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