Document the just-added UDP facility in gpsfake.

1 files changed, 10 insertions, 3 deletions

diff --git a/gpsfake.xml b/gpsfake.xml
index 5d4a7440..a3aa1e7d 100644
--- a/gpsfake.xml
+++ b/gpsfake.xml
@@ -110,13 +110,14 @@ notifications generated by the log to standard output. This is useful
 for regression-testing.</para>
 
 <para>The -r option specifies an initialization command to use in pipe mode.  
-The default is "w+r+"; "r=2" might be another interesting value.</para>
+The default is <command>?WATCH={"enable":true,"json":true}</command>.</para>
 
 <para>The -s option sets the baud rate for the slave tty.  The
 default is 4800.</para>
 
-<para>The -v option enables verbose progress reports to stderr.  It
-is mainly useful for debugging <application>gpsfake</application> itself.</para>
+<para>The -v option enables verbose progress reports to stderr.  It is
+mainly useful for debugging <application>gpsfake</application>
+itself.</para>
 
 <para>The -x option dumps packets as
 <application>gpsfake</application> gathers them.  It is mainly useful
@@ -129,6 +130,12 @@ a usage message and exit.</para>
 data to be cycled at the device. <application>gpsfake</application> 
 will print a notification each time it cycles.</para>
 
+<para>Normally, gpsfake creates a pty for each logfile and passes the
+slave side of the debice to the daemon.  If the header comment in the
+logfile contains the string "UDP", packets are instead shipped via UDP
+port 5000 to the addess 192.168.0.1.255.  You can monitoer them with
+this: <command>tcpdump -s0 -n -A -i lo udp and port 5000</command>.</para>
+
 </refsect1>
 <refsect1 id='custom'><title>CUSTOM TESTS</title>