[R-SIG-Mac] system('man R') works in Mac unix R but not in GUI R

[Prof Brian Ripley]

On Fri, 25 Mar 2011, Kasper Daniel Hansen wrote:

> On Fri, Mar 25, 2011 at 9:14 AM, Joseph Kunkel <joe at bio.umass.edu> wrote:
>> Using  R 2.12.2 GUI 1.36 Leopard build 64-bit (5691)
>>
>> system('man R') gives error: 'No manual entry for R' ...  ??
>>
>> Running R in a unix window the system('man R') function provides 
>> the expected manual entry.
>>
>> This complicates my teaching of R with the Gui if I want to use the 
>> system('R ...') function.   Students need to know unix-window-use 
>> as a prereq.
>>
>> system('man vi')  however does provide the correct unix vi manual 
>> in either unix or GUI.
>
> Well, as you might know, setting PATH and other environment variables
> in the terminal using, say .profile or .bashrc, does not make them set
> inside of a GUI.  This has been discussed many times on this list (and
> really has nothing to do with R at all).

Note though that this is slightly different: it is about what is set 
in the shell which system() launches from R.app, not the usual 
question of what variables are set for R.app itself.

> In this case it is because vi ships with the system and the man page
> for vi is in
> # man -w vi
> /usr/share/man/man1/vi.1.gz
>
> I do not have the GUI (CRAN) version of R installed, but I would guess
> that the man page is in /usr/local/share ..., and you can check the
> directories man searches by
> # man -d

I do, and 'man R' does not find it (and it is not under 
/usr/local/share/man, which is on my system searched from system() in 
R.app).  My reading of the CRAN installation scripts is that it is 
only installed in 
/Library/Frameworks/R.framework/Versions/2.13/Resources/man1
(Try 'locate R.1': all the other instances are in my own development 
area.)

So I think the question should rather be why 'man R' works in a 'unix 
window' (whatever that really is).

And also why you think 'man R' is useful for your students, rather 
than say 'R --help' (from which it is derived by a Perl script) or the 
'Introduction to R' manual.

-- 
Brian D. Ripley,                  ripley at stats.ox.ac.uk
Professor of Applied Statistics,  http://www.stats.ox.ac.uk/~ripley/
University of Oxford,             Tel:  +44 1865 272861 (self)
1 South Parks Road,                     +44 1865 272866 (PA)
Oxford OX1 3TG, UK                Fax:  +44 1865 272595