--- /dev/null
+<?xml version='1.0'?> <!--*-nxml-*-->
+<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.2//EN"
+"http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
+
+<!--
+This file is part of systemd.
+
+Copyright 2014 Zbigniew Jędrzejewski-Szmek
+
+systemd is free software; you can redistribute it and/or modify it
+under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 of the License, or
+(at your option) any later version.
+
+systemd is distributed in the hope that it will be useful, but
+WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License
+along with systemd; If not, see <http://www.gnu.org/licenses/>.
+-->
+
+<refentry id="sd_bus_error">
+
+ <refentryinfo>
+ <title>sd_bus_error</title>
+ <productname>systemd</productname>
+
+ <authorgroup>
+ <author>
+ <contrib>A monkey with a typewriter</contrib>
+ <firstname>Zbigniew</firstname>
+ <surname>Jędrzejewski-Szmek</surname>
+ <email>zbyszek@in.waw.pl</email>
+ </author>
+ </authorgroup>
+ </refentryinfo>
+
+ <refmeta>
+ <refentrytitle>sd_bus_error</refentrytitle>
+ <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>sd_bus_error</refname>
+ <refname>sd_bus_error_free</refname>
+ <refname>sd_bus_error_set</refname>
+ <refname>sd_bus_error_set_const</refname>
+ <refname>sd_bus_error_set_errno</refname>
+ <refname>sd_bus_error_set_errnof</refname>
+ <refname>sd_bus_error_get_errno</refname>
+ <refname>sd_bus_error_copy</refname>
+ <refname>sd_bus_error_is_set</refname>
+ <refname>sd_bus_error_has_name</refname>
+
+ <refpurpose>libsystemd-bus error handling</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcsynopsisinfo>#include <systemd/sd-bus.h></funcsynopsisinfo>
+
+ <funcsynopsisinfo>typedef struct {
+ const char *name;
+ const char *message;
+ ...
+} sd_bus_error;</funcsynopsisinfo>
+
+ <para>
+ <constant>SD_BUS_ERROR_MAKE_CONST(<replaceable>name</replaceable>, <replaceable>message</replaceable>)</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_NULL</constant>
+ </para>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_error_free</function></funcdef>
+ <paramdef>sd_bus_error *<parameter>e</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_error_set</function></funcdef>
+ <paramdef>sd_bus_error *<parameter>e</parameter></paramdef>
+ <paramdef>const char *<parameter>name</parameter></paramdef>
+ <paramdef>const char *<parameter>message</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_error_setf</function></funcdef>
+ <paramdef>sd_bus_error *<parameter>e</parameter></paramdef>
+ <paramdef>const char *<parameter>name</parameter></paramdef>
+ <paramdef>const char *<parameter>format</parameter></paramdef>
+ <paramdef>...</paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_error_set_const</function></funcdef>
+ <paramdef>sd_bus_error *<parameter>e</parameter></paramdef>
+ <paramdef>const char *<parameter>name</parameter></paramdef>
+ <paramdef>const char *<parameter>message</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_error_set_errno</function></funcdef>
+ <paramdef>sd_bus_error *<parameter>e</parameter></paramdef>
+ <paramdef>int <parameter>error</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_error_set_errnof</function></funcdef>
+ <paramdef>sd_bus_error *<parameter>e</parameter></paramdef>
+ <paramdef>int <parameter>error</parameter></paramdef>
+ <paramdef>const char *<parameter>format</parameter></paramdef>
+ <paramdef>...</paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_error_get_errno</function></funcdef>
+ <paramdef>const sd_bus_error *<parameter>e</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_error_copy</function></funcdef>
+ <paramdef>sd_bus_error *<parameter>dst</parameter></paramdef>
+ <paramdef>const sd_bus_error *<parameter>e</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_error_is_set</function></funcdef>
+ <paramdef>const sd_bus_error *<parameter>e</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_bus_error_has_name</function></funcdef>
+ <paramdef>const sd_bus_error *<parameter>e</parameter></paramdef>
+ <paramdef>const char *<parameter>name</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+
+ <para>
