man/sd_session_get_tty.html

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  22   <a href="../libudev/index.html">gudev </a><span style="float:right">systemd 220</span><hr><div class="refentry"><a name="sd_session_is_active"></a><div class="titlepage"></div><div class="refnamediv"><h2>Name</h2><p>sd_session_is_active, sd_session_is_remote, sd_session_get_state, sd_session_get_uid, sd_session_get_seat, sd_session_get_service, sd_session_get_type, sd_session_get_class, sd_session_get_desktop, sd_session_get_display, sd_session_get_tty, sd_session_get_vt, sd_session_get_remote_host, sd_session_get_remote_user — Determine state of a specific session</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_session_is_active</b>(</code></td><td>const 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_session_is_remote</b>(</code></td><td>const 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_session_get_state</b>(</code></td><td>const char *<var class="pdparam">session</var>, </td></tr><tr><td> </td><td>char **<var class="pdparam">state</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_session_get_uid</b>(</code></td><td>const char *<var class="pdparam">session</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_session_get_seat</b>(</code></td><td>const char *<var class="pdparam">session</var>, </td></tr><tr><td> </td><td>char **<var class="pdparam">seat</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_session_get_service</b>(</code></td><td>const char *<var class="pdparam">session</var>, </td></tr><tr><td> </td><td>char **<var class="pdparam">service</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_session_get_type</b>(</code></td><td>const char *<var class="pdparam">session</var>, </td></tr><tr><td> </td><td>char **<var class="pdparam">type</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_session_get_class</b>(</code></td><td>const char *<var class="pdparam">session</var>, </td></tr><tr><td> </td><td>char **<var class="pdparam">class</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_session_get_desktop</b>(</code></td><td>const char *<var class="pdparam">session</var>, </td></tr><tr><td> </td><td>char **<var class="pdparam">desktop</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_session_get_display</b>(</code></td><td>const char *<var class="pdparam">session</var>, </td></tr><tr><td> </td><td>char **<var class="pdparam">display</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_session_get_remote_host</b>(</code></td><td>const char *<var class="pdparam">session</var>, </td></tr><tr><td> </td><td>char **<var class="pdparam">remote_host</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_session_get_remote_user</b>(</code></td><td>const char *<var class="pdparam">session</var>, </td></tr><tr><td> </td><td>char **<var class="pdparam">remote_user</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_session_get_tty</b>(</code></td><td>const char *<var class="pdparam">session</var>, </td></tr><tr><td> </td><td>char **<var class="pdparam">tty</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_session_get_vt</b>(</code></td><td>const char *<var class="pdparam">session</var>, </td></tr><tr><td> </td><td>unsigned int *<var class="pdparam">vt</var><code>)</code>;</td></tr></table><div class="funcprototype-spacer"> </div></div></div><div class="refsect1"><a name="idm140689458568224"></a><h2 id="Description">Description<a class="headerlink" title="Permalink to this headline" href="#Description">¶</a></h2><p><code class="function">sd_session_is_active()</code> may be used to
  23     determine whether the session identified by the specified session
  24     identifier is currently active (i.e. currently in the foreground
  25     and available for user input) or not.</p><p><code class="function">sd_session_is_remote()</code> may be used to
  26     determine whether the session identified by the specified session
  27     identifier is a remote session (i.e. its remote host is known) or
  28     not.</p><p><code class="function">sd_session_get_state()</code> may be used to
  29     determine the state of the session identified by the specified
  30     session identifier. The following states are currently known:
  31     "<code class="literal">online</code>" (session logged in, but session not
  32     active, i.e. not in the foreground), "<code class="literal">active</code>"
  33     (session logged in and active, i.e. in the foreground),
  34     "<code class="literal">closing</code>" (session nominally logged out, but some
  35     processes belonging to it are still around). In the future
  36     additional states might be defined, client code should be written
  37     to be robust in regards to additional state strings being
  38     returned. This function is a more generic version of
  39     <code class="function">sd_session_is_active()</code>. The returned string
  40     needs to be freed with the libc
  41     <a href="http://man7.org/linux/man-pages/man3/free.3.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  42     call after use.</p><p><code class="function">sd_session_get_uid()</code> may be used to
  43     determine the user identifier of the Unix user the session
  44     identified by the specified session identifier belongs to.</p><p><code class="function">sd_session_get_seat()</code> may be used to
  45     determine the seat identifier of the seat the session identified
  46     by the specified session identifier belongs to. Note that not all
  47     sessions are attached to a seat, this call will fail for them. The
  48     returned string needs to be freed with the libc
  49     <a href="http://man7.org/linux/man-pages/man3/free.3.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  50     call after use.</p><p><code class="function">sd_session_get_service()</code> may be used to
  51     determine the name of the service (as passed during PAM session
  52     setup) that registered the session identified by the specified
  53     session identifier. The returned string needs to be freed with the
  54     libc
  55     <a href="http://man7.org/linux/man-pages/man3/free.3.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  56     call after use.</p><p><code class="function">sd_session_get_type()</code> may be used to
  57     determine the type of the session identified by the specified
  58     session identifier. The returned string is one of
  59     "<code class="literal">x11</code>", "<code class="literal">wayland</code>",
  60     "<code class="literal">tty</code>", "<code class="literal">mir</code>" or
