l open files
<tt>stdin</tt>, <tt>stdout</tt>, and <tt>stderr</tt>, and it doesn't
receive much information through environment variables.  The key
piece of initial state in a FastCGI process is a listening
socket, through which it accepts connections from a Web server.<p>

After a FastCGI process accepts a connection on its listening socket,
the process executes a simple protocol to receive and send data.  The
protocol serves two purposes.  First, the protocol
multiplexes a single transport connection betwe