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Revision of shell.exec?

14 messages · Stephen Weston, Brian, Henrik Bengtsson +5 more

Original
Brian
# 
Hi List,
I hope this is correct list to propose function extensions, sorry if not.
I am preparing for a (hopefully painless) migration to linux. As far as 
I am aware of, the function "shell.exec" only comes with the windows 
version. I think this is a handy little function and would like to see 
my scripts work when I migrate.

May I propose something (like the following)?

open.file <- function(file) {
     if(.Platform$OS.type=="windows") {shell.exec(file)} else 
{system(paste("open ",file))}
}

Or just a small addition to the shell.exec function and no new named 
function.
Hope the idea isn't received as "too stupid".

Cheers,
Brian
Uwe Ligges
#
On 14.09.2011 12:27, Brian Oney wrote:
What is "open" supposed to do on a non-Windows machine? I do not have it 
on the only Linux installation I looked at now, hence we obviously 
cannot assume it exists on an arbitrary installation.

Best,
Uwe Ligges
Stephen Weston
# 
2011/9/14 Uwe Ligges <ligges at statistik.tu-dortmund.de>:
I think the nearest equivalent for those running Gnome or KDE may be
"xdg-open".  So there would probably need to be a new option for specifying
the appropriate command.

Personally, I am more inclined to use "system" for executing commands,
and "browseURL" for opening documents.  "browseURL" even uses
"xdg-open" in my R installation on my Linux machine.

- Steve
Brian
# 
Hi Steve,

a quick look at "browseURL" will tell you that indeed "system" or 
"shell.exec" (on a windows platform) is used to open up a URL.
The "open " part of the proposed function was written to work on a Mac. 
Because Mac is a unix platform, I assumed that the function "open" would 
be omnipresent on unix platforms, my mistake. Well I guess, we know how 
to make to work on a mac.

I will make the transition to Linux and get back to this in a while, ok?

Cheers,
Brian
On 9/14/2011 2:50 PM, Stephen Weston wrote:
Simon Urbanek
#
On Sep 14, 2011, at 11:08 AM, Brian Oney wrote:

            

      
      
      
    

        
Well, the problem is that "open" is unfortunately mapped to openvt on Linux systems which is a quite obscure anachronism. But since Linux is Linux there is no standard way to open a file, so it doesn't really matter ;) -- xdg-utils come closest to what one may call standard but on many systems they are not installed by default (in fact on none of the Linux machines I have around). For URLs R does the hard work to try to figure out what to do with them (it also does the same for PDFs), but you may end up opening things in a browser although that's not what you had in mind.

            

      
      
      
    

        
Yes, "open" works very well on Macs and is extremely useful (I use it all the time - among other things you can use it with directories to browse them...) - it is still beyond me why other unices don't bother ...

Cheers,
Simon

            

      
      
      
    

        

      
      
    

        

      
      
    

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Henrik Bengtsson
    

    

      
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On Wed, Sep 14, 2011 at 8:35 AM, Simon Urbanek

        
<simon.urbanek at r-project.org> wrote:

            

      
      
      
    

        
Apple probably patented it.

/Henrik

            

      
      
      
    

        

      
      
    

        

      
      
    

            

      
      
      
    

        

      
      
    

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Brian
    

    

      
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Hi there,
new idea (at 10 at night). All the emails keep me thinking (btw thanks 
for all the feedback).
What does this do on linux?

getOption("pdfviewer")
### I got this idea from: getS3method("print","vignette")

On windows, (an advantage...) somebody wrote a little program "open.exe" 
that comes stock with an R-installation, which somehow accesses the file 
system to find the default program to for a certain file type. I am 
guessing this little beauty is the engine of "shell.exec".

(An honest) cheers,
Brian

        
On 9/14/2011 7:49 PM, Simon Urbanek wrote:

            

      
      
      
    

        

      
      
    

        

      
      
    

        

      
      
    

        

      
      
    

            

      
      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Simon Urbanek
    

    

      
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On Sep 14, 2011, at 4:15 PM, Brian Oney wrote:

        

            

      
      
      
    

        
It gives you the detected PDF viewer as I was explaining (essentially R_PDFVIEWER). The two detected settings I was referring to are R_PDFVIEWER (for PDF) and R_BROWSER (for URLs) which are the initial settings for the "pdfviewer" and "browser" options.

Note that it's what it say it is - R_PDFVIEWER is usually something like acroread or evince so not particularly useful for your purpose ...

Cheers,
Simon

            

      
      
      
    

        

      
      
    

        

      
      
    

        

      
      
    

        

      
      
    

            

      
      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Dirk Eddelbuettel
    

    

      
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On 14 September 2011 at 16:22, Simon Urbanek wrote:

        
|

        
| On Sep 14, 2011, at 4:15 PM, Brian Oney wrote:

        
| 
| > Hi there,
| > new idea (at 10 at night). All the emails keep me thinking (btw thanks for all the feedback).
| > What does this do on linux?
| > 
| > getOption("pdfviewer")
| > ### I got this idea from: getS3method("print","vignette")
| > 
| 
| It gives you the detected PDF viewer as I was explaining (essentially R_PDFVIEWER). The two detected settings I was referring to are R_PDFVIEWER (for PDF) and R_BROWSER (for URLs) which are the initial settings for the "pdfviewer" and "browser" options.
| 
| Note that it's what it say it is - R_PDFVIEWER is usually something like acroread or evince so not particularly useful for your purpose ...

R> getOption("pdfviewer")
[1] "/usr/bin/xdg-open"
R> 

We've had that as xdg-open in Debian / Ubuntu for a while now...

