]>
Commit | Line | Data |
---|---|---|
12355095 LP |
1 | <?xml version='1.0'?> <!--*-nxml-*--> |
2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" | |
12b42c76 | 3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
12355095 LP |
4 | |
5 | <!-- | |
572eb058 ZJS |
6 | SPDX-License-Identifier: LGPL-2.1+ |
7 | ||
12355095 | 8 | Copyright 2012 Lennart Poettering |
12355095 LP |
9 | --> |
10 | ||
7d6b2723 | 11 | <refentry id="sd_id128_to_string" xmlns:xi="http://www.w3.org/2001/XInclude"> |
12355095 | 12 | |
798d3a52 ZJS |
13 | <refentryinfo> |
14 | <title>sd_id128_to_string</title> | |
15 | <productname>systemd</productname> | |
16 | ||
17 | <authorgroup> | |
18 | <author> | |
19 | <contrib>Developer</contrib> | |
20 | <firstname>Lennart</firstname> | |
21 | <surname>Poettering</surname> | |
22 | <email>lennart@poettering.net</email> | |
23 | </author> | |
24 | </authorgroup> | |
25 | </refentryinfo> | |
26 | ||
27 | <refmeta> | |
28 | <refentrytitle>sd_id128_to_string</refentrytitle> | |
29 | <manvolnum>3</manvolnum> | |
30 | </refmeta> | |
31 | ||
32 | <refnamediv> | |
33 | <refname>sd_id128_to_string</refname> | |
34 | <refname>sd_id128_from_string</refname> | |
35 | <refpurpose>Format or parse 128-bit IDs as strings</refpurpose> | |
36 | </refnamediv> | |
37 | ||
38 | <refsynopsisdiv> | |
39 | <funcsynopsis> | |
40 | <funcsynopsisinfo>#include <systemd/sd-id128.h></funcsynopsisinfo> | |
41 | ||
42 | <funcprototype> | |
43 | <funcdef>char *<function>sd_id128_to_string</function></funcdef> | |
44 | <paramdef>sd_id128_t <parameter>id</parameter>, char <parameter>s</parameter>[33]</paramdef> | |
45 | </funcprototype> | |
46 | ||
47 | <funcprototype> | |
48 | <funcdef>int <function>sd_id128_from_string</function></funcdef> | |
49 | <paramdef>const char *<parameter>s</parameter>, sd_id128_t *<parameter>ret</parameter></paramdef> | |
50 | </funcprototype> | |
51 | ||
52 | </funcsynopsis> | |
53 | </refsynopsisdiv> | |
54 | ||
55 | <refsect1> | |
56 | <title>Description</title> | |
57 | ||
58 | <para><function>sd_id128_to_string()</function> formats a 128-bit | |
59 | ID as a character string. It expects the ID and a string array | |
60 | capable of storing 33 characters. The ID will be formatted as 32 | |
61 | lowercase hexadecimal digits and be terminated by a | |
62 | <constant>NUL</constant> byte.</para> | |
63 | ||
9ca8d434 LP |
64 | <para><function>sd_id128_from_string()</function> implements the reverse operation: it takes a 33 character string |
65 | with 32 hexadecimal digits (either lowercase or uppercase, terminated by <constant>NUL</constant>) and parses them | |
66 | back into a 128-bit ID returned in <parameter>ret</parameter>. Alternatively, this call can also parse a | |
67 | 37-character string with a 128-bit ID formatted as RFC UUID. If <parameter>ret</parameter> is passed as NULL the | |
68 | function will validate the passed ID string, but not actually return it in parsed form.</para> | |
798d3a52 ZJS |
69 | |
70 | <para>For more information about the <literal>sd_id128_t</literal> | |
71 | type see | |
72 | <citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>. | |
73 | Note that these calls operate the same way on all architectures, | |
74 | i.e. the results do not depend on endianness.</para> | |
75 | ||
76 | <para>When formatting a 128-bit ID into a string, it is often | |
77 | easier to use a format string for | |
78 | <citerefentry project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>. | |
79 | This is easily done using the | |
80 | <function>SD_ID128_FORMAT_STR</function> and | |
81 | <function>SD_ID128_FORMAT_VAL()</function> macros. For more | |
82 | information see | |
83 | <citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>.</para> | |
84 | </refsect1> | |
85 | ||
86 | <refsect1> | |
87 | <title>Return Value</title> | |
88 | ||
89 | <para><function>sd_id128_to_string()</function> always succeeds | |
90 | and returns a pointer to the string array passed in. | |
91 | <function>sd_id128_from_string</function> returns 0 on success, in | |
92 | which case <parameter>ret</parameter> is filled in, or a negative | |
93 | errno-style error code.</para> | |
94 | </refsect1> | |
95 | ||
7d6b2723 | 96 | <xi:include href="libsystemd-pkgconfig.xml" /> |
798d3a52 ZJS |
97 | |
98 | <refsect1> | |
99 | <title>See Also</title> | |
100 | ||
101 | <para> | |
102 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
103 | <citerefentry><refentrytitle>sd-id128</refentrytitle><manvolnum>3</manvolnum></citerefentry>, | |
104 | <citerefentry project='man-pages'><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry> | |
105 | </para> | |
106 | </refsect1> | |
12355095 LP |
107 | |
108 | </refentry> |