1 <?xml version='
1.0'
?> <!--*-nxml-*-->
2 <!DOCTYPE refentry PUBLIC
"-//OASIS//DTD DocBook XML V4.2//EN"
3 "http://www.oasis-open.org/docbook/xml/4.2/docbookx.dtd">
6 This file is part of systemd.
8 Copyright 2010 Lennart Poettering
10 systemd is free software; you can redistribute it and/or modify it
11 under the terms of the GNU Lesser General Public License as published by
12 the Free Software Foundation; either version 2.1 of the License, or
13 (at your option) any later version.
15 systemd is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 Lesser General Public License for more details.
20 You should have received a copy of the GNU Lesser General Public License
21 along with systemd; If not, see <http://www.gnu.org/licenses/>.
24 <refentry id=
"sd_session_is_active" conditional='HAVE_PAM'
>
27 <title>sd_session_is_active
</title>
28 <productname>systemd
</productname>
32 <contrib>Developer
</contrib>
33 <firstname>Lennart
</firstname>
34 <surname>Poettering
</surname>
35 <email>lennart@poettering.net
</email>
41 <refentrytitle>sd_session_is_active
</refentrytitle>
42 <manvolnum>3</manvolnum>
46 <refname>sd_session_is_active
</refname>
47 <refname>sd_session_get_state
</refname>
48 <refname>sd_session_get_uid
</refname>
49 <refname>sd_session_get_seat
</refname>
50 <refname>sd_session_get_service
</refname>
51 <refname>sd_session_get_type
</refname>
52 <refname>sd_session_get_class
</refname>
53 <refname>sd_session_get_display
</refname>
54 <refname>sd_session_get_tty
</refname>
55 <refpurpose>Determine state of a specific session
</refpurpose>
60 <funcsynopsisinfo>#include
<systemd/sd-login.h
></funcsynopsisinfo>
63 <funcdef>int
<function>sd_session_is_active
</function></funcdef>
64 <paramdef>const char*
<parameter>session
</parameter></paramdef>
68 <funcdef>int
<function>sd_session_get_state
</function></funcdef>
69 <paramdef>const char*
<parameter>session
</parameter></paramdef>
70 <paramdef>char**
<parameter>state
</parameter></paramdef>
74 <funcdef>int
<function>sd_session_get_uid
</function></funcdef>
75 <paramdef>const char*
<parameter>session
</parameter></paramdef>
76 <paramdef>uid_t*
<parameter>uid
</parameter></paramdef>
80 <funcdef>int
<function>sd_session_get_seat
</function></funcdef>
81 <paramdef>const char*
<parameter>session
</parameter></paramdef>
82 <paramdef>char**
<parameter>seat
</parameter></paramdef>
86 <funcdef>int
<function>sd_session_get_service
</function></funcdef>
87 <paramdef>const char*
<parameter>session
</parameter></paramdef>
88 <paramdef>char**
<parameter>service
</parameter></paramdef>
92 <funcdef>int
<function>sd_session_get_type
</function></funcdef>
93 <paramdef>const char*
<parameter>session
</parameter></paramdef>
94 <paramdef>char**
<parameter>type
</parameter></paramdef>
98 <funcdef>int
<function>sd_session_get_class
</function></funcdef>
99 <paramdef>const char*
<parameter>session
</parameter></paramdef>
100 <paramdef>char**
<parameter>class
</parameter></paramdef>
104 <funcdef>int
<function>sd_session_get_display
</function></funcdef>
105 <paramdef>const char*
<parameter>session
</parameter></paramdef>
106 <paramdef>char**
<parameter>display
</parameter></paramdef>
110 <funcdef>int
<function>sd_session_get_tty
</function></funcdef>
111 <paramdef>const char*
<parameter>session
</parameter></paramdef>
112 <paramdef>char**
<parameter>tty
</parameter></paramdef>
118 <title>Description
</title>
120 <para><function>sd_session_is_active()
</function> may
121 be used to determine whether the session identified by
122 the specified session identifier is currently active
123 (i.e. currently in the foreground and available for
124 user input) or not.
</para>
126 <para><function>sd_session_get_state()
</function> may
127 be used to determine the state of the session
128 identified by the specified session identifier. The
129 following states are currently known:
130 <literal>online
</literal> (session logged in, but
131 session not active, i.e. not in the foreground),
132 <literal>active
</literal> (session logged in and
133 active, i.e. in the foreground),
134 <literal>closing
</literal> (session nominally logged
135 out, but some processes belonging to it are still
136 around). In the future additional states might be
137 defined, client code should be written to be robust in
138 regards to additional state strings being
139 returned. This function is a more generic version of
140 <function>sd_session_is_active()
</function>. The returned
141 string needs to be freed with the libc
142 <citerefentry><refentrytitle>free
</refentrytitle><manvolnum>3</manvolnum></citerefentry>
143 call after use.
