along with systemd; If not, see <http://www.gnu.org/licenses/>.
-->
-<refentry id="sd_listen_fds">
+<refentry id="sd_listen_fds"
+ xmlns:xi="http://www.w3.org/2001/XInclude">
<refentryinfo>
<title>sd_listen_fds</title>
<para>If the <parameter>unset_environment</parameter>
parameter is non-zero,
<function>sd_listen_fds()</function> will unset the
- <varname>$LISTEN_FDS</varname>/<varname>$LISTEN_PID</varname>
+ <varname>$LISTEN_FDS</varname> and <varname>$LISTEN_PID</varname>
environment variables before returning (regardless of
whether the function call itself succeeded or
not). Further calls to
<para>If a daemon receives more than one file
descriptor, they will be passed in the same order as
- configured in the systemd socket definition
- file. Nonetheless, it is recommended to verify the
- correct socket types before using them. To simplify
- this checking, the functions
+ configured in the systemd socket unit file (see
+ <citerefentry><refentrytitle>systemd.socket</refentrytitle><manvolnum>5</manvolnum></citerefentry>
+ for details). Nonetheless, it is recommended to verify
+ the correct socket types before using them. To
+ simplify this checking, the functions
<citerefentry><refentrytitle>sd_is_fifo</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_is_socket</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<citerefentry><refentrytitle>sd_is_socket_inet</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
<para>This function call will set the FD_CLOEXEC flag
for all passed file descriptors to avoid further
inheritance to children of the calling process.</para>
+
+ <para>If multiple socket units activate the same
+ service the order of the file descriptors passed to
+ its main process is undefined. If additional file
+ descriptors have been passed to the service manager
+ using
+ <citerefentry><refentrytitle>sd_pid_notify_with_fds</refentrytitle><manvolnum>3</manvolnum></citerefentry>'s
+ <literal>FDSTORE=1</literal> messages, these file
+ descriptors are passed last, in arbitrary order, and
+ with duplicates removed.</para>
</refsect1>
<refsect1>
<refsect1>
<title>Notes</title>
- <para>These APIs are implemented as a shared library,
- which can be compiled and linked to with the
- <constant>libsystemd</constant> <citerefentry><refentrytitle>pkg-config</refentrytitle><manvolnum>1</manvolnum></citerefentry>
- file.</para>
+ <xi:include href="libsystemd-pkgconfig.xml" xpointer="pkgconfig-text"/>
<para>Internally, this function checks whether the
<varname>$LISTEN_PID</varname> environment variable