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3802a3d3 | 1 | <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*--> |
a6278b88 | 2 | <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN" |
12b42c76 | 3 | "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd"> |
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4 | |
5 | <!-- | |
b975b0d5 | 6 | This file is part of systemd. |
a6278b88 | 7 | |
b975b0d5 | 8 | Copyright 2014 Zbigniew Jędrzejewski-Szmek |
a6278b88 | 9 | |
b975b0d5 ZJS |
10 | systemd is free software; you can redistribute it and/or modify it |
11 | under the terms of the GNU Lesser General Public License as published by | |
12 | the Free Software Foundation; either version 2.1 of the License, or | |
13 | (at your option) any later version. | |
a6278b88 | 14 | |
b975b0d5 ZJS |
15 | systemd is distributed in the hope that it will be useful, but |
16 | WITHOUT ANY WARRANTY; without even the implied warranty of | |
17 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
18 | Lesser General Public License for more details. | |
a6278b88 | 19 | |
b975b0d5 ZJS |
20 | You should have received a copy of the GNU Lesser General Public License |
21 | along with systemd; If not, see <http://www.gnu.org/licenses/>. | |
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22 | --> |
23 | ||
48f69d8f | 24 | <refentry id="sd_bus_path_encode"> |
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25 | |
26 | <refentryinfo> | |
27 | <title>sd_bus_path_encode</title> | |
28 | <productname>systemd</productname> | |
29 | ||
30 | <authorgroup> | |
31 | <author> | |
32 | <contrib>A monkey with a typewriter</contrib> | |
33 | <firstname>Zbigniew</firstname> | |
34 | <surname>Jędrzejewski-Szmek</surname> | |
35 | <email>zbyszek@in.waw.pl</email> | |
36 | </author> | |
37 | </authorgroup> | |
38 | </refentryinfo> | |
39 | ||
40 | <refmeta> | |
41 | <refentrytitle>sd_bus_path_encode</refentrytitle> | |
42 | <manvolnum>3</manvolnum> | |
43 | </refmeta> | |
44 | ||
45 | <refnamediv> | |
46 | <refname>sd_bus_path_encode</refname> | |
47 | <refname>sd_bus_path_decode</refname> | |
48 | ||
49 | <refpurpose>Convert an external identifier into an object path and back</refpurpose> | |
50 | </refnamediv> | |
51 | ||
52 | <refsynopsisdiv> | |
53 | <funcsynopsis> | |
54 | <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo> | |
55 | ||
56 | <funcprototype> | |
57 | <funcdef>int <function>sd_bus_path_encode</function></funcdef> | |
58 | <paramdef>const char *<parameter>prefix</parameter></paramdef> | |
59 | <paramdef>const char *<parameter>external_id</parameter></paramdef> | |
60 | <paramdef>char **<parameter>ret_path</parameter></paramdef> | |
61 | </funcprototype> | |
62 | ||
63 | <funcprototype> | |
64 | <funcdef>int <function>sd_bus_path_decode</function></funcdef> | |
a6278b88 | 65 | <paramdef>const char *<parameter>path</parameter></paramdef> |
53d68375 | 66 | <paramdef>const char *<parameter>prefix</parameter></paramdef> |
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67 | <paramdef>char **<parameter>ret_external_id</parameter></paramdef> |
68 | </funcprototype> | |
69 | </funcsynopsis> | |
70 | </refsynopsisdiv> | |
71 | ||
72 | <refsect1> | |
73 | <title>Description</title> | |
74 | ||
75 | <para><function>sd_bus_path_encode()</function> and | |
76 | <function>sd_bus_path_decode()</function> convert external | |
77 | identifier strings into object paths and back. These functions are | |
78 | useful to map application-specific string identifiers of any kind | |
79 | into bus object paths in a simple, reversible and safe way.</para> | |
80 | ||
81 | <para><function>sd_bus_path_encode()</function> takes a bus path | |
82 | prefix and an external identifier string as arguments, plus a | |
83 | place to store the returned bus path string. The bus path prefix | |
84 | must be a valid bus path, starting with a slash | |
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85 | <literal>/</literal>, and not ending in one. The external |
86 | identifier string may be in any format, may be the empty string, | |
87 | and has no restrictions on the charset — however, it must | |
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88 | always be <constant>NUL</constant>-terminated. The returned string |
89 | will be the concatenation of the bus path prefix plus an escaped | |
90 | version of the external identifier string. This operation may be | |
91 | reversed with <function>sd_bus_decode()</function>. It is | |
b8bde116 | 92 | recommended to only use external identifiers that generally |
a6278b88 | 93 | require little escaping to be turned into valid bus path |
b8bde116 | 94 | identifiers (for example, by sticking to a 7-bit ASCII character |
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95 | set), in order to ensure the resulting bus path is still short and |
96 | easily processed.</para> | |
97 | ||
98 | <para><function>sd_bus_path_decode()</function> reverses the | |
99 | operation of <function>sd_bus_path_encode()</function> and thus | |
100 | regenerates an external identifier string from a bus path. It | |
101 | takes a bus path and a prefix string, plus a place to store the | |
102 | returned external identifier string. If the bus path does not | |
103 | start with the specified prefix, 0 is returned and the returned | |
b8bde116 | 104 | string is set to <constant>NULL</constant>. Otherwise, the |
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105 | string following the prefix is unescaped and returned in the |
106 | external identifier string.</para> | |
107 | ||
dca348bc | 108 | <para>The escaping used will replace all characters which are |
b8bde116 | 109 | invalid in a bus object path by <literal>_</literal>, followed by a |
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110 | hexadecimal value. As a special case, the empty string will be |
111 | replaced by a lone <literal>_</literal>.</para> | |
112 | </refsect1> | |
113 | ||
114 | <refsect1> | |
115 | <title>Return Value</title> | |
116 | ||
117 | <para>On success, <function>sd_bus_path_encode()</function> | |
118 | returns positive or 0, and a valid bus path in the return | |
119 | argument. On success, <function>sd_bus_path_decode()</function> | |
120 | returns a positive value if the prefixed matched, or 0 if it | |
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121 | did not. If the prefix matched, the external identifier is returned |
122 | in the return parameter. If it did not match, NULL is returned in | |
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123 | the return parameter. On failure, a negative errno-style error |
124 | number is returned by either function. The returned strings must | |
125 | be | |
5aded369 | 126 | <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>'d |
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127 | by the caller.</para> |
128 | </refsect1> | |
129 | ||
130 | <refsect1> | |
131 | <title>Notes</title> | |
132 | ||
133 | <para><function>sd_bus_path_encode()</function> and | |
134 | <function>sd_bus_path_decode()</function> are available as a | |
135 | shared library, which can be compiled and linked to with the | |
5aded369 | 136 | <constant>libsystemd</constant> <citerefentry project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry> |
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137 | file.</para> |
138 | </refsect1> | |
139 | ||
140 | <refsect1> | |
141 | <title>See Also</title> | |
142 | ||
143 | <para> | |
144 | <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>, | |
145 | <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>, | |
5aded369 | 146 | <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> |
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147 | </para> |
148 | </refsect1> | |
149 | ||
150 | </refentry> |