[R] system() command in R

[Mike Marchywka]

----------------------------------------
> Date: Tue, 5 Apr 2011 13:37:12 +0530
> From: nandan.amar at gmail.com
> To: rasanpreet.kaur at gmail.com
> CC: r-help at r-project.org
> Subject: Re: [R] system() command in R
>
> On 4 April 2011 16:54, rasanpreet kaur suri wrote:
>
> > Hi all,
> > I have a local server insalled on my system and have to start that from
> > within my R function.
> >
> > here is how I start it:
> >
> > cmd<-"sh start-server.sh"
> >
> > system(cmd, wait=FALSE)
> >
> > My function has to start the server and proceed with further steps. The
> > server starts but the further steps of the program are not executed.The
> > cursor keeps waiting after the server is started.
> >
> > How r u executing further steps after starting server, meant for server
> from R ??
>
>
> i tried removing the wait=FALSE, but it still keeps waiting.
> >
> > I also tried putting the start-server in a separate function and my further
> > script in a separate function and then run them together, but it still
> > waits. The transition from the start of server to next step is not
> > happening.
> >
> > Please help. I have been stuck on this for quite some time now.
> >
> > --

I hadn't done this in R but expect to do so soon.
I just got done with some java code to do something similar
and you can expect in any implementation these things will be 
system dependent. It often helps to have simple test cases
to isolate the problem. Here I made a tst script called "foo"
that takes a minute or so to exevute and generates some output.

If I type
system("./foo",wait=F) 

the prompt comes back right away but stdout seems to still
go to my console and maybe stdin is not redicrected either
and it could eat your input ( no idea, but this is probably not what you
want).

I did try this that could fix your problem, on debian anyway
it seems to work,

system("nohup ./foo &")

you can "man nohup" for details. 














> > Rasanpreet Kaur
> >
> > [[alternative HTML version deleted]]
> >
> > ______________________________________________
> > R-help at r-project.org mailing list
> > https://stat.ethz.ch/mailman/listinfo/r-help
> > PLEASE do read the posting guide
> > http://www.R-project.org/posting-guide.html
> > and provide commented, minimal, self-contained, reproducible code.
> >
>
>
>
> --
> Amar Kumar Nandan
> Karnataka, India, 560100
> http://aknandan.co.nr
>
> [[alternative HTML version deleted]]
>
> ______________________________________________
> R-help at r-project.org mailing list
> https://stat.ethz.ch/mailman/listinfo/r-help
> PLEASE do read the posting guide http://www.R-project.org/posting-guide.html
> and provide commented, minimal, self-contained, reproducible code.