Thanks for the answers...
I got the file .. mine is in bash so I got the .bash_history file
I removed the contents of the file.
hyper20:~ 22> cat .bash_history
hyper20:~ 23>
but then when I agian type the command history :- it is still showing the history of commands executed
==========
hyper20:~ 23> history
1 1:53 showbl
2 2:05 cd
3 2:05 while [1]
4 2:10 while {1}
5 2:10 while [ 1 ]
6 2:13 pwd
7 2:13 cd
8 2:14 ls -a
9 2:14 vi .bash_history
10 2:14 ll .bash_history
11 2:16 env | grep HISTFILE
12 2:16 env
13 2:17 ls -a
14 2:18 vi .bash_history
15 2:18 history
16 2:18 vi .bash_
17 2:18 vi .bash_history
18 2:19 vi .bashrc
19 2:19 vi .viminfo
20 2:19 history
21 2:19 ll -a
22 2:19 cat .bash_history
23 2:20 history
===============
Could you please help me in this as to how still I am getting the history ?
Thanks.