R help - May 2012 - In R, how do I execute a script that sets environment variables within the same shell session?

In R, how do I execute a script that sets environment variables within the
same shell session?

Hi all,

Could you please shed some lights on how to do this?

In a shell, I launched the R session.

But then in R, I realized that some environment variables need to be set up.

Of course I can use "Sys.setenv()"...

But I have so many of them...

And for some special reason, I have to first launch R and then run the
script from within R to set up the environment variables...

i.e.

I cannot do the other way around, which is first execute the script in the
shell,

and then launch the R session(which is the usual sequenc of ordering)...

So my question is:

I have to launch R session first, and then run the scrip from within R.

But if I naively use "shell" or "system", that's going
to not affect the
same shell that the R is using...

I would like the R session to be able to access those "global"
environment
variables...

How do I do that?

Thank you!

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On 12-05-22 1:24 PM, Michael wrote:
> In R, how do I execute a script that sets environment variables within the
> same shell session?
>
> Hi all,
>
> Could you please shed some lights on how to do this?
>
> In a shell, I launched the R session.
>
> But then in R, I realized that some environment variables need to be set
up.
>
> Of course I can use "Sys.setenv()"...
>
> But I have so many of them...
>
> And for some special reason, I have to first launch R and then run the
> script from within R to set up the environment variables...
>
> i.e.
>
> I cannot do the other way around, which is first execute the script in the
> shell,
>
> and then launch the R session(which is the usual sequenc of ordering)...
>
> So my question is:
>
> I have to launch R session first, and then run the scrip from within R.
>
> But if I naively use "shell" or "system", that's
going to not affect the
> same shell that the R is using...
>
> I would like the R session to be able to access those "global"
environment
> variables...
>
> How do I do that?
You already answered it.  Use Sys.setenv(). It will only affect the 
current process.

Duncan Murdoch