summaryrefslogtreecommitdiff
path: root/man/sd_get_seats.xml
blob: 9fb0732c109a8078e8d1d0a66be6eca0094d06ad (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
<?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 2010 Lennart Poettering

  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_get_seats" conditional='HAVE_PAM'>

        <refentryinfo>
                <title>sd_get_seats</title>
                <productname>systemd</productname>

                <authorgroup>
                        <author>
                                <contrib>Developer</contrib>
                                <firstname>Lennart</firstname>
                                <surname>Poettering</surname>
                                <email>lennart@poettering.net</email>
                        </author>
                </authorgroup>
        </refentryinfo>

        <refmeta>
                <refentrytitle>sd_get_seats</refentrytitle>
                <manvolnum>3</manvolnum>
        </refmeta>

        <refnamediv>
                <refname>sd_get_seats</refname>
                <refname>sd_get_sessions</refname>
                <refname>sd_get_uids</refname>
                <refname>sd_get_machine_names</refname>
                <refpurpose>Determine available seats, sessions, logged in users and virtual machines/containers</refpurpose>
        </refnamediv>

        <refsynopsisdiv>
                <funcsynopsis>
                        <funcsynopsisinfo>#include &lt;systemd/sd-login.h&gt;</funcsynopsisinfo>

                        <funcprototype>
                                <funcdef>int <function>sd_get_seats</function></funcdef>
                                <paramdef>char*** <parameter>seats</parameter></paramdef>
                        </funcprototype>

                        <funcprototype>
                                <funcdef>int <function>sd_get_sessions</function></funcdef>
                                <paramdef>char*** <parameter>sessions</parameter></paramdef>
                        </funcprototype>

                        <funcprototype>
                                <funcdef>int <function>sd_get_uids</function></funcdef>
                                <paramdef>uid_t** <parameter>users</parameter></paramdef>
                        </funcprototype>

                        <funcprototype>
                                <funcdef>int <function>sd_get_machine_names</function></funcdef>
                                <paramdef>char*** <parameter>machines</parameter></paramdef>
                        </funcprototype>

                </funcsynopsis>
        </refsynopsisdiv>

        <refsect1>
                <title>Description</title>

                <para><function>sd_get_seats()</function> may be used
                to determine all currently available local
                seats. Returns a <constant>NULL</constant> terminated array of seat
                identifiers. The returned array and all strings it
                references need to be freed with the libc
                <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                call after use. Note that instead of an empty array
                <constant>NULL</constant> may be returned and should be considered
                equivalent to an empty array.</para>

                <para>Similar, <function>sd_get_sessions()</function> may
                be used to determine all current login sessions.</para>

                <para>Similar, <function>sd_get_uids()</function> may
                be used to determine all Unix users who currently have login sessions.</para>

                <para>Similar,
                <function>sd_get_machine_names()</function> may be
                used to determine all current virtual machines and
                containers on the system.</para>

                <para>Note that the returned lists are not sorted and in an undefined order.</para>
        </refsect1>

        <refsect1>
                <title>Return Value</title>

                <para>On success <function>sd_get_seats()</function>,
                <function>sd_get_sessions()</function>,
                <function>sd_get_uids()</function> and
                <function>sd_get_machine_names()</function> return the
                number of entries in the arrays. On failure, these
                calls return a negative errno-style error code.</para>
        </refsect1>

        <refsect1>
                <title>Notes</title>

                <para>The <function>sd_get_seats()</function>,
                <function>sd_get_sessions()</function>,
                <function>sd_get_uids()</function> and
                <function>sd_get_machine_names()</function> interfaces
                are available as shared library, which can be compiled
                and linked to with the
                <constant>libsystemd-login</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-login</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>sd_session_get_seat</refentrytitle><manvolnum>3</manvolnum></citerefentry>
                </para>
        </refsect1>

</refentry>