Archive for June, 2008

Reset N70 (hard reset)

Try this easy way dial *#7370# after that it will ask for security code dial 12345 it’s by default!

Protect your eye when working too much in front of a monitor

Don’t quit your IT job or trade your Wii for bifocals just yet. According to Dr. G. John Lach, president of the MOA, a few simple steps can significantly reduce your chances of developing CVS:

– Avoid glare by sitting directly in front of the screen instead of at an angle

– Lower your monitor or television to just below eye level

– Consider using specially-designed computer glasses (nerd!)

– Take frequent breaks from gaming or intense computer work

– Remember to blink!

source: Yahoo! games.

Unix tips 2 (from wikipal)

Edit a simple text file

Without windows, you can use:

vi myFile.txt

With X-Windows you can use:

gedit myFile.txt

Editing Software

There are several possible editor to use:

* vim: is a simple editor that can be interesting because it does not use any windowing system. The difficulty is to learn the commands because there is no menu, of course. If you learn some command it is in fact a powerful editor with syntax highlighting.

* gedit: is a simple editor from gnome but it can recognize the syntax of most languages.

* kedit: is the editor of the KDE environment. It is less interesting than gedit for software because ther is no syntax highlighting.

You can also use integrated environment:

  • kate: seems a nice environment
  • kdevelop: the environment from KDE
  • eclipse: initially developed for Java. Now work with C and C++. Seems well integrated and advanced.

UML diagrams can also be created and edited:

  • umbrello: seems to be a nice software for UML diagram edition.

Cut and Paste under X-Windows

Selecting is equivalent to copy. To paste use the middle button.

Login to a Unix machine enabling X-Windows

The usual command for connecting to a unix machine is ssh. Example:

ssh ipal-server2

If you need to login in with a different default name just put it before the machine name. Example:

ssh user@ipal-server2

If you need a graphical environment for your remote program, you need an X-Windows server to be up and runing. It depends on the system you are using:

  • Unix: an X server is up by defaut. Nothing special needed.
  • MacOs: an X server is available but must be manually lauched (X11).
  • Windows: no X server are available by default. One must download the software X-WIN32 from core web site.

Once your X windows server is up and running you can add the ”-X” option to the ssh login command so to have access to windowed software. Be careful: display are thought the network and hence are slower than on the server screen. Example:

ssh -X ipal-server2

Then you can lauche a gnome program like:


NB: the character ”&” is used to put this program on the background of your shell.

Copy between two Unix machines

The command to use is normally:


This means “secure copy”. For copying directories uses the option ”-r”. See manual for more details. Important: one must have the right to read the source and to write the destination. Example: copy the whole SHARE directory from one machine to location /home/ipal on ipal-server2 machine, under the user name “chevalet”.

scp -r SHARE chevalet@ipal-server2:/home/ipal

WARNING: progress meter is display for each file and can slowdown the transfer of a lot of small files.

An automatic backup

Backing up a server is mandatory for a safety usage. Nowadays as disks are not expensive, using external disk is a simple backup solution. This external disk should have the exact size of the disk to be backup.

In a Unix system on need two command:

  1. an incremental copy command to save the changed files.
  2. an daemon that execute the backup automatically.

The command to use for the incremental copy is “rsync”. The deamon that execute any script is called “cron”.

This is a simple example of script that do a backup. This script should be put in an accessible location like ”/root/bin”.


# This is the path where the backup disk should be mounted
# email adress to send in case of error
# Check if the disk is mounted
mounted=`df -a|grep $dest`
if [ "$mounted" ]
# Do the backup
/usr/bin/rsync -a --delete /home/ipal/ $dest/ipal/
# Disk not mounted: send an email
/bin/mail -s "Cannot do backup" $email <<-EOF Message from $0
The disk $dest is not mounted in $HOSTNAME.
Backup not done at $now.

Then to activate this script, use the command:

crontab -e

Then one can add the automatic launch of the script every day at 1AM using the line below, providing the script is named “” and is located at ”/root/bin”.

00 01 * * * /root/bin/>>/var/log/backup.log

The output is automatically added to the log file backup.log.

Change the system hostname

The hostname is managed by the network administrator. It enable to automatically associate the name of the machine to an IP address and alleviates the necessity to remember the IP number. On the machine the hostname has to be changed manually by modifiying the file /etc/hosts.

See also :

Unix tips (contains duplicated)

A right terminal console when launching SSH

When run SSH, the terminal they give us may sick us due to the ugly interface. To have a proper one, as if run directly on the Unix server, is gnome-terminal.

Some helpful GUI application

Run a console and call the following commands :

  • A GUI-explorer : nautilus
  • Text editor with syntax highlight: kate
  • File manager – a very powerful & useful tool to work with your files: krusader
  • A great IDE application: eclipse

If you want to continue on your current terminal-console, you should run the application in background by adding the & at the end of the program name. E.g.:

vgnam@/home/vgnam> krusader&

“.bashrc” tips

The followings format the prompt of the terminal to the form of username@workingFolder and also colorize it.

export PS1="\[$usernameColor\]\u\[$default$pathColor\] \w $ \[$defaultColor\]"

Colorful ls command

alias ls='ls --color'

Note: The above scripts should be put in the .bashrc file in your home folder, e.g. /home/vgnam/.bashrc

Search and replace in bash command.

google:bash perl replace -> One-line shell script for find and replace

Using perl-like command:

perl -pi -e 's/find/replace/g' *.txt

Used with multiple files:

find . -name '*.txt' |xargs perl -pi -e 's/find/replace/g'

Another way using sed Use the sed command with inline option and regular-expression as :

sed -i -e 's/source/destination/g' *.html

In program //kate//, how to execute the current open file?

Simply press Ctrl-Shift-X

Install new font in Unix system?

Firts, extract and copy fonts to:


Login as root user. Then, continue to use the command:

fc-cache /usr/share/fonts/yourFontsFolder

Print elapsed time from bash command ?

time1=`date +%s`
# your program that need to measure time runs here
time2=`date +%s`
elapsed=`echo $time2-$time1 | bc`
echo "Elapsed time: $elapsed seconds."

Delete recursive files, e.g. the “name.ext~” – How to?

find . -type f -name "yourPatter" -delete

How to get numbers of lines of a huge file? Call the wc command with -l option :

wc -l

How to get memory (RAM) size in Linux OS system by command line?

I need to know the memory size, RAM size, of the server which is a Linux OS. I look on the web and found this quite not easy since the input keyword must be precise.

cat /proc/meminfo

There u can see the line that says: MemFree : ### kB (or mB) is where the free memory is showed. For a brief information output let’s used :

cat /proc/meminfo | grep MemFree

This will show only the MemFree line! What a command!