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      1 \input texinfo    @c -*-texinfo-*-
      2 @c %**start of header
      3 @setfilename ntpdc.info
      4 @settitle ntpdc: NTPD Control User's Manual
      5 @include ../sntp/include/version.texi
      6 @paragraphindent 2
      7 @c %**end of header
      8 
      9 @ifinfo
     10 This file documents the use of the NTP Project's ntpdc, a program for
     11 controlling ntpd.
     12 @end ifinfo
     13 
     14 @direntry
     15 * ntpdc: (ntpdc).                               ntpd Control program
     16 @end direntry
     17 
     18 @titlepage
     19 @title ntpdc: NTPD Control User's Manual
     20 @subtitle ntpdc, version @value{VERSION}, @value{UPDATED}
     21 @c @author Max @email{foo (a] ntp.org}
     22 @end titlepage
     23 
     24 @c @page
     25 @c @vskip 0pt plus 1filll
     26 
     27 @node Top, ntpdc Description, (dir), (dir)
     28 @top ntpdc: NTPD Control User Manual
     29 
     30 This document describes the use of the NTP Project's @code{ntpdc} program,
     31 that can be used to query a Network Time Protocol (NTP) server and
     32 display the time offset of the system clock relative to the server
     33 clock.  Run as root, it can correct the system clock to this offset as
     34 well.  It can be run as an interactive command or from a cron job.
     35 
     36 This document applies to version @value{VERSION} of @code{ntpdc}.
     37 
     38 The program implements the SNTP protocol as defined by RFC 5905, the NTPv4
     39 IETF specification.
     40 
     41 @shortcontents
     42 
     43 @menu
     44 * ntpdc Description::            Description
     45 * ntpdc Invocation::		Invoking ntpdc
     46 * Usage::                       Usage
     47 @end menu
     48 
     49 @node ntpdc Description
     50 @comment  node-name,  next,  previous,  up
     51 @section Description
     52 
     53 By default, @code{ntpdc} writes the local data and time (i.e., not UTC) to the
     54 standard output in the format:
     55 
     56 @example
     57 1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 secs
     58 @end example
     59 
     60 where
     61 YYYY-MM-DD HH:MM:SS.SUBSEC is the local date and time,
     62 (+0800) is the local timezone adjustment (so we would add 8 hours and 0 minutes to convert the reported local time to UTC),
     63 and
     64 the +4.567 +/- 0.089 secs indicates the time offset and
     65 error bound of the system clock relative to the server clock.
     66 
     67 @include invoke-ntpdc.texi
     68 
     69 @node Usage
     70 @comment  node-name,  next,  previous,  up
     71 @section Usage
     72 
     73 The simplest use of this program is as an unprivileged command to
     74 check the current time, offset, and error in the local clock.
     75 For example:
     76 
     77 @example
     78 ntpdc ntpserver.somewhere
     79 @end example
     80 
     81 With suitable privilege, it can be run as a command or in a
     82 @code{cron} job to reset the local clock from a reliable server, like
     83 the @code{ntpdate} and @code{rdate} commands.
     84 For example:
     85 
     86 @example
     87 ntpdc -a ntpserver.somewhere
     88 @end example
     89