[R-SIG-Mac] Multiple R versions: set Current via symbolic link: permissions?

[Marius Hofert]

On 2011-10-11, at 16:19 , Simon Urbanek wrote:

> 
> On Oct 11, 2011, at 6:24 AM, Marius Hofert wrote:
> 
>> Hi,
>> 
>> I have multiple R versions installed and would like to switch between them via setting the symblic link "Current". To make this a bit more convenient, I defined two "aliases" in .bashrc:
>> 
>> alias R2.13='d=/Library/Frameworks/R.framework/Versions; rm $d/Current; ln -s $d/2.13 $d/Current'
>> alias R2.14='d=/Library/Frameworks/R.framework/Versions; rm $d/Current; ln -s $d/2.14 $d/Current'
>> 
> 
> Try
> 
> ln -sfn 2.13 /Library/Frameworks/R.framework/Versions/Current
> 

Dear Simon,

thanks, I put it in the alias. It now looks like this:
alias R2.13='d=/Library/Frameworks/R.framework/Versions; rm $d/Current; ln -sfn $d/2.13 $d/Current'
(and similarly for R 2.14)


> You'll need to be admin of the computer, otherwise you'll need sudo

If I execute (in a new shell, as usual) R2.13, I (still) get:

bash-3.2$ R2.13
rm: /Library/Frameworks/R.framework/Versions/Current: Permission denied
ln: /Library/Frameworks/R.framework/Versions/Current: Permission denied

So the obvious would be to "sudo R2.13", but I obtain:

bash-3.2$ sudo R2.13
Password:
sudo: R2.13: command not found

> or change permissions. Note that for symlinks you'll need extra -h in chown otherwise you're changing ownership of the target not the link.

This I also realized :-) I tried that:
sudo chown -h myuser /Library/Frameworks/R.framework/Versions/Current

bash-3.2$ ls -al
total 8
drwxrwxr-x  5 root     wheel  170 Oct 11 15:54 .
drwxrwxr-x  9 root     wheel  306 Oct 11 11:38 ..
drwxrwxr-x  8 root     wheel  272 Oct 11 12:16 2.13
drwxrwxr-x  6 root     wheel  204 Oct 11 11:38 2.14
lrwxr-xr-x  1 myuser  wheel   45 Oct 11 15:54 Current -> /Library/Frameworks/R.framework/Versions/2.13
bash-3.2$ 

=> okay, root was changed to myuser, that's good. But again, I get 

bash-3.2$ R2.13
rm: /Library/Frameworks/R.framework/Versions/Current: Permission denied
ln: /Library/Frameworks/R.framework/Versions/Current: Permission denied



> If in doubt (ie., you messed with permissions before), run sudo chmod g+w -R /Library/Frameworks/R.framework

okay, thanks a lot, that's good to know.

> 
> Cheers,
> Simon
> 
> 
>> On executing R2.13 in the terminal, I get:
>> rm: /Library/Frameworks/R.framework/Versions/Current: Permission denied
>> ln: /Library/Frameworks/R.framework/Versions/Current/2.13: Permission denied
>> 
>> If I chown Current, I still get:
>> rm: /Library/Frameworks/R.framework/Versions/Current: Permission denied
>> 
>> I (bad) solution is to put in "sudo" in the alias... 
>> 
>> How is it done correctly? 
>> 
>> Cheers,
>> 
>> Marius
>> 
>> PS: I also posted it for future reference, I've only found the idea of using ln -s on the help pages/FAQ, but not how to get around the permission issue.
>> _______________________________________________
>> R-SIG-Mac mailing list
>> R-SIG-Mac at r-project.org
>> https://stat.ethz.ch/mailman/listinfo/r-sig-mac
>> 
>> 
> 

ETH Zurich
Dr. Marius Hofert
RiskLab, Department of Mathematics
HG E 65.2
Rämistrasse 101
8092 Zurich
Switzerland

Phone +41 44 632 2423
marius.hofert at math.ethz.ch
http://www.math.ethz.ch/~hofertj