--- /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 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_seat_get_active" conditional='HAVE_PAM'>
+
+ <refentryinfo>
+ <title>sd_seat_get_active</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_seat_get_active</refentrytitle>
+ <manvolnum>3</manvolnum>
+ </refmeta>
+
+ <refnamediv>
+ <refname>sd_seat_get_active</refname>
+ <refname>sd_seat_get_sessions</refname>
+ <refname>sd_seat_can_multi_session</refname>
+ <refname>sd_seat_can_tty</refname>
+ <refname>sd_seat_can_graphical</refname>
+ <refpurpose>Determine state of a specific seat</refpurpose>
+ </refnamediv>
+
+ <refsynopsisdiv>
+ <funcsynopsis>
+ <funcsynopsisinfo>#include <systemd/sd-login.h></funcsynopsisinfo>
+
+ <funcprototype>
+ <funcdef>int <function>sd_seat_get_active</function></funcdef>
+ <paramdef>const char *<parameter>seat</parameter></paramdef>
+ <paramdef>char **<parameter>session</parameter></paramdef>
+ <paramdef>uid_t *<parameter>uid</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_seat_get_sessions</function></funcdef>
+ <paramdef>const char *<parameter>seat</parameter></paramdef>
+ <paramdef>char ***<parameter>sessions</parameter></paramdef>
+ <paramdef>uid_t **<parameter>uid</parameter></paramdef>
+ <paramdef>unsigned int *<parameter>n_uids</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_seat_can_multi_session</function></funcdef>
+ <paramdef>const char *<parameter>seat</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_seat_can_tty</function></funcdef>
+ <paramdef>const char *<parameter>seat</parameter></paramdef>
+ </funcprototype>
+
+ <funcprototype>
+ <funcdef>int <function>sd_seat_can_graphical</function></funcdef>
+ <paramdef>const char *<parameter>seat</parameter></paramdef>
+ </funcprototype>
+ </funcsynopsis>
+ </refsynopsisdiv>
+
+ <refsect1>
+ <title>Description</title>
+
+ <para><function>sd_seat_get_active()</function> may be used to
+ determine which session is currently active on a seat, if there is
+ any. Returns the session identifier and the user identifier of the
+ Unix user the session is belonging to. Either the session or the
+ user identifier parameter can be passed <constant>NULL</constant>,
+ in case only one of the parameters shall be queried. The returned
+ string needs to be freed with the libc
+ <citerefentry project='man-pages'><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ call after use.</para>
+
+ <para><function>sd_seat_get_sessions()</function> may be used to
+ determine all sessions on the specified seat. Returns two arrays,
+ one (<constant>NULL</constant> terminated) with the session
+ identifiers of the sessions and one with the user identifiers of
+ the Unix users the sessions belong to. An additional parameter may
+ be used to return the number of entries in the latter array. The
+ two arrays and the latter parameter may be passed as
+ <constant>NULL</constant> in case these values need not to be
+ determined. The arrays and the strings referenced by them 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><function>sd_seat_can_multi_session()</function> may be used
+ to determine whether a specific seat is capable of multi-session,
+ i.e. allows multiple login sessions in parallel (with only one
+ being active at a time).</para>
+
+ <para><function>sd_seat_can_tty()</function> may be used to
+ determine whether a specific seat provides TTY functionality, i.e.
+ is useful as a text console.</para>
+
+ <para><function>sd_seat_can_graphical()</function> may be used to
+ determine whether a specific seat provides graphics functionality,
+ i.e. is useful as a graphics display.</para>
+
+ <para>If the <varname>seat</varname> parameter of any of these
+ functions is passed as <constant>NULL</constant>, the operation is
+ executed for the seat of the session of the calling process, if
+ there is any.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Return Value</title>
+
+ <para> On success, <function>sd_seat_get_active()</function>
+ returns 0 or a positive integer. On success,
+ <function>sd_seat_get_sessions()</function> returns the number of
+ entries in the session identifier array. If the test succeeds,
+ <function>sd_seat_can_multi_session</function>,
+ <function>sd_seat_can_tty</function> and
+ <function>sd_seat_can_graphical</function> return a positive
+ integer, if it fails 0. On failure, these calls return a negative
+ errno-style error code.</para>
+ </refsect1>
+
+ <refsect1>
+ <title>Notes</title>
+
+ <para>The <function>sd_seat_get_active()</function>,
+ <function>sd_seat_get_sessions()</function>,
+ <function>sd_seat_can_multi_session()</function>,
+ <function>sd_seat_can_tty()</function> and
+ <function>sd_seat_can_grapical()</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>
~ianmdlvl / elogind.git / blobdiff