Dirk

  
    

      
      
    

  


  


      

    

    

      
      

        


  

        

      Simon Urbanek
    

    

      
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On Sep 14, 2011, at 4:44 PM, Dirk Eddelbuettel wrote:

        

            

      
      
      
    

        
Yes, but that's merely a side-effect. For example on Ubuntu (R from sources) I get

gis:~$ Rscript -e 'cat(getOption("pdfviewer"),"\n")'
/usr/bin/X11/evince 

because xdg-open is not installed by default. My point is that the setting is meant for something else, so misappropriating it, although possible, may not be wise. If you really want to go down that alley, you could use some logic like

if (identical(getOption("pdfviewer"), getOption("browser"))) { # better chance that it's something that can open things universally
} else { ## well, bad luck ... }

That will work on Macs and possibly on OSes that have generic open commands ... (but is not guaranteed to ...).

Cheers,
Simon

            

      
      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Uwe Ligges
    

    

      
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On 14.09.2011 22:15, Brian Oney wrote:

            

      
      
      
    

        
No. It simply uses ShellExecute() in windows.h, i.e. defined in 
Microsoft's Windows User Interface.?:
http://msdn.microsoft.com/en-us/library/bb762153%28v=vs.85%29.aspx


Uwe Ligges

            

      
      
      
    

        

      
      
    

        

      
      
    

        

      
      
    

        

      
      
    

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Duncan Murdoch
    

    

      
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On 11-09-15 4:27 AM, Uwe Ligges wrote:

            

      
      
      
    

        
Yes, and open.exe is a simple command line wrapper for that call.

Duncan Murdoch

            

      
      
      
    

        

      
      
    

        

      
      
    

        

      
      
    

        

      
      
    

            

      
      
      
    

        

      
      
    

            

      
      
      
    

        

      
      
    

  
  


  


      

    

    

      
      

        


  

        

      Dirk Eddelbuettel
    

    

      
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On 14 September 2011 at 16:56, Simon Urbanek wrote:

        
|

        
| On Sep 14, 2011, at 4:44 PM, Dirk Eddelbuettel wrote:

        
| 
| >

        
| > On 14 September 2011 at 16:22, Simon Urbanek wrote:

        
| > |

        
| > | On Sep 14, 2011, at 4:15 PM, Brian Oney wrote:

        
| > | 
| > | > Hi there,
| > | > new idea (at 10 at night). All the emails keep me thinking (btw thanks for all the feedback).
| > | > What does this do on linux?
| > | > 
| > | > getOption("pdfviewer")
| > | > ### I got this idea from: getS3method("print","vignette")
| > | > 
| > | 
| > | It gives you the detected PDF viewer as I was explaining (essentially R_PDFVIEWER). The two detected settings I was referring to are R_PDFVIEWER (for PDF) and R_BROWSER (for URLs) which are the initial settings for the "pdfviewer" and "browser" options.
| > | 
| > | Note that it's what it say it is - R_PDFVIEWER is usually something like acroread or evince so not particularly useful for your purpose ...
| > 
| > R> getOption("pdfviewer")
| > [1] "/usr/bin/xdg-open"
| > R> 
| > 
| > We've had that as xdg-open in Debian / Ubuntu for a while now...
| > 
| 
| Yes, but that's merely a side-effect. For example on Ubuntu (R from sources) I get
| 
| gis:~$ Rscript -e 'cat(getOption("pdfviewer"),"\n")'
| /usr/bin/X11/evince 
| 
| because xdg-open is not installed by default. My point is that the setting is meant for something else, so misappropriating it, although possible, may not be wise. If you really want to go down that alley, you could use some logic like
| 
| if (identical(getOption("pdfviewer"), getOption("browser"))) { # better chance that it's something that can open things universally
| } else { ## well, bad luck ... }
| 
| That will work on Macs and possibly on OSes that have generic open commands ... (but is not guaranteed to ...).

Not a side-effect, but carefully planned by several parties :)

Kurt has this in m4/R.m4 for R's configure:

  AC_DEFUN([R_PROG_BROWSER],
  [if test -z "${R_BROWSER}"; then
    AC_PATH_PROGS(R_BROWSER, [firefox mozilla galeon opera xdg-open kfmclient gnome-moz-remote open])
  fi

and

  AC_DEFUN([R_PROG_PDFVIEWER],
  [AC_PATH_PROGS(R_PDFVIEWER,
                 [${R_PDFVIEWER} acroread acroread4 xdg-open evince xpdf gv gnome-gv ggv okular kpdf open gpdf kghostview])

so xdg-open can be use as R_BROWSER and R_PDFVIEWER. That is a 'Good Thing'
because xdg-open is itself a wrapper which finds the appropriate _installed_
binary via the desktop resources -- shifting the choice from compile-time to
run-time. 

I then ensure via a Build-Depends on the xdg-utils package ensure that
xdg-open is present when R is built (as the Debian / Ubuntu binary). (I also
set 'R_BROWSER=xdg-open' in the call to configure which may be redundant.)

So we could try to generalize this and, if on Linux, look for xdg-open and
call that.

Dirk

  
    

      
      
    

  


  


      

    

    
3 days later

    

      
      

        


  

        

      Brian Ripley
    

    

      
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On Wed, 14 Sep 2011, Simon Urbanek wrote:

        

            

      
      
      
    

        
They do: as 'open' is already taken, they use xdg-open.

I am not at all convinced base R needs any such addition: we manage to 
open anything R itself needs with the existing code.