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 General Public License as published by
12 the Free Software Foundation; either version 2 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 General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with systemd; If not, see <http://www.gnu.org/licenses/>.
24 <refentry id="sd_pid_get_session">
27 <title>sd_pid_get_session</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_pid_get_session</refentrytitle>
42 <manvolnum>3</manvolnum>
46 <refname>sd_pid_get_session</refname>
47 <refname>sd_pid_get_owner_uid</refname>
48 <refpurpose>Determine session or owner of a session of a specific PID</refpurpose>
53 <funcsynopsisinfo>#include <systemd/sd-login.h></funcsynopsisinfo>
56 <funcdef>int <function>sd_pid_get_session</function></funcdef>
57 <paramdef>pid_t <parameter>pid</parameter></paramdef>
58 <paramdef>char** <parameter>session</parameter></paramdef>
62 <funcdef>int <function>sd_pid_get_owner_uid</function></funcdef>
63 <paramdef>pid_t <parameter>pid</parameter></paramdef>
64 <paramdef>uid_t* <parameter>uid</parameter></paramdef>
70 <title>Description</title>
72 <para><function>sd_pid_get_session()</function> may be
73 used to determine the login session identifier of a
74 process identified by the specified process
75 identifier. The session identifier is a short string,
76 suitable for usage in file system paths. Note that not
77 all processes are part of a login session (e.g. system
78 service processes and user processes that are shared
79 between multiple sessions of the same user). For
80 processes not being part of a login session this
81 function will fail. The returned string needs to be
83 <citerefentry><refentrytitle>free</refentrytitle><manvolnum>3</manvolnum></citerefentry>
84 call after use.</para>
86 <para><function>sd_pid_get_owner_uid()</function> may
87 be used to determine the Unix user identifier of the
88 owner of the session of a process identified the
89 specified PID. Note that this function will succeed
90 for user processes which are shared between multiple
91 login sessions of the same user, where
92 <function>sd_pid_get_session()</function> will
93 fail. For processes not being part of a login session
94 and not being a shared process of a user this function
99 <title>Return Value</title>
101 <para>On success these calls return 0 or a positive
102 integer. On failure, these calls return a negative
103 errno-style error code.</para>
109 <para>The <function>sd_pid_get_session()</function>
110 and <function>sd_pid_get_owner_uid()</function>
111 interfaces are available as shared library, which can
112 be compiled and linked to with the
113 <literal>libsystemd-login</literal>
114 <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
117 <para>Note that the login session identifier as
118 returned by <function>sd_pid_get_session()</function>
119 is completely unrelated to the process session
120 identifier as returned by
121 <citerefentry><refentrytitle>getsid</refentrytitle><manvolnum>2</manvolnum></citerefentry>.</para>
125 <title>See Also</title>
128 <citerefentry><refentrytitle>systemd</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
129 <citerefentry><refentrytitle>sd-login</refentrytitle><manvolnum>7</manvolnum></citerefentry>,
130 <citerefentry><refentrytitle>sd_session_is_active</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
131 <citerefentry><refentrytitle>getsid</refentrytitle><manvolnum>2</manvolnum></citerefentry>