[R] Environmental variables

Gad Abraham gabraham at csse.unimelb.edu.au
Mon Feb 2 05:45:33 CET 2009

David Epstein wrote:
> I use a Mac (10.4.11 Mac Os X).
> In my .tcshrc I define an environmental variable MY.
> Is it possible to find out its value from inside R? When one loads
> R for Mac OS X Cocoa GUI written by:
> 	Simon Urbanek
> 	Stefano M. Iacus
> are files like .tcshrc read by R?
> Can I make the value of this environmental variable available to R?
> Sys.getenv() produces a lot of output, with the values of many environmental
> variables, but not this one.
> Do I need a file with the correct value of MY, and have both R and my Unix
> shell read the same file, or is there a better way to proceed? I want to
> avoid duplicating the information in source files, as this can lead to a
> setup that is very hard to maintain.

R launched from the dock will not inherit variables from .bashrc or 
.tcshrc because it's not a child process of the shell.

You have to set the variables in an XML file called environment.plist, 
inside a directory .MacOSX in your home directory (create it if it 
doesn't exist), e.g.:

macbook:~ gad$ cat .MacOSX/environment.plist
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" 
<plist version="1.0">

Gad Abraham
Dept. CSSE and NICTA
The University of Melbourne
Parkville 3010, Victoria, Australia
email: gabraham at csse.unimelb.edu.au
web: http://www.csse.unimelb.edu.au/~gabraham

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