  61     "<code class="literal">unspecified</code>" and needs to be freed with the libc
  62     <a href="http://man7.org/linux/man-pages/man3/free.3.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  63     call after use.</p><p><code class="function">sd_session_get_class()</code> may be used to
  64     determine the class of the session identified by the specified
  65     session identifier. The returned string is one of
  66     "<code class="literal">user</code>", "<code class="literal">greeter</code>",
  67     "<code class="literal">lock-screen</code>", or "<code class="literal">background</code>"
  68     and needs to be freed with the libc
  69     <a href="http://man7.org/linux/man-pages/man3/free.3.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  70     call after use.</p><p><code class="function">sd_session_get_desktop()</code> may be used to
  71     determine the brand of the desktop running on the session
  72     identified by the specified session identifier. This field can be
  73     set freely by desktop environments and does not follow any special
  74     formatting. However, desktops are strongly recommended to use the
  75     same identifiers and capitalization as for
  76     <code class="varname">$XDG_CURRENT_DESKTOP</code>, as defined by the <a class="ulink" href="http://standards.freedesktop.org/desktop-entry-spec/latest/" target="_top">Desktop
  77     Entry Specification</a>. The returned string needs to be freed
  78     with the libc
  79     <a href="http://man7.org/linux/man-pages/man3/free.3.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  80     call after use.</p><p><code class="function">sd_session_get_display()</code> may be used to
  81     determine the X11 display of the session identified by the
  82     specified session identifier. The returned string needs to be
  83     freed with the libc
  84     <a href="http://man7.org/linux/man-pages/man3/free.3.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  85     call after use.</p><p><code class="function">sd_session_get_remote_host()</code> may be
  86     used to determine the remote hostname of the session identified by
  87     the specified session identifier. The returned string needs to be
  88     freed with the libc
  89     <a href="http://man7.org/linux/man-pages/man3/free.3.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  90     call after use.</p><p><code class="function">sd_session_get_remote_user()</code> may be
  91     used to determine the remote username of the session identified by
  92     the specified session identifier. The returned string needs to be
  93     freed with the libc
  94     <a href="http://man7.org/linux/man-pages/man3/free.3.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
  95     call after use. Note that this value is rarely known to the
  96     system, and even then should not be relied on.</p><p><code class="function">sd_session_get_tty()</code> may be used to
  97     determine the TTY device of the session identified by the
  98     specified session identifier. The returned string needs to be
  99     freed with the libc
 100     <a href="http://man7.org/linux/man-pages/man3/free.3.html"><span class="citerefentry"><span class="refentrytitle">free</span>(3)</span></a>
 101     call after use.</p><p><code class="function">sd_session_get_vt()</code> may be used to
 102     determine the VT number of the session identified by the specified
 103     session identifier. This function will return an error if the seat
 104     does not support VTs.</p><p>If the <code class="varname">session</code> parameter of any of these
 105     functions is passed as <code class="constant">NULL</code>, the operation is
 106     executed for the session the calling process is a member of, if
 107     there is any.</p></div><div class="refsect1"><a name="idm140689461855952"></a><h2 id="Return Value">Return Value<a class="headerlink" title="Permalink to this headline" href="#Return%20Value">¶</a></h2><p>If the test succeeds,
 108     <code class="function">sd_session_is_active()</code> and
 109     <code class="function">sd_session_is_remote()</code> return a
 110     positive integer; if it fails, 0.  On success,
 111     <code class="function">sd_session_get_state()</code>,
 112     <code class="function">sd_session_get_uid()</code>,
 113     <code class="function">sd_session_get_seat()</code>,
 114     <code class="function">sd_session_get_service()</code>,
 115     <code class="function">sd_session_get_type()</code>,
 116     <code class="function">sd_session_get_class()</code>,
 117     <code class="function">sd_session_get_display()</code>,
 118     <code class="function">sd_session_get_remote_user()</code>,
 119     <code class="function">sd_session_get_remote_host()</code> and
 120     <code class="function">sd_session_get_tty()</code> return 0 or
 121     a positive integer. On failure, these calls return a
 122     negative errno-style error code.</p></div><div class="refsect1"><a name="idm140689461845952"></a><h2 id="Notes">Notes<a class="headerlink" title="Permalink to this headline" href="#Notes">¶</a></h2><p>The <code class="function">sd_session_is_active()</code>,
 123     <code class="function">sd_session_get_state()</code>,
 124     <code class="function">sd_session_get_uid()</code>,
 125     <code class="function">sd_session_get_seat()</code>,
 126     <code class="function">sd_session_get_service()</code>,
 127     <code class="function">sd_session_get_type()</code>,
 128     <code class="function">sd_session_get_class()</code>,
 129     <code class="function">sd_session_get_display()</code>,
 130     <code class="function">sd_session_get_remote_host()</code>,
 131     <code class="function">sd_session_get_remote_user()</code> and
 132     <code class="function">sd_session_get_tty()</code>
 133     interfaces are available as a shared library, which can
 134     be compiled and linked to with the
 135     <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>
 136     file.</p></div><div class="refsect1"><a name="idm140689461835104"></a><h2 id="See Also">See Also<a class="headerlink" title="Permalink to this headline" href="#See%20Also">¶</a></h2><p>
 137       <a href="systemd.html"><span class="citerefentry"><span class="refentrytitle">systemd</span>(1)</span></a>,
 138       <a href="sd-login.html"><span class="citerefentry"><span class="refentrytitle">sd-login</span>(3)</span></a>,
 139       <a href="sd_pid_get_session.html"><span class="citerefentry"><span class="refentrytitle">sd_pid_get_session</span>(3)</span></a>
 140     </p></div></div></body></html>