Systemd/man/sd_journal_get_catalog.xml
Lennart Poettering 5d13a15b1d tree-wide: drop spurious newlines (#8764)
Double newlines (i.e. one empty lines) are great to structure code. But
let's avoid triple newlines (i.e. two empty lines), quadruple newlines,
quintuple newlines, …, that's just spurious whitespace.

It's an easy way to drop 121 lines of code, and keeps the coding style
of our sources a bit tigther.
2018-04-19 12:13:23 +02:00

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<?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">
<!--
SPDX-License-Identifier: LGPL-2.1+
This file is part of systemd.
Copyright 2012 Lennart Poettering
-->
<refentry id="sd_journal_get_catalog">
<refentryinfo>
<title>sd_journal_get_catalog</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_get_catalog</refentrytitle>
<manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd_journal_get_catalog</refname>
<refname>sd_journal_get_catalog_for_message_id</refname>
<refpurpose>Retrieve message catalog entry</refpurpose>
</refnamediv>
<refsynopsisdiv>
<funcsynopsis>
<funcsynopsisinfo>#include &lt;systemd/sd-journal.h&gt;</funcsynopsisinfo>
<funcprototype>
<funcdef>int <function>sd_journal_get_catalog</function></funcdef>
<paramdef>sd_journal *<parameter>j</parameter></paramdef>
<paramdef>char **<parameter>ret</parameter></paramdef>
</funcprototype>
<funcprototype>
<funcdef>int <function>sd_journal_get_catalog_for_message_id</function></funcdef>
<paramdef>sd_id128_t <parameter>id</parameter></paramdef>
<paramdef>char **<parameter>ret</parameter></paramdef>
</funcprototype>
</funcsynopsis>
</refsynopsisdiv>
<refsect1>
<title>Description</title>
<para><function>sd_journal_get_catalog()</function> retrieves a
message catalog entry for the current journal entry. This will
look up an entry in the message catalog by using the
<literal>MESSAGE_ID=</literal> field of the current journal entry.
Before returning the entry all journal field names in the catalog
entry text enclosed in "@" will be replaced by the respective
field values of the current entry. If a field name referenced in
the message catalog entry does not exist, in the current journal
entry, the "@" will be removed, but the field name otherwise left
untouched.</para>
<para><function>sd_journal_get_catalog_for_message_id()</function>
works similar to <function>sd_journal_get_catalog()</function> but
the entry is looked up by the specified message ID (no open
journal context is necessary for this), and no field substitution
is performed.</para>
<para>For more information about the journal message catalog
please refer to the <ulink
url="https://www.freedesktop.org/wiki/Software/systemd/catalog">Journal
Message Catalogs</ulink> documentation page.</para>
</refsect1>
<refsect1>
<title>Return Value</title>
<para><function>sd_journal_get_catalog()</function> and
<function>sd_journal_get_catalog_for_message_id()</function>
return 0 on success or a negative errno-style error code. If no
matching message catalog entry is found, -ENOENT is
returned.</para>
<para>On successful return, <parameter>ret</parameter> points to a
new string, which must be freed with
<citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>.
</para>
</refsect1>
<refsect1>
<title>Notes</title>
<para>Function <function>sd_journal_get_catalog()</function> is thread-agnostic and only a
single thread may operate on a given <structname>sd_journal</structname> object. Function
<function>sd_journal_get_catalog_for_message_id()</function> is thread-safe.</para>
<para>The <function>sd_journal_get_catalog()</function> and
<function>sd_journal_get_catalog_for_message_id()</function>
interfaces are available as a shared library, which can be
compiled and linked to with the
<constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
file.</para>
</refsect1>
<refsect1>
<title>See Also</title>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>systemd.journal-fields</refentrytitle><manvolnum>7</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 project='man-pages'><refentrytitle>malloc</refentrytitle><manvolnum>3</manvolnum></citerefentry>
</para>
</refsect1>
</refentry>