<title>Description</title>
<para>Entries in the journal resemble an environment
- block in their syntax, however with fields that can
+ block in their syntax but 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
+ optional. In some cases, fields may appear more than
once per entry.</para>
</refsect1>
(formatted as decimal string),
the identifier string
(i.e. "tag"), and the client
- PID.</para>
+ PID. (Note that the tag is
+ usually derived from glibc's
+ <varname>program_invocation_short_name</varname>
+ variable, see <citerefentry><refentrytitle>program_invocation_short_name</refentrytitle><manvolnum>3</manvolnum></citerefentry>.)</para>
</listitem>
</varlistentry>
<term><varname>_UID=</varname></term>
<term><varname>_GID=</varname></term>
<listitem>
- <para>The process, user and
+ <para>The process, user, and
group ID of the process the
journal entry originates from
formatted as a decimal
<term><varname>_CMDLINE=</varname></term>
<listitem>
<para>The name, the executable
- path and the command line of
+ path, and the command line of
the process the journal entry
originates from.</para>
</listitem>
<term><varname>_SELINUX_CONTEXT=</varname></term>
<listitem>
<para>The SELinux security
- context of the process the
- journal entry originates
+ context (label) of the process
+ the journal entry originates
from.</para>
</listitem>
</varlistentry>
the major and minor of the
device node, separated by <literal>:</literal>
and prefixed by <literal>b</literal>. Similar
- for character devices, but
+ for character devices but
prefixed by <literal>c</literal>. For network
- devices the interface index,
+ devices, this is the interface index
prefixed by <literal>n</literal>. For all other
- devices <literal>+</literal> followed by the
- subsystem name, followed by
+ devices, this is the subsystem name
+ prefixed by <literal>+</literal>, followed by
<literal>:</literal>, followed by the kernel
device name.</para>
</listitem>
JSON Format</ulink>, the addresses of journal entries
are serialized into fields prefixed with double
underscores. Note that these are not proper fields when
- stored in the journal but for addressing meta data of
+ stored in the journal but for addressing metadata 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