update-leap(1update-leapman) User Commands update-leap(1update-leapman)

update-leap - leap-seconds file manager/updater

update-leap [-flags] [-flag [value]] [--option-name[[=| ]value]]

All arguments must be options.

update-leap will validate the file currently on the local system and if necessary, updates leap-second definition file.

Ordinarily, the file is found using the "leapfile" directive in ntp.conf(5). However, an alternate location can be specified on the command line.

If the file does not exist, is not valid, has expired, or is expiring soon, a new copy will be downloaded. If the new copy validates, it is installed and NTP is (optionally) restarted.

If the current file is acceptable, no download or restart occurs.

-c can also be used to invoke another script to perform administrative functions, e.g. to copy the file to other local systems.

This can be run as a cron job. As the file is rarely updated, and leap seconds are announced at least one month in advance (usually longer), it need not be run more frequently than about once every three weeks.

For cron-friendly behavior, define CRONJOB=1 in the crontab.

This script depends on$REQUIREDCMDS


The URL of the master copy of the leapseconds file.

Specify the URL of the master copy to download $LEAPSRC

-4, --ipv4

Use only IPv4 addresses for DNS name resolution. This option must not appear in combination with any of the following options: ipv6.


Force DNS resolution of following host names on the command line
to the IPv4 namespace.
_EndOfDoc_; };

flag = {
name = ipv6;
flags-cant = ipv4, prefer;
value = 6;
descrip = "Use only IPv6 addresses for DNS name resolution";
doc = <<- _EndOfDoc_
Force DNS resolution of following host names on the command line
to the IPv6 namespace.
_EndOfDoc_; };

flag = {
name = prefer;
flags-cant = ipv4, ipv6;
value = p;
arg-type = keyword;
keyword = 4, 6;
descrip = 'Prefer IPv4 or IPv6 (as specified) addresses, but use either';
doc = <<- _EndOfDoc_ Prefer IPv4 or IPv6 (as specified) addresses, but use either.


Filename on the local system.

The name to use to store the leapfile on the local system. $LEAPFILE


Refresh the leapfile this long before it expires.

Specify how long before expiration the file is to be refreshed Units are required, e.g. "-e 60 days" Note that larger values imply more frequent refreshes. "$PREFETCH"


Location of the ntp.conf file.

Specify location of ntp.conf (used to make sure leapfile directive is present and to default leapfile) /etc/ntp.conf


Force update of the leapfile.

Force update even if current file is OK and not close to expiring.


Don't wait for keystroke between plots.
-?, --help

Display usage information and exit.
-!, --more-help

Pass the extended usage information through a pager.

Output version of program and exit. The default mode is `v', a simple version. The `c' mode will print copyright information and `n' will print the full copyright notice.

Usage stuff

One of the following exit values will be returned:

0 (EXIT_SUCCESS)

Successful program execution.
1 (EXIT_FAILURE)

The operation failed or the command syntax was not valid.
70 (EX_SOFTWARE)

libopts had an internal operational error. Please report it to autogen-users@lists.sourceforge.net. Thank you.

Timothe Litt

This manual page was AutoGen-erated from the update-leap option definitions.

06 Jun 2023 ntp (4.2.8p17)