+ <constant>SD_BUS_ERROR_FAILED</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_NO_MEMORY</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_SERVICE_UNKNOWN</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_NAME_HAS_NO_OWNER</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_NO_REPLY</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_IO_ERROR</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_BAD_ADDRESS</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_NOT_SUPPORTED</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_LIMITS_EXCEEDED</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_ACCESS_DENIED</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_AUTH_FAILED</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_NO_SERVER</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_TIMEOUT</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_NO_NETWORK</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_ADDRESS_IN_USE</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_DISCONNECTED</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_INVALID_ARGS</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_FILE_NOT_FOUND</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_FILE_EXISTS</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_UNKNOWN_METHOD</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_UNKNOWN_OBJECT</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_UNKNOWN_INTERFACE</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_UNKNOWN_PROPERTY</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_PROPERTY_READ_ONLY</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_UNIX_PROCESS_ID_UNKNOWN</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_INVALID_SIGNATURE</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_INCONSISTENT_MESSAGE</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_MATCH_RULE_NOT_FOUND</constant>
+ </para>
+ <para>
+ <constant>SD_BUS_ERROR_MATCH_RULE_INVALID</constant>
+ </para>
+
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><structname>sd_bus_error</structname> structure carries
+ information for a <filename>libsystemd-bus</filename> error.
+ Functions described below can be used to set and query fields in
+ this structure. Field <structfield>name</structfield> contains a
+ short identifier of an error. It should follow the rules for error
+ names described in the D-Bus specification, subsection <ulink
+ url="http://dbus.freedesktop.org/doc/dbus-specification.html#message-protocol-names">Valid
+ Names</ulink>. The <structfield>message</structfield> is a human
+ readable string describing the details. When no longer necessary,
+ resources held by this structure should be destroyed with
+ <function>sd_bus_error_free</function>.</para>
+
+ <para><function>sd_bus_error_set</function> will return an
+ errno-like negative value returned based on parameter
+ <parameter>name</parameter> (see
+ <citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>).
+ Various well-known D-Bus errors are converted to specific values,
+ and the remaining ones to <constant>-ENXIO</constant>. Well-known
+ D-Bus error names are available as constants
+ <constant>SD_BUS_ERROR_FAILED</constant>, etc., listed above. If
+ <parameter>name</parameter> is <constant>NULL</constant>, it is is
+ assumed that no error occured, and 0 is returned. This means that
+ this function may be conveniently used in a
+ <function>return</function> statement.</para>
+
+ <para>If <parameter>e</parameter> is not
+ <constant>NULL</constant>, <structfield>name</structfield> and
+ <structfield>message</structfield> will be filled-in in the
+ <structname>sd_bus_error</structname> structure
+ <parameter>e</parameter> points at. As described above,
+ <parameter>name</parameter> may be <constant>NULL</constant>,
+ which is treated as no error. Parameter
+ <parameter>message</parameter> may also be
+ <constant>NULL</constant>, in which case no message is specified.
+ <function>sd_bus_error_set</function> will make internal copies of
+ specified strings.</para>
+
+ <para><function>sd_bus_error_setf</function> is similar to
+ <function>sd_bus_error_set</function>, but takes a
+ <citerefentry><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ format string and corresponding arguments to generate
+ <structname>message</structname>.</para>
+
+ <para><function>sd_bus_error_set_const</function> is similar to
+ <function>sd_bus_error_set</function>, but string parameters are
+ not copied internally, and must remain valid for the lifetime of
+ <parameter>e</parameter>.</para>
+
+ <para><function>sd_bus_error_set_errno</function> will set
+ <structfield>name</structfield> based on an errno-like value.
+ <citerefentry><refentrytitle>strerror</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ will be used to set <structfield>message</structfield>. Well-known
+ D-Bus error names will be used for <structfield>name</structfield>
+ if available, otherwise a name in the
+ <literal>System.Error</literal> namespace will be generated.
+ </para>
+
+ <para><function>sd_bus_error_set_errnof</function> is similar to
+ <function>sd_bus_error_set_errno</function>, but in addition to
+ <parameter>name</parameter>, takes a
+ <citerefentry><refentrytitle>printf</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ format and corresponding arguments.