</para>
145 <para><function>sd_session_get_uid()
</function> may be
146 used to determine the user identifier of the Unix user the session
147 identified by the specified session identifier belongs
150 <para><function>sd_session_get_seat()
</function> may
151 be used to determine the seat identifier of the seat
152 the session identified by the specified session
153 identifier belongs to. Note that not all sessions are
154 attached to a seat, this call will fail for them. The
155 returned string needs to be freed with the libc
156 <citerefentry><refentrytitle>free
</refentrytitle><manvolnum>3</manvolnum></citerefentry>
157 call after use.
</para>
159 <para><function>sd_session_get_service()
</function>
160 may be used to determine the name of the service (as
161 passed during PAM session setup) that registered the
162 session identified by the specified session
163 identifier. The returned string needs to be freed with
165 <citerefentry><refentrytitle>free
</refentrytitle><manvolnum>3</manvolnum></citerefentry>
166 call after use.
</para>
168 <para><function>sd_session_get_type()
</function> may
169 be used to determine the type of the session
170 identified by the specified session identifier. The
171 returned string is one of
<literal>x11
</literal>,
172 <literal>tty
</literal> or
173 <literal>unspecified
</literal> and needs to be freed
175 <citerefentry><refentrytitle>free
</refentrytitle><manvolnum>3</manvolnum></citerefentry>
176 call after use.
</para>
178 <para><function>sd_session_get_class()
</function> may
179 be used to determine the class of the session
180 identified by the specified session identifier. The
181 returned string is one of
<literal>user
</literal>,
182 <literal>greeter
</literal>,
183 <literal>lock-screen
</literal>, or
184 <literal>background
</literal> and needs to be freed
186 <citerefentry><refentrytitle>free
</refentrytitle><manvolnum>3</manvolnum></citerefentry>
187 call after use.
</para>
189 <para><function>sd_session_get_display()
</function>
190 may be used to determine the X11 display of the
191 session identified by the specified session
192 identifier. The returned string needs to be
194 <citerefentry><refentrytitle>free
</refentrytitle><manvolnum>3</manvolnum></citerefentry>
195 call after use.
</para>
197 <para><function>sd_session_get_tty()
</function>
198 may be used to determine the TTY device of the
199 session identified by the specified session
200 identifier. The returned string needs to be
202 <citerefentry><refentrytitle>free
</refentrytitle><manvolnum>3</manvolnum></citerefentry>
203 call after use.
</para>
205 <para>If the
<literal>session
</literal> parameter of
206 any of these functions is passed as NULL the operation
207 is executed for the session the calling process is a
208 member of, if there is any.
</para>
212 <title>Return Value
</title>
214 <para>If the test succeeds
215 <function>sd_session_is_active()
</function> returns a
216 positive integer, if it fails
0. On success
217 <function>sd_session_get_state()
</function>,
218 <function>sd_session_get_uid()
</function>,
219 <function>sd_session_get_seat()
</function>,
220 <function>sd_session_get_service()
</function>,
221 <function>sd_session_get_type()
</function>,
222 <function>sd_session_get_class()
</function>,
223 <function>sd_session_get_display()
</function> and
224 <function>sd_session_get_tty()
</function> return
0 or
225 a positive integer. On failure, these calls return a
226 negative errno-style error code.
</para>
232 <para>The
<function>sd_session_is_active()
</function>,
233 <function>sd_session_get_state()
</function>,
234 <function>sd_session_get_uid()
</function>,
235 <function>sd_session_get_seat()
</function>,
236 <function>sd_session_get_service()
</function>,
237 <function>sd_session_get_type()
</function>,
238 <function>sd_session_get_class()
</function>,
239 <function>sd_session_get_display()
</function> and
240 <function>sd_session_get_tty()
</function>
241 interfaces are available as shared library, which can
242 be compiled and linked to with the
243 <literal>libsystemd-login
</literal>
244 <citerefentry><refentrytitle>pkg-config
</refentrytitle><manvolnum>1</manvolnum></citerefentry>
249 <title>See Also
</title>
252 <citerefentry><refentrytitle>systemd
</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
253 <citerefentry><refentrytitle>sd-login
</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
254 <citerefentry><refentrytitle>sd_pid_get_session
</refentrytitle><manvolnum>3</manvolnum></citerefentry>