<?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_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> <refname>sd_session_get_service</refname> <refname>sd_session_get_type</refname> <refname>sd_session_get_class</refname> <refname>sd_session_get_display</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> <funcprototype> <funcdef>int <function>sd_session_get_service</function></funcdef> <paramdef>const char* <parameter>session</parameter></paramdef> <paramdef>char** <parameter>service</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_session_get_type</function></funcdef> <paramdef>const char* <parameter>session</parameter></paramdef> <paramdef>char** <parameter>type</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_session_get_class</function></funcdef> <paramdef>const char* <parameter>session</parameter></paramdef> <paramdef>char** <parameter>class</parameter></paramdef> </funcprototype> <funcprototype> <funcdef>int <function>sd_session_get_display</function></funcdef> <paramdef>const char* <parameter>session</parameter></paramdef> <paramdef>char** <parameter>display</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> <para><function>sd_session_get_service()</function> may be used to determine the name of the service (as passed during PAM session setup) that registered the session identified by the specified session identifier. The returned string needs to be freed with the libc <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> call after use.</para> <para><function>sd_session_get_type()</function> may be used to determine the type of the session identified by the specified session identifier. The returned string is one of <literal>x11</literal>, <literal>tty</literal> or <literal>unspecified</literal> and needs to be freed with the libc <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> call after use.</para> <para><function>sd_session_get_class()</function> may be used to determine the class of the session identified by the specified session identifier. The returned string is one of <literal>user</literal>, <literal>greeter</literal> or <literal>lock-screen</literal> and needs to be freed with the libc <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> call after use.</para> <para><function>sd_session_get_display()</function> may be used to determine the X11 display of the session identified by the specified session identifier. The returned string is one of needs to be freed with the libc <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry> call after use.</para> <para>If the <literal>session</literal> parameter of any of these functions is passed as NULL the operation is executed for the session the calling process is a member of, if there is any.</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>, <function>sd_session_get_service()</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>, <function>sd_session_get_service()</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>