i need to run a shell script in background untill i kill it
 

how to run a run a shell script in background even if i exit the terminal or logout,

the process end only when i kill with command kill

End your command with an "&"


Regards,

Fordeck

but with a single & it got scope only for current terminal

my need is to execute the command up to when i kill it using kill command

use screen.

man screen

try this ...

open a terminal and type screen

The title bar will change to read [screen 0: bash]
type Ctrl + A then c
the title bar will change to read [screen 1: bash]
run ls -Rl /

when that is running type Ctrl + A then 0 (zero)
You will change back to the screen 0 window
Now type Ctrl + A then d
You will detach from the screen session and the title bar will return to normal.

You can shut the terminal now and log out, but not shut down, obviously.
When you open a new terminal, type screen -r and you go back to the session you started earlier.
To kill screen, just type exit until you have closed all the screen sessions.

I also wonder how to do this.

Try
nohup command &
http://linux.101hacks.com/unix/nohup-command/