<refnamediv>
<refname>sd_id128_randomize</refname>
- <refname>sd_id128_get_machine</refname>
- <refname>sd_id128_get_boot</refname>
- <refpurpose>Generate or retrieve 128 bit IDs</refpurpose>
+ <refpurpose>Generate 128-bit IDs</refpurpose>
</refnamediv>
<refsynopsisdiv>
<paramdef>sd_id128_t* <parameter>ret</parameter></paramdef>
</funcprototype>
- <funcprototype>
- <funcdef>int <function>sd_id128_get_machine</function></funcdef>
- <paramdef>sd_id128_t* <parameter>ret</parameter></paramdef>
- </funcprototype>
-
- <funcprototype>
- <funcdef>int <function>sd_id128_get_boot</function></funcdef>
- <paramdef>sd_id128_t* <parameter>ret</parameter></paramdef>
- </funcprototype>
-
</funcsynopsis>
</refsynopsisdiv>
<title>Description</title>
<para><function>sd_id128_randomize()</function>
- generates a new randomized 128 bit ID and returns it
+ 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><function>sd_id128_get_machine()</function>
- returns the machine ID of the executing host. This
- reads and parses the
- <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>
- file. This function caches the machine ID internally
- to make retrieving the machine ID a cheap
- operation.</para>
-
- <para><function>sd_id128_get_boot()</function> returns
- the boot ID of the executing kernel. This reads and
- parses the
- <filename>/proc/sys/kernel/random/boot_id</filename>
- file exposed by the kernel. It is randomly generated
- early at boot and is unique for every running kernel
- instance. See
- <citerefentry><refentrytitle>random</refentrytitle><manvolnum>4</manvolnum></citerefentry>
- for more information. This function also internally
- caches the returned ID to make this call a cheap
- operation.</para>
-
<para>Note that
- <function>sd_id128_randomize()</function> and
- <function>sd_id128_get_boot()</function> always return
- a UUID v4 compatible
- ID. <function>sd_id128_get_machine()</function> will
- also return a UUID v4 compatible ID on new
- installations, but might not on older. It is possible
- to convert the machine ID into an UUID v4 compatible
- one. For more information see
- <citerefentry><refentrytitle>machine-id</refentrytitle><manvolnum>5</manvolnum></citerefentry>.</para>
+ <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>7</manvolnum></citerefentry>.</para>
+ <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
- <literal>--new-id</literal> command may be used as
- command line front-end for
+ <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 three calls return 0 on success (in which
+ <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>,
- <function>sd_id128_get_machine()</function> and
- <function>sd_id128_get_boot()</function> interfaces
- are available as shared library, which can be compiled
+ <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-id128</literal>
- <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ <literal>libsystemd-id128</literal> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
file.</para>
</refsect1>
<para>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
- <citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>7</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>random</refentrytitle><manvolnum>4</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry>
</para>
</refsect1>