+++ /dev/null
-<?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_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>
- <refname>sd_journal_test_cursor</refname>
- <refpurpose>Get cursor string for or test cursor string against the current journal entry</refpurpose>
- </refnamediv>
-
- <refsynopsisdiv>
- <funcsynopsis>
- <funcsynopsisinfo>#include <systemd/sd-journal.h></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>
-
- <funcprototype>
- <funcdef>int <function>sd_journal_test_cursor</function></funcdef>
- <paramdef>sd_journal *<parameter>j</parameter></paramdef>
- <paramdef>const 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 formatted as text.
- 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 project='man-pages'><refentrytitle>malloc</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- and should be freed after use with
- <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
-
- <para>Note that <function>sd_journal_get_cursor()</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>
-
- <para><function>sd_journal_test_cursor()</function>
- may be used to check whether the current position in
- the journal matches the specified cursor. This is
- useful since cursor strings do not uniquely identify
- an entry: the same entry might be referred to by
- multiple different cursor strings, and hence string
- comparing cursors is not possible. Use this call to
- verify after an invocation of
- <citerefentry><refentrytitle>sd_journal_seek_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- whether the entry being sought to was actually found
- in the journal or the next closest entry was used
- instead.</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.
- <function>sd_journal_test_cursor()</function> returns positive if
- the current entry matches the specified cursor, 0 if it does not
- match the specified cursor or a negative errno-style error code on
- failure.</para>
- </refsect1>
-
- <refsect1>
- <title>Notes</title>
-
- <para>The <function>sd_journal_get_cursor()</function> and
- <function>sd_journal_test_cursor()</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>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>
~ianmdlvl / elogind.git / blobdiff