summaryrefslogtreecommitdiff
path: root/man/sd_pid_get_session.xml
blob: 9517795f78eb3c11fea00aaf1b84e44b315f3566 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
<?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_pid_get_session">

        <refentryinfo>
                <title>sd_pid_get_session</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_pid_get_session</refentrytitle>
                <manvolnum>3</manvolnum>
        </refmeta>

        <refnamediv>
                <refname>sd_pid_get_session</refname>
                <refname>sd_pid_get_unit</refname>
                <refname>sd_pid_get_owner_uid</refname>
                <refpurpose>Determine session, service or owner of a session of a specific PID</refpurpose>
        </refnamediv>

        <refsynopsisdiv>
                <funcsynopsis>
                        <funcsynopsisinfo>#include &lt;systemd/sd-login.h&gt;</funcsynopsisinfo>

                        <funcprototype>
                                <funcdef>int <function>sd_pid_get_session</function></funcdef>
                                <paramdef>pid_t <parameter>pid</parameter></paramdef>
                                <paramdef>char** <parameter>session</parameter></paramdef>
                        </funcprototype>

                        <funcprototype>
                                <funcdef>int <function>sd_pid_get_unit</function></funcdef>
                                <paramdef>pid_t <parameter>pid</parameter></paramdef>
                                <paramdef>char** <parameter>unit</parameter></paramdef>
                        </funcprototype>

                        <funcprototype>
                                <funcdef>int <function>sd_pid_get_owner_uid</function></funcdef>
                                <paramdef>pid_t <parameter>pid</parameter></paramdef>
                                <paramdef>uid_t* <parameter>uid</parameter></paramdef>
                        </funcprototype>
                </funcsynopsis>
        </refsynopsisdiv>

        <refsect1>
                <title>Description</title>

                <para><function>sd_pid_get_session()</function> may be
                used to determine the login session identifier of a
                process identified by the specified process
                identifier. The session identifier is a short string,
                suitable for usage in file system paths. Note that not
                all processes are part of a login session (e.g. system
                service processes, user processes that are shared
                between multiple sessions of the same user, or kernel
                threads). For processes not being part of a login
                session this function will fail. 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_pid_get_unit()</function> may be
                used to determine the systemd unit (i.e. system
                service) identifier of a process identified by the
                specified process identifier. The unit name is a short
                string, suitable for usage in file system paths. Note
                that not all processes are part of a unit/service
                (e.g. user processes, or kernel threads). For
                processes not being part of a systemd unit/system
                service this function will fail. 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_pid_get_owner_uid()</function> may
                be used to determine the Unix user identifier of the
                owner of the session of a process identified the
                specified PID. Note that this function will succeed
                for user processes which are shared between multiple
                login sessions of the same user, where
                <function>sd_pid_get_session()</function> will
                fail. For processes not being part of a login session
                and not being a shared process of a user this function
                will fail.</para>

                <para>If the <literal>pid</literal> parameter of any
                of these functions is passed as 0 the operation is
                executed for the calling process.</para>
        </refsect1>

        <refsect1>
                <title>Return Value</title>

                <para>On success these calls 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_pid_get_session()</function>,
                <function>sd_pid_get_pid()</function>, and
                <function>sd_pid_get_owner_uid()</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>

                <para>Note that the login session identifier as
                returned by <function>sd_pid_get_session()</function>
                is completely unrelated to the process session
                identifier as returned by
                <citerefentry><refentrytitle>getsid</refentrytitle><manvolnum>2</manvolnum></citerefentry>.</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_is_active</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
                        <citerefentry><refentrytitle>getsid</refentrytitle><manvolnum>2</manvolnum></citerefentry>
                </para>
        </refsect1>

</refentry>