Systemd/man/sd_get_seats.xml
Zbigniew Jędrzejewski-Szmek 7d6b27238f man: xinclude the generic text to talk about libsystemd pkgconfig
The only difference is that functions are not individually listed by name,
but that seems completely pointless, since all functions that are documented
are always exported, so the generic text tells the user all she or he needs
to know.
2018-06-06 23:01:25 +02:00

138 lines
4.3 KiB
XML

<?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">
<!--
SPDX-License-Identifier: LGPL-2.1+
This file is part of systemd.
Copyright 2010 Lennart Poettering
-->
<refentry id="sd_get_seats" conditional='HAVE_PAM'
xmlns:xi="http://www.w3.org/2001/XInclude">
<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 the number of seat
identifiers and if the input pointer is non-NULL, a
<constant>NULL</constant>-terminated array of seat identifiers
is stored at the address.
The returned array and all strings it references need to be freed
with the libc
<citerefentry project='man-pages'><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>Similarly, <function>sd_get_sessions()</function> may be
used to determine all current login sessions.</para>
<para>Similarly, <function>sd_get_uids()</function> may be used to
determine all Unix users who currently have login sessions.</para>
<para>Similarly, <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>Errors</title>
<para>Returned errors may indicate the following problems:</para>
<variablelist>
<varlistentry>
<term><constant>-ENOMEM</constant></term>
<listitem><para>Memory allocation failed.</para></listitem>
</varlistentry>
</variablelist>
</refsect1>
<xi:include href="libsystemd-pkgconfig.xml" />
<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>