contrib/ntp/scripts/ntp-wait/ntp-wait.html

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   3 <title>Ntp-wait User's Manual</title>
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  22 <h1 class="settitle">Ntp-wait User's Manual</h1>
  23 <div class="node">
  24 <p><hr>
  25 <a name="Top"></a>Next:&nbsp;<a rel="next" accesskey="n" href="#ntp_002dwait-Description">ntp-wait Description</a>,
  26 Previous:&nbsp;<a rel="previous" accesskey="p" href="#dir">(dir)</a>,
  27 Up:&nbsp;<a rel="up" accesskey="u" href="#dir">(dir)</a>
  28 <br>
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  30
  31   <p>This document describes the use of the NTP Project's <code>ntp-wait</code> program.
  32
  33   <p>If there are time-sensitive applications,
  34 the proper sequence of events is to
  35 run <code>ntpd -g</code> as early as possible,
  36 then invoke all of the non-time-sensitive process,
  37 run <code>ntp-wait</code> to block
  38 until the system's time has stabilized and synchronized,
  39 and only then start any applicaitons (like database servers) that require
  40 accurate and stable time.
  41
  42   <p>This document applies to version 4.2.8p11 of <code>ntp-wait</code>.
  43
  44 <div class="shortcontents">
  45 <h2>Short Contents</h2>
  46 <ul>
  47 </ul>
  48 </div>
  49
  50 <ul class="menu">
  51 <li><a accesskey="1" href="#ntp_002dwait-Description">ntp-wait Description</a>:             Description
  52 <li><a accesskey="2" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>:           Invoking ntp-wait
  53 </ul>
  54
  55 <div class="node">
  56 <p><hr>
  57 <a name="ntp_002dwait-Invocation"></a>
  58 <br>
  59 </div>
  60
  61 <h3 class="section">0.1 Invoking ntp-wait</h3>
  62
  63 <p><a name="index-ntp_002dwait-1"></a><a name="index-Wait-for-ntpd-to-stabilize-the-system-clock-2"></a>
  64
  65   <p><code>ntp-wait</code>
  66 will send at most
  67 <kbd>num-tries</kbd>
  68 queries to
  69 <code>ntpd(8)</code>,
  70 sleeping for
  71 <kbd>secs-between-tries</kbd>
  72 after each status return that says
  73 <code>ntpd(8)</code>
  74 has not yet produced a synchronized and stable system clock.
  75
  76   <p><code>ntp-wait</code>
  77 will do this quietly, unless the
  78 <code>-v</code>
  79 flag is provided.
  80 This can be useful at boot time, to delay the boot sequence until after
  81 <kbd>ntpd</kbd> <kbd>-g</kbd>
  82 has set the time.
  83
  84   <p>This section was generated by <strong>AutoGen</strong>,
  85 using the <code>agtexi-cmd</code> template and the option descriptions for the <code>ntp-wait</code> program.
  86
  87 <ul class="menu">
  88 <li><a accesskey="1" href="#ntp_002dwait-usage">ntp-wait usage</a>:                   ntp-wait help/usage (<span class="option">--help</span>)
  89 <li><a accesskey="2" href="#ntp_002dwait-tries">ntp-wait tries</a>:                   tries option (-n)
  90 <li><a accesskey="3" href="#ntp_002dwait-sleep">ntp-wait sleep</a>:                   sleep option (-s)
  91 <li><a accesskey="4" href="#ntp_002dwait-verbose">ntp-wait verbose</a>:                 verbose option (-v)
  92 <li><a accesskey="5" href="#ntp_002dwait-exit-status">ntp-wait exit status</a>:             exit status
  93 <li><a accesskey="6" href="#ntp_002dwait-Authors">ntp-wait Authors</a>:                 Authors
  94 <li><a accesskey="7" href="#ntp_002dwait-Notes">ntp-wait Notes</a>:                   Notes
  95 </ul>
  96
  97 <div class="node">
  98 <p><hr>
  99 <a name="ntp_002dwait-usage"></a>Next:&nbsp;<a rel="next" accesskey="n" href="#ntp_002dwait-tries">ntp-wait tries</a>,
 100 Up:&nbsp;<a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
 101 <br>
 102 </div>
 103
 104 <h4 class="subsection">0.1.1 ntp-wait help/usage (<span class="option">--help</span>)</h4>
 105
 106 <p><a name="index-ntp_002dwait-help-3"></a>
 107 This is the automatically generated usage text for ntp-wait.
 108
 109   <p>The text printed is the same whether selected with the <code>help</code> option
 110 (<span class="option">--help</span>) or the <code>more-help</code> option (<span class="option">--more-help</span>).  <code>more-help</code> will print
 111 the usage text by passing it through a pager program.
 112 <code>more-help</code> is disabled on platforms without a working
 113 <code>fork(2)</code> function.  The <code>PAGER</code> environment variable is
 114 used to select the program, defaulting to <span class="file">more</span>.  Both will exit
 115 with a status code of 0.
