<refmeta>
<refentrytitle>sd-id128</refentrytitle>
- <manvolnum>7</manvolnum>
+ <manvolnum>3</manvolnum>
</refmeta>
<refnamediv>
<refname>sd-id128</refname>
<refname>sd_id128_t</refname>
<refname>SD_ID128_MAKE</refname>
+ <refname>SD_ID128_CONST_STR</refname>
<refname>SD_ID128_FORMAT_STR</refname>
<refname>SD_ID128_FORMAT_VAL</refname>
<refname>sd_id128_equal</refname>
- <refpurpose>APIs for processing 128 bit IDs</refpurpose>
+ <refpurpose>APIs for processing 128-bit IDs</refpurpose>
</refnamediv>
<refsynopsisdiv>
<title>Description</title>
<para><filename>sd-id128.h</filename> provides APIs to
- process and generate 128 bit ID values. The 128 bit ID
+ process and generate 128-bit ID values. The 128-bit ID
values processed and generated by these APIs are a
generalization of OSF UUIDs as defined by <ulink
- url="http://tools.ietf.org/html/rfc4122">RFC
- 4122</ulink>, though use a simpler string
- formatting. These functions impose no structure on the
+ url="https://tools.ietf.org/html/rfc4122">RFC
+ 4122</ulink> but use a simpler string
+ format. These functions impose no structure on the
used IDs, much unlike OSF UUIDs or Microsoft GUIDs,
but are fully compatible with those types of IDs.
</para>
<para>See
- <citerefentry><refentrytitle>sd_id128_to_string</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
- <citerefentry><refentrytitle>sd_id128_randomize</refentrytitle><manvolnum>3</manvolnum></citerefentry>
- for more information about the functions
- implemented.</para>
+ <citerefentry><refentrytitle>sd_id128_to_string</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_id128_randomize</refentrytitle><manvolnum>3</manvolnum></citerefentry> and
+ <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ for more information about the implemented
+ functions.</para>
- <para>A 128 bit ID is implemented as the following
+ <para>A 128-bit ID is implemented as the following
union type:</para>
<programlisting>typedef union sd_id128 {
uint64_t qwords[2];
} sd_id128_t;</programlisting>
- <para>This union type allows accessing the 128 bit ID
- as 16 separate bytes or 2 64 bit words. It is generally
- safer to access the ID components by their 8 bit array
- to avoid endianess issues. This union is intended to
+ <para>This union type allows accessing the 128-bit ID
+ as 16 separate bytes or two 64-bit words. It is generally
+ safer to access the ID components by their 8-bit array
+ to avoid endianness issues. This union is intended to
be passed call-by-value (as opposed to
call-by-reference) and may be directly manipulated by
clients.</para>
<para>A couple of macros are defined to denote and
- decode 128 bit IDs:</para>
+ decode 128-bit IDs:</para>
<para><function>SD_ID128_MAKE()</function> may be used
- to write a 128 bit ID in source code. A commonly used
- idiom is to give 128 bit IDs names using this macro:</para>
+ to denote a constant 128-bit ID in source code. A
+ commonly used idiom is to assign a name to a 128-bit
+ ID using this macro:</para>
<programlisting>#define SD_MESSAGE_COREDUMP SD_ID128_MAKE(fc,2e,22,bc,6e,e6,47,b6,b9,07,29,ab,34,a2,50,b1)</programlisting>
+ <para><function>SD_ID128_CONST_STR()</function> may be
+ used to convert constant 128-bit IDs into constant
+ strings for output. The following example code will
+ output the string
+ "fc2e22bc6ee647b6b90729ab34a250b1":</para>
+ <programlisting>int main(int argc, char *argv[]) {
+ puts(SD_ID128_CONST_STR(SD_MESSAGE_COREDUMP));
+}</programlisting>
+
<para><function>SD_ID128_FORMAT_STR</function> and
<function>SD_ID128_FORMAT_VAL()</function> may be used
- to format a 128 bit ID in a
+ to format a 128-bit ID in a
<citerefentry><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>
format string, as shown in the following
example:</para>
return 0;
}</programlisting>
- <para>Use <function>sd_id128_equal()</function> to compare two 128 bit IDs:</para>
+ <para>Use <function>sd_id128_equal()</function> to compare two 128-bit IDs:</para>
<programlisting>int main(int argc, char *argv[]) {
sd_id128_t a, b, c;
<para>Note that new, randomized IDs may be generated
with
<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>'s
- <literal>--new-id</literal> command.</para>
+ <option>--new-id</option> option.</para>
</refsect1>
<refsect1>
<title>Notes</title>
- <para>These APIs are implemented as shared library,
+ <para>These APIs are implemented 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>
<citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_id128_to_string</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_id128_randomize</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd_id128_get_machine</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>journalctl</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd-journal</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
~ianmdlvl / elogind.git / blobdiff