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Diffstat (limited to 'src/libsystemd/sd_journal_get_realtime_usec.xml')
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diff --git a/src/libsystemd/sd_journal_get_realtime_usec.xml b/src/libsystemd/sd_journal_get_realtime_usec.xml new file mode 100644 index 0000000000..607d74666b --- /dev/null +++ b/src/libsystemd/sd_journal_get_realtime_usec.xml @@ -0,0 +1,141 @@ +<?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_realtime_usec"> + + <refentryinfo> + <title>sd_journal_get_realtime_usec</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_realtime_usec</refentrytitle> + <manvolnum>3</manvolnum> + </refmeta> + + <refnamediv> + <refname>sd_journal_get_realtime_usec</refname> + <refname>sd_journal_get_monotonic_usec</refname> + <refpurpose>Read timestamps from the current journal entry</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcsynopsisinfo>#include <systemd/sd-journal.h></funcsynopsisinfo> + + <funcprototype> + <funcdef>int <function>sd_journal_get_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_get_monotonic_usec</function></funcdef> + <paramdef>sd_journal *<parameter>j</parameter></paramdef> + <paramdef>uint64_t *<parameter>usec</parameter></paramdef> + <paramdef>sd_id128_t *<parameter>boot_id</parameter></paramdef> + </funcprototype> + + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Description</title> + + <para><function>sd_journal_get_realtime_usec()</function> gets the + realtime (wallclock) timestamp of the current journal entry. It + takes two arguments: the journal context object and a pointer to a + 64-bit unsigned integer to store the timestamp in. The timestamp + is in microseconds since the epoch, i.e. + <constant>CLOCK_REALTIME</constant>.</para> + + <para><function>sd_journal_get_monotonic_usec()</function> gets + the monotonic timestamp of the current journal entry. It takes + three arguments: the journal context object, a pointer to a 64-bit + unsigned integer to store the timestamp in, as well as a 128-bit + ID buffer to store the boot ID of the monotonic timestamp. The + timestamp is in microseconds since boot-up of the specific boot, + i.e. <constant>CLOCK_MONOTONIC</constant>. Since the monotonic + clock begins new with every reboot, it only defines a well-defined + point in time when used together with an identifier identifying + the boot. See + <citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry> + for more information. If the boot ID parameter is passed + <constant>NULL</constant>, the function will fail if the monotonic + timestamp of the current entry is not of the current system + boot.</para> + + <para>Note that these functions 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_realtime_usec()</function> and + <function>sd_journal_get_monotonic_usec()</function> returns 0 on + success or a negative errno-style error code. If the boot ID + parameter was passed <constant>NULL</constant> and the monotonic + timestamp of the current journal entry is not of the current + system boot, <constant>-ESTALE</constant> is returned by + <function>sd_journal_get_monotonic_usec()</function>.</para> + </refsect1> + + <refsect1> + <title>Notes</title> + + <para>The <function>sd_journal_get_realtime_usec()</function> and + <function>sd_journal_get_monotonic_usec()</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_next</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_journal_get_data</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_id128_get_boot</refentrytitle><manvolnum>3</manvolnum></citerefentry>, + <citerefentry><refentrytitle>clock_gettime</refentrytitle><manvolnum>2</manvolnum></citerefentry>, + <citerefentry><refentrytitle>sd_journal_get_cutoff_realtime_usec</refentrytitle><manvolnum>3</manvolnum></citerefentry> + </para> + </refsect1> + +</refentry> |