[Rd] Revision of shell.exec?

Simon Urbanek simon.urbanek at r-project.org
Wed Sep 14 22:22:13 CEST 2011


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 ...

Cheers,
Simon


> 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:
>> On Sep 14, 2011, at 1:10 PM, Henrik Bengtsson wrote:
>> 
>>> On Wed, Sep 14, 2011 at 8:35 AM, Simon Urbanek
>>> <simon.urbanek at r-project.org>  wrote:
>>>> On Sep 14, 2011, at 11:08 AM, Brian Oney wrote:
>>>> 
>>>>> 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, 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.
>>>> 
>>>> 
>>>>> Well I guess, we know how to make to work on a mac.
>>>>> 
>>>> 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 ...
>>> Apple probably patented it.
>>> 
>> I'm pretty sure it's at least as old as NeXT so that's way before the abuse of software patents ;) - but who knows ...
>> 
>> Cheers,
>> S
>> 
>> 
>> 
>>> /Henrik
>>> 
>>>> Cheers,
>>>> Simon
>>>> 
>>>> 
>>>> 
>>>>> 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:
>>>>>> 2011/9/14 Uwe Ligges<ligges at statistik.tu-dortmund.de>:
>>>>>>> On 14.09.2011 12:27, Brian Oney wrote:
>>>>>>>> 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".
>>>>>>> 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.
>>>>>> 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
>>>>>> 
>>>>>> 
>>>>>>> Best,
>>>>>>> Uwe Ligges
>>>>>>> 
>>>>>>> 
>>>>>>>> Cheers,
>>>>>>>> Brian
>>>>>>>> 
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>>>>> 
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>>> 
> 
> 



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