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Diffstat (limited to 'src/libsystemd/sd_seat_get_active.xml')
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diff --git a/src/libsystemd/sd_seat_get_active.xml b/src/libsystemd/sd_seat_get_active.xml new file mode 100644 index 0000000000..c5e6ddab02 --- /dev/null +++ b/src/libsystemd/sd_seat_get_active.xml @@ -0,0 +1,212 @@ +<?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>Errors</title> + + <para>Returned errors may indicate the following problems:</para> + + <variablelist> + + <varlistentry> + <term><constant>-ENODATA</constant></term> + + <listitem><para>The given field is not specified for the described + seat.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENXIO</constant></term> + + <listitem><para>The specified seat is unknown.</para> + </listitem> + </varlistentry> + + <varlistentry> + <term><constant>-EINVAL</constant></term> + + <listitem><para>An input parameter was invalid (out of range, + or NULL, where that is not accepted).</para></listitem> + </varlistentry> + + <varlistentry> + <term><constant>-ENOMEM</constant></term> + + <listitem><para>Memory allocation failed.</para></listitem> + </varlistentry> + </variablelist> + </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_graphical()</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> |