man/sd_journal_get_cursor.xml


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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">

<!--
  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
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  You should have received a copy of the GNU Lesser General Public License
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-->

<refentry id="sd_journal_get_cursor">

        <refentryinfo>
                <title>sd_journal_get_cursor</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_cursor</refentrytitle>
                <manvolnum>3</manvolnum>
        </refmeta>

        <refnamediv>
                <refname>sd_journal_get_cursor</refname>
                <refpurpose>Get cursor string for the current journal entry</refpurpose>
        </refnamediv>

        <refsynopsisdiv>
                <funcsynopsis>
                        <funcsynopsisinfo>#include &lt;systemd/sd-journal.h&gt;</funcsynopsisinfo>

                        <funcprototype>
                                <funcdef>int <function>sd_journal_get_cursor</function></funcdef>
                                <paramdef>sd_journal* <parameter>j</parameter></paramdef>
                                <paramdef>char ** <parameter>cursor</parameter></paramdef>
                        </funcprototype>

                </funcsynopsis>
        </refsynopsisdiv>

        <refsect1>
                <title>Description</title>

                <para><function>sd_journal_get_cursor()</function>
                returns a cursor string for the current journal
                entry. A cursor is a serialization of the current
                journal position in text form. The string only
                contains printable characters and can be passed around
                in text form. The cursor identifies a journal entry
                globally and in a stable way and may be used to later
                seek to it via
                <citerefentry><refentrytitle>sd_journal_seek_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>. The
                cursor string should be considered opaque and not be
                parsed by clients. Seeking to a cursor position
                without the specific entry being available locally
                will seek to the next closest (in terms of time)
                available entry. The call takes two arguments: a
                journal context object and a pointer to a
                string pointer where the cursor string will be
                placed. The string is allocated via libc <citerefentry><refentrytitle>malloc</refentrytitle><manvolnum>3</manvolnum></citerefentry> and should
                be freed after use with
                <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>

                <para>Note that this function will not work before
                <citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                (or related call) has been called at least
                once, in order to position the read pointer at a valid entry.</para>
        </refsect1>

        <refsect1>
                <title>Return Value</title>

                <para><function>sd_journal_get_cursor()</function>
                returns 0 on success or a negative errno-style error
                code.</para>
        </refsect1>

        <refsect1>
                <title>Notes</title>

                <para>The <function>sd_journal_get_cursor()</function>
                interface is 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>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_seek_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                </para>
        </refsect1>

</refentry>