1
0
mirror of https://github.com/systemd/systemd.git synced 2024-11-02 10:51:20 +03:00
systemd/man/sd_get_seats.xml
Lennart Poettering 5d13a15b1d tree-wide: drop spurious newlines (#8764)
Double newlines (i.e. one empty lines) are great to structure code. But
let's avoid triple newlines (i.e. two empty lines), quadruple newlines,
quintuple newlines, …, that's just spurious whitespace.

It's an easy way to drop 121 lines of code, and keeps the coding style
of our sources a bit tigther.
2018-04-19 12:13:23 +02:00

148 lines
4.7 KiB
XML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<?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'>
<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>
<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 a shared library, which can be compiled and linked to
with the
<constant>libsystemd</constant> <citerefentry project='die-net'><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>