1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<html> 3<head> 4<meta http-equiv="content-type" content="text/html;charset=iso-8859-1"> 5<meta name="generator" content="HTML Tidy, see www.w3.org"> 6<title>ntptime - read and set kernel time variables</title> 7<link href="scripts/style.css" type="text/css" rel="stylesheet"> 8</head> 9<body> 10<h3><tt>ntptime</tt> - read and set kernel time variables</h3> 11<img src="pic/pogo5.gif" alt="gif" align="left"><a href="http://www.eecis.udel.edu/~mills/pictures.html">from <i>Pogo</i>, Walt Kelly</a> 12<p>The turtle has been swimming in the kernel.</p> 13<p>Last update: 14 <!-- #BeginDate format:En2m -->11-Sep-2010 05:55<!-- #EndDate --> 15 UTC</p> 16<br clear="left"> 17<hr> 18<h4>Synopsis</h4> 19<tt>ntptime [ -chr ] [ -e <i>est_error</i> ] [ -f <i>frequency</i> ] [ -m <i>max_error</i> ] [ -o <i>offset</i> ] [ -s <i>status</i> ] [ -t <i>time_constant</i>]</tt> 20<h4>Description</h4> 21<p>This program is useful only with special kernels described in the <a href="kern.html">A Kernel Model for Precision Timekeeping</a> page. It reads and displays time-related kernel variables using the <tt>ntp_gettime()</tt> system call. A similar display can be obtained using the <tt>ntpdc</tt> program and <tt>kerninfo</tt> command.</p> 22<h4>Options</h4> 23<dl> 24 <dt><tt>-c</tt></dt> 25 <dd>Display the execution time of <tt>ntptime</tt> itself.</dd> 26 <dt><tt>-e <i>est_error</i></tt></dt> 27 <dd>Specify estimated error, in microseconds.</dd> 28 <dt><tt>-f <i>frequency</i></tt></dt> 29 <dd>Specify frequency offset, in parts per million.</dd> 30 <dt><tt>-h</tt></dt> 31 <dd>Display help information.</dd> 32 <dt><tt>-m <i>max_error</i></tt></dt> 33 <dd>Specify max possible errors, in microseconds.</dd> 34 <dt><tt>-o <i>offset</i></tt></dt> 35 <dd>Specify clock offset, in microseconds.</dd> 36 <dt><tt>-r</tt></dt> 37 <dd>Display Unix and NTP times in raw format.</dd> 38 <dt><tt>-s <i>status</i></tt></dt> 39 <dd>Specify clock status. Better know what you are doing.</dd> 40 <dt><tt>-t <i>time_constant</i></tt></dt> 41 <dd>Specify time constant, an integer in the range 0-10.</dd> 42</dl> 43<hr> 44<script type="text/javascript" language="javascript" src="scripts/footer.txt"></script> 45</body> 46</html> 47