b LP	286	<listitem>
	287	<para>How the entry was
	288	received by the journal
	289	service. One of
	290	<literal>driver</literal>,
	291	<literal>syslog</literal>,
	292	<literal>journal</literal>,
	293	<literal>stdout</literal>,
	294	<literal>kernel</literal> for
	295	internally generated messages,
	296	for those received via the
	297	local syslog socket with the
	298	syslog protocol, for those
	299	received via the native
	300	journal protocol, for the
	301	those read from a services'
	302	standard output or error
16dad32e AE	303	output, or for those read
16dad32e AE	304	from the kernel, respectively.
6bc3bf5b LP	305	</para>
	306	</listitem>
	307	</varlistentry>
ffa16db0 LP	308	</variablelist>
	309	</refsect1>
	310
6f7ea7df LP	311	<refsect1>
	312	<title>Kernel Journal Fields</title>
	313
	314	<para>Kernel fields are fields that are used by
	315	messages originating in the kernel and stored in the
	316	journal.</para>
	317
53057ef9	318	<variablelist class='journal-directives'>
6f7ea7df	319	<varlistentry>
53057ef9	320	<term><varname>_KERNEL_DEVICE=</varname></term>
6f7ea7df LP	321	<listitem>
	322	<para>The kernel device
	323	name. If the entry is
	324	associated to a block device,
	325	the major and minor of the
	326	device node, separated by ':'
	327	and prefixed by 'b'. Similar
	328	for character devices, but
	329	prefixed by 'c'. For network
	330	devices the interface index,
	331	prefixed by 'n'. For all other
	332	devices '+' followed by the
	333	subsystem name, followed by
	334	':', followed by the kernel
	335	device name.</para>
	336	</listitem>
	337	</varlistentry>
	338	<varlistentry>
53057ef9	339	<term><varname>_KERNEL_SUBSYSTEM=</varname></term>
6f7ea7df LP	340	<listitem>
	341	<para>The kernel subsystem name.</para>
	342	</listitem>
	343	</varlistentry>
bdfb9e7f	344	<varlistentry>
53057ef9	345	<term><varname>_UDEV_SYSNAME=</varname></term>
bdfb9e7f LP	346	<listitem>
	347	<para>The kernel device name
	348	as it shows up in the device
	349	tree below
	350	<filename>/sys</filename>.</para>
	351	</listitem>
	352	</varlistentry>
	353	<varlistentry>
53057ef9	354	<term><varname>_UDEV_DEVNODE=</varname></term>
bdfb9e7f LP	355	<listitem>
	356	<para>The device node path of
	357	this device in
	358	<filename>/dev</filename>.</para>
	359	</listitem>
	360	</varlistentry>
	361	<varlistentry>
53057ef9	362	<term><varname>_UDEV_DEVLINK=</varname></term>
bdfb9e7f LP	363	<listitem>
	364	<para>Additional symlink names
	365	pointing to the device node in
	366	<filename>/dev</filename>. This
	367	field is frequently set more
	368	than once per entry.</para>
	369	</listitem>
	370	</varlistentry>
6f7ea7df LP	371	</variablelist>
	372	</refsect1>
	373
53057ef9 ZJS	374	<refsect1>
	375	<title>Special Journal Fields</title>
	376
	377	<para>Fields used by the <command>systemd-coredump</command>
	378	coredump kernel helper.
	379	</para>
	380
	381	<variablelist class='journal-directives'>
	382	<varlistentry>
	383	<term><varname>COREDUMP_UNIT=</varname></term>
	384	<term><varname>COREDUMP_USER_UNIT=</varname></term>
	385	<listitem>
	386	<para>Used to annotate
	387	messages containing coredumps from
	388	system and session units.
	389	See
	390	<citerefentry><refentrytitle>systemd-coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
	391	</para>
	392	</listitem>
	393	</varlistentry>
	394	</variablelist>
	395	</refsect1>
	396
ffa16db0 LP	397	<refsect1>
	398	<title>Address Fields</title>
	399
df688b23 LP	400	<para>During serialization into external formats, such
	401	as the <ulink
	402	url="http://www.freedesktop.org/wiki/Software/systemd/export">Journal
	403	Export Format</ulink> or the <ulink
	404	url="http://www.freedesktop.org/wiki/Software/systemd/json">Journal
	405	JSON Format</ulink>, the addresses of journal entries
	406	are serialized into fields prefixed with double
	407	underscores. Note that these aren't proper fields when
	408	stored in the journal, but addressing meta data of
	409	entries. They cannot be written as part of structured
	410	log entries via calls such as
cbdca852 LP	411	<citerefentry><refentrytitle>sd_journal_send</refentrytitle><manvolnum>3</manvolnum></citerefentry>. They
	412	may also not be used as matches for
	413	<citerefentry><refentrytitle>sd_journal_add_match</refentrytitle><manvolnum>3</manvolnum></citerefentry></para>
ffa16db0	414
f6c2e28b	415	<variablelist class='journal-directives'>
ffa16db0	416	<varlistentry>
f6c2e28b	417	<term><varname>__CURSOR=</varname></term>
ffa16db0 LP	418	<listitem>
	419	<para>The cursor for the
	420	entry. A cursor is an opaque
	421	text string that uniquely
	422	describes the position of an
	423	entry in the journal and is
	424	portable across machines,
	425	platforms and journal
	426	files.</para>
	427	</listitem>
	428	</varlistentry>
	429
	430	<varlistentry>
f6c2e28b	431	<term><varname>__REALTIME_TIMESTAMP=</varname></term>
ffa16db0 LP	432	<listitem>
	433	<para>The wallclock time
	434	(CLOCK_REALTIME) at the point
	435	in time the entry was received
41048afa LP	436	by the journal, in usec since
	437	the epoch UTC formatted as
	438	decimal string. This has
ffa16db0 LP	439	different properties from
	440	<literal>_SOURCE_REALTIME_TIMESTAMP=</literal>
	441	as it is usually a bit later
	442	but more likely to be
	443	monotonic.</para>
	444	</listitem>
	445	</varlistentry>
	446
	447	<varlistentry>
f6c2e28b	448	<term><varname>__MONOTONIC_TIMESTAMP=</varname></term>
ffa16db0 LP	449	<listitem>
	450	<para>The monotonic time
	451	(CLOCK_MONOTONIC) at the point
	452	in time the entry was received
41048afa LP	453	by the journal in usec
	454	formatted as decimal
	455	string. To be useful as an
	456	address for the entry this
	457	should be combined with with
	458	boot ID in
ffa16db0 LP	459	<literal>_BOOT_ID=</literal>.</para>
	460	</listitem>
	461	</varlistentry>
	462	</variablelist>
	463	</refsect1>
	464
	465	<refsect1>
	466	<title>See Also</title>
	467	<para>
	468	<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
	469	<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
a8eedf49	470	<citerefentry><refentrytitle>journald.conf</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
9cc2c8b7	471	<citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
53057ef9	472	<citerefentry><refentrytitle>systemd-coredumpctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
9cc2c8b7	473	<citerefentry><refentrytitle>systemd.directives</refentrytitle><manvolnum>7</manvolnum></citerefentry>
ffa16db0 LP	474	</para>
	475	</refsect1>
	476
	477	</refentry>