chiark / gitweb /
man: updates to the passive target section
[elogind.git] / man / sd_uid_get_state.xml
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">
4
5 <!--
6   This file is part of systemd.
7
8   Copyright 2010 Lennart Poettering
9
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.
14
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.
19
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/>.
22 -->
23
24 <refentry id="sd_uid_get_state" conditional='HAVE_PAM'>
25
26         <refentryinfo>
27                 <title>sd_uid_get_state</title>
28                 <productname>systemd</productname>
29
30                 <authorgroup>
31                         <author>
32                                 <contrib>Developer</contrib>
33                                 <firstname>Lennart</firstname>
34                                 <surname>Poettering</surname>
35                                 <email>lennart@poettering.net</email>
36                         </author>
37                 </authorgroup>
38         </refentryinfo>
39
40         <refmeta>
41                 <refentrytitle>sd_uid_get_state</refentrytitle>
42                 <manvolnum>3</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>sd_uid_get_state</refname>
47                 <refname>sd_uid_is_on_seat</refname>
48                 <refname>sd_uid_get_sessions</refname>
49                 <refname>sd_uid_get_seats</refname>
50                 <refname>sd_uid_get_display</refname>
51                 <refpurpose>Determine login state of a specific Unix user ID</refpurpose>
52         </refnamediv>
53
54         <refsynopsisdiv>
55                 <funcsynopsis>
56                         <funcsynopsisinfo>#include &lt;systemd/sd-login.h&gt;</funcsynopsisinfo>
57
58                         <funcprototype>
59                                 <funcdef>int <function>sd_uid_get_state</function></funcdef>
60                                 <paramdef>uid_t <parameter>uid</parameter></paramdef>
61                                 <paramdef>char **<parameter>state</parameter></paramdef>
62                         </funcprototype>
63
64                         <funcprototype>
65                                 <funcdef>int <function>sd_uid_is_on_seat</function></funcdef>
66                                 <paramdef>uid_t <parameter>uid</parameter></paramdef>
67                                 <paramdef>int <parameter>require_active</parameter></paramdef>
68                                 <paramdef>const char *<parameter>seat</parameter></paramdef>
69                         </funcprototype>
70
71                         <funcprototype>
72                                 <funcdef>int <function>sd_uid_get_sessions</function></funcdef>
73                                 <paramdef>uid_t <parameter>uid</parameter></paramdef>
74                                 <paramdef>int <parameter>require_active</parameter></paramdef>
75                                 <paramdef>char ***<parameter>sessions</parameter></paramdef>
76                         </funcprototype>
77
78                         <funcprototype>
79                                 <funcdef>int <function>sd_uid_get_seats</function></funcdef>
80                                 <paramdef>uid_t <parameter>uid</parameter></paramdef>
81                                 <paramdef>int <parameter>require_active</parameter></paramdef>
82                                 <paramdef>char ***<parameter>seats</parameter></paramdef>
83                         </funcprototype>
84
85                         <funcprototype>
86                                 <funcdef>int <function>sd_uid_get_display</function></funcdef>
87                                 <paramdef>uid_t <parameter>uid</parameter></paramdef>
88                                 <paramdef>char **<parameter>session</parameter></paramdef>
89                         </funcprototype>
90                 </funcsynopsis>
91         </refsynopsisdiv>
92
93         <refsect1>
94                 <title>Description</title>
95
96                 <para><function>sd_uid_get_state()</function> may be
97                 used to determine the login state of a specific Unix
98                 user identifier. The following states are currently
99                 known: <literal>offline</literal> (user not logged in
100                 at all), <literal>lingering</literal> (user not logged
101                 in, but some user services running),
102                 <literal>online</literal> (user logged in, but not
103                 active, i.e. has no session in the foreground),
104                 <literal>active</literal> (user logged in, and has at
105                 least one active session, i.e. one session in the
106                 foreground), <literal>closing</literal> (user not
107                 logged in, and not lingering, but some processes are
108                 still around). In the future additional states might
109                 be defined, client code should be written to be robust
110                 in regards to additional state strings being
111                 returned. The returned string needs to be freed with
112                 the libc
113                 <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
114                 call after use.</para>
115
116                 <para><function>sd_uid_is_on_seat()</function> may be
