Moxa W321-LX [35/80] Updating the time automatically

W321/341 Linux Managing Embedded Linux

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Visit http://www.ntp.org for more information about NTP and NTP server addresses.

10.120.53.100 – PuTTY

root@Moxa:/etc/rc.d/rc3.d# ntpdate 192.168.1.97

Looking for host 192.168.1.97 and service ntp

host found : 192.168.1.97

18 Mar 19:30:36 ntpdate[192]:

step time server 192.168.1.97 offset

211195575.886041 sec

root@Moxa:/etc/rc.d/rc3.d# hwclock -w

root@Moxa:/etc/rc.d/rc3.d# hwclock

Mon Mar 18 19:30:46 2013 0.000000 seconds

NOTE

Before using the NTP client utility, check your IP and DNS settings to make sure that an Internet connection is

available. Refer to Chapter 2 for instructions on how to configure the Ethernet interface, and see Chapter 4 for

DNS setting information.

Updating the Time Automatically

In this subsection, we show how to use a shell script to update the time automatically.

Example shell script to update the system time periodically

#!/bin/sh

ntpdate time.nist.gov

# You can use the time server’s ip address or domain

# name directly. If you use domain name, you must

# enable the domain client on the system by updating

# /etc/resolv.conf file.

hwclock –-systohc

sleep 100

# Updates every 100 seconds. The min. time is 100 seconds. Change

# 100 to a larger number to update RTC less often.

Save the shell script using any file name. E.g., fixtime

How to run the shell script automatically when the kernel boots up

Copy the example shell script fixtime to directory /etc/init.d, and then use chmod 755 fixtime to change

the shell script mode. Next, use vi editor to edit the file /etc/inittab. Add the following line to the bottom

of the file:

ntp : 2345 : respawn : /etc/init.d/fixtime

Use the command #init q to re-init the kernel.