Juha Vierinen wrote:
> Hi,
>
> I am considering if I should invest in learning R. Based on the
> language definition and introductory documents, it seems nice. But now
> I am faced with a problem: I want to be able to run R programs easily
> from the unix shell, and write scripts that can automatically select R
> as the interpreter:
>
> #!