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man: updates to the passive target section
[elogind.git] / man / sd_id128_randomize.xml
1 <?xml version='1.0'?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
3         "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
4
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8   Copyright 2012 Lennart Poettering
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23
24 <refentry id="sd_id128_randomize">
25
26         <refentryinfo>
27                 <title>sd_id128_randomize</title>
28                 <productname>systemd</productname>
29
30                 <authorgroup>
31                         <author>
32                                 <contrib>Developer</contrib>
33                                 <firstname>Lennart</firstname>
34                                 <surname>Poettering</surname>
35                                 <email>lennart@poettering.net</email>
36                         </author>
37                 </authorgroup>
38         </refentryinfo>
39
40         <refmeta>
41                 <refentrytitle>sd_id128_randomize</refentrytitle>
42                 <manvolnum>3</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>sd_id128_randomize</refname>
47                 <refpurpose>Generate 128-bit IDs</refpurpose>
48         </refnamediv>
49
50         <refsynopsisdiv>
51                 <funcsynopsis>
52                         <funcsynopsisinfo>#include &lt;systemd/sd-id128.h&gt;</funcsynopsisinfo>
53
54                         <funcprototype>
55                                 <funcdef>int <function>sd_id128_randomize</function></funcdef>
56                                 <paramdef>sd_id128_t *<parameter>ret</parameter></paramdef>
57                         </funcprototype>
58
59                 </funcsynopsis>
60         </refsynopsisdiv>
61
62         <refsect1>
63                 <title>Description</title>
64
65                 <para><function>sd_id128_randomize()</function>
66                 generates a new randomized 128-bit ID and returns it
67                 in <parameter>ret</parameter>. Every invocation
68                 returns a new randomly generated ID. This uses the
69                 <filename>/dev/urandom</filename> kernel random number
70                 generator.</para>
71
72                 <para>Note that
73                 <function>sd_id128_randomize()</function> always returns
74                 a UUID v4-compatible ID.</para>
75
76                 <para>For more information about the
77                 <literal>sd_id128_t</literal> type, see
78                 <citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
79
80                 <para><citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
81                 <option>--new-id</option> option may be used as a
82                 command-line front-end for
83                 <function>sd_id128_randomize()</function>.</para>
84         </refsect1>
85
86         <refsect1>
87                 <title>Return Value</title>
88
89                 <para>The call returns 0 on success (in which
90                 case <parameter>ret</parameter> is filled in), or a
91                 negative errno-style error code.</para>
92         </refsect1>
93
94         <refsect1>
95                 <title>Notes</title>
96
97                 <para>The <function>sd_id128_randomize()</function> interface
98                 is available as a shared library, which can be compiled
99                 and linked to with the
100                 <literal>libsystemd</literal> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
101                 file.</para>
102         </refsect1>
103
104         <refsect1>
105                 <title>See Also</title>
106
107                 <para>
108                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
109                         <citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
110                         <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>,
111                         <citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
112                         <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry>
113                 </para>
114         </refsect1>
115
116 </refentry>