1<?xml version='1.0'?>
2<!DOCTYPE refentry PUBLIC "-//OASIS//DTD DocBook XML V4.5//EN"
3  "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
4<!-- SPDX-License-Identifier: LGPL-2.1-or-later -->
5
6<refentry id="sd_bus_can_send"
7          xmlns:xi="http://www.w3.org/2001/XInclude">
8
9  <refentryinfo>
10    <title>sd_bus_can_send</title>
11    <productname>systemd</productname>
12  </refentryinfo>
13
14  <refmeta>
15    <refentrytitle>sd_bus_can_send</refentrytitle>
16    <manvolnum>3</manvolnum>
17  </refmeta>
18
19  <refnamediv>
20    <refname>sd_bus_can_send</refname>
21
22    <refpurpose>Check which types can be sent over a bus object</refpurpose>
23  </refnamediv>
24
25  <refsynopsisdiv>
26    <funcsynopsis>
27      <funcsynopsisinfo>#include &lt;systemd/sd-bus.h&gt;</funcsynopsisinfo>
28
29      <funcprototype>
30        <funcdef>void <function>sd_bus_can_send</function></funcdef>
31        <paramdef>sd_bus *<parameter>bus</parameter></paramdef>
32        <paramdef>char <parameter>type</parameter></paramdef>
33      </funcprototype>
34    </funcsynopsis>
35  </refsynopsisdiv>
36
37  <refsect1>
38    <title>Description</title>
39
40    <para><function>sd_bus_can_send()</function> is mostly used for checking if file descriptor
41    passing is available on the given bus. <parameter>type</parameter> can be any of the
42    <constant>SD_BUS_TYPE</constant> constants.</para>
43  </refsect1>
44
45  <refsect1>
46    <title>Return Value</title>
47
48    <para>On failure, <function>sd_bus_can_send()</function> returns a negative errno-style error
49    code. If values of the given type can be sent over the given bus, it returns a positive integer.
50    Otherwise, it returns zero.</para>
51
52    <refsect2>
53      <title>Errors</title>
54
55      <para>Returned errors may indicate the following problems:</para>
56
57      <variablelist>
58        <varlistentry>
59          <term><constant>-ENOPKG</constant></term>
60
61          <listitem><para>The bus object <parameter>bus</parameter> could not be resolved.</para>
62          </listitem>
63        </varlistentry>
64
65        <varlistentry>
66          <term><constant>-ENOTCONN</constant></term>
67
68          <listitem><para>The input parameter <parameter>bus</parameter> is
69          <constant>NULL</constant> or the bus is not connected.</para></listitem>
70        </varlistentry>
71
72        <varlistentry>
73          <term><constant>-ECHILD</constant></term>
74
75          <listitem><para>The bus object <parameter>bus</parameter> was created in a different
76          process.</para></listitem>
77        </varlistentry>
78      </variablelist>
79    </refsect2>
80  </refsect1>
81
82  <xi:include href="libsystemd-pkgconfig.xml" />
83
84  <refsect1>
85    <title>See Also</title>
86
87    <para>
88      <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
89      <citerefentry><refentrytitle>sd-bus</refentrytitle><manvolnum>3</manvolnum></citerefentry>
90    </para>
91  </refsect1>
92
93</refentry>
94