 116
 117 <pre class="example">ntp-wait - Wait for ntpd to stabilize the system clock - Ver. 4.2.8p11
 118 USAGE: ntp-wait [ -&lt;flag&gt; [&lt;val&gt;] | --&lt;name&gt;[{=| }&lt;val&gt;] ]...
 119
 120     -n, --tries=num              Number of times to check ntpd
 121     -s, --sleep=num              How long to sleep between tries
 122     -v, --verbose                Be verbose
 123     -?, --help                   Display usage information and exit
 124         --more-help              Pass the extended usage text through a pager
 125
 126 Options are specified by doubled hyphens and their name or by a single
 127 hyphen and the flag character.
 128 </pre>
 129   <div class="node">
 130 <p><hr>
 131 <a name="ntp_002dwait-tries"></a>Next:&nbsp;<a rel="next" accesskey="n" href="#ntp_002dwait-sleep">ntp-wait sleep</a>,
 132 Previous:&nbsp;<a rel="previous" accesskey="p" href="#ntp_002dwait-usage">ntp-wait usage</a>,
 133 Up:&nbsp;<a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
 134 <br>
 135 </div>
 136
 137 <h4 class="subsection">0.1.2 tries option (-n)</h4>
 138
 139 <p><a name="index-ntp_002dwait_002dtries-4"></a>
 140 This is the &ldquo;number of times to check ntpd&rdquo; option.
 141 This option takes a number argument.
 142         The maximum number of times we will check <code>ntpd</code> to see if
 143         it has been able to synchronize and stabilize the system clock.
 144 <div class="node">
 145 <p><hr>
 146 <a name="ntp_002dwait-sleep"></a>Next:&nbsp;<a rel="next" accesskey="n" href="#ntp_002dwait-verbose">ntp-wait verbose</a>,
 147 Previous:&nbsp;<a rel="previous" accesskey="p" href="#ntp_002dwait-tries">ntp-wait tries</a>,
 148 Up:&nbsp;<a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
 149 <br>
 150 </div>
 151
 152 <h4 class="subsection">0.1.3 sleep option (-s)</h4>
 153
 154 <p><a name="index-ntp_002dwait_002dsleep-5"></a>
 155 This is the &ldquo;how long to sleep between tries&rdquo; option.
 156 This option takes a number argument <span class="file">secs-between-tries</span>.
 157         We will sleep for <span class="file">secs-between-tries</span> after each query
 158         of <code>ntpd</code> that returns "the time is not yet stable".
 159 <div class="node">
 160 <p><hr>
 161 <a name="ntp_002dwait-verbose"></a>Next:&nbsp;<a rel="next" accesskey="n" href="#ntp_002dwait-exit-status">ntp-wait exit status</a>,
 162 Previous:&nbsp;<a rel="previous" accesskey="p" href="#ntp_002dwait-sleep">ntp-wait sleep</a>,
 163 Up:&nbsp;<a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
 164 <br>
 165 </div>
 166
 167 <h4 class="subsection">0.1.4 verbose option (-v)</h4>
 168
 169 <p><a name="index-ntp_002dwait_002dverbose-6"></a>
 170 This is the &ldquo;be verbose&rdquo; option.
 171         By default, <code>ntp-wait</code> is silent.
 172         With this option, <code>ntp-wait</code> will provide status information.
 173 <div class="node">
 174 <p><hr>
 175 <a name="ntp_002dwait-exit-status"></a>Next:&nbsp;<a rel="next" accesskey="n" href="#ntp_002dwait-Authors">ntp-wait Authors</a>,
 176 Previous:&nbsp;<a rel="previous" accesskey="p" href="#ntp_002dwait-verbose">ntp-wait verbose</a>,
 177 Up:&nbsp;<a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
 178 <br>
 179 </div>
 180
 181 <h4 class="subsection">0.1.5 ntp-wait exit status</h4>
 182
 183 <p>One of the following exit values will be returned:
 184      <dl>
 185 <dt><span class="samp">0 (EXIT_SUCCESS)</span><dd>Successful program execution.
 186 <br><dt><span class="samp">1 (EXIT_FAILURE)</span><dd>The operation failed or the command syntax was not valid.
 187 </dl>
 188   <div class="node">
 189 <p><hr>
 190 <a name="ntp_002dwait-Authors"></a>Next:&nbsp;<a rel="next" accesskey="n" href="#ntp_002dwait-Notes">ntp-wait Notes</a>,
 191 Previous:&nbsp;<a rel="previous" accesskey="p" href="#ntp_002dwait-exit-status">ntp-wait exit status</a>,
 192 Up:&nbsp;<a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
 193 <br>
 194 </div>
 195
 196 <h4 class="subsection">0.1.6 ntp-wait Authors</h4>
 197
 198 <div class="node">
 199 <p><hr>
 200 <a name="ntp_002dwait-Notes"></a>Previous:&nbsp;<a rel="previous" accesskey="p" href="#ntp_002dwait-Authors">ntp-wait Authors</a>,
 201 Up:&nbsp;<a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
 202 <br>
 203 </div>
 204
 205 <h4 class="subsection">0.1.7 ntp-wait Notes</h4>
 206
 207 </body></html>
 208