1 <html><head><meta http-equiv=
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219</span><hr><div class=
"refentry"><a name=
"sd_pid_get_session"></a><div class=
"titlepage"></div><div class=
"refnamediv"><h2>Name
</h2><p>sd_pid_get_session, sd_pid_get_unit, sd_pid_get_user_unit, sd_pid_get_owner_uid, sd_pid_get_machine_name, sd_pid_get_slice, sd_peer_get_session, sd_peer_get_unit, sd_peer_get_user_unit, sd_peer_get_owner_uid, sd_peer_get_machine_name, sd_peer_get_slice — Determine session, service, owner of a
23 session, container/VM or slice of a specific
24 PID or socket peer
</p></div><div class=
"refsynopsisdiv"><h2>Synopsis
</h2><div class=
"funcsynopsis"><pre class=
"funcsynopsisinfo">#include
<systemd/sd-login.h
></pre><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_pid_get_session
</b>(
</code></td><td>pid_t
<var class=
"pdparam">pid
</var>,
</td></tr><tr><td> </td><td>char **
<var class=
"pdparam">session
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_pid_get_unit
</b>(
</code></td><td>pid_t
<var class=
"pdparam">pid
</var>,
</td></tr><tr><td> </td><td>char **
<var class=
"pdparam">unit
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_pid_get_user_unit
</b>(
</code></td><td>pid_t
<var class=
"pdparam">pid
</var>,
</td></tr><tr><td> </td><td>char **
<var class=
"pdparam">unit
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_pid_get_owner_uid
</b>(
</code></td><td>pid_t
<var class=
"pdparam">pid
</var>,
</td></tr><tr><td> </td><td>uid_t *
<var class=
"pdparam">uid
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_pid_get_machine_name
</b>(
</code></td><td>pid_t
<var class=
"pdparam">pid
</var>,
</td></tr><tr><td> </td><td>char **
<var class=
"pdparam">name
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_pid_get_slice
</b>(
</code></td><td>pid_t
<var class=
"pdparam">pid
</var>,
</td></tr><tr><td> </td><td>char **
<var class=
"pdparam">slice
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_peer_get_session
</b>(
</code></td><td>int
<var class=
"pdparam">fd
</var>,
</td></tr><tr><td> </td><td>char **
<var class=
"pdparam">session
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_peer_get_unit
</b>(
</code></td><td>int
<var class=
"pdparam">fd
</var>,
</td></tr><tr><td> </td><td>char **
<var class=
"pdparam">unit
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_peer_get_user_unit
</b>(
</code></td><td>int
<var class=
"pdparam">fd
</var>,
</td></tr><tr><td> </td><td>char **
<var class=
"pdparam">unit
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_peer_get_owner_uid
</b>(
</code></td><td>int
<var class=
"pdparam">fd
</var>,
</td></tr><tr><td> </td><td>uid_t *
<var class=
"pdparam">uid
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_peer_get_machine_name
</b>(
</code></td><td>int
<var class=
"pdparam">fd
</var>,
</td></tr><tr><td> </td><td>char **
<var class=
"pdparam">name
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div><table border=
"0" class=
"funcprototype-table" summary=
"Function synopsis" style=
"cellspacing: 0; cellpadding: 0;"><tr><td><code class=
"funcdef">int
<b class=
"fsfunc">sd_peer_get_slice
</b>(
</code></td><td>int
<var class=
"pdparam">fd
</var>,
</td></tr><tr><td> </td><td>char **
<var class=
"pdparam">slice
</var><code>)
</code>;
</td></tr></table><div class=
"funcprototype-spacer"> </div></div></div><div class=
"refsect1"><a name=
"idm139799154390592"></a><h2 id=
"Description">Description
<a class=
"headerlink" title=
"Permalink to this headline" href=
"#Description">¶
</a></h2><p><code class=
"function">sd_pid_get_session()
</code> may be used to
25 determine the login session identifier of a process identified by
26 the specified process identifier. The session identifier is a
27 short string, suitable for usage in file system paths. Note that
28 not all processes are part of a login session (e.g. system service
29 processes, user processes that are shared between multiple
30 sessions of the same user, or kernel threads). For processes not
31 being part of a login session this function will fail. The
32 returned string needs to be freed with the libc
33 <a href=
"http://man7.org/linux/man-pages/man3/free.3.html"><span class=
"citerefentry"><span class=
"refentrytitle">free
</span>(
3)
</span></a>
34 call after use.
</p><p><code class=
"function">sd_pid_get_unit()
</code> may be used to
35 determine the systemd system unit (i.e. system service) identifier
36 of a process identified by the specified PID. The unit name is a
37 short string, suitable for usage in file system paths. Note that
38 not all processes are part of a system unit/service (e.g. user
39 processes, or kernel threads). For processes not being part of a
40 systemd system unit this function will fail. (More specifically:
41 this call will not work for processes that are part of user units,
42 use
<code class=
"function">sd_pid_get_user_unit()
</code> for that.) The
43 returned string needs to be freed with the libc
44 <a href=
"http://man7.org/linux/man-pages/man3/free.3.html"><span class=
"citerefentry"><span class=
"refentrytitle">free
</span>(
3)
</span></a>
45 call after use.
</p><p><code class=
"function">sd_pid_get_user_unit()
</code> may be used to
46 determine the systemd user unit (i.e. user service) identifier of
47 a process identified by the specified PID. This is similar to
48 <code class=
"function">sd_pid_get_unit()
</code> but applies to user units
49 instead of system units.
