System Time (Files and Commands)

Important Files

/usr/share/zoneinfo — contains time zone information for many different regions
/etc/timezone — holds the timezone
/etc/localtime — a symbolic link to the correct file in /path/usr/share/zoneinfo/
etc/ntp.conf — configuration file for NTP
/etc/ntp.drift — where NTP stores correction for local clock being fast/slow

Commands

date — display/set system time
hwclock — query and set the hardware clock (RTC)
ntpdate — used to set system date and time via NTP

The Hardware and The System Clock

The hardware or Real Time Clock (RTC) hardware clock is located on the motherboard.
System Clock is maintained in the Linux kernel and is used while the system is running.

hwclock options

Set the system time from the RTC

hwclock -s or hwclock --hctosys

Set the RTC from the system time

hwclock -w or hwclock --systohc

Display the contents of the RTC

hwclock -r or hwclock --show 

Ajust the RTC for clock drift

hwclock -a or hwclock --adjust

The file /etc/adjtime is used to hold information about the extent to which (and direction) the RTC drifts.

Find Files and Commands in Linux

find – search a file from a certain criteria.
syntax:

find directory criteria [-exec command {} \;]

e.g.:

remove all files belonging to user 502:
find / - type f -user 502 –exec rm –f {} \;

locate – list all files and directories that match the expression.
syntax:

locate string

locate queries the /var/lib/slocate/slocate.db database. This database is kept up to date via a daily cron job which runs updatedb. updatedb read /etc/updatedb.conf file. The Security Enhanced version of the GNU locate is slocate.

whereis – return the full path to source or binaries as well as documentation files matching string by scanning the PATH variable as well as a number of well known locations.
syntax:

whereis string

which – return the full path to the file called string by scanning the directories defined in the user’s PATH variable only. which is only used to find commands.
syntax:

which string

apropos – search manual page names and description.
syntax:

apropros string

whatis – display manual page description.
syntax:

whatis string

Sync files from different PC’s with Dropbox

If you haven’t heard of Dropbox, Dropbox is the easiest way to sync and share your files.

For months of using Dropbox, the use of my flash drive was eliminated and sharing of files to my friends and colleagues became efficient. Documents from my office PC are synchronized to a Dropbox folder on my PC/Laptop at home. Aside from file synchronization, Dropbox also serves as a sharing and back-up tool for my files. Isn’t that amazing?

I suggest you should try it.

Just go to Dropbox website or you may use my link below to create an account.

www.dropbox.com

Once signed up, you’ll have a free 2GB disk space. You’ll have two options to increase your disk space; either upgrade to PRO or by referral. You’ll get additional 250MB once your friends used Dropbox for their files. The next step is download the installer, then install it to your Office/School/Home computer.

After the installation, you’ll see a Dropbox folder stored on your My Documents folder. You may now start adding files or create shared folders.

Dropbox made syncing and sharing of files easy! 🙂