problem with environment variable

[donny750]

hello,

I've a perl script;
In this script , i use a environmental variable;
But if my variable is not defined, i prompt and i can write a value for this environnemental variables.
I've a problem;
How can i do , to export this variable and use this in another script ?

Thanks;

 

[donny750]

i've try this
but the export not run

#!/usr/bin/perl

my $envone;
if ( !defined( $ENV{"envone"} ) ) {
    print "Enter value for envone : ";
    $envone = <STDIN>;
    chomp ($envone);

  
  my $run = system("envone=".$envone);
  
  if ($run == 0 )
{
    print "YES\n";
}
else 
{
    print "NO!\n";
    
}   

  
  
   $run = system("export envone");
  
  if ($run == 0 )
{
    print "exporting\n";
}

 

[PC888]

In the line:
$run = system("export envone");
if you change that to:
$run = system("export $envone");
Would it have a better chance?

 

[donny750]

i think no,
because envone is the name of my environment variable and $envone is the value;
i add a new value to my variable with this :
envone = $envone
and after i export my variable :
export envone

 

[donny750]

and the export don't run

 

[KevinADC]

is "export" a program?

- Kevin, perl coder unexceptional!

 

[donny750]

it's not a program it's a unix command;
If you have an environnement variable not defined or you want to change the value;
You make this :
environnementvariable = newvalue
and
export environnementvariable

and so your environnement variable has the new value and you can use it in your script

 

[KevinADC]

try changing this line:

my $run = system("envone=".$envone);

to:

my $run = system("envone=$envone");

and see if that helps.

But you can do this:

$ENV{'envone'} = $envone;

and it should work as long as the script is running.


- Kevin, perl coder unexceptional!

 

[donny750]

i've try this
$ENV{'envone'} = $envone;
if the script run ,it works

but if i use the variable in another script;
the variable are not defined

 

[KevinADC]

OK, well, I am not familiar with the export unix command so I do not know why it will not works like you want.

- Kevin, perl coder unexceptional!

 

[Mike042]

Hi donny750,

In UNIX, each script runs in its own 'process space'. A parent process can 'export' environmental variables to child processes. Child processes cannot easily* 'export' environmental variables to parent processes OR to other child processes. Parent processes cannot easily* 'export' to other parent processes.
(* I say cannot easily because it requires in-depth knowledge of 'Inter-process Links' (IPL) and attending courses in 'Internals' - which is beyond me)

A way round it, is to use a common 'source' file (see unix man pages - man source) that scripts can access and obtain values for environmental variables. These could be made available to all users or groups of users, etc.

For further info, please re-post specific questions.

I hope that helps.

Mike

 

[donny750]

that's helps a lot;
thanks