Re: initialisation bash variables

[Patrick]

On 17.08.2011 20:53, Stephane CHAZELAS wrote:
> 2011-08-17, 08:32(+02), Francky Leyn:
> > On 8/16/2011 10:53 PM, Stephane CHAZELAS wrote:
> > 2) If VAR coincides with an environment variable, and in the
> >      script I change it value, is this then propagated to outside
> >      the script? Is the environment variable affected?
>
> The environment is a list of strings (by convention of the format
> [...]
>
> In no circumstance are variable definitions in one process going
> to affect the environment of other processes (an exception to
> that is the "fish" shell)

Could it be that the two of you are not talking about the same thing?

Just for clarity: environment variables (henceforth "the environment") 
of a process are (is) inherited by its children.

Therefore, what *does* happen, is that if Stephane, as in 2), changes 
VAR in script, the change gets propagated to the scripts *child* processes.

$ X=1 bash             1*)
 $ echo $X
 1
 $ X=2
 $ bash
  $ echo $X
  2

But what does of course not happen, is that the change would get 
propagated to the *parent* process.

$ export X=1            2*)
$ echo $X
1
 $ bash
 $ X=2
 $ exit
$ echo $X
1

1*) X will exist only in the environment of the child process being started
2*) X will exist in the environment of the current process and will 
therefore be inherited and exist in the environment of its children as well

(What is the "fish" shell ???)