<listitem><para>In the daemon process, write the daemon PID
(as returned by <function>getpid()</function>) to a PID file,
- for example <filename>/run/foobar.pid</filename> (for a
+ for example <filename index='false'>/run/foobar.pid</filename> (for a
hypothetical daemon "foobar") to ensure that the daemon cannot
be started more than once. This must be implemented in
race-free fashion so that the PID file is only updated when it