136 lines
5.9 KiB
XML
136 lines
5.9 KiB
XML
<?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_to_string">
|
||
|
||
<refentryinfo>
|
||
<title>sd_id128_to_string</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_to_string</refentrytitle>
|
||
<manvolnum>3</manvolnum>
|
||
</refmeta>
|
||
|
||
<refnamediv>
|
||
<refname>sd_id128_to_string</refname>
|
||
<refname>sd_id128_from_string</refname>
|
||
<refpurpose>Format or parse 128-bit IDs as strings</refpurpose>
|
||
</refnamediv>
|
||
|
||
<refsynopsisdiv>
|
||
<funcsynopsis>
|
||
<funcsynopsisinfo>#include <systemd/sd-id128.h></funcsynopsisinfo>
|
||
|
||
<funcprototype>
|
||
<funcdef>char* <function>sd_id128_to_string</function></funcdef>
|
||
<paramdef>sd_id128_t <parameter>id</parameter>, char <parameter>s</parameter>[33]</paramdef>
|
||
</funcprototype>
|
||
|
||
<funcprototype>
|
||
<funcdef>int <function>sd_id128_from_string</function></funcdef>
|
||
<paramdef>const char* <parameter>s</parameter>, sd_id128_t* <parameter>ret</parameter></paramdef>
|
||
</funcprototype>
|
||
|
||
</funcsynopsis>
|
||
</refsynopsisdiv>
|
||
|
||
<refsect1>
|
||
<title>Description</title>
|
||
|
||
<para><function>sd_id128_to_string()</function>
|
||
formats a 128-bit ID as a character string. It expects
|
||
the ID and a string array capable of storing 33
|
||
characters. The ID will be formatted as 32 lowercase
|
||
hexadecimal digits and be terminated by a NUL
|
||
byte.</para>
|
||
|
||
<para><function>sd_id128_from_string()</function>
|
||
implements the reverse operation: it takes a 33
|
||
character string with 32 hexadecimal digits
|
||
(either lowercase or uppercase, terminated by NUL) and
|
||
parses them back into a 128-bit ID returned in
|
||
<parameter>ret</parameter>. Alternatively, this call
|
||
can also parse a 37-character string with a 128-bit ID
|
||
formatted as RFC UUID.</para>
|
||
|
||
<para>For more information about the
|
||
<literal>sd_id128_t</literal> type see
|
||
<citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>. Note
|
||
that these calls operate the same way on all
|
||
architectures, i.e. the results do not depend on
|
||
endianness.</para>
|
||
|
||
<para>When formatting a 128-bit ID into a string, it is
|
||
often easier to use a format string for
|
||
<citerefentry><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>. This
|
||
is easily done using the
|
||
<function>SD_ID128_FORMAT_STR</function> and
|
||
<function>SD_ID128_FORMAT_VAL()</function> macros. For
|
||
more information see
|
||
<citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para>
|
||
</refsect1>
|
||
|
||
<refsect1>
|
||
<title>Return Value</title>
|
||
|
||
<para><function>sd_id128_to_string()</function> always
|
||
succeeds and returns a pointer to the string array
|
||
passed in. <function>sd_id128_from_string</function>
|
||
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_to_string()</function>
|
||
and <function>sd_id128_from_string()</function> interfaces are
|
||
available as shared library, which can be compiled and
|
||
linked to with the <literal>libsystemd-id128</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>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>
|
||
</para>
|
||
</refsect1>
|
||
|
||
</refentry>
|