swaping
 

Hello!
it is linux bash shell script language.
i have a variable

var=abcdef

now i want to replace the a with z, b with y, c with x.
how can i do this.
that the new values of variable will be

var=zyxwvu

Ahhh.... What programming language? Does it matter?

You directly stated your problem, but did not define a configuration set for the problem to be on top of.

That depends at least partially on:

a) what language you're using
b) what data type the variable is

Did you really read the post?

The OP said "bash shell script".

so, what you've done so far? any code to show? we're not going to write it for you

Look at the 'last edit' time of the OP. My guess is that the bash part was added in the OP after the first two responses.

Didn't notice that.

The desired result seems to be poorly stated. According to this:
"replace the a with z, b with y, c with x"
the end result should be:
$var = zyxdef
This is simply the reverse of the original:
var=fedcba

Maybe he meant that is the string were the alphabet, a would become z, etc. I agree that it's a impossible to understand and dumb way of saying "reverse a string", but maybe.

If that is the case, then:
var=abcdef
var=$(echo $var|rev)