[Bug 969] Clarify ntpdate.html documentation about -u and ntpd

bk: 50a04c41eMEqbLzYrW27Og6N1YCPvg

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+* [Bug 969] Clarify ntpdate.html documentation about -u and ntpd.
 (4.2.7p319) 2012/11/11 Released by Harlan Stenn <stenn@ntp.org>
 * [Bug 2296] Fix compile problem with building with old OpenSSL.
 (4.2.7p318) 2012/11/05 Released by Harlan Stenn <stenn@ntp.org>

diff --git a/html/ntpdate.html b/html/ntpdate.html
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 <tt>ntpdate</tt> sets the local date and time by polling the Network Time Protocol (NTP) server(s) given as the <i>server</i> arguments to determine the correct time. It must be run as root on the local host. A number of samples are obtained from each of the servers specified and a subset of the NTP clock filter and selection algorithms are applied to select the best of these. Note that the accuracy and reliability of <tt>ntpdate</tt> depends on the number of servers, the number of polls each time it is run and the interval between runs.
 <p><tt>ntpdate</tt> can be run manually as necessary to set the host clock, or it can be run from the host startup script to set the clock at boot time. This is useful in some cases to set the clock initially before starting the NTP daemon <tt>ntpd</tt>. It is also possible to run <tt>ntpdate</tt> from a <tt>cron</tt> script. However, it is important to note that <tt>ntpdate</tt> with contrived <tt>cron</tt> scripts is no substitute for the NTP daemon, which uses sophisticated algorithms to maximize accuracy and reliability while minimizing resource use. Finally, since <tt>ntpdate</tt> does not discipline the host clock frequency as does <tt>ntpd</tt>, the accuracy using <tt>ntpdate</tt> is limited.</p>
 <p>Time adjustments are made by <tt>ntpdate</tt> in one of two ways. If <tt>ntpdate</tt> determines the clock is in error more than 0.5 second it will simply step the time by calling the system <tt>settimeofday()</tt> routine. If the error is less than 0.5 seconds, it will slew the time by calling the system <tt>adjtime()</tt> routine. The latter technique is less disruptive and more accurate when the error is small, and works quite well when <tt>ntpdate</tt> is run by <tt>cron</tt> every hour or two.</p>
-<p><tt>ntpdate</tt> will decline to set the date if an NTP server daemon (e.g., <tt>ntpd</tt>) is running on the same host. When running <tt>ntpdate</tt> on a regular basis from <tt>cron</tt> as an alternative to running a daemon, doing so once every hour or two will result in precise enough timekeeping to avoid stepping the clock.</p>
+<p><tt>ntpdate</tt> will, if the <tt>-u</tt> flag was not specified, decline to set the date if an NTP server daemon (e.g., <tt>ntpd</tt>) is running on the same host. When running <tt>ntpdate</tt> on a regular basis from <tt>cron</tt> as an alternative to running a daemon, doing so once every hour or two will result in precise enough timekeeping to avoid stepping the clock.</p>
 <p>Note that in contexts where a host name is expected, a <tt>-4</tt> qualifier preceding the host name forces DNS resolution to the IPv4 namespace, while a <tt>-6</tt> qualifier forces DNS resolution to the IPv6 namespace.</p>
 <p>If NetInfo support is compiled into <tt>ntpdate</tt>, then the <tt>server</tt> argument is optional if <tt>ntpdate</tt> can find a time server in the NetInfo configuration for <tt>ntpd</tt>.</p>
 <h4>Command Line Options</h4>