Revision of shell.exec?

On 14.09.2011 22:15, 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")

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".

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

(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