man/sd_pid_get_unit.html

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  22   <a href="../libudev/index.html">gudev </a><span style="float:right">systemd 208</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 — Determine session, service, owner of a
  23                 session, container/VM or slice of a specific
  24                 PID</p></div><div class="refsynopsisdiv"><h2>Synopsis</h2><div class="funcsynopsis"><pre class="funcsynopsisinfo">#include &lt;systemd/sd-login.h&gt;</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></div></div><div class="refsect1"><a name="idm274676596000"></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
  25                 used to determine the login session identifier of a
  26                 process identified by the specified process
  27                 identifier. The session identifier is a short string,
  28                 suitable for usage in file system paths. Note that not
  29                 all processes are part of a login session (e.g. system
  30                 service processes, user processes that are shared
  31                 between multiple sessions of the same user, or kernel
  32                 threads). For processes not being part of a login
  33                 session this function will fail. The returned string
  34                 needs to be freed with the libc
  35                 <a href="free.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  36                 call after use.</p><p><code class="function">sd_pid_get_unit()</code> may be
  37                 used to determine the systemd system unit (i.e. system
  38                 service) identifier of a process identified by the
  39                 specified PID. The unit name is a short string,
  40                 suitable for usage in file system paths. Note that not
  41                 all processes are part of a system unit/service
  42                 (e.g. user processes, or kernel threads). For
  43                 processes not being part of a systemd system unit this
  44                 function will fail. (More specifically: this call will
  45                 not work for processes that are part of user units,
  46                 use <code class="function">sd_pid_get_user_unit()</code> for
  47                 that.) The returned string needs to be freed with the
  48                 libc
  49                 <a href="free.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  50                 call after use.</p><p><code class="function">sd_pid_get_user_unit()</code> may
  51                 be used to determine the systemd user unit (i.e. user
  52                 service) identifier of a process identified by the
  53                 specified PID. This is similar to
  54                 <code class="function">sd_pid_get_unit()</code> but applies to
  55                 user units instead of system units.</p><p><code class="function">sd_pid_get_owner_uid()</code> may
  56                 be used to determine the Unix user identifier of the
  57                 owner of the session of a process identified the
  58                 specified PID. Note that this function will succeed
  59                 for user processes which are shared between multiple
  60                 login sessions of the same user, where
  61                 <code class="function">sd_pid_get_session()</code> will
  62                 fail. For processes not being part of a login session
  63                 and not being a shared process of a user this function
  64                 will fail.</p><p><code class="function">sd_pid_get_machine_name()</code>
  65                 may be used to determine the name of the VM or
  66                 container is a member of. The machine name is a short
  67                 string, suitable for usage in file system paths. The
  68                 returned string needs to be freed with the libc
  69                 <a href="free.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  70                 call after use.</p><p><code class="function">sd_pid_get_slice()</code> may be
  71                 used to determine the slice unit the process is a
  72                 member of. See
  73                 <a href="systemd.slice.html"><span class="citerefentry"><span class="refentrytitle">systemd.slice</span>(5)</span></a>
  74                 for details about slices. The returned string needs to
  75                 be freed with the libc
  76                 <a href="free.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  77                 call after use.</p><p>If the <code class="varname">pid</code> parameter of any
  78                 of these functions is passed as 0, the operation is
  79                 executed for the calling process.</p></div><div class="refsect1"><a name="idm274676555824"></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
  80                 integer. On failure, these calls return a negative
  81                 errno-style error code.</p></div><div class="refsect1"><a name="idm274676666736"></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>,
  82                 <code class="function">sd_pid_get_unit()</code>,
  83                 <code class="function">sd_pid_get_user_unit()</code>,
  84                 <code class="function">sd_pid_get_owner_uid()</code>,
  85                 <code class="function">sd_pid_get_machine_name()</code> and
  86                 <code class="function">sd_pid_get_slice()</code> interfaces are
  87                 available as shared library, which can be compiled and
  88                 linked to with the
  89                 <code class="constant">libsystemd-login</code> <a href="pkg-config.html"><span class="citerefentry"><span class="refentrytitle">pkg-config</span>(1)</span></a>
  90                 file.</p><p>Note that the login session identifier as
  91                 returned by <code class="function">sd_pid_get_session()</code>
  92                 is completely unrelated to the process session
  93                 identifier as returned by
  94                 <a href="getsid.html"><span class="citerefentry"><span class="refentrytitle">getsid</span>(2)</span></a>.</p></div><div class="refsect1"><a name="idm274671644288"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
  95                         <a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
  96                         <a href="sd-login.html"><span class="citerefentry"><span class="refentrytitle">sd-login</span>(3)</span></a>,
  97                         <a href="sd_session_is_active.html"><span class="citerefentry"><span class="refentrytitle">sd_session_is_active</span>(3)</span></a>,
  98                         <a href="getsid.html"><span class="citerefentry"><span class="refentrytitle">getsid</span>(2)</span></a>,
  99                         <a href="systemd.slice.html"><span class="citerefentry"><span class="refentrytitle">systemd.slice</span>(5)</span></a>
 100                 </p></div></div></body></html>