I suspect the intend is to send a value from R to compiled code. Which
happens to be a problem for which Rcpp offers a pretty convenient solution.
And if you really, really want to, you can even program in C inside of an
Rcpp interface:
R> cppFunction("int foo(std::string txt) { Rprintf(\"Var is %s\\n\",
txt.c_str()); return 0; }")
R> foo("A")
Var is A
[1] 0
R>
Dirk
On 3 June 2014 at 19:06, Barry Rowlingson wrote:
| What does c_fun look like? Here's mine:
|
| #include <stdio.h>
| #include <stdlib.h>
| void c_fun(){
| printf("TMP is %s\n", getenv("TMP"));
| }
|
| and I then do this at the shell prompt:
|
| R CMD SHLIB c_fun.c
|
| and this at the R prompt:
|
| dyn.load("c_fun.so")
| wrapper()
|
| and I get:
|
| > wrapper()
| [1] "A"
| TMP is A
| list()
|
| Is that not what you want?
|
| tldr; works for me.
|
|
| On Tue, Jun 3, 2014 at 5:55 PM, Bowen Meng <bowen....@gmail.com> wrote:
| > wrapper <- function(){
| > Sys.setenv(TMP="A")
| > print(Sys.getenv("TMP"))
| >
| > .C("c_fun")
| > }
| >
| >
| > As the example above, I hope to set an env var $TMP inside the R function
| > "wrapper", which affects the functionality of the C function call "c_fun".
| > Also the print line shows that $TMP is set to be "A", but the function call
| > of "c_fun" was not affected.
| >
| > Does anyone know why and how to correctly set the env var for subsequent
| > functions?
| >
| > Thanks,
| > BW
| >
| > [[alternative HTML version deleted]]
| >
| > ______________________________________________
| > R-devel@r-project.org mailing list
| > https://stat.ethz.ch/mailman/listinfo/r-devel
|
| ______________________________________________
| R-devel@r-project.org mailing list
| https://stat.ethz.ch/mailman/listinfo/r-devel
--
Dirk Eddelbuettel | e...@debian.org | http://dirk.eddelbuettel.com
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