1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
|
<html lang="en">
<head>
<title>Ntp-wait User's Manual</title>
<meta http-equiv="Content-Type" content="text/html">
<meta name="description" content="Ntp-wait User's Manual">
<meta name="generator" content="makeinfo 4.7">
<link title="Top" rel="top" href="#Top">
<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage">
<meta http-equiv="Content-Style-Type" content="text/css">
<style type="text/css"><!--
pre.display { font-family:inherit }
pre.format { font-family:inherit }
pre.smalldisplay { font-family:inherit; font-size:smaller }
pre.smallformat { font-family:inherit; font-size:smaller }
pre.smallexample { font-size:smaller }
pre.smalllisp { font-size:smaller }
span.sc { font-variant:small-caps }
span.roman { font-family: serif; font-weight: normal; }
--></style>
</head>
<body>
<h1 class="settitle">Ntp-wait User's Manual</h1>
<div class="node">
<p><hr>
<a name="Top"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dwait-Description">ntp-wait Description</a>,
Previous: <a rel="previous" accesskey="p" href="#dir">(dir)</a>,
Up: <a rel="up" accesskey="u" href="#dir">(dir)</a>
<br>
</div>
<p>This document describes the use of the NTP Project's <code>ntp-wait</code> program.
<p>If there are time-sensitive applications,
the proper sequence of events is to
run <code>ntpd -g</code> as early as possible,
then invoke all of the non-time-sensitive process,
run <code>ntp-wait</code> to block
until the system's time has stabilized and synchronized,
and only then start any applicaitons (like database servers) that require
accurate and stable time.
<p>This document applies to version 4.2.8p8 of <code>ntp-wait</code>.
<div class="shortcontents">
<h2>Short Contents</h2>
<ul>
</ul>
</div>
<ul class="menu">
<li><a accesskey="1" href="#ntp_002dwait-Description">ntp-wait Description</a>: Description
<li><a accesskey="2" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>: Invoking ntp-wait
</ul>
<div class="node">
<p><hr>
<a name="ntp_002dwait-Invocation"></a>
<br>
</div>
<h3 class="section">0.1 Invoking ntp-wait</h3>
<p><a name="index-ntp_002dwait-1"></a><a name="index-Wait-for-ntpd-to-stabilize-the-system-clock-2"></a>
<p><code>ntp-wait</code>
will send at most
<kbd>num-tries</kbd>
queries to
<code>ntpd(8)</code>,
sleeping for
<kbd>secs-between-tries</kbd>
after each status return that says
<code>ntpd(8)</code>
has not yet produced a synchronized and stable system clock.
<p><code>ntp-wait</code>
will do this quietly, unless the
<code>-v</code>
flag is provided.
This can be useful at boot time, to delay the boot sequence until after
<kbd>ntpd</kbd> <kbd>-g</kbd>
has set the time.
<p>This section was generated by <strong>AutoGen</strong>,
using the <code>agtexi-cmd</code> template and the option descriptions for the <code>ntp-wait</code> program.
<ul class="menu">
<li><a accesskey="1" href="#ntp_002dwait-usage">ntp-wait usage</a>: ntp-wait help/usage (<span class="option">--help</span>)
<li><a accesskey="2" href="#ntp_002dwait-tries">ntp-wait tries</a>: tries option (-n)
<li><a accesskey="3" href="#ntp_002dwait-sleep">ntp-wait sleep</a>: sleep option (-s)
<li><a accesskey="4" href="#ntp_002dwait-verbose">ntp-wait verbose</a>: verbose option (-v)
<li><a accesskey="5" href="#ntp_002dwait-exit-status">ntp-wait exit status</a>: exit status
<li><a accesskey="6" href="#ntp_002dwait-Authors">ntp-wait Authors</a>: Authors
<li><a accesskey="7" href="#ntp_002dwait-Notes">ntp-wait Notes</a>: Notes
</ul>
<div class="node">
<p><hr>
<a name="ntp_002dwait-usage"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dwait-tries">ntp-wait tries</a>,
Up: <a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
<br>
</div>
<h4 class="subsection">0.1.1 ntp-wait help/usage (<span class="option">--help</span>)</h4>
<p><a name="index-ntp_002dwait-help-3"></a>
This is the automatically generated usage text for ntp-wait.
