- data in this directory the user should
- include the value of <varname>$XDG_SESSION_ID</varname>
- in the filename. This directory shall
- be used for runtime file system
- objects such as AF_UNIX sockets,
- FIFOs, PID files and similar. It is
- guaranteed that this directory is
- local and offers the greatest possible
- file system feature set the
- operating system
- provides.</para></listitem>
+ data in this directory, the user
+ should include the value of
+ <varname>$XDG_SESSION_ID</varname> in
+ the filename. This directory shall be
+ used for runtime file system objects
+ such as <constant>AF_UNIX</constant>
+ sockets, FIFOs, PID files and
+ similar. It is guaranteed that this
+ directory is local and offers the
+ greatest possible file system feature
+ set the operating system provides. For
+ further details see the <ulink
+ url="http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html">XDG
+ Base Directory
+ Specification</ulink>.</para></listitem>
+ </varlistentry>
+
+ </variablelist>
+
+ <para>The following environment variables are read by
+ the module and may be used by the PAM service to pass
+ metadata to the module:</para>
+
+ <variablelist class='environment-variables'>
+ <varlistentry>
+ <term><varname>$XDG_SESSION_TYPE</varname></term>
+
+ <listitem><para>The session type. This
+ may be used instead of
+ <option>session=</option> on the
+ module parameter line, and is usually
+ preferred.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>$XDG_SESSION_CLASS</varname></term>
+
+ <listitem><para>The session class. This
+ may be used instead of
+ <option>class=</option> on the
+ module parameter line, and is usually
+ preferred.</para></listitem>
+ </varlistentry>
+
+ <varlistentry>
+ <term><varname>$XDG_SESSION_DESKTOP</varname></term>
+
+ <listitem><para>A single, short
+ identifier string for the desktop
+ environment. This may be used to
+ indicate the session desktop used,
+ where this applies and if this
+ information is available. For example:
+ <literal>GNOME</literal>, or
+ <literal>KDE</literal>. It is
+ recommended to use the same
+ identifiers and capitalization as for
+ <varname>$XDG_CURRENT_DESKTOP</varname>,
+ as defined by the <ulink
+ url="http://standards.freedesktop.org/desktop-entry-spec/latest/">Desktop
+ Entry Specification</ulink>. (However,
+ note that
+ <varname>$XDG_SESSION_DESKTOP</varname>
+ only takes a single item, and not a
+ colon-separated list like
+ <varname>$XDG_CURRENT_DESKTOP</varname>.)
+ See
+ <citerefentry><refentrytitle>sd_session_get_desktop</refentrytitle><manvolnum>3</manvolnum></citerefentry>
+ for more details.</para></listitem>