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.Rhistory created with wrong permissions (PR#13752)

4 messages · Nicolas.Thierry-Mieg at imag.fr, Paul Gilbert, Brian Ripley +1 more

#
Hi,


This is with a centos 5.3 x86_64 system, using R 2.8.1 (details below).

In a directory where R is invoked, at the end of a session R offers to 
"Save workspace image". Replying yes creates/updates at least two files 
in the current directory: .Rhistory and .RData.
.Rhistory is created with permissions 0600, therefore it effectively 
ignores umask. In particular, .Rhistory cannot be group-readable, which 
can be problematic in some environments.
This is not the case for .RData (created 0666, modified by umask as 
usual), so I doubt that the .Rhistory permissions are restrictive by design?
If not, it would be better to create .Rhistory 0666 and let the user 
control the actual permissions through umask.

Regards,
Nicolas Thierry-Mieg

*****************************
Steps to reproduce:

[nthierry at tryo ~]$ mkdir ttt
[nthierry at tryo ~]$ cd ttt
[nthierry at tryo ttt]$ R
<snip copyright and greeting message>
 > y<-3
 > q()
Save workspace image? [y/n/c]: y
[nthierry at tryo ttt]$ ls -la
total 20
drwxr-xr-x  2 nthierry timb 4096 Jun 10 16:21 .
drwxr-x--- 80 nthierry timb 4096 Jun 10 15:18 ..
-rw-r--r--  1 nthierry timb   61 Jun 10 16:21 .RData
-rw-------  1 nthierry timb    9 Jun 10 16:21 .Rhistory
[nthierry at tryo ttt]$



Using strace on the R process shows the following, which seems to 
confirm that the problem comes from R itself:

open(".RDataTmp", O_WRONLY|O_CREAT|O_TRUNC, 0666)
<snip>
rename(".RDataTmp", ".RData")
open(".Rhistory", O_WRONLY|O_CREAT|O_TRUNC, 0600)



*****************************
 > version
platform       x86_64-redhat-linux-gnu
arch           x86_64
os             linux-gnu
system         x86_64, linux-gnu
status
major          2
minor          8.1
year           2008
month          12
day            22
svn rev        47281
language       R
version.string R version 2.8.1 (2008-12-22)
#
Nicolas.Thierry-Mieg at imag.fr wrote:
I`m not sure, but it may be by design.  For example, users sometimes use 
passwords to connections, which one might not want accidentally recorded 
in a readable file.

Paul
====================================================================================

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#
Yes, it is by design, and not R's design at that.

How (or if) the history is saved is determined by the GUI interface in 
use.  In this case it appears to be command-line R built with readline 
support, in which case the saving is done by readline's write_history. 
And although the history.info manual does not say so, it does open 
files with pemissions 0600 (and there is no provison to change this).

To claim 'wrong permissions' implies that you 'know for certain' what 
the permissions should be -- I don't now how you can know them unless 
you can point to documentation that asserts the correct value as 
something different.
On Wed, 10 Jun 2009, Paul Gilbert wrote:

            
Not at all: it comes from a library R uses.

  
    
#
Prof Brian Ripley wrote:
OK, undocumented feature of a library R links to.
Thanks for explaining.
Woah! No need to get snappy or pedantic. There's no documentation one 
way or the other, so "wrong" has to be relative to standard procedure.
There's no documentation saying R doesn't "rm -rf /" on full moons, but 
one still expects that it doesn't.

Most programs create files 0666 modified by umask, except if there's a 
good reason to restrict things.
0666 is also what fopen does when creating a file.
Furthermore .RData is created 0666, and I didn't think a user's history 
was more sensitive than his data, so I thought .Rhistory should be 0666 
as well. Paul's answer about passwords clears that up.

OK, I should have written "unusual permissions".
And I realize now that I should have posted to r-devel instead of 
submitting a bug. Sorry for the noise, I'm new to R.


Regards,
Nicolas Thierry-Mieg
<snip>