2012-07-13 20:18:17 +00:00
|
|
|
|
<?xml version='1.0'?> <!--*-nxml-*-->
|
|
|
|
|
<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
|
2015-06-18 17:47:44 +00:00
|
|
|
|
"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
|
2012-07-13 20:18:17 +00:00
|
|
|
|
|
|
|
|
|
<!--
|
2017-11-18 16:22:32 +00:00
|
|
|
|
SPDX-License-Identifier: LGPL-2.1+
|
|
|
|
|
|
2012-07-13 20:18:17 +00:00
|
|
|
|
Copyright 2012 Lennart Poettering
|
|
|
|
|
-->
|
|
|
|
|
|
2018-06-06 09:59:04 +00:00
|
|
|
|
<refentry id="sd_journal_add_match" xmlns:xi="http://www.w3.org/2001/XInclude">
|
2012-07-13 20:18:17 +00:00
|
|
|
|
|
2015-02-04 02:14:13 +00:00
|
|
|
|
<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_add_conjunction</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_add_conjunction</function></funcdef>
|
|
|
|
|
<paramdef>sd_journal *<parameter>j</parameter></paramdef>
|
|
|
|
|
</funcprototype>
|
|
|
|
|
|
|
|
|
|
<funcprototype>
|
|
|
|
|
<funcdef>void <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>.
|
2016-04-22 02:52:25 +00:00
|
|
|
|
Parameter <parameter>data</parameter> must be of the form
|
|
|
|
|
<literal><replaceable>FIELD</replaceable>=<replaceable>value</replaceable></literal>,
|
|
|
|
|
where the <replaceable>FIELD</replaceable> 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 <replaceable>value</replaceable> part may be anything, including binary. Parameter
|
|
|
|
|
<parameter>size</parameter> specifies the number of bytes in <parameter>data</parameter>
|
|
|
|
|
(i.e. the length of <replaceable>FIELD</replaceable>, plus one, plus the length of
|
|
|
|
|
<replaceable>value</replaceable>). Parameter <parameter>size</parameter> may also be
|
|
|
|
|
specified as <constant>0</constant>, in which case <parameter>data</parameter>
|
|
|
|
|
must be a <constant>NUL</constant>-terminated string, and the bytes before the terminating
|
|
|
|
|
zero are used as the match.</para>
|
|
|
|
|
|
|
|
|
|
<para>If a match is applied, only entries with this field set
|
2015-02-04 02:14:13 +00:00
|
|
|
|
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 since the
|
|
|
|
|
last invocation of
|
|
|
|
|
<function>sd_journal_add_disjunction()</function> or
|
|
|
|
|
<function>sd_journal_add_conjunction()</function> are combined in
|
|
|
|
|
an OR with all matches added afterwards, until
|
|
|
|
|
<function>sd_journal_add_disjunction()</function> or
|
|
|
|
|
<function>sd_journal_add_conjunction()</function> is invoked again
|
|
|
|
|
to begin the next OR or AND term. </para>
|
|
|
|
|
|
|
|
|
|
<para><function>sd_journal_add_conjunction()</function> may be
|
|
|
|
|
used to insert a conjunction (i.e. logical AND) in the match list.
|
|
|
|
|
If this call is invoked, all previously added matches since the
|
|
|
|
|
last invocation of
|
|
|
|
|
<function>sd_journal_add_conjunction()</function> are combined in
|
|
|
|
|
an AND with all matches added afterwards, until
|
|
|
|
|
<function>sd_journal_add_conjunction()</function> is invoked again
|
|
|
|
|
to begin the next AND term. The combination of
|
|
|
|
|
<function>sd_journal_add_match()</function>,
|
|
|
|
|
<function>sd_journal_add_disjunction()</function> and
|
|
|
|
|
<function>sd_journal_add_conjunction()</function> may be used to
|
|
|
|
|
build complex search terms, even though full logical expressions
|
|
|
|
|
are not available. Note that
|
|
|
|
|
<function>sd_journal_add_conjunction()</function> operates one
|
|
|
|
|
level 'higher' than
|
|
|
|
|
<function>sd_journal_add_disjunction()</function>. It is hence
|
|
|
|
|
possible to build an expression of AND terms, consisting of OR
|
|
|
|
|
terms, consisting of AND terms, consisting of OR terms of matches
|
|
|
|
|
(the latter OR expression is implicitly created for matches with
|
|
|
|
|
the same field name, see above).</para>
|
|
|
|
|
|
|
|
|
|
<para><function>sd_journal_flush_matches()</function> may be used
|
|
|
|
|
to flush all matches, disjunction and conjunction 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 the 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>,
|
|
|
|
|
<function>sd_journal_add_disjunction()</function> and
|
|
|
|
|
<function>sd_journal_add_conjunction()</function>
|
|
|
|
|
return 0 on success or a negative errno-style error
|
|
|
|
|
code. <function>sd_journal_flush_matches()</function>
|
|
|
|
|
returns nothing.</para>
|
|
|
|
|
</refsect1>
|
|
|
|
|
|
2018-06-06 09:59:04 +00:00
|
|
|
|
<xi:include href="libsystemd-pkgconfig.xml" />
|
2015-02-04 02:14:13 +00:00
|
|
|
|
|
|
|
|
|
<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>
|
|
|
|
|
|
2016-12-11 22:01:07 +00:00
|
|
|
|
<programlisting>…
|
2012-07-13 20:18:17 +00:00
|
|
|
|
int add_matches(sd_journal *j) {
|
2015-02-04 02:14:13 +00:00
|
|
|
|
sd_journal_add_match(j, "_SYSTEMD_UNIT=avahi-daemon.service", 0);
|
|
|
|
|
sd_journal_add_match(j, "PRIORITY=0", 0);
|
|
|
|
|
sd_journal_add_match(j, "PRIORITY=1", 0);
|
|
|
|
|
sd_journal_add_match(j, "PRIORITY=2", 0);
|
|
|
|
|
sd_journal_add_match(j, "PRIORITY=3", 0);
|
|
|
|
|
sd_journal_add_disjunction(j);
|
|
|
|
|
sd_journal_add_match(j, "MESSAGE_ID=03bb1dab98ab4ecfbf6fff2738bdd964", 0);
|
2012-07-13 20:18:17 +00:00
|
|
|
|
}</programlisting>
|
2015-02-04 02:14:13 +00:00
|
|
|
|
</refsect1>
|
2012-07-13 20:18:17 +00:00
|
|
|
|
|
2015-02-04 02:14:13 +00:00
|
|
|
|
<refsect1>
|
|
|
|
|
<title>See Also</title>
|
2012-07-13 20:18:17 +00:00
|
|
|
|
|
2015-02-04 02:14:13 +00:00
|
|
|
|
<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>
|
2012-07-13 20:18:17 +00:00
|
|
|
|
|
|
|
|
|
</refentry>
|