Htpdate
The HTTP Time Protocol (HTP) is used to synchronize a computer's time
with web servers as reference time source. Htpdate will synchronize your
computer's time by extracting timestamps from HTTP headers found
in web server responses. Htpdate can be used as a daemon, to keep your
computer synchronized.
The accuracy of htpdate is at least -+0.5 seconds (better with multiple
servers). If this is not good enough for you, try the ntpd package.
Install the htpdate package if you need tools for keeping your system's time synchronized via the HTP protocol. Htpdate works also through proxy servers.
Installation from source
Tested on Linux and FreeBSD only, but should work for most Unix flavors.
$ tar zxvf htpdate-x.y.z.tar.gz
or
$ tar jxvf htpdate-x.y.z.tar.bz2
$ cd htpdate-X.Y.Z
$ make
$ make install
An example init script in /etc/init.d/ is included, but not installed
automatically.
This give the user the option to run htpdate as daemon or run it
periodically from cron.
Installation from RPM
The easiest way to install (Redhat, SuSE, Mandriva etc..)
$ rpm -i htpdate-x.y.z.i386.rpm
or when upgrading
$ rpm -Uvh htpdate-x.y.z.i386.rpm
By default the htpdate daemon is activated (with chkconfig). If you only want to run htpdate from cron, disable the htpdate service with 'chkconfig --del htpdate'.
Usage
Usage: htpdate [-046adhlqstxD] [-i pid file] [-m minpoll] [-M maxpoll]
[-p precision] [-P <proxyserver>[:port]] [-u user[:group]]
<host[:port]> ...
In general more web servers (multiple the same is allowed) will increase accuracy.
See manpage for more details.
To do
- I'm open for suggestions :)
Eddy Vervest <eddy@cleVervest.com>