[R] a --no-save option for Rprofile.site?

Barry Rowlingson b.rowlingson at lancaster.ac.uk
Fri Aug 21 09:21:52 CEST 2009

On Fri, Aug 21, 2009 at 4:33 AM, Scott Hyde<hydes at byuh.edu> wrote:

> I've found that I can use "--no-save" after the RCMDR=TRUE above that will
> do what I want -- don't save any data after exiting.  However, this isn't
> the most secure -- a student only has to delete the option, or start R a
> different way.
> Is there a way to place an option or statement in Rprofile.site file to
> accomplish the same thing?

 Do you also want to stop the student saving things by using the
'save' or 'save.image' functions? Or any of the other file
manipulation functions (sink, cat, connection etc etc etc)?

 This sounds like something best done at the operating system level.
Set permissions and ownerships on your file systems so users can't
overwrite any data you don't want overwritten.

 I'm not sure if Windows will work on a completely read-only file
system (it probably needs the user to be able to write to C:\Temp and
so forth) so there will always be somewhere that users can squirrel
data away. If this is in the users' own profile directory then it
won't affect other users.

 However, if you are using the same username (I'm guessing maybe you
have a single user called 'test' for your test centre logins rather
than giving individual logins for each test subject, or test subjects
don't login, they just sit down at a currently running session) you'll
have to do something else to clear things out, again probably at the
OS level, like a Windows logout script that deletes anything owned by
the user, or some kind of hunter-killer function in R that traverses
the file system and deletes anything that shouldn't be there.

 Also note that R has a system() function so if you don't want users
getting to Windows you'll have to fix that as well.

 How secure do you want this???


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