</p><p><code class=
"function">sd_pid_get_owner_uid()
</code> may be used to
50 determine the Unix user identifier of the owner of the session of
51 a process identified the specified PID. Note that this function
52 will succeed for user processes which are shared between multiple
53 login sessions of the same user, where
54 <code class=
"function">sd_pid_get_session()
</code> will fail. For processes
55 not being part of a login session and not being a shared process
56 of a user this function will fail.
</p><p><code class=
"function">sd_pid_get_machine_name()
</code> may be used
57 to determine the name of the VM or container is a member of. The
58 machine name is a short string, suitable for usage in file system
59 paths. The returned string needs to be freed with the libc
60 <a href=
"http://man7.org/linux/man-pages/man3/free.3.html"><span class=
"citerefentry"><span class=
"refentrytitle">free
</span>(
3)
</span></a>
61 call after use.
</p><p><code class=
"function">sd_pid_get_slice()
</code> may be used to
62 determine the slice unit the process is a member of. See
63 <a href=
"systemd.slice.html"><span class=
"citerefentry"><span class=
"refentrytitle">systemd.slice
</span>(
5)
</span></a>
64 for details about slices. The returned string needs to be freed
66 <a href=
"http://man7.org/linux/man-pages/man3/free.3.html"><span class=
"citerefentry"><span class=
"refentrytitle">free
</span>(
3)
</span></a>
67 call after use.
</p><p>If the
<code class=
"varname">pid
</code> parameter of any of these
68 functions is passed as
0, the operation is executed for the
69 calling process.
</p><p>The
<code class=
"function">sd_peer_get_session()
</code>,
70 <code class=
"function">sd_peer_get_unit()
</code>,
71 <code class=
"function">sd_peer_get_user_unit()
</code>,
72 <code class=
"function">sd_peer_get_owner_uid()
</code>,
73 <code class=
"function">sd_peer_get_machine_name()
</code> and
74 <code class=
"function">sd_peer_get_slice()
</code> calls operate similar to
75 their PID counterparts, but operate on a connected AF_UNIX socket
76 and retrieve information about the connected peer process.
</p></div><div class=
"refsect1"><a name=
"idm139799149455248"></a><h2 id=
"Return Value">Return Value
<a class=
"headerlink" title=
"Permalink to this headline" href=
"#Return%20Value">¶
</a></h2><p>On success, these calls return
0 or a positive integer. On
77 failure, these calls return a negative errno-style error
78 code.
</p></div><div class=
"refsect1"><a name=
"idm139799149453952"></a><h2 id=
"Notes">Notes
<a class=
"headerlink" title=
"Permalink to this headline" href=
"#Notes">¶
</a></h2><p>The
<code class=
"function">sd_pid_get_session()
</code>,
79 <code class=
"function">sd_pid_get_unit()
</code>,
80 <code class=
"function">sd_pid_get_user_unit()
</code>,
81 <code class=
"function">sd_pid_get_owner_uid()
</code>,
82 <code class=
"function">sd_pid_get_machine_name()
</code>,
83 <code class=
"function">sd_pid_get_slice()
</code>,
84 <code class=
"function">sd_peer_get_session()
</code>,
85 <code class=
"function">sd_peer_get_unit()
</code>,
86 <code class=
"function">sd_peer_get_user_unit()
</code>,
87 <code class=
"function">sd_peer_get_owner_uid()
</code>,
88 <code class=
"function">sd_peer_get_machine_name()
</code> and
89 <code class=
"function">sd_peer_get_slice()
</code> interfaces are
90 available as a shared library, which can be compiled
91 and linked to with the
92 <code class=
"constant">libsystemd
</code> <a href=
"http://linux.die.net/man/1/pkg-config"><span class=
"citerefentry"><span class=
"refentrytitle">pkg-config
</span>(
1)
</span></a>
93 file.
</p><p>Note that the login session identifier as
94 returned by
<code class=
"function">sd_pid_get_session()
</code>
95 is completely unrelated to the process session
96 identifier as returned by
97 <a href=
"http://man7.org/linux/man-pages/man2/getsid.2.html"><span class=
"citerefentry"><span class=
"refentrytitle">getsid
</span>(
2)
</span></a>.
</p></div><div class=
"refsect1"><a name=
"idm139799149442016"></a><h2 id=
"See Also">See Also
<a class=
"headerlink" title=
"Permalink to this headline" href=
"#See%20Also">¶
</a></h2><p>
98 <a href=
"systemd.html"><span class=
"citerefentry"><span class=
"refentrytitle">systemd
</span>(
1)
</span></a>,
99 <a href=
"sd-login.html"><span class=
"citerefentry"><span class=
"refentrytitle">sd-login
</span>(
3)
</span></a>,
100 <a href=
"sd_session_is_active.html"><span class=
"citerefentry"><span class=
"refentrytitle">sd_session_is_active
</span>(
3)
</span></a>,
101 <a href=
"http://man7.org/linux/man-pages/man2/getsid.2.html"><span class=
"citerefentry"><span class=
"refentrytitle">getsid
</span>(
2)
</span></a>,
102 <a href=
"systemd.slice.html"><span class=
"citerefentry"><span class=
"refentrytitle">systemd.slice
</span>(
5)
</span></a>,
103 <a href=
"systemd-machined.service.html"><span class=
"citerefentry"><span class=
"refentrytitle">systemd-machined.service
</span>(
8)
</span></a>
104 </p></div></div></body></html>