1 <?xml version='1.0'?> <!--*- Mode: nxml; nxml-child-indent: 2; indent-tabs-mode: nil -*-->
2 <!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
6 SPDX-License-Identifier: LGPL-2.1+
9 <refentry id="sd_bus_error_add_map">
12 <title>sd_bus_error_add_map</title>
13 <productname>systemd</productname>
17 <refentrytitle>sd_bus_error_add_map</refentrytitle>
18 <manvolnum>3</manvolnum>
22 <refname>sd_bus_error_add_map</refname>
23 <refname>sd_bus_error_map</refname>
24 <refname>SD_BUS_ERROR_MAP</refname>
25 <refname>SD_BUS_ERROR_END</refname>
27 <refpurpose>Additional sd-dbus error mappings</refpurpose>
32 <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
34 <funcsynopsisinfo>typedef struct {
38 } sd_bus_error_map;</funcsynopsisinfo>
43 <constant>SD_BUS_ERROR_MAP(<replaceable>name</replaceable>, <replaceable>code</replaceable>)</constant>
46 <constant>SD_BUS_ERROR_MAP_END</constant>
50 <funcdef>int <function>sd_bus_error_add_map</function></funcdef>
51 <paramdef>const sd_bus_map *<parameter>map</parameter></paramdef>
57 <title>Description</title>
59 <para>The <function>sd_bus_error_add_map()</function> call may be
60 used to register additional mappings for converting D-Bus errors
61 to Linux <varname>errno</varname>-style errors. The mappings
62 defined with this call are consulted by calls such as
63 <citerefentry><refentrytitle>sd_bus_error_set</refentrytitle><manvolnum>3</manvolnum></citerefentry>
65 <citerefentry><refentrytitle>sd_bus_error_get_errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>. By
66 default, a number of generic, standardized mappings are known, as
68 <citerefentry><refentrytitle>sd-bus-errors</refentrytitle><manvolnum>3</manvolnum></citerefentry>. Use
69 this call to add further, application-specific mappings.</para>
71 <para>The function takes a pointer to an array of
72 <structname>sd_bus_error_map</structname> structures. A reference
73 to the specified array is added to the lookup tables for error
74 mappings. Note that the structure is not copied, and that it is hence
75 essential that the array stays available and constant during the
76 entire remaining runtime of the process.</para>
78 <para>The mapping array should be put together with a series of
79 <constant>SD_BUS_ERROR_MAP()</constant> macro invocations that
80 take a literal name string and a (positive)
81 <varname>errno</varname>-style error number. The last entry of the
82 array should be an invocation of the
83 <constant>SD_BUS_ERROR_MAP_END</constant> macro. The array should not be
84 put together without use of these two macros.</para>
86 <para>Note that the call is idempotent: it is safe to invoke it
87 multiple times with the parameter, which will only add the passed
88 mapping array once.</para>
90 <para>Note that the memory allocated by this call is not intended
91 to be freed during the lifetime of the process. It should not be
92 freed explicitly.</para>
96 <title>Return Value</title>
98 <para><function>sd_bus_error_add_map()</function> returns a
99 positive value when the new array was added to the lookup
100 tables. It returns zero when the same array was already added
101 before. On error, a negative <varname>errno</varname>-style error
102 code is returned. See below for known error codes.</para>
106 <title>Errors</title>
108 <para>Returned errors may indicate the following problems:</para>
113 <term><constant>-EINVAL</constant></term>
115 <listitem><para>The specified mapping array is invalid.</para></listitem>
119 <term><constant>-ENOMEM</constant></term>
121 <listitem><para>Memory allocation failed.</para></listitem>
129 <para>The various error definitions described here are available
130 as a shared library, which can be compiled and linked to with the
131 <constant>libelogind</constant> <citerefentry
132 project='die-net'><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
137 <title>See Also</title>
140 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
141 <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
142 <citerefentry><refentrytitle>sd_bus_error</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
143 <citerefentry><refentrytitle>sd-bus-errors</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
144 <citerefentry project='man-pages'><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
145 <citerefentry project='die-net'><refentrytitle>strerror_r</refentrytitle><manvolnum>3</manvolnum></citerefentry>