R.app cannot see tar but R (console) can

On 01-08-2011, at 06:15, <Ross.Darnell at csiro.au> <Ross.Darnell at csiro.au> wrote:

If I run

system('tar')

within the console version of R I get

system('tar')

tar: Must specify one of -c, -r, -t, -u, -x

If I try using R.app  I get

R version 2.13.1 (2011-07-08)
Copyright (C) 2011 The R Foundation for Statistical Computing
ISBN 3-900051-07-0
Platform: x86_64-apple-darwin9.8.0/x86_64 (64-bit)

R is free software and comes with ABSOLUTELY NO WARRANTY.
You are welcome to redistribute it under certain conditions.
Type 'license()' or 'licence()' for distribution details.

Natural language support but running in an English locale

R is a collaborative project with many contributors.
Type 'contributors()' for more information and
'citation()' on how to cite R or R packages in publications.

Type 'demo()' for some demos, 'help()' for on-line help, or
'help.start()' for an HTML browser interface to help.
Type 'q()' to quit R.

[R.app GUI 1.41 (5874) x86_64-apple-darwin9.8.0]

[Workspace restored from /Users/dar143/.RData]
[History restored from /Users/dar143/.Rapp.history]

system(tar)

Error in system(tar) : non-empty character argument expected

1. You should have done system("tar"). Now R is looking for an object tar which is empty.

2. GUI applications in Mac OS X don't inherit/receive  the environment used in Terminal.

You can check this in R.app with Sys.getenv("PATH").
You could use Sys.setenv(PATH="...") in R.app to set PATH for that session.

If you want GUI applications to always receive certain environment variables then  see

http://stackoverflow.com/questions/135688/setting-environment-variables-in-os-x
http://developer.apple.com/library/mac/#qa/qa1067/_index.html
http://developer.apple.com/library/mac/#documentation/MacOSX/Conceptual/BPRuntimeConfig/Articles/EnvironmentVars.html

If you would like to set environment variables for GUI applications in a "nice" way (would also work for Emacs I think) you can use RCenvironment which provides a preference pane for setting environment variables for GUI applications. See

http://www.rubicode.com/Software/RCEnvironment/

best

Berend