mirror of
https://github.com/AuxXxilium/eudev.git
synced 2024-12-21 06:03:39 +07:00
190 lines
8.9 KiB
XML
190 lines
8.9 KiB
XML
<?xml version='1.0'?> <!--*-nxml-*-->
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
|
|
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
|
|
|
<!--
|
|
This file is part of systemd.
|
|
|
|
Copyright 2012 Lennart Poettering
|
|
|
|
systemd is free software; you can redistribute it and/or modify it
|
|
under the terms of the GNU Lesser General Public License as published by
|
|
the Free Software Foundation; either version 2.1 of the License, or
|
|
(at your option) any later version.
|
|
|
|
systemd is distributed in the hope that it will be useful, but
|
|
WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public License
|
|
along with systemd; If not, see <http://www.gnu.org/licenses/>.
|
|
-->
|
|
|
|
<refentry id="sd_journal_add_match">
|
|
|
|
<refentryinfo>
|
|
<title>sd_journal_add_match</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>sd_journal_add_match</refentrytitle>
|
|
<manvolnum>3</manvolnum>
|
|
</refmeta>
|
|
|
|
<refnamediv>
|
|
<refname>sd_journal_add_match</refname>
|
|
<refname>sd_journal_add_disjunction</refname>
|
|
<refname>sd_journal_flush_matches</refname>
|
|
<refpurpose>Add or remove entry matches</refpurpose>
|
|
</refnamediv>
|
|
|
|
<refsynopsisdiv>
|
|
<funcsynopsis>
|
|
<funcsynopsisinfo>#include <systemd/sd-journal.h></funcsynopsisinfo>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_journal_add_match</function></funcdef>
|
|
<paramdef>sd_journal* <parameter>j</parameter></paramdef>
|
|
<paramdef>const void* <parameter>data</parameter></paramdef>
|
|
<paramdef>size_t <parameter>size</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_journal_add_disjunction</function></funcdef>
|
|
<paramdef>sd_journal* <parameter>j</parameter></paramdef>
|
|
</funcprototype>
|
|
|
|
<funcprototype>
|
|
<funcdef>int <function>sd_journal_flush_matches</function></funcdef>
|
|
<paramdef>sd_journal* <parameter>j</parameter></paramdef>
|
|
</funcprototype>
|
|
</funcsynopsis>
|
|
</refsynopsisdiv>
|
|
|
|
<refsect1>
|
|
<title>Description</title>
|
|
|
|
<para><function>sd_journal_add_match()</function> adds
|
|
a match by which to filter the entries of the journal
|
|
file. Matches applied with this call will filter what
|
|
can be iterated through and read from the journal file
|
|
via calls like
|
|
<citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
|
and
|
|
<citerefentry><refentrytitle>sd_journal_get_data</refentrytitle><manvolnum>3</manvolnum></citerefentry>. Matches
|
|
are of the form <literal>FIELD=value</literal>, where
|
|
the field part is a short uppercase string consisting
|
|
only of 0-9, A-Z and the underscore. It may not begin
|
|
with two underscores or be the empty string. The value
|
|
part may be any value, including binary. If a match is
|
|
applied only entries with this field set will be
|
|
iterated. Multiple matches may be active at the same
|
|
time: if they apply to different fields only entries
|
|
with both fields set like this will be iterated, if
|
|
they apply to the same fields only entries where the
|
|
field takes one of the specified values will be
|
|
iterated. Well known fields are documented in
|
|
<citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>. Whenever
|
|
a new match is added the current entry position is
|
|
reset, and
|
|
<citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry> (or a similar call)
|
|
needs to be called before entries can be read
|
|
again.</para>
|
|
|
|
<para><function>sd_journal_add_disjunction()</function>
|
|
may be used to insert a disjunction (i.e. logical OR)
|
|
in the match list. If this call is invoked all
|
|
previously added matches are combined in an OR with
|
|
all matches added afterwards, until
|
|
<function>sd_journal_add_disjunction()</function> is
|
|
invoked again to begin the next OR term. The
|
|
combination of
|
|
<function>sd_journal_add_match()</function> and
|
|
<function>sd_journal_add_disjunction()</function> may
|
|
be used to build complex search terms, even though
|
|
full logical expressions are not available.</para>
|
|
|
|
<para><function>sd_journal_flush_matches()</function>
|
|
may be used to flush all matches and disjunction terms
|
|
again. After this call all filtering is removed and
|
|
all entries in the journal will be iterated
|
|
again.</para>
|
|
|
|
<para>Note that filtering via matches only applies to
|
|
way the journal is read, it has no effect on storage
|
|
on disk.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Return Value</title>
|
|
|
|
<para><function>sd_journal_add_match()</function> and
|
|
<function>sd_journal_add_disjunction()</function>
|
|
return 0 on success or a negative errno-style error
|
|
code. <function>sd_journal_flush_matches()</function>
|
|
returns nothing.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Notes</title>
|
|
|
|
<para>The <function>sd_journal_add_match()</function>,
|
|
<function>sd_journal_add_disjunction()</function> and
|
|
<function>sd_journal_flush_matches()</function> interfaces are
|
|
available as shared library, which can be compiled and
|
|
linked to with the
|
|
<literal>libsystemd-journal</literal>
|
|
<citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
|
|
file.</para>
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>Examples</title>
|
|
|
|
<para>The following example adds matches to a journal
|
|
context object to iterate only through messages
|
|
generated by the Avahi service at the four error log
|
|
levels, plus all messages of the message ID
|
|
03bb1dab98ab4ecfbf6fff2738bdd964 coming from any
|
|
service (this example lacks the necessary error
|
|
checking):</para>
|
|
|
|
<programlisting>...
|
|
int add_matches(sd_journal *j) {
|
|
sd_journal_add_match(j, "_SYSTEMD_UNIT=avahi-daemon.service");
|
|
sd_journal_add_match(j, "PRIORITY=0");
|
|
sd_journal_add_match(j, "PRIORITY=1");
|
|
sd_journal_add_match(j, "PRIORITY=2");
|
|
sd_journal_add_match(j, "PRIORITY=3");
|
|
sd_journal_add_disjunction(j);
|
|
sd_journal_add_match(j, "MESSAGE_ID=03bb1dab98ab4ecfbf6fff2738bdd964");
|
|
}</programlisting>
|
|
|
|
</refsect1>
|
|
|
|
<refsect1>
|
|
<title>See Also</title>
|
|
|
|
<para>
|
|
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_journal_open</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>sd_journal_get_data</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
|
|
<citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</manvolnum></citerefentry>
|
|
</para>
|
|
</refsect1>
|
|
|
|
</refentry>
|