[R] Pass String from R to C

[Duncan Murdoch]

On 25/04/2011 1:03 PM, Duncan Murdoch wrote:
> On 25/04/2011 12:51 PM, Jaimin Dave wrote:
> >  I tried using char ** but it is printing some random string.
>
> str is a pointer to an array of pointers to strings.  That's what char**
> means.  So you need to declare it that way, and use it that way.
>
> This works for me:
>
> File test.c:
>
> void test(char **str)
> {
>     Rprintf("%s",*str);
> }

Oops, I just noticed that the include was missing.  The full file should 
have

#include "R.h"

at the beginning.

Duncan Murdoch


> Duncan Murdoch
> >  On Sat, Apr 23, 2011 at 6:08 PM, Duncan Murdoch<murdoch.duncan at gmail.com>wrote:
> >
> >  >   On 11-04-23 7:04 PM, Jaimin Dave wrote:
> >  >
> >  >>   Hi,
> >  >>   I am using a function which accepts the string from R and prints it.
> >  >>   But when I am calling .C("main","hello");
> >  >>   it is printing any random thing.
> >  >>   My C function is
> >  >>   void main(char *str)
> >  >>
> >  >
> >  >   See Writing R Extensions.  The declaration should be char **str.
> >  >
> >  >   Duncan Murdoch
> >  >
> >  >    {
> >  >>   Rprintf("%s",str);
> >  >>   }
> >  >>
> >  >>   Can you help how to achieve this using .C interface?
> >  >>
> >  >>   Thanks
> >  >>   Jaimin
> >  >>
> >  >>          [[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<http://www.r-project.org/posting-guide.html>
> >  >>   and provide commented, minimal, self-contained, reproducible code.
> >  >>
> >  >
> >  >
> >
> >  	[[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.
>