89 lines
2.4 KiB
Plaintext
89 lines
2.4 KiB
Plaintext
\input texinfo @c -*-texinfo-*-
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@c %**start of header
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@setfilename ntpdc.info
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@settitle ntpdc: NTPD Control User's Manual
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@include ../sntp/include/version.texi
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@paragraphindent 2
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@c %**end of header
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@ifinfo
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This file documents the use of the NTP Project's ntpdc, a program for
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controlling ntpd.
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@end ifinfo
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@direntry
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* ntpdc: (ntpdc). ntpd Control program
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@end direntry
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@titlepage
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@title ntpdc: NTPD Control User's Manual
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@subtitle ntpdc, version @value{VERSION}, @value{UPDATED}
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@c @author Max @email{foo@ntp.org}
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@end titlepage
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@c @page
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@c @vskip 0pt plus 1filll
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@node Top, ntpdc Description, (dir), (dir)
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@top ntpdc: NTPD Control User Manual
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This document describes the use of the NTP Project's @code{ntpdc} program,
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that can be used to query a Network Time Protocol (NTP) server and
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display the time offset of the system clock relative to the server
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clock. Run as root, it can correct the system clock to this offset as
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well. It can be run as an interactive command or from a cron job.
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This document applies to version @value{VERSION} of @code{ntpdc}.
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The program implements the SNTP protocol as defined by RFC 5905, the NTPv4
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IETF specification.
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@shortcontents
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@menu
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* ntpdc Description:: Description
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* ntpdc Invocation:: Invoking ntpdc
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* Usage:: Usage
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@end menu
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@node ntpdc Description
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@comment node-name, next, previous, up
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@section Description
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By default, @code{ntpdc} writes the local data and time (i.e., not UTC) to the
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standard output in the format:
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@example
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1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 secs
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@end example
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where
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YYYY-MM-DD HH:MM:SS.SUBSEC is the local date and time,
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(+0800) is the local timezone adjustment (so we would add 8 hours and 0 minutes to convert the reported local time to UTC),
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and
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the +4.567 +/- 0.089 secs indicates the time offset and
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error bound of the system clock relative to the server clock.
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@include invoke-ntpdc.texi
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@node Usage
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@comment node-name, next, previous, up
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@section Usage
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The simplest use of this program is as an unprivileged command to
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check the current time, offset, and error in the local clock.
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For example:
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@example
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ntpdc ntpserver.somewhere
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@end example
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With suitable privilege, it can be run as a command or in a
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@code{cron} job to reset the local clock from a reliable server, like
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the @code{ntpdate} and @code{rdate} commands.
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For example:
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@example
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ntpdc -a ntpserver.somewhere
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@end example
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