<p>The text printed is the same whether selected with the <code>help</code> option
(<span class="option">--help</span>) or the <code>more-help</code> option (<span class="option">--more-help</span>). <code>more-help</code> will print
the usage text by passing it through a pager program.
<code>more-help</code> is disabled on platforms without a working
<code>fork(2)</code> function. The <code>PAGER</code> environment variable is
used to select the program, defaulting to <span class="file">more</span>. Both will exit
with a status code of 0.
<pre class="example">ntp-wait - Wait for ntpd to stabilize the system clock - Ver. 4.2.8p8
USAGE: ntp-wait [ -<flag> [<val>] | --<name>[{=| }<val>] ]...
-n, --tries=num Number of times to check ntpd
-s, --sleep=num How long to sleep between tries
-v, --verbose Be verbose
-?, --help Display usage information and exit
--more-help Pass the extended usage text through a pager
Options are specified by doubled hyphens and their name or by a single
hyphen and the flag character.
</pre>
<div class="node">
<p><hr>
<a name="ntp_002dwait-tries"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dwait-sleep">ntp-wait sleep</a>,
Previous: <a rel="previous" accesskey="p" href="#ntp_002dwait-usage">ntp-wait usage</a>,
Up: <a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
<br>
</div>
<h4 class="subsection">0.1.2 tries option (-n)</h4>
<p><a name="index-ntp_002dwait_002dtries-4"></a>
This is the “number of times to check ntpd” option.
This option takes a number argument.
The maximum number of times we will check <code>ntpd</code> to see if
it has been able to synchronize and stabilize the system clock.
<div class="node">
<p><hr>
<a name="ntp_002dwait-sleep"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dwait-verbose">ntp-wait verbose</a>,
Previous: <a rel="previous" accesskey="p" href="#ntp_002dwait-tries">ntp-wait tries</a>,
Up: <a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
<br>
</div>
<h4 class="subsection">0.1.3 sleep option (-s)</h4>
<p><a name="index-ntp_002dwait_002dsleep-5"></a>
This is the “how long to sleep between tries” option.
This option takes a number argument <span class="file">secs-between-tries</span>.
We will sleep for <span class="file">secs-between-tries</span> after each query
of <code>ntpd</code> that returns "the time is not yet stable".
<div class="node">
<p><hr>
<a name="ntp_002dwait-verbose"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dwait-exit-status">ntp-wait exit status</a>,
Previous: <a rel="previous" accesskey="p" href="#ntp_002dwait-sleep">ntp-wait sleep</a>,
Up: <a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
<br>
</div>
<h4 class="subsection">0.1.4 verbose option (-v)</h4>
<p><a name="index-ntp_002dwait_002dverbose-6"></a>
This is the “be verbose” option.
By default, <code>ntp-wait</code> is silent.
With this option, <code>ntp-wait</code> will provide status information.
<div class="node">
<p><hr>
<a name="ntp_002dwait-exit-status"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dwait-Authors">ntp-wait Authors</a>,
Previous: <a rel="previous" accesskey="p" href="#ntp_002dwait-verbose">ntp-wait verbose</a>,
Up: <a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
<br>
</div>
<h4 class="subsection">0.1.5 ntp-wait exit status</h4>
<p>One of the following exit values will be returned:
<dl>
<dt><span class="samp">0 (EXIT_SUCCESS)</span><dd>Successful program execution.
<br><dt><span class="samp">1 (EXIT_FAILURE)</span><dd>The operation failed or the command syntax was not valid.
</dl>
<div class="node">
<p><hr>
<a name="ntp_002dwait-Authors"></a>Next: <a rel="next" accesskey="n" href="#ntp_002dwait-Notes">ntp-wait Notes</a>,
Previous: <a rel="previous" accesskey="p" href="#ntp_002dwait-exit-status">ntp-wait exit status</a>,
Up: <a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
<br>
</div>
<h4 class="subsection">0.1.6 ntp-wait Authors</h4>
<div class="node">
<p><hr>
<a name="ntp_002dwait-Notes"></a>Previous: <a rel="previous" accesskey="p" href="#ntp_002dwait-Authors">ntp-wait Authors</a>,
Up: <a rel="up" accesskey="u" href="#ntp_002dwait-Invocation">ntp-wait Invocation</a>
<br>
</div>
<h4 class="subsection">0.1.7 ntp-wait Notes</h4>
</body></html>
|
