UNIX for Dummies Questions & Answers

Does this help, or did I read this funny?

`printenv | more`

Here is the small practical example. Just check it.
Just type them on the shell & observe the output.

$a=10 (I'm creating a shell variable named as 'a' with value 10.
$set (This will show the newly created variable & its value i.e. 'a=10').
$env (This will list some set of variables other than 'a=10'.

$export a (Now Execute this statement).
$set (Now this still shows a=10 other along with some more..)
$env (Now this will show a=10 also...).

I mean, 'set' display only local & un-exported variable.
Where as 'env' shows all global & exported variable variables.

When you think of why Global & local variables, the difference
comes when using shell scripts. In a shell script if you create a
a variable, then this will be visible only for the executing script.

But, in a script if you create a variable & if you export, then it will
become a global variable, so that all scripts will be able to see this
variable.

So, using export you are making a locallly visible varialbe a Globally visible variable.

You can also do this in a single shot.

ex:- $export a=10

$ env...shows the output.

Hope this makes some sense.

Now this may sound really funny..but

Can u tell me if I can unexport some variable....
I mean... suppose i did export a=10... now how to undo it.

Sorry folks....!!!

I got the answer ..... unset


Regds