chiark / gitweb /
zsh_completion: Split out zsh _systemd-analyze
[elogind.git] / man / sd_pid_get_session.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_pid_get_session" conditional='HAVE_PAM'>
25
26         <refentryinfo>
27                 <title>sd_pid_get_session</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_pid_get_session</refentrytitle>
42                 <manvolnum>3</manvolnum>
43         </refmeta>
44
45         <refnamediv>
46                 <refname>sd_pid_get_session</refname>
47                 <refname>sd_pid_get_unit</refname>
48                 <refname>sd_pid_get_user_unit</refname>
49                 <refname>sd_pid_get_owner_uid</refname>
50                 <refname>sd_pid_get_machine_name</refname>
51                 <refname>sd_pid_get_slice</refname>
52                 <refpurpose>Determine session, service, owner of a
53                 session, container/VM or slice of a specific
54                 PID</refpurpose>
55         </refnamediv>
56
57         <refsynopsisdiv>
58                 <funcsynopsis>
59                         <funcsynopsisinfo>#include &lt;systemd/sd-login.h&gt;</funcsynopsisinfo>
60
61                         <funcprototype>
62                                 <funcdef>int <function>sd_pid_get_session</function></funcdef>
63                                 <paramdef>pid_t <parameter>pid</parameter></paramdef>
64                                 <paramdef>char** <parameter>session</parameter></paramdef>
65                         </funcprototype>
66
67                         <funcprototype>
68                                 <funcdef>int <function>sd_pid_get_unit</function></funcdef>
69                                 <paramdef>pid_t <parameter>pid</parameter></paramdef>
70                                 <paramdef>char** <parameter>unit</parameter></paramdef>
71                         </funcprototype>
72
73                         <funcprototype>
74                                 <funcdef>int <function>sd_pid_get_user_unit</function></funcdef>
75                                 <paramdef>pid_t <parameter>pid</parameter></paramdef>
76                                 <paramdef>char** <parameter>unit</parameter></paramdef>
77                         </funcprototype>
78
79                         <funcprototype>
80                                 <funcdef>int <function>sd_pid_get_owner_uid</function></funcdef>
81                                 <paramdef>pid_t <parameter>pid</parameter></paramdef>
82                                 <paramdef>uid_t* <parameter>uid</parameter></paramdef>
83                         </funcprototype>
84
85                         <funcprototype>
86                                 <funcdef>int <function>sd_pid_get_machine_name</function></funcdef>
87                                 <paramdef>pid_t <parameter>pid</parameter></paramdef>
88                                 <paramdef>char** <parameter>name</parameter></paramdef>
89                         </funcprototype>
90
91                         <funcprototype>
92                                 <funcdef>int <function>sd_pid_get_slice</function></funcdef>
93                                 <paramdef>pid_t <parameter>pid</parameter></paramdef>
94                                 <paramdef>char** <parameter>slice</parameter></paramdef>
95                         </funcprototype>
96                 </funcsynopsis>
97         </refsynopsisdiv>
98
99         <refsect1>
100                 <title>Description</title>
101
102                 <para><function>sd_pid_get_session()</function> may be
103                 used to determine the login session identifier of a
104                 process identified by the specified process
105                 identifier. The session identifier is a short string,
106                 suitable for usage in file system paths. Note that not
107                 all processes are part of a login session (e.g. system
108                 service processes, user processes that are shared
109                 between multiple sessions of the same user, or kernel
110                 threads). For processes not being part of a login
111                 session this function will fail. The returned string
112                 needs to be freed with the libc
113                 <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
114                 call after use.</para>
115
116                 <para><function>sd_pid_get_unit()</function> may be
117                 used to determine the systemd system unit (i.e. system
118                 service) identifier of a process identified by the
119                 specified PID. The unit name is a short string,
120                 suitable for usage in file system paths. Note that not
121                 all processes are part of a system unit/service
122                 (e.g. user processes, or kernel threads). For
123                 processes not being part of a systemd system unit this
124                 function will fail. (More specifically: this call will
125                 not work for processes that are part of user units,
126                 use <function>sd_pid_get_user_unit()</function> for
127                 that.) The returned string needs to be freed with the
128                 libc
129                 <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
130                 call after use.</para>
131
132                 <para><function>sd_pid_get_user_unit()</function> may
133                 be used to determine the systemd user unit (i.e. user
134                 service) identifier of a process identified by the
135                 specified PID. This is similar to
136                 <function>sd_pid_get_unit()</function> but applies to
137                 user units instead of system units.</para>
138
139                 <para><function>sd_pid_get_owner_uid()</function> may
140                 be used to determine the Unix user identifier of the
141                 owner of the session of a process identified the
142                 specified PID. Note that this function will succeed
143                 for user processes which are shared between multiple
144                 login sessions of the same user, where
145                 <function>sd_pid_get_session()</function> will
146                 fail. For processes not being part of a login session
147                 and not being a shared process of a user this function
148                 will fail.</para>
149
150                 <para><function>sd_pid_get_machine_name()</function>
151                 may be used to determine the name of the VM or
152                 container is a member of. The machine name is a short
153                 string, suitable for usage in file system paths. The
154                 returned string needs to be freed with the libc
155                 <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
156                 call after use.</para>
157
158                 <para><function>sd_pid_get_slice()</function> may be
159                 used to determine the slice unit the process is a
160                 member of. See
161                 <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>
162                 for details about slices. The returned string needs to
163                 be freed with the libc
164                 <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
165                 call after use.</para>
166
167                 <para>If the <varname>pid</varname> parameter of any
168                 of these functions is passed as 0 the operation is
169                 executed for the calling process.</para>
170         </refsect1>
171
172         <refsect1>
173                 <title>Return Value</title>
174
175                 <para>On success these calls return 0 or a positive
176                 integer. On failure, these calls return a negative
177                 errno-style error code.</para>
178         </refsect1>
179
180         <refsect1>
181                 <title>Notes</title>
182
183                 <para>The <function>sd_pid_get_session()</function>,
184                 <function>sd_pid_get_unit()</function>,
185                 <function>sd_pid_get_user_unit()</function>,
186                 <function>sd_pid_get_owner_uid()</function>,
187                 <function>sd_pid_get_machine_name()</function> and
188                 <function>sd_pid_get_slice()</function> interfaces are
189                 available as shared library, which can be compiled and
190                 linked to with the
191                 <constant>libsystemd-login</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
192                 file.</para>
193
194                 <para>Note that the login session identifier as
195                 returned by <function>sd_pid_get_session()</function>
196                 is completely unrelated to the process session
197                 identifier as returned by
198                 <citerefentry><refentrytitle>getsid</refentrytitle><manvolnum>2</manvolnum></citerefentry>.</para>
199         </refsect1>
200
201         <refsect1>
202                 <title>See Also</title>
203
204                 <para>
205                         <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
206                         <citerefentry><refentrytitle>sd-login</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
207                         <citerefentry><refentrytitle>sd_session_is_active</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
208                         <citerefentry><refentrytitle>getsid</refentrytitle><manvolnum>2</manvolnum></citerefentry>,
209                         <citerefentry><refentrytitle>systemd.slice</refentrytitle><manvolnum>5</manvolnum></citerefentry>
210                 </para>
211         </refsect1>
212
213 </refentry>