1*2b15cb3dSCy Schubert\input texinfo @c -*-texinfo-*- 2*2b15cb3dSCy Schubert@c %**start of header 3*2b15cb3dSCy Schubert@setfilename ntpdc.info 4*2b15cb3dSCy Schubert@settitle ntpdc: NTPD Control User's Manual 5*2b15cb3dSCy Schubert@include ../sntp/include/version.texi 6*2b15cb3dSCy Schubert@paragraphindent 2 7*2b15cb3dSCy Schubert@c %**end of header 8*2b15cb3dSCy Schubert 9*2b15cb3dSCy Schubert@ifinfo 10*2b15cb3dSCy SchubertThis file documents the use of the NTP Project's ntpdc, a program for 11*2b15cb3dSCy Schubertcontrolling ntpd. 12*2b15cb3dSCy Schubert@end ifinfo 13*2b15cb3dSCy Schubert 14*2b15cb3dSCy Schubert@direntry 15*2b15cb3dSCy Schubert* ntpdc: (ntpdc). ntpd Control program 16*2b15cb3dSCy Schubert@end direntry 17*2b15cb3dSCy Schubert 18*2b15cb3dSCy Schubert@titlepage 19*2b15cb3dSCy Schubert@title ntpdc: NTPD Control User's Manual 20*2b15cb3dSCy Schubert@subtitle ntpdc, version @value{VERSION}, @value{UPDATED} 21*2b15cb3dSCy Schubert@c @author Max @email{foo@ntp.org} 22*2b15cb3dSCy Schubert@end titlepage 23*2b15cb3dSCy Schubert 24*2b15cb3dSCy Schubert@c @page 25*2b15cb3dSCy Schubert@c @vskip 0pt plus 1filll 26*2b15cb3dSCy Schubert 27*2b15cb3dSCy Schubert@node Top, ntpdc Description, (dir), (dir) 28*2b15cb3dSCy Schubert@top ntpdc: NTPD Control User Manual 29*2b15cb3dSCy Schubert 30*2b15cb3dSCy SchubertThis document describes the use of the NTP Project's @code{ntpdc} program, 31*2b15cb3dSCy Schubertthat can be used to query a Network Time Protocol (NTP) server and 32*2b15cb3dSCy Schubertdisplay the time offset of the system clock relative to the server 33*2b15cb3dSCy Schubertclock. Run as root, it can correct the system clock to this offset as 34*2b15cb3dSCy Schubertwell. It can be run as an interactive command or from a cron job. 35*2b15cb3dSCy Schubert 36*2b15cb3dSCy SchubertThis document applies to version @value{VERSION} of @code{ntpdc}. 37*2b15cb3dSCy Schubert 38*2b15cb3dSCy SchubertThe program implements the SNTP protocol as defined by RFC 5905, the NTPv4 39*2b15cb3dSCy SchubertIETF specification. 40*2b15cb3dSCy Schubert 41*2b15cb3dSCy Schubert@shortcontents 42*2b15cb3dSCy Schubert 43*2b15cb3dSCy Schubert@menu 44*2b15cb3dSCy Schubert* ntpdc Description:: Description 45*2b15cb3dSCy Schubert* ntpdc Invocation:: Invoking ntpdc 46*2b15cb3dSCy Schubert* Usage:: Usage 47*2b15cb3dSCy Schubert@end menu 48*2b15cb3dSCy Schubert 49*2b15cb3dSCy Schubert@node ntpdc Description 50*2b15cb3dSCy Schubert@comment node-name, next, previous, up 51*2b15cb3dSCy Schubert@section Description 52*2b15cb3dSCy Schubert 53*2b15cb3dSCy SchubertBy default, @code{ntpdc} writes the local data and time (i.e., not UTC) to the 54*2b15cb3dSCy Schubertstandard output in the format: 55*2b15cb3dSCy Schubert 56*2b15cb3dSCy Schubert@example 57*2b15cb3dSCy Schubert1996-10-15 20:17:25.123 (+0800) +4.567 +/- 0.089 secs 58*2b15cb3dSCy Schubert@end example 59*2b15cb3dSCy Schubert 60*2b15cb3dSCy Schubertwhere 61*2b15cb3dSCy SchubertYYYY-MM-DD HH:MM:SS.SUBSEC is the local date and time, 62*2b15cb3dSCy Schubert(+0800) is the local timezone adjustment (so we would add 8 hours and 0 minutes to convert the reported local time to UTC), 63*2b15cb3dSCy Schubertand 64*2b15cb3dSCy Schubertthe +4.567 +/- 0.089 secs indicates the time offset and 65*2b15cb3dSCy Schuberterror bound of the system clock relative to the server clock. 66*2b15cb3dSCy Schubert 67*2b15cb3dSCy Schubert@include invoke-ntpdc.texi 68*2b15cb3dSCy Schubert 69*2b15cb3dSCy Schubert@node Usage 70*2b15cb3dSCy Schubert@comment node-name, next, previous, up 71*2b15cb3dSCy Schubert@section Usage 72*2b15cb3dSCy Schubert 73*2b15cb3dSCy SchubertThe simplest use of this program is as an unprivileged command to 74*2b15cb3dSCy Schubertcheck the current time, offset, and error in the local clock. 75*2b15cb3dSCy SchubertFor example: 76*2b15cb3dSCy Schubert 77*2b15cb3dSCy Schubert@example 78*2b15cb3dSCy Schubertntpdc ntpserver.somewhere 79*2b15cb3dSCy Schubert@end example 80*2b15cb3dSCy Schubert 81*2b15cb3dSCy SchubertWith suitable privilege, it can be run as a command or in a 82*2b15cb3dSCy Schubert@code{cron} job to reset the local clock from a reliable server, like 83*2b15cb3dSCy Schubertthe @code{ntpdate} and @code{rdate} commands. 84*2b15cb3dSCy SchubertFor example: 85*2b15cb3dSCy Schubert 86*2b15cb3dSCy Schubert@example 87*2b15cb3dSCy Schubertntpdc -a ntpserver.somewhere 88*2b15cb3dSCy Schubert@end example 89