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"
10 xmlns:
xi=
"http://www.w3.org/2001/XInclude">
13 <title>sd_bus_error_add_map
</title>
14 <productname>systemd
</productname>
18 <refentrytitle>sd_bus_error_add_map
</refentrytitle>
19 <manvolnum>3</manvolnum>
23 <refname>sd_bus_error_add_map
</refname>
24 <refname>sd_bus_error_map
</refname>
25 <refname>SD_BUS_ERROR_MAP
</refname>
26 <refname>SD_BUS_ERROR_END
</refname>
28 <refpurpose>Additional sd-dbus error mappings
</refpurpose>
33 <funcsynopsisinfo>#include
<systemd/sd-bus.h
></funcsynopsisinfo>
35 <funcsynopsisinfo>typedef struct {
39 } sd_bus_error_map;
</funcsynopsisinfo>
44 <constant>SD_BUS_ERROR_MAP(
<replaceable>name
</replaceable>,
<replaceable>code
</replaceable>)
</constant>
47 <constant>SD_BUS_ERROR_MAP_END
</constant>
51 <funcdef>int
<function>sd_bus_error_add_map
</function></funcdef>
52 <paramdef>const sd_bus_map *
<parameter>map
</parameter></paramdef>
58 <title>Description
</title>
60 <para>The
<function>sd_bus_error_add_map()
</function> call may be
61 used to register additional mappings for converting D-Bus errors
62 to Linux
<varname>errno
</varname>-style errors. The mappings
63 defined with this call are consulted by calls such as
64 <citerefentry><refentrytitle>sd_bus_error_set
</refentrytitle><manvolnum>3</manvolnum></citerefentry>
66 <citerefentry><refentrytitle>sd_bus_error_get_errno
</refentrytitle><manvolnum>3</manvolnum></citerefentry>. By
67 default, a number of generic, standardized mappings are known, as
69 <citerefentry><refentrytitle>sd-bus-errors
</refentrytitle><manvolnum>3</manvolnum></citerefentry>. Use
70 this call to add further, application-specific mappings.
</para>
72 <para>The function takes a pointer to an array of
73 <structname>sd_bus_error_map
</structname> structures. A reference
74 to the specified array is added to the lookup tables for error
75 mappings. Note that the structure is not copied, and that it is hence
76 essential that the array stays available and constant during the
77 entire remaining runtime of the process.
</para>
79 <para>The mapping array should be put together with a series of
80 <constant>SD_BUS_ERROR_MAP()
</constant> macro invocations that
81 take a literal name string and a (positive)
82 <varname>errno
</varname>-style error number. The last entry of the
83 array should be an invocation of the
84 <constant>SD_BUS_ERROR_MAP_END
</constant> macro. The array should not be
85 put together without use of these two macros.
</para>
87 <para>Note that the call is idempotent: it is safe to invoke it
88 multiple times with the parameter, which will only add the passed
89 mapping array once.
</para>
91 <para>Note that the memory allocated by this call is not intended
92 to be freed during the lifetime of the process. It should not be
93 freed explicitly.
</para>
97 <title>Return Value
</title>
99 <para><function>sd_bus_error_add_map()
</function> returns a
100 positive value when the new array was added to the lookup
101 tables. It returns zero when the same array was already added
102 before. On error, a negative
<varname>errno
</varname>-style error
103 code is returned. See below for known error codes.
</para>
107 <title>Errors
</title>
109 <para>Returned errors may indicate the following problems:
</para>
114 <term><constant>-EINVAL
</constant></term>
116 <listitem><para>The specified mapping array is invalid.
</para></listitem>
120 <term><constant>-ENOMEM
</constant></term>
122 <listitem><para>Memory allocation failed.
</para></listitem>
127 <xi:include href=
"libsystemd-pkgconfig.xml" />
130 <title>See Also
</title>
133 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
134 <citerefentry><refentrytitle>sd-bus
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
135 <citerefentry><refentrytitle>sd_bus_error
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
136 <citerefentry><refentrytitle>sd-bus-errors
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
137 <citerefentry project='man-pages'
><refentrytitle>errno
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
138 <citerefentry project='die-net'
><refentrytitle>strerror_r
</refentrytitle><manvolnum>3</manvolnum></citerefentry>