<?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_id128_randomize"> <refentryinfo> <title>sd_id128_randomize</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_id128_randomize</refentrytitle> <manvolnum>3</manvolnum> </refmeta> <refnamediv> <refname>sd_id128_randomize</refname> <refpurpose>Generate 128-bit IDs</refpurpose> </refnamediv> <refsynopsisdiv> <funcsynopsis> <funcsynopsisinfo>#include <systemd/sd-id128.h></funcsynopsisinfo> <funcprototype> <funcdef>int <function>sd_id128_randomize</function></funcdef> <paramdef>sd_id128_t *<parameter>ret</parameter></paramdef> </funcprototype> </funcsynopsis> </refsynopsisdiv> <refsect1> <title>Description</title> <para><function>sd_id128_randomize()</function> generates a new randomized 128-bit ID and returns it in <parameter>ret</parameter>. Every invocation returns a new randomly generated ID. This uses the <filename>/dev/urandom</filename> kernel random number generator.</para> <para>Note that <function>sd_id128_randomize()</function> always returns a UUID v4-compatible ID.</para> <para>For more information about the <literal>sd_id128_t</literal> type, see <citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> <para><citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s <option>--new-id</option> option may be used as a command-line front-end for <function>sd_id128_randomize()</function>.</para> </refsect1> <refsect1> <title>Return Value</title> <para>The call returns 0 on success (in which case <parameter>ret</parameter> is filled in), or a negative errno-style error code.</para> </refsect1> <refsect1> <title>Notes</title> <para>The <function>sd_id128_randomize()</function> interface is available as a shared library, which can be compiled and linked to with the <literal>libsystemd</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-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>, <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>, <citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry> </para> </refsect1> </refentry>