export Variable problem

[Vasudevan MV]

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

[Stefan Farrelly]

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.

[Thierry Poels_1]

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.

[Justo Exposito]

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.

[Peter Kloetgen]

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