QNX Operating System/Discussion/OSTech/Set global environment variable using Setenv/putenv/List of Posts
 
Forum Topic - Set global environment variable using Setenv/putenv:
   
Update
sathish kumar
02/16/2009 9:02 AM
post22312
Set global environment variable using Setenv/putenv   
Hi All,

I tried modifying PATH environment variable using Setenv/putenv but when i exit from the application the values are not 
reflected in the global environment variables. I have a requirement where the global environment variables need to 
updated and should be reflected in the parent shell.

Thanks,
Sean Boudreau(deleted)
02/16/2009 4:03 PM
post22322
Re: Set global environment variable using Setenv/putenv   
On Mon, Feb 16, 2009 at 09:02:30AM -0500, sathish kumar wrote:
> Hi All,
> 
> I tried modifying PATH environment variable using Setenv/putenv but when i exit from the application the values are 
not reflected in the global environment variables. I have a requirement where the global environment variables need to 
updated and should be reflected in the parent shell.

Changing your environment doesn't affect your parent (the
environment is inherited).  You'd have devise a scheme
whereby the parent would listen for requests to alter its
own environment.

-seanb
sathish kumar
02/16/2009 11:20 PM
post22326
Re: Set global environment variable using Setenv/putenv   
Hi.
HOw is it possible to do any modification in the Korne shell (ksh) to reflect the environment variable changes made in 
the child process. In our case the parent in the korne shell (ksh) from where the executables are invoked.

Thanks,
Mario Charest
02/17/2009 9:40 AM
post22346
RE: Set global environment variable using Setenv/putenv   
For existing children it`s not possible.  For new children you do an "export VARIABLE=..."

> -----Original Message-----
> From: sathish kumar [mailto:community-noreply@qnx.com]
> Sent: February-16-09 11:20 PM
> To: ostech-core_os
> Subject: Re: Set global environment variable using Setenv/putenv
> 
> Hi.
> HOw is it possible to do any modification in the Korne shell (ksh) to
> reflect the environment variable changes made in the child process. In
> our case the parent in the korne shell (ksh) from where the executables
> are invoked.
> 
> Thanks,
> 
> 
> _______________________________________________
> OSTech
> http://community.qnx.com/sf/go/post22326
>
Thomas Haupt
02/17/2009 10:15 AM
post22349
Re: Set global environment variable using Setenv/putenv   
Process environment is data which is local to the process. Every process has its *very own* environment, like every 
process has its own, private memory area[s]. 

Parents can not modify their childrens' environments, they can just pass an environment when the child is created; 
children can not modify their parents' envirnoments.

In short: No process can modify any other existing process'es environment.

You will need to find a different approach.

What are you trying to do?
sathish kumar
02/17/2009 10:39 AM
post22351
Re: Set global environment variable using Setenv/putenv   
I am trying to return a value from a executable file and use the returned value in Korne shell script. As my return 
values are restricted to 8 bit when i access $? in shell script, i try loading a environment variable in my executable 
and use the environment variable in the shell script to know the return values of my executable.

For example
#./a.out
#echo $PROG_OUTPUT 

Where a.out loads the PROG_OUTPUT with the return value to be used in the shell script.

Thanks
Mario Charest
02/17/2009 10:41 AM
post22352
RE: Set global environment variable using Setenv/putenv   

> -----Original Message-----
> From: sathish kumar [mailto:community-noreply@qnx.com]
> Sent: February-17-09 10:39 AM
> To: ostech-core_os
> Subject: Re: Set global environment variable using Setenv/putenv
> 
> I am trying to return a value from a executable file and use the
> returned value in Korne shell script. As my return values are
> restricted to 8 bit when i access $? in shell script, i try loading a
> environment variable in my executable and use the environment variable
> in the shell script to know the return values of my executable.

Have your process "print" the value. And then in the shell do

PROG_OUTPUT=`./a.out`
echo $PROG_OUTPUT


> 
> For example
> #./a.out
> #echo $PROG_OUTPUT
> 
> Where a.out loads the PROG_OUTPUT with the return value to be used in
> the shell script.
> 
> Thanks
> 
> _______________________________________________
> OSTech
> http://community.qnx.com/sf/go/post22351
>

Return