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23<h1 class="settitle">Sntp User's Manual</h1>
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31</div>
32
33<h2 class="unnumbered">Simple Network Time Protocol User Manual</h2>
34
35<p>This document describes the use of the NTP Project's <code>sntp</code> program,
36that can be used to query a Network Time Protocol (NTP) server and
37display the time offset of the system clock relative to the server
38clock.  Run as root, it can correct the system clock to this offset as
39well.  It can be run as an interactive command or from a cron job.
40
41  <p>This document applies to version 4.2.6 of <code>sntp</code>.
42
43  <p>The program implements the SNTP protocol as defined by the draft NTPv4
44IETF specification.
45
46  <div class="shortcontents">
47<h2>Short Contents</h2>
48<ul>
49<a href="#Top">Simple Network Time Protocol User Manual</a>
50</ul>
51</div>
52
53<ul class="menu">
54<li><a accesskey="1" href="#sntp-Description">sntp Description</a>:             Description
55* sntp Invocation::                Invoking sntp
56<li><a accesskey="2" href="#Usage">Usage</a>:                        Usage
57</ul>
58
59<div class="node">
60<a name="sntp-Description"></a>
61<p><hr>
62Next:&nbsp;<a rel="next" accesskey="n" href="#Usage">Usage</a>,
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69<h3 class="section">Description</h3>
70
71<p>By default, <code>sntp</code> writes the local data and time (i.e., not UTC) to the
72standard output in the format:
73
74<pre class="example">     1996 Oct 15 20:17:25.123 +4.567 +/- 0.089 secs
75</pre>
76  <p>where the +4.567 +/- 0.089 secs indicates the time offset and
77error bound of the system clock relative to the server clock.
78
79<!-- @include sntp-opts.texi -->
80<div class="node">
81<a name="Usage"></a>
82<p><hr>
83Previous:&nbsp;<a rel="previous" accesskey="p" href="#sntp-Description">sntp Description</a>,
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85
86</div>
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88<!-- node-name,  next,  previous,  up -->
89<h3 class="section">Usage</h3>
90
91<p>The simplest use of this program is as an unprivileged command to
92check the current time, offset, and error in the local clock. 
93For example:
94
95<pre class="example">     sntp ntpserver.somewhere
96</pre>
97  <p>With suitable privilege, it can be run as a command or in a
98<code>crom</code> job to reset the local clock from a reliable server, like
99the <code>ntpdate</code> and <code>rdate</code> commands. 
100For example:
101
102<pre class="example">     sntp -a ntpserver.somewhere
103</pre>
104  </body></html>
105
106