1 <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
3 <!-- Created by GNU Texinfo 6.5, http://www.gnu.org/software/texinfo/ -->
5 <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
6 <title>ntpdc: NTPD Control User’s Manual</title>
8 <meta name="description" content="ntpdc: NTPD Control User’s Manual">
9 <meta name="keywords" content="ntpdc: NTPD Control User’s Manual">
10 <meta name="resource-type" content="document">
11 <meta name="distribution" content="global">
12 <meta name="Generator" content="makeinfo">
13 <link href="#Top" rel="start" title="Top">
14 <link href="dir.html#Top" rel="up" title="(dir)">
15 <style type="text/css">
17 a.summary-letter {text-decoration: none}
18 blockquote.indentedblock {margin-right: 0em}
19 blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
20 blockquote.smallquotation {font-size: smaller}
21 div.display {margin-left: 3.2em}
22 div.example {margin-left: 3.2em}
23 div.lisp {margin-left: 3.2em}
24 div.smalldisplay {margin-left: 3.2em}
25 div.smallexample {margin-left: 3.2em}
26 div.smalllisp {margin-left: 3.2em}
27 kbd {font-style: oblique}
28 pre.display {font-family: inherit}
29 pre.format {font-family: inherit}
30 pre.menu-comment {font-family: serif}
31 pre.menu-preformatted {font-family: serif}
32 pre.smalldisplay {font-family: inherit; font-size: smaller}
33 pre.smallexample {font-size: smaller}
34 pre.smallformat {font-family: inherit; font-size: smaller}
35 pre.smalllisp {font-size: smaller}
36 span.nolinebreak {white-space: nowrap}
37 span.roman {font-family: initial; font-weight: normal}
38 span.sansserif {font-family: sans-serif; font-weight: normal}
39 ul.no-bullet {list-style: none}
47 <h1 class="settitle" align="center">ntpdc: NTPD Control User’s Manual</h1>
56 Next: <a href="#ntpdc-Description" accesskey="n" rel="next">ntpdc Description</a>, Previous: <a href="dir.html#Top" accesskey="p" rel="prev">(dir)</a>, Up: <a href="dir.html#Top" accesskey="u" rel="up">(dir)</a> </p>
58 <a name="ntpdc_003a-NTPD-Control-User-Manual"></a>
59 <h1 class="top">ntpdc: NTPD Control User Manual</h1>
61 <p>This document describes the use of the NTP Project’s <code>ntpdc</code> program,
62 that can be used to query a Network Time Protocol (NTP) server and
63 display the time offset of the system clock relative to the server
64 clock. Run as root, it can correct the system clock to this offset as
65 well. It can be run as an interactive command or from a cron job.
67 <p>This document applies to version 4.2.8p15 of <code>ntpdc</code>.
69 <p>The program implements the SNTP protocol as defined by RFC 5905, the NTPv4
72 <a name="SEC_Overview"></a>
73 <h2 class="shortcontents-heading">Short Table of Contents</h2>
75 <div class="shortcontents">
76 <ul class="no-bullet">
77 <li><a name="stoc-Description" href="#toc-Description">1 Description</a></li>
82 <table class="menu" border="0" cellspacing="0">
83 <tr><td align="left" valign="top">• <a href="#ntpdc-Description" accesskey="1">ntpdc Description</a>:</td><td> </td><td align="left" valign="top">Description
85 <tr><td align="left" valign="top">• <a href="#ntpdc-Invocation" accesskey="2">ntpdc Invocation</a>:</td><td> </td><td align="left" valign="top">Invoking ntpdc
87 <tr><td align="left" valign="top">• <a href="#Usage" accesskey="3">Usage</a>:</td><td> </td><td align="left" valign="top">Usage
92 <a name="ntpdc-Description"></a>
95 Next: <a href="#ntpdc-Invocation" accesskey="n" rel="next">ntpdc Invocation</a>, Up: <a href="#Top" accesskey="u" rel="up">Top</a> </p>
97 <a name="Description"></a>
98 <h2 class="chapter">1 Description</h2>
100 <p>By default, <code>ntpdc</code> writes the local data and time (i.e., not UTC) to the
101 standard output in the format:
103 <div class="example">
104 <pre class="example">1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 secs
108 YYYY-MM-DD HH:MM:SS.SUBSEC is the local date and time,
109 (+0800) is the local timezone adjustment (so we would add 8 hours and 0 minutes to convert the reported local time to UTC),
111 the +4.567 +/- 0.089 secs indicates the time offset and
112 error bound of the system clock relative to the server clock.
114 <table class="menu" border="0" cellspacing="0">
115 <tr><td align="left" valign="top">• <a href="#ntpdc-Invocation" accesskey="1">ntpdc Invocation</a>:</td><td> </td><td align="left" valign="top">
117 <tr><td align="left" valign="top">• <a href="#Usage" accesskey="2">Usage</a>:</td><td> </td><td align="left" valign="top">
122 <a name="ntpdc-Invocation"></a>
125 Next: <a href="#Usage" accesskey="n" rel="next">Usage</a>, Previous: <a href="#ntpdc-Description" accesskey="p" rel="prev">ntpdc Description</a>, Up: <a href="#ntpdc-Description" accesskey="u" rel="up">ntpdc Description</a> </p>
127 <a name="Invoking-ntpdc"></a>
128 <h3 class="section">1.1 Invoking ntpdc</h3>
129 <a name="index-ntpdc"></a>
130 <a name="index-vendor_002dspecific-NTPD-control-program"></a>
134 <p><code>ntpdc</code>
137 <code>ntpq(1ntpqmdoc)</code> instead - it can do everything
139 used to do, and it does so using a much more sane interface.
141 <p><code>ntpdc</code>
142 is a utility program used to query
143 <code>ntpd(1ntpdmdoc)</code>
145 current state and to request changes in that state.
146 It uses NTP mode 7 control message formats described in the source code.
148 be run either in interactive mode or controlled using command line
150 Extensive state and statistics information is available
154 In addition, nearly all the
155 configuration options which can be specified at startup using
156 ntpd’s configuration file may also be specified at run time using
159 <p>This section was generated by <strong>AutoGen</strong>,
160 using the <code>agtexi-cmd</code> template and the option descriptions for the <code>ntpdc</code> program.
161 This software is released under the NTP license, <http://ntp.org/license>.
163 <table class="menu" border="0" cellspacing="0">
164 <tr><td align="left" valign="top">• <a href="#ntpdc-usage" accesskey="1">ntpdc usage</a>:</td><td> </td><td align="left" valign="top">ntpdc help/usage (<samp>--help</samp>)
166 <tr><td align="left" valign="top">• <a href="#ntpdc-ipv4" accesskey="2">ntpdc ipv4</a>:</td><td> </td><td align="left" valign="top">ipv4 option (-4)
168 <tr><td align="left" valign="top">• <a href="#ntpdc-ipv6" accesskey="3">ntpdc ipv6</a>:</td><td> </td><td align="left" valign="top">ipv6 option (-6)
170 <tr><td align="left" valign="top">• <a href="#ntpdc-command" accesskey="4">ntpdc command</a>:</td><td> </td><td align="left" valign="top">command option (-c)
172 <tr><td align="left" valign="top">• <a href="#ntpdc-interactive" accesskey="5">ntpdc interactive</a>:</td><td> </td><td align="left" valign="top">interactive option (-i)
174 <tr><td align="left" valign="top">• <a href="#ntpdc-listpeers" accesskey="6">ntpdc listpeers</a>:</td><td> </td><td align="left" valign="top">listpeers option (-l)
176 <tr><td align="left" valign="top">• <a href="#ntpdc-numeric" accesskey="7">ntpdc numeric</a>:</td><td> </td><td align="left" valign="top">numeric option (-n)
178 <tr><td align="left" valign="top">• <a href="#ntpdc-peers" accesskey="8">ntpdc peers</a>:</td><td> </td><td align="left" valign="top">peers option (-p)
180 <tr><td align="left" valign="top">• <a href="#ntpdc-showpeers" accesskey="9">ntpdc showpeers</a>:</td><td> </td><td align="left" valign="top">showpeers option (-s)
182 <tr><td align="left" valign="top">• <a href="#ntpdc-config">ntpdc config</a>:</td><td> </td><td align="left" valign="top">presetting/configuring ntpdc
184 <tr><td align="left" valign="top">• <a href="#ntpdc-exit-status">ntpdc exit status</a>:</td><td> </td><td align="left" valign="top">exit status
186 <tr><td align="left" valign="top">• <a href="#ntpdc-Usage">ntpdc Usage</a>:</td><td> </td><td align="left" valign="top">Usage
188 <tr><td align="left" valign="top">• <a href="#ntpdc-See-Also">ntpdc See Also</a>:</td><td> </td><td align="left" valign="top">See Also
190 <tr><td align="left" valign="top">• <a href="#ntpdc-Authors">ntpdc Authors</a>:</td><td> </td><td align="left" valign="top">Authors
192 <tr><td align="left" valign="top">• <a href="#ntpdc-Bugs">ntpdc Bugs</a>:</td><td> </td><td align="left" valign="top">Bugs
197 <a name="ntpdc-usage"></a>
200 Next: <a href="#ntpdc-ipv4" accesskey="n" rel="next">ntpdc ipv4</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
202 <a name="ntpdc-help_002fusage-_0028_002d_002dhelp_0029"></a>
203 <h4 class="subsection">1.1.1 ntpdc help/usage (<samp>--help</samp>)</h4>
204 <a name="index-ntpdc-help"></a>
206 <p>This is the automatically generated usage text for ntpdc.
208 <p>The text printed is the same whether selected with the <code>help</code> option
209 (<samp>--help</samp>) or the <code>more-help</code> option (<samp>--more-help</samp>). <code>more-help</code> will print
210 the usage text by passing it through a pager program.
211 <code>more-help</code> is disabled on platforms without a working
212 <code>fork(2)</code> function. The <code>PAGER</code> environment variable is
213 used to select the program, defaulting to <samp>more</samp>. Both will exit
214 with a status code of 0.
216 <div class="example">
217 <pre class="example">ntpdc - vendor-specific NTPD control program - Ver. 4.2.8p15
218 Usage: ntpdc [ -<flag> [<val>] | --<name>[{=| }<val>] ]... [ host ...]
219 Flg Arg Option-Name Description
220 -4 no ipv4 Force IPv4 DNS name resolution
221 - prohibits the option 'ipv6'
222 -6 no ipv6 Force IPv6 DNS name resolution
223 - prohibits the option 'ipv4'
224 -c Str command run a command and exit
225 - may appear multiple times
226 -d no debug-level Increase debug verbosity level
227 - may appear multiple times
228 -D Num set-debug-level Set the debug verbosity level
229 - may appear multiple times
230 -i no interactive Force ntpq to operate in interactive mode
231 - prohibits these options:
236 -l no listpeers Print a list of the peers
237 - prohibits the option 'command'
238 -n no numeric numeric host addresses
239 -p no peers Print a list of the peers
240 - prohibits the option 'command'
241 -s no showpeers Show a list of the peers
242 - prohibits the option 'command'
243 opt version output version information and exit
244 -? no help display extended usage information and exit
245 -! no more-help extended usage information passed thru pager
246 -> opt save-opts save the option state to a config file
247 -< Str load-opts load options from a config file
248 - disabled as '--no-load-opts'
249 - may appear multiple times
251 Options are specified by doubled hyphens and their name or by a single
252 hyphen and the flag character.
255 The following option preset mechanisms are supported:
256 - reading file $HOME/.ntprc
257 - reading file ./.ntprc
258 - examining environment variables named NTPDC_*
260 Please send bug reports to: <http://bugs.ntp.org, bugs@ntp.org>
264 <a name="ntpdc-ipv4"></a>
267 Next: <a href="#ntpdc-ipv6" accesskey="n" rel="next">ntpdc ipv6</a>, Previous: <a href="#ntpdc-usage" accesskey="p" rel="prev">ntpdc usage</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
269 <a name="ipv4-option-_0028_002d4_0029"></a>
270 <h4 class="subsection">1.1.2 ipv4 option (-4)</h4>
271 <a name="index-ntpdc_002dipv4"></a>
273 <p>This is the “force ipv4 dns name resolution” option.
275 <p>This option has some usage constraints. It:
277 <li> must not appear in combination with any of the following options:
281 <p>Force DNS resolution of following host names on the command line
282 to the IPv4 namespace.
284 <a name="ntpdc-ipv6"></a>
287 Next: <a href="#ntpdc-command" accesskey="n" rel="next">ntpdc command</a>, Previous: <a href="#ntpdc-ipv4" accesskey="p" rel="prev">ntpdc ipv4</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
289 <a name="ipv6-option-_0028_002d6_0029"></a>
290 <h4 class="subsection">1.1.3 ipv6 option (-6)</h4>
291 <a name="index-ntpdc_002dipv6"></a>
293 <p>This is the “force ipv6 dns name resolution” option.
295 <p>This option has some usage constraints. It:
297 <li> must not appear in combination with any of the following options:
301 <p>Force DNS resolution of following host names on the command line
302 to the IPv6 namespace.
304 <a name="ntpdc-command"></a>
307 Next: <a href="#ntpdc-interactive" accesskey="n" rel="next">ntpdc interactive</a>, Previous: <a href="#ntpdc-ipv6" accesskey="p" rel="prev">ntpdc ipv6</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
309 <a name="command-option-_0028_002dc_0029"></a>
310 <h4 class="subsection">1.1.4 command option (-c)</h4>
311 <a name="index-ntpdc_002dcommand"></a>
313 <p>This is the “run a command and exit” option.
314 This option takes a string argument <samp>cmd</samp>.
316 <p>This option has some usage constraints. It:
318 <li> may appear an unlimited number of times.
321 <p>The following argument is interpreted as an interactive format command
322 and is added to the list of commands to be executed on the specified
325 <a name="ntpdc-interactive"></a>
328 Next: <a href="#ntpdc-listpeers" accesskey="n" rel="next">ntpdc listpeers</a>, Previous: <a href="#ntpdc-command" accesskey="p" rel="prev">ntpdc command</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
330 <a name="interactive-option-_0028_002di_0029"></a>
331 <h4 class="subsection">1.1.5 interactive option (-i)</h4>
332 <a name="index-ntpdc_002dinteractive"></a>
334 <p>This is the “force ntpq to operate in interactive mode” option.
336 <p>This option has some usage constraints. It:
338 <li> must not appear in combination with any of the following options:
339 command, listpeers, peers, showpeers.
342 <p>Force ntpq to operate in interactive mode. Prompts will be written
343 to the standard output and commands read from the standard input.
345 <a name="ntpdc-listpeers"></a>
348 Next: <a href="#ntpdc-numeric" accesskey="n" rel="next">ntpdc numeric</a>, Previous: <a href="#ntpdc-interactive" accesskey="p" rel="prev">ntpdc interactive</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
350 <a name="listpeers-option-_0028_002dl_0029"></a>
351 <h4 class="subsection">1.1.6 listpeers option (-l)</h4>
352 <a name="index-ntpdc_002dlistpeers"></a>
354 <p>This is the “print a list of the peers” option.
356 <p>This option has some usage constraints. It:
358 <li> must not appear in combination with any of the following options:
362 <p>Print a list of the peers known to the server as well as a summary of
363 their state. This is equivalent to the ’listpeers’ interactive command.
365 <a name="ntpdc-numeric"></a>
368 Next: <a href="#ntpdc-peers" accesskey="n" rel="next">ntpdc peers</a>, Previous: <a href="#ntpdc-listpeers" accesskey="p" rel="prev">ntpdc listpeers</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
370 <a name="numeric-option-_0028_002dn_0029"></a>
371 <h4 class="subsection">1.1.7 numeric option (-n)</h4>
372 <a name="index-ntpdc_002dnumeric"></a>
374 <p>This is the “numeric host addresses” option.
375 Output all host addresses in dotted-quad numeric format rather than
376 converting to the canonical host names.
378 <a name="ntpdc-peers"></a>
381 Next: <a href="#ntpdc-showpeers" accesskey="n" rel="next">ntpdc showpeers</a>, Previous: <a href="#ntpdc-numeric" accesskey="p" rel="prev">ntpdc numeric</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
383 <a name="peers-option-_0028_002dp_0029"></a>
384 <h4 class="subsection">1.1.8 peers option (-p)</h4>
385 <a name="index-ntpdc_002dpeers"></a>
387 <p>This is the “print a list of the peers” option.
389 <p>This option has some usage constraints. It:
391 <li> must not appear in combination with any of the following options:
395 <p>Print a list of the peers known to the server as well as a summary
396 of their state. This is equivalent to the ’peers’ interactive command.
398 <a name="ntpdc-showpeers"></a>
401 Next: <a href="#ntpdc-config" accesskey="n" rel="next">ntpdc config</a>, Previous: <a href="#ntpdc-peers" accesskey="p" rel="prev">ntpdc peers</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
403 <a name="showpeers-option-_0028_002ds_0029"></a>
404 <h4 class="subsection">1.1.9 showpeers option (-s)</h4>
405 <a name="index-ntpdc_002dshowpeers"></a>
407 <p>This is the “show a list of the peers” option.
409 <p>This option has some usage constraints. It:
411 <li> must not appear in combination with any of the following options:
415 <p>Print a list of the peers known to the server as well as a summary
416 of their state. This is equivalent to the ’dmpeers’ interactive command.
420 <a name="ntpdc-config"></a>
423 Next: <a href="#ntpdc-exit-status" accesskey="n" rel="next">ntpdc exit status</a>, Previous: <a href="#ntpdc-showpeers" accesskey="p" rel="prev">ntpdc showpeers</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
425 <a name="presetting_002fconfiguring-ntpdc"></a>
426 <h4 class="subsection">1.1.10 presetting/configuring ntpdc</h4>
428 <p>Any option that is not marked as <i>not presettable</i> may be preset by
429 loading values from configuration ("rc" or "ini") files, and values from environment variables named <code>NTPDC</code> and <code>NTPDC_<OPTION_NAME></code>. <code><OPTION_NAME></code> must be one of
430 the options listed above in upper case and segmented with underscores.
431 The <code>NTPDC</code> variable will be tokenized and parsed like
432 the command line. The remaining variables are tested for existence and their
433 values are treated like option arguments.
436 <p><code>libopts</code> will search in 2 places for configuration files:
441 <p>The environment variables <code>HOME</code>, and <code>PWD</code>
442 are expanded and replaced when <samp>ntpdc</samp> runs.
443 For any of these that are plain files, they are simply processed.
444 For any that are directories, then a file named <samp>.ntprc</samp> is searched for
445 within that directory and processed.
447 <p>Configuration files may be in a wide variety of formats.
448 The basic format is an option name followed by a value (argument) on the
449 same line. Values may be separated from the option name with a colon,
450 equal sign or simply white space. Values may be continued across multiple
451 lines by escaping the newline with a backslash.
453 <p>Multiple programs may also share the same initialization file.
454 Common options are collected at the top, followed by program specific
455 segments. The segments are separated by lines like:
456 </p><div class="example">
457 <pre class="example">[NTPDC]
460 </p><div class="example">
461 <pre class="example"><?program ntpdc>
463 <p>Do not mix these styles within one configuration file.
465 <p>Compound values and carefully constructed string values may also be
466 specified using XML syntax:
467 </p><div class="example">
468 <pre class="example"><option-name>
469 <sub-opt>...&lt;...&gt;...</sub-opt>
472 <p>yielding an <code>option-name.sub-opt</code> string value of
473 </p><div class="example">
474 <pre class="example">"...<...>..."
476 <p><code>AutoOpts</code> does not track suboptions. You simply note that it is a
477 hierarchicly valued option. <code>AutoOpts</code> does provide a means for searching
478 the associated name/value pair list (see: optionFindValue).
480 <p>The command line options relating to configuration and/or usage help are:
482 <a name="version-_0028_002d_0029"></a>
483 <h4 class="subsubheading">version (-)</h4>
485 <p>Print the program version to standard out, optionally with licensing
486 information, then exit 0. The optional argument specifies how much licensing
487 detail to provide. The default is to print just the version. The licensing infomation may be selected with an option argument.
488 Only the first letter of the argument is examined:
490 <dl compact="compact">
491 <dt>‘<samp>version</samp>’</dt>
492 <dd><p>Only print the version. This is the default.
494 <dt>‘<samp>copyright</samp>’</dt>
495 <dd><p>Name the copyright usage licensing terms.
497 <dt>‘<samp>verbose</samp>’</dt>
498 <dd><p>Print the full copyright usage licensing terms.
503 <a name="ntpdc-exit-status"></a>
506 Next: <a href="#ntpdc-Usage" accesskey="n" rel="next">ntpdc Usage</a>, Previous: <a href="#ntpdc-config" accesskey="p" rel="prev">ntpdc config</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
508 <a name="ntpdc-exit-status-1"></a>
509 <h4 class="subsection">1.1.11 ntpdc exit status</h4>
511 <p>One of the following exit values will be returned:
512 </p><dl compact="compact">
513 <dt>‘<samp>0 (EXIT_SUCCESS)</samp>’</dt>
514 <dd><p>Successful program execution.
516 <dt>‘<samp>1 (EXIT_FAILURE)</samp>’</dt>
517 <dd><p>The operation failed or the command syntax was not valid.
519 <dt>‘<samp>66 (EX_NOINPUT)</samp>’</dt>
520 <dd><p>A specified configuration file could not be loaded.
522 <dt>‘<samp>70 (EX_SOFTWARE)</samp>’</dt>
523 <dd><p>libopts had an internal operational error. Please report
524 it to autogen-users@lists.sourceforge.net. Thank you.
528 <a name="ntpdc-Usage"></a>
531 Next: <a href="#ntpdc-See-Also" accesskey="n" rel="next">ntpdc See Also</a>, Previous: <a href="#ntpdc-exit-status" accesskey="p" rel="prev">ntpdc exit status</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
533 <a name="ntpdc-Usage-1"></a>
534 <h4 class="subsection">1.1.12 ntpdc Usage</h4>
536 <a name="ntpdc-See-Also"></a>
539 Next: <a href="#ntpdc-Authors" accesskey="n" rel="next">ntpdc Authors</a>, Previous: <a href="#ntpdc-Usage" accesskey="p" rel="prev">ntpdc Usage</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
541 <a name="ntpdc-See-Also-1"></a>
542 <h4 class="subsection">1.1.13 ntpdc See Also</h4>
544 <a name="ntpdc-Authors"></a>
547 Next: <a href="#ntpdc-Bugs" accesskey="n" rel="next">ntpdc Bugs</a>, Previous: <a href="#ntpdc-See-Also" accesskey="p" rel="prev">ntpdc See Also</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
549 <a name="ntpdc-Authors-1"></a>
550 <h4 class="subsection">1.1.14 ntpdc Authors</h4>
552 <a name="ntpdc-Bugs"></a>
555 Previous: <a href="#ntpdc-Authors" accesskey="p" rel="prev">ntpdc Authors</a>, Up: <a href="#ntpdc-Invocation" accesskey="u" rel="up">ntpdc Invocation</a> </p>
557 <a name="ntpdc-Bugs-1"></a>
558 <h4 class="subsection">1.1.15 ntpdc Bugs</h4>
564 Previous: <a href="#ntpdc-Invocation" accesskey="p" rel="prev">ntpdc Invocation</a>, Up: <a href="#ntpdc-Description" accesskey="u" rel="up">ntpdc Description</a> </p>
566 <a name="Usage-1"></a>
567 <h3 class="section">1.2 Usage</h3>
569 <p>The simplest use of this program is as an unprivileged command to
570 check the current time, offset, and error in the local clock.
573 <div class="example">
574 <pre class="example">ntpdc ntpserver.somewhere
577 <p>With suitable privilege, it can be run as a command or in a
578 <code>cron</code> job to reset the local clock from a reliable server, like
579 the <code>ntpdate</code> and <code>rdate</code> commands.
582 <div class="example">
583 <pre class="example">ntpdc -a ntpserver.somewhere