+ <structfield>name</structfield> will be generated from
+ <parameter>format</parameter> and the arguments.</para>
+
+ <para><function>sd_bus_error_get_errno</function> is will convert
+ <structname>e->name</structname> to an errno-like value
+ using the same rules as <function>sd_bus_error_set</function>.
+ </para>
+
+ <para><function>sd_bus_error_copy</function> will initialize
+ <parameter>dst</parameter> using the values in
+ <parameter>e</parameter>. If the strings in
+ <parameter>e</parameter> were set using
+ <function>sd_bus_set_error_const</function>, they will be shared.
+ Otherwie they wil be copied.</para>
+
+ <para><function>sd_bus_error_is_set</function> will return
+ <constant>true</constant> if <parameter>e</parameter> is
+ non-<constant>NULL</constant> and an error has been set,
+ <constant>false</constant> otherwise.</para>
+
+ <para><function>sd_bus_error_has_name</function> will return true
+ if <parameter>e</parameter> is non-<constant>NULL</constant> and
+ an error with the same <parameter>name</parameter> has been set,
+ <constant>false</constant> otherwise.</para>
+
+ <para><function>sd_bus_error_free</function> will destroy resources
+ held by <parameter>e</parameter>. The parameter itself will not
+ be deallocated, and must be
+ <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>d
+ by the caller if necessary.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Return Value</title>
+
+ <para>Functions <function>sd_bus_error_set</function>,
+ <function>sd_bus_error_setf</function>,
+ <function>sd_bus_error_set_const</function>, when successful,
+ return the negative errno value corresponding to the
+ <parameter>name</parameter> parameter. Functions
+ <function>sd_bus_error_set_errno</function> and
+ <function>sd_bus_error_set_errnof</function>, when successful,
+ return the value of the <parameter>errno</parameter> parameter. If
+ an error occurs, one of the negative error values listed below
+ will be returned.</para>
+
+ <para><function>sd_bus_error_get_errno</function> returns
+ <constant>false</constant> when <parameter>e</parameter> is
+ <constant>NULL</constant>, and a positive errno value mapped from
+ <parameter>e->name</parameter> otherwise.</para>
+
+ <para><function>sd_bus_error_copy</function> returns 0 or a
+ positive integer on success, and one of the negative error values
+ listed below otherwise.</para>
+
+ <para><function>sd_bus_error_is_set</function> returns
+ <constant>true</constant> when <parameter>e</parameter> and
+ <parameter>e->name</parameter> are non-<constant>NULL</constant>,
+ <constant>false</constant> otherwise.</para>
+
+ <para><function>sd_bus_error_has_name</function> returns
+ <constant>true</constant> when <parameter>e</parameter> is
+ non-<constant>NULL</constant> and <parameter>e->name</parameter>
+ is equal to <parameter>name</parameter>,
+ <constant>false</constant> otherwise.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Reference ownership</title>
+ <para><structname>sd_bus_error</structname> is not reference
+ counted. Users should destroy resources held by it by calling
+ <function>sd_bus_error_free</function>.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Errors</title>
+
+ <para>Returned errors may indicate the following problems:</para>
+
+ <variablelist>
+
+ <varlistentry>
+ <term><varname>-EINVAL</varname></term>
+
+ <listitem><para>Error was already set in
+ <structname>sd_bus_error</structname> structure when one the
+ error-setting functions was called.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>-ENOMEM</varname></term>
+
+ <listitem><para>Memory allocation failed.</para></listitem>
+ </varlistentry>
+ </variablelist>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para><function>sd_bus_set_error()</function> and other functions
+ described here are available as a shared library, which can be
+ compiled and linked to with the
+ <constant>libsystemd-bus</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
+ file.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>See Also</title>
+
+ <para>
+ <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>errno</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+ <citerefentry><refentrytitle>strerror</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ </para>
+ </refsect1>
+
+</refentry>
~ianmdlvl / elogind.git / commitdiff