>

A FastCGI application exits with zero status to indicate that it
terminated on purpose, e.g. in order to perform a crude form of
garbage collection.  A FastCGI application that exits with nonzero
status is assumed to have crashed.  How a Web server or other
application manager responds to
applications that exit with zero or nonzero status is outside the
scope of this specification.<p>

A Web server can request that a FastCGI application exit by sending it
<tt>SIGTERM</tt>.  If the application ignores <tt