ntp_time - Tcl Time Service Client

package require Tcl 8.0 package require time ?1.1? ::time::gettime ?options? timeserver ?port? ::time::getsntp ?options? timeserver ?port? ::time::configure ?options? ::time::cget name ::time::unixtime token ::time::status token ::time::error token ::time::reset token ?reason? ::time::wait token ::time::cleanup token

This package implements a client for the RFC 868 TIME protocol (http://www.rfc-editor.org/rfc/rfc868.txt) and also a minimal client for the RFC 2030 Simple Network Time Protocol (http://www.rfc-editor.org/rfc/rfc2030.txt). RFC 868 returns the time in seconds since 1 January 1900 to either tcp or udp clients. RFC 2030 also gives this time but also provides a fractional part which is not used in this client.

::time::gettime ?options? timeserver ?port?

Get the time from timeserver. You may specify any of the options listed for the configure command here. This command returns a token which must then be used with the remaining commands in this package. Once you have finished, you should use cleanup to release all resources. The default port is 37.

::time::getsntp ?options? timeserver ?port?

Get the time from an SNTP server. This accepts exactly the same arguments as ::time::gettime except that the default port is 123. The result is a token as per ::time::gettime and should be handled in the same way.

::time::configure ?options?

Called with no arguments this command returns all the current configuration options and values. Otherwise it should be called with pairs of option name and value.

-protocol number

Set the default network protocol. This defaults to udp if the tcludp package is available. Otherwise it will use tcp.

-port number

Set the default port to use. RFC 868 uses port 37, RFC 2030 uses port 123.

-timeout number

Set the default timeout value in milliseconds. The default is 10 seconds.

-command number

Set a command procedure to be run when a reply is received. The procedure is called with the time token appended to the argument list.

-loglevel number

Set the logging level. The default is 'warning'.

::time::cget name

Get the current value for the named configuration option.

::time::unixtime token

Format the returned time for the unix epoch. RFC 868 time defines time 0 as 1 Jan 1900, while unix time defines time 0 as 1 Jan 1970. This command converts the reply to unix time.

::time::status token

Returns the status flag. For a successfully completed query this will be ok. May be error or timeout or eof. See also ::time::error

::time::error token

Returns the error message provided for requests whose status is error. If there is no error message then an empty string is returned.

::time::reset token ?reason?

Reset or cancel the query optionally specfying the reason to record for the error command.

::time::wait token

Wait for a query to complete and return the status upon completion.

::time::cleanup token

Remove all state variables associated with the request.

% set tok [::time::gettime ntp2a.mcc.ac.uk]
% set t [::time::unixtime $tok]
% ::time::cleanup $tok

% set tok [::time::getsntp ntp.blueyonder.co.uk]
% set t [::time::unixtime $tok]
% ::time::cleanup $tok

Pat Thoyts

ntp

NTP, SNTP, rfc 2030, rfc 868, time

Copyright (c) 2002, Pat Thoyts <patthoyts@users.sourceforge.net>