1 files changed, 165 insertions, 0 deletions
diff --git a/man/ntpshmmon.xml b/man/ntpshmmon.xml
new file mode 100644
index 00000000..bcb083a3
--- /dev/null
+++ b/man/ntpshmmon.xml
@@ -0,0 +1,165 @@
+<?xml version="1.0" encoding="ISO-8859-1"?>
+<!--
+This file is Copyright (c) 2010 by the GPSD project
+SPDX-License-Identifier: BSD-2-clause
+-->
+<!DOCTYPE refentry PUBLIC
+   "-//OASIS//DTD DocBook XML V4.1.2//EN"
+   "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd">
+<refentry id='ntpshmmon.1'>
+<refentryinfo><date>25 Jan 2015</date></refentryinfo>
+<refmeta>
+<refentrytitle>ntpshmmon</refentrytitle>
+<manvolnum>1</manvolnum>
+<refmiscinfo class="source">The GPSD Project</refmiscinfo>
+<refmiscinfo class="manual">GPSD Documentation</refmiscinfo>
+</refmeta>
+<refnamediv id='name'>
+<refname>ntpshmmon</refname>
+<refpurpose>capture samples from GPS or other ntpd refclock sources</refpurpose>
+</refnamediv>
+<refsynopsisdiv id='synopsis'>
+
+<cmdsynopsis>
+  <command>ntpshmmon</command>
+      <arg choice='opt'>-h </arg>
+      <arg choice='opt'>-n <replaceable>nsamples</replaceable></arg>
+      <arg choice='opt'>-s </arg>
+      <arg choice='opt'>-t <replaceable>seconds</replaceable></arg>
+      <arg choice='opt'>-v </arg>
+      <arg choice='opt'>-V </arg>
+</cmdsynopsis>
+</refsynopsisdiv>
+
+<refsect1 id='description'><title>DESCRIPTION</title>
+
+<para>This program monitors the shared-memory segments updated by
+<citerefentry><refentrytitle>gpsd</refentrytitle><manvolnum>8</manvolnum></citerefentry>
+(and possibly other refclock sources) as a way of communicating with
+ntpd, the Network Time Protocol daemon. It reads these in exactly the way an
+ntpd instance does. It can be run concurrently with ntpd without
+interfering with ntpd's normal operation.</para>
+
+<para>This program runs forever, or until a termination option is
+matched, or until interrupted, generating sample reports to standard
+output.  Each line consists of whitespace-separated textual
+fields.</para>
+
+<para>Here is an example of the beginning of a report file:
+
+<screen>
+ntpshmmon version 1
+#      Name   Seen@                Clock                Real               L Prec
+sample NTP2 1424926256.443030206 1424926256.115869233 1424926256.000000000 0  -1
+sample NTP3 1424926256.443060517 1424926255.995430821 1424926256.000000000 0 -20
+sample NTP3 1424926256.995747347 1424926256.995422728 1424926257.000000000 0 -20
+sample NTP2 1424926257.112433572 1424926257.111936726 1424926257.000000000 0  -1
+sample NTP3 1424926257.996221153 1424926257.995410232 1424926258.000000000 0 -20
+sample NTP2 1424926258.107769409 1424926258.107451006 1424926258.000000000 0  -1
+sample NTP3 1424926258.995647636 1424926258.995406476 1424926259.000000000 0 -20
+</screen></para>
+
+<para>The output always begins with a header line expressing the
+version of the output format; the version line begins with "ntpshmmon
+version" and is followed by a numeric version field.</para>
+
+<para>The remainder of the file is either commments or sample lines. A
+comment line begins with a # and should ignored by programs that
+interpret this format.</para>
+
+<para>The fields of a sample line are as follows:
+
+<orderedlist>
+<listitem><para>The keyword "sample"</para></listitem>
+
+<listitem><para>The NTP unit from which it was collected.</para></listitem>
+
+<listitem><para>Collection time of day, seconds.</para></listitem>
+
+<listitem><para>Receiver time of day, seconds.</para></listitem>
+
+<listitem><para>Clock time of day, seconds.</para></listitem>
+
+<listitem><para>Leap-second notification status.</para></listitem>
+
+<listitem><para>Source precision (log(2) of source jitter).</para></listitem>
+</orderedlist>
+</para>
+
+<para>In these fields, "clock time" is the high-precision time
+measured by the source and "receiver time" is Unix UTC time at the
+receiver. It is normal for the seconds part of receiver time to
+coincide with the seconds part of collection time and for the
+nanoseconds part of receiver time to be zero.</para>
+
+<variablelist>
+<varlistentry>
+<term>-v</term>
+<listitem>
+<para>Enable verbose status messages.</para>
+</listitem>
+</varlistentry>
+
+<varlistentry>
+<term>-c</term>
+<listitem>
+<para>Device poll interval in fractional seconds - defaults to 1.</para>
+</listitem>
+</varlistentry>
+
+<varlistentry>
+<term>-n</term>
+<listitem>
+<para>Set maximum number of samples to collect.</para>
+</listitem>
+</varlistentry>
+
+<varlistentry>
+<term>-s</term>
+<listitem>
+<para>Remove all SHM segments used by GPSD. This
+option will normally only be of interest to GPSD developers.</para>
+</listitem>
+</varlistentry>
+
+<varlistentry>
+<term>-t</term>
+<listitem>
+<para>Set maximum time to collect samples in seconds.</para>
+</listitem>
+</varlistentry>
+
+<varlistentry>
+<term>-h</term>
+<listitem>
+<para>Display program usage and exit.</para>
+</listitem>
+</varlistentry>
+
+<varlistentry>
+<term>-V</term>
+<listitem>
+<para>Display program version and exit.</para>
+</listitem>
+</varlistentry>
+</variablelist>
+
+</refsect1>
+
+<refsect1 id='see_also'><title>SEE ALSO</title>
+<para>
+<citerefentry><refentrytitle>gpsd</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+<citerefentry><refentrytitle>gpsdctl</refentrytitle><manvolnum>8</manvolnum></citerefentry>,
+<citerefentry><refentrytitle>gps</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+<citerefentry><refentrytitle>libgps</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+<citerefentry><refentrytitle>libgpsmm</refentrytitle><manvolnum>3</manvolnum></citerefentry>,
+<citerefentry><refentrytitle>gpsprof</refentrytitle><manvolnum>1</manvolnum></citerefentry>,
+<citerefentry><refentrytitle>gpsfake</refentrytitle><manvolnum>1</manvolnum></citerefentry>.
+</para>
+</refsect1>
+
+<refsect1 id='maintainer'><title>AUTHOR</title>
+
+<para>Eric S. Raymond <email>esr@thyrsus.com</email>.</para>
+</refsect1>
+</refentry>