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diff --git a/man/sd_journal_seek_head.xml b/man/sd_journal_seek_head.xml new file mode 100644 index 0000000..869889a --- /dev/null +++ b/man/sd_journal_seek_head.xml @@ -0,0 +1,131 @@ +<?xml version='1.0'?> <!--*-nxml-*--> +<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN" + "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> +<!-- SPDX-License-Identifier: LGPL-2.1-or-later --> + +<refentry id="sd_journal_seek_head" xmlns:xi="http://www.w3.org/2001/XInclude"> + + <refentryinfo> + <title>sd_journal_seek_head</title> + <productname>systemd</productname> + </refentryinfo> + + <refmeta> + <refentrytitle>sd_journal_seek_head</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_journal_seek_head</refname> + <refname>sd_journal_seek_tail</refname> + <refname>sd_journal_seek_monotonic_usec</refname> + <refname>sd_journal_seek_realtime_usec</refname> + <refname>sd_journal_seek_cursor</refname> + <refpurpose>Seek to a position in the + journal</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-journal.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_journal_seek_head</function></funcdef> + <paramdef>sd_journal *<parameter>j</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_journal_seek_tail</function></funcdef> + <paramdef>sd_journal *<parameter>j</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_journal_seek_monotonic_usec</function></funcdef> + <paramdef>sd_journal *<parameter>j</parameter></paramdef> + <paramdef>sd_id128_t <parameter>boot_id</parameter></paramdef> + <paramdef>uint64_t <parameter>usec</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_journal_seek_realtime_usec</function></funcdef> + <paramdef>sd_journal *<parameter>j</parameter></paramdef> + <paramdef>uint64_t <parameter>usec</parameter></paramdef> + </funcprototype> + + <funcprototype> + <funcdef>int <function>sd_journal_seek_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_seek_head()</function> seeks to the beginning of the journal, i.e. to the + position before the oldest available entry.</para> + + <para>Similarly, <function>sd_journal_seek_tail()</function> may be used to seek to the end of the + journal, i.e. the position after the most recent available entry.</para> + + <para><function>sd_journal_seek_monotonic_usec()</function> seeks to a position with the specified + monotonic timestamp, i.e. <constant>CLOCK_MONOTONIC</constant>. Since monotonic time restarts on every + reboot a boot ID needs to be specified as well.</para> + + <para><function>sd_journal_seek_realtime_usec()</function> seeks to a position with the specified + realtime (wallclock) timestamp, i.e. <constant>CLOCK_REALTIME</constant>. Note that the realtime clock is + not necessarily monotonic. If a realtime timestamp is ambiguous, it is not defined which position is + sought to.</para> + + <para><function>sd_journal_seek_cursor()</function> seeks to the position at the specified cursor + string. For details on cursors, see + <citerefentry><refentrytitle>sd_journal_get_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + If no entry matching the specified cursor is found the call will seek to the next closest entry (in terms + of time) instead. To verify whether the newly selected entry actually matches the cursor, use + <citerefentry><refentrytitle>sd_journal_test_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> + + <para>Note that these calls do not actually make any entry the new current entry, this needs to be done + in a separate step with a subsequent + <citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry> + invocation (or a similar call). Only then, entry data may be retrieved via + <citerefentry><refentrytitle>sd_journal_get_data</refentrytitle><manvolnum>3</manvolnum></citerefentry> + or an entry cursor be retrieved via + <citerefentry><refentrytitle>sd_journal_get_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>. + If no entry exists that matches exactly the specified seek address, the next closest is sought to. If + <citerefentry><refentrytitle>sd_journal_next</refentrytitle><manvolnum>3</manvolnum></citerefentry> is + used, the closest following entry will be sought to, if + <citerefentry><refentrytitle>sd_journal_previous</refentrytitle><manvolnum>3</manvolnum></citerefentry> + is used the closest preceding entry is sought to.</para> + </refsect1> + + <refsect1> + <title>Return Value</title> + + <para>The functions return 0 on success or a negative errno-style + error code.</para> + </refsect1> + + <refsect1> + <title>Notes</title> + + <xi:include href="threads-aware.xml" xpointer="strict"/> + + <xi:include href="libsystemd-pkgconfig.xml" xpointer="pkgconfig-text"/> + </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>sd_journal_get_cursor</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_journal_get_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |