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22 <h1 class="settitle">update-leap User's Manual</h1>
25 <a name="Top"></a>Next: <a rel="next" accesskey="n" href="#update_002dleap-Description">update-leap Description</a>,
26 Previous: <a rel="previous" accesskey="p" href="#dir">(dir)</a>,
27 Up: <a rel="up" accesskey="u" href="#dir">(dir)</a>
31 <p>This document describes the use of the NTP Project's <code>update-leap</code> program.
33 <p>This document applies to version 4.2.8p12 of <code>update-leap</code>.
35 <div class="shortcontents">
36 <h2>Short Contents</h2>
42 <li><a accesskey="1" href="#update_002dleap-Description">update-leap Description</a>: Description
43 <li><a accesskey="2" href="#update_002dleap-Invocation">update-leap Invocation</a>: Invoking update-leap
48 <a name="update_002dleap-Invocation"></a>
52 <h3 class="section">0.1 Invoking update-leap</h3>
54 <p><a name="index-update_002dleap-1"></a><a name="index-leap_002dseconds-file-manager_002fupdater-2"></a>
56 <p><code>update-leap</code>
57 will validate the file currently on the local system
58 and if necessary, updates leap-second definition file.
60 <p>Ordinarily, the file is found using the "leapfile" directive in
61 <code>ntp.conf(5)</code>.
62 However, an alternate location can be specified on the command line.
64 <p>If the file does not exist, is not valid, has expired, or is expiring soon,
65 a new copy will be downloaded. If the new copy validates, it is installed and
66 NTP is (optionally) restarted.
68 <p>If the current file is acceptable, no download or restart occurs.
70 <p>-c can also be used to invoke another script to perform administrative
71 functions, e.g. to copy the file to other local systems.
73 This can be run as a cron job. As the file is rarely updated, and leap
74 seconds are announced at least one month in advance (usually longer), it
75 need not be run more frequently than about once every three weeks.
77 For cron-friendly behavior, define CRONJOB=1 in the crontab.
79 This script depends on$REQUIREDCMDS
81 <p>This section was generated by <strong>AutoGen</strong>,
82 using the <code>agtexi-cmd</code> template and the option descriptions for the <code>update-leap</code> program.
85 <li><a accesskey="1" href="#update_002dleap-usage">update-leap usage</a>: update-leap help/usage (<span class="option">--help</span>)
86 <li><a accesskey="2" href="#update_002dleap-source_002durl">update-leap source-url</a>: source-url option (-s)
87 <li><a accesskey="3" href="#update_002dleap-ipv4">update-leap ipv4</a>: ipv4 option (-4)
88 <li><a accesskey="4" href="#update_002dleap-destination">update-leap destination</a>: destination option (-d)
89 <li><a accesskey="5" href="#update_002dleap-expiration">update-leap expiration</a>: expiration option (-e)
90 <li><a accesskey="6" href="#update_002dleap-ntp_002dconf_002dfile">update-leap ntp-conf-file</a>: ntp-conf-file option (-f)
91 <li><a accesskey="7" href="#update_002dleap-force_002dupdate">update-leap force-update</a>: force-update option (-F)
92 <li><a accesskey="8" href="#update_002dleap-exit-status">update-leap exit status</a>: exit status
93 <li><a accesskey="9" href="#update_002dleap-Usage">update-leap Usage</a>: Usage
94 <li><a href="#update_002dleap-Authors">update-leap Authors</a>: Authors
99 <a name="update_002dleap-usage"></a>Next: <a rel="next" accesskey="n" href="#update_002dleap-source_002durl">update-leap source-url</a>,
100 Up: <a rel="up" accesskey="u" href="#update_002dleap-Invocation">update-leap Invocation</a>
104 <h4 class="subsection">0.1.1 update-leap help/usage (<span class="option">--help</span>)</h4>
106 <p><a name="index-update_002dleap-help-3"></a>
107 This is the automatically generated usage text for update-leap.
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.
117 <pre class="example">
118 Usage: update-leap [options]
120 Verifies and if necessary, updates leap-second definition file
122 All arguments are optional: Default (or current value) shown:
123 -C Absolute path to CA Cert (see SSL/TLS Considerations)
124 -D Path to a CAdir (see SSL/TLS Considerations)
125 -e Specify how long (in days) before expiration the file is to be
126 refreshed. Note that larger values imply more frequent refreshes.
128 -F Force update even if current file is OK and not close to expiring.
129 -f Absolute path ntp.conf file (default /etc/ntp.conf)
132 -i Specify number of minutes between retries
134 -L Absolute path to leapfile on the local system
135 (overrides value in ntp.conf)
136 -l Specify the syslog(3) facility for logging
138 -q Only report errors (cannot be used with -v)
139 -r Specify number of attempts to retrieve file
141 -s Send output to syslog(3) - implied if STDOUT has no tty or redirected
142 -t Send output to terminal - implied if STDOUT attached to terminal
143 -u Specify the URL of the master copy to download
144 https://www.ietf.org/timezones/data/leap-seconds.list
145 -v Verbose - show debug messages (cannot be used with -q)
147 The following options are not (yet) implemented in the perl version:
150 -c Command to restart NTP after installing a new file
151 <none> - ntpd checks file daily
153 Prefer IPv4 or IPv6 (as specified) addresses, but use either
155 update-leap will validate the file currently on the local system.
157 Ordinarily, the leapfile is found using the 'leapfile' directive in
158 /etc/ntp.conf. However, an alternate location can be specified on the
159 command line with the -L flag.
161 If the leapfile does not exist, is not valid, has expired, or is
162 expiring soon, a new copy will be downloaded. If the new copy is
163 valid, it is installed.
165 If the current file is acceptable, no download or restart occurs.
167 This can be run as a cron job. As the file is rarely updated, and
168 leap seconds are announced at least one month in advance (usually
169 longer), it need not be run more frequently than about once every
172 SSL/TLS Considerations
173 -----------------------
174 The perl modules can usually locate the CA certificate used to verify
177 On BSDs, the default is typically the file /etc/ssl/certs.pem. On
178 Linux, the location is typically a path to a CAdir - a directory of
179 symlinks named according to a hash of the certificates' subject names.
181 The -C or -D options are available to pass in a location if no CA cert
182 is found in the default location.
184 External Dependencies
185 ---------------------
186 The following perl modules are required:
187 HTTP::Tiny - version >= 0.056
188 IO::Socket::SSL - version >= 1.56
189 NET::SSLeay - version >= 1.49
195 <a name="update_002dleap-source_002durl"></a>Next: <a rel="next" accesskey="n" href="#update_002dleap-ipv4">update-leap ipv4</a>,
196 Previous: <a rel="previous" accesskey="p" href="#update_002dleap-usage">update-leap usage</a>,
197 Up: <a rel="up" accesskey="u" href="#update_002dleap-Invocation">update-leap Invocation</a>
201 <h4 class="subsection">0.1.2 source-url option (-s)</h4>
203 <p><a name="index-update_002dleap_002dsource_002durl-4"></a>
204 This is the “the url of the master copy of the leapseconds file” option.
205 This option takes a string argument.
206 Specify the URL of the master copy to download
210 <a name="update_002dleap-ipv4"></a>Next: <a rel="next" accesskey="n" href="#update_002dleap-destination">update-leap destination</a>,
211 Previous: <a rel="previous" accesskey="p" href="#update_002dleap-source_002durl">update-leap source-url</a>,
212 Up: <a rel="up" accesskey="u" href="#update_002dleap-Invocation">update-leap Invocation</a>
216 <h4 class="subsection">0.1.3 ipv4 option (-4)</h4>
218 <p><a name="index-update_002dleap_002dipv4-5"></a>
219 This is the “use only ipv4 addresses for dns name resolution” option.
221 <p class="noindent">This option has some usage constraints. It:
223 <li>must not appear in combination with any of the following options:
227 <p>Force DNS resolution of following host names on the command line
228 to the IPv4 namespace.
234 flags-cant = ipv4, prefer;
236 descrip = "Use only IPv6 addresses for DNS name resolution";
237 doc = <<- _EndOfDoc_
238 Force DNS resolution of following host names on the command line
239 to the IPv6 namespace.
245 flags-cant = ipv4, ipv6;
249 descrip = 'Prefer IPv4 or IPv6 (as specified) addresses, but use either';
250 doc = <<- _EndOfDoc_
251 Prefer IPv4 or IPv6 (as specified) addresses, but use either.
254 <a name="update_002dleap-destination"></a>Next: <a rel="next" accesskey="n" href="#update_002dleap-expiration">update-leap expiration</a>,
255 Previous: <a rel="previous" accesskey="p" href="#update_002dleap-ipv4">update-leap ipv4</a>,
256 Up: <a rel="up" accesskey="u" href="#update_002dleap-Invocation">update-leap Invocation</a>
260 <h4 class="subsection">0.1.4 destination option (-d)</h4>
262 <p><a name="index-update_002dleap_002ddestination-6"></a>
263 This is the “filename on the local system” option.
264 This option takes a string argument <span class="file">float</span>.
265 The name to use to store the leapfile on the local system.
269 <a name="update_002dleap-expiration"></a>Next: <a rel="next" accesskey="n" href="#update_002dleap-ntp_002dconf_002dfile">update-leap ntp-conf-file</a>,
270 Previous: <a rel="previous" accesskey="p" href="#update_002dleap-destination">update-leap destination</a>,
271 Up: <a rel="up" accesskey="u" href="#update_002dleap-Invocation">update-leap Invocation</a>
275 <h4 class="subsection">0.1.5 expiration option (-e)</h4>
277 <p><a name="index-update_002dleap_002dexpiration-7"></a>
278 This is the “refresh the leapfile this long before it expires” option.
279 This option takes a string argument.
280 Specify how long before expiration the file is to be refreshed
281 Units are required, e.g. "-e 60 days" Note that larger values
282 imply more frequent refreshes.
286 <a name="update_002dleap-ntp_002dconf_002dfile"></a>Next: <a rel="next" accesskey="n" href="#update_002dleap-force_002dupdate">update-leap force-update</a>,
287 Previous: <a rel="previous" accesskey="p" href="#update_002dleap-expiration">update-leap expiration</a>,
288 Up: <a rel="up" accesskey="u" href="#update_002dleap-Invocation">update-leap Invocation</a>
292 <h4 class="subsection">0.1.6 ntp-conf-file option (-f)</h4>
294 <p><a name="index-update_002dleap_002dntp_002dconf_002dfile-8"></a>
295 This is the “location of the ntp.conf file” option.
296 This option takes a string argument.
297 Specify location of ntp.conf (used to make sure leapfile directive is
298 present and to default leapfile)
302 <a name="update_002dleap-force_002dupdate"></a>Next: <a rel="next" accesskey="n" href="#update_002dleap-exit-status">update-leap exit status</a>,
303 Previous: <a rel="previous" accesskey="p" href="#update_002dleap-ntp_002dconf_002dfile">update-leap ntp-conf-file</a>,
304 Up: <a rel="up" accesskey="u" href="#update_002dleap-Invocation">update-leap Invocation</a>
308 <h4 class="subsection">0.1.7 force-update option (-F)</h4>
310 <p><a name="index-update_002dleap_002dforce_002dupdate-9"></a>
311 This is the “force update of the leapfile” option.
312 Force update even if current file is OK and not close to expiring.
315 <a name="update_002dleap-exit-status"></a>Next: <a rel="next" accesskey="n" href="#update_002dleap-Usage">update-leap Usage</a>,
316 Previous: <a rel="previous" accesskey="p" href="#update_002dleap-force_002dupdate">update-leap force-update</a>,
317 Up: <a rel="up" accesskey="u" href="#update_002dleap-Invocation">update-leap Invocation</a>
321 <h4 class="subsection">0.1.8 update-leap exit status</h4>
323 <p>One of the following exit values will be returned:
325 <dt><span class="samp">0 (EXIT_SUCCESS)</span><dd>Successful program execution.
326 <br><dt><span class="samp">1 (EXIT_FAILURE)</span><dd>The operation failed or the command syntax was not valid.
330 <a name="update_002dleap-Usage"></a>Next: <a rel="next" accesskey="n" href="#update_002dleap-Authors">update-leap Authors</a>,
331 Previous: <a rel="previous" accesskey="p" href="#update_002dleap-exit-status">update-leap exit status</a>,
332 Up: <a rel="up" accesskey="u" href="#update_002dleap-Invocation">update-leap Invocation</a>
336 <h4 class="subsection">0.1.9 update-leap Usage</h4>
340 <a name="update_002dleap-Authors"></a>Previous: <a rel="previous" accesskey="p" href="#update_002dleap-Usage">update-leap Usage</a>,
341 Up: <a rel="up" accesskey="u" href="#update_002dleap-Invocation">update-leap Invocation</a>
345 <h4 class="subsection">0.1.10 update-leap Authors</h4>