117                 used to determine whether a specific user is logged in
118                 or active on a specific seat. Accepts a Unix user
119                 identifier and a seat identifier string as
120                 parameters. The <parameter>require_active</parameter>
121                 parameter is a boolean value. If non-zero (true), this
122                 function will test if the user is active (i.e. has a
123                 session that is in the foreground and accepting user
124                 input) on the specified seat, otherwise (false) only
125                 if the user is logged in (and possibly inactive) on
126                 the specified seat.</para>
127
128                 <para><function>sd_uid_get_sessions()</function> may
129                 be used to determine the current sessions of the
130                 specified user. Accepts a Unix user identifier as
131                 parameter. The <parameter>require_active</parameter>
132                 parameter controls whether the returned list shall
133                 consist of only those sessions where the user is
134                 currently active (&gt; 0), where the user is currently
135                 online but possibly inactive (= 0), or
136                 logged in at all but possibly closing the session (&lt; 0). The call returns a
137                 <constant>NULL</constant> terminated string array of session identifiers in
138                 <parameter>sessions</parameter> which needs to be
139                 freed by the caller with the libc
140                 <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
141                 call after use, including all the strings
142                 referenced. If the string array parameter is passed as
143                 <constant>NULL</constant>, the array will not be filled in, but the return
144                 code still indicates the number of current
145                 sessions. Note that instead of an empty array <constant>NULL</constant> may
146                 be returned and should be considered equivalent to an
147                 empty array.</para>
148
149                 <para>Similarly, <function>sd_uid_get_seats()</function>
150                 may be used to determine the list of seats on which
151                 the user currently has sessions. Similar semantics
152                 apply, however note that the user may have
153                 multiple sessions on the same seat as well as sessions
154                 with no attached seat and hence the number of entries
155                 in the returned array may differ from the one returned
156                 by <function>sd_uid_get_sessions()</function>.</para>
157
158                 <para><function>sd_uid_get_display()</function>
159                 returns the name of the "primary" session of a user.
160                 If the user has graphical sessions, it will be the
161                 oldest graphical session. Otherwise, it will be the
162                 oldest open session.</para>
163         </refsect1>
164
165         <refsect1>
166                 <title>Return Value</title>
167
168                 <para>On success,
169                 <function>sd_uid_get_state()</function> returns 0 or a
170                 positive integer. If the test succeeds,
171                 <function>sd_uid_is_on_seat()</function> returns a
172                 positive integer; if it fails,
173                 0. <function>sd_uid_get_sessions()</function> and
174                 <function>sd_uid_get_seats()</function> return the
175                 number of entries in the returned arrays.
176                 <function>sd_uid_get_display()</function> returns
177                 a non-negative code on success. On failure,
178                 these calls return a negative errno-style error
179                 code.</para>
180         </refsect1>
181
182         <refsect1>
183                 <title>Notes</title>
184
185                 <para>Functions described here are available as a
186                 shared library, and can be compiled and linked to
187                 using the
188                 <constant>libsystemd</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
189                 entry.</para>
190         </refsect1>
191
192         <refsect1>
193                 <title>History</title>
194
195                 <function>sd_uid_get_state()</function>,
196                 <function>sd_uid_is_on_seat()</function>,
197                 <function>sd_uid_get_sessions()</function>,
198                 and <function>sd_uid_get_seats()</function> functions
199                 were added in systemd-31.
200
201                 <para><function>sd_uid_get_display()</function> was
202                 added in systemd-213.</para>
203         </refsect1>
204
205         <refsect1>
206                 <title>See Also</title>
207
208                 <para>
209                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
210                         <citerefentry><refentrytitle>sd-login</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
211                         <citerefentry><refentrytitle>sd_pid_get_owner_uid</refentrytitle><manvolnum>3</manvolnum></citerefentry>
212                 </para>
213         </refsect1>
214
215 </refentry>