<?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 General Public License as published by the Free Software Foundation; either version 2 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 General Public License for more details. You should have received a copy of the GNU General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. --> <refentry id="sd_session_is_active"> <refentryinfo> <title>sd_session_is_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_session_is_active</refentrytitle> <manvolnum>3</manvolnum> </refmeta> <refnamediv> <refname>sd_session_is_active</refname> <refname>sd_session_get_uid</refname> <refname>sd_session_get_seat</refname> <refpurpose>Determine state of a specific session</refpurpose> </refnamediv> <refsynopsisdiv> <funcsynopsis> <funcsynopsisinfo>#include <systemd/sd-login.h></funcsynopsisinfo> <funcprototype> <funcdef>int <function>sd_session_is_active</function></funcdef> <paramdef>const char* <parameter>session</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_session_get_uid</function></funcdef> <paramdef>const char* <parameter>session</parameter></paramdef> <paramdef>uid_t* <parameter>uid</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_session_get_seat</function></funcdef> <paramdef>const char* <parameter>session</parameter></paramdef> <paramdef>char** <parameter>seat</parameter></paramdef> </funcprototype> </funcsynopsis> </refsynopsisdiv> <refsect1> <title>Description</title> <para><function>sd_session_is_active()</function> may be used to determine whether the session identified by the specified session identifier is currently active (i.e. currently in the foreground and available for user input) or not.</para> <para><function>sd_session_get_uid()</function> may be used to determine the user identifier of the Unix user the session identified by the specified session identifier belongs to.</para> <para><function>sd_session_get_seat()</function> may be used to determine the seat identifier of the seat the session identified by the specified session identifier belongs to. Note that not all sessions are attached to a seat, this call will fail for them. The returned string needs to be freed with the libc <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> call after use.</para> </refsect1> <refsect1> <title>Return Value</title> <para>If the test succeeds <function>sd_session_is_active()</function> returns a positive integer, if it fails 0. On success <function>sd_session_get_uid()</function> and <function>sd_session_get_seat()</function> return 0 or a positive integer. On failure, these calls return a negative errno-style error code.</para> </refsect1> <refsect1> <title>Notes</title> <para>The <function>sd_session_is_active()</function>, <function>sd_session_get_uid()</function>, and <function>sd_session_get_seat()</function> interfaces are available as shared library, which can be compiled and linked to with the <literal>libsystemd-login</literal> <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>7</manvolnum></citerefentry>, <citerefentry><refentrytitle>sd_pid_get_session</refentrytitle><manvolnum>3</manvolnum></citerefentry> </para> </refsect1> </refentry>