topic Re: export Variable problem in Operating System - HP-UX

export Variable problem

Vasudevan MV — Wed, 26 Jun 2002 08:06:59 GMT

Hi,

How do I export a variable from child to parent shell?.
Example:
A.sh
-----
export XYZ=10
B.sh
echo $XYZ

B.sh
------
export XYZ=30

but I can NOT run the B.sh in the same shell using this way like ". ./B.sh" in the A.sh script.

Thanks
Vasu

Re: export Variable problem

Stefan Farrelly — Wed, 26 Jun 2002 08:13:28 GMT

I believe the only way to do this is export the variable to a file and then in the parent sell check for the file and load the variable.

A better way to do it is declare the variable first in the parent, then when it gets modified in the child it will also be set back in the parent.

Re: export Variable problem

Thierry Poels_1 — Wed, 26 Jun 2002 08:17:46 GMT

Hi,

simple answer: you cannot. The environment of a child process is lost when it exits.

You will need to "source" the script if you want to keep the environment. Why would you not use this option? :
. /dir/B.sh

Other tricks are to put the value in a temp file and read it, put the export command in a temp file and source it, ....

good luck,
Thierry.

Re: export Variable problem

Justo Exposito — Wed, 26 Jun 2002 08:21:08 GMT

Hi Vasu,

If you need only one value to be returned to the parent shell, you can do it by the exit from the child script like that:

A.sh
-----
export XYZ=10
sh B.sh
XYZ=$?
export XYZ
echo $XYZ

B.sh
------
export XYZ=30
exit $XYZ

Regards,

Justo.

Re: export Variable problem

Peter Kloetgen — Wed, 26 Jun 2002 08:33:07 GMT

Hi Vasudevan,

*No way*, you can't do this, exporting works only in one direction, from parent processes to child processes, not the other direction. You have to put the value into a file which you read in parent process later to make the value existent here.

Allways stay on the bright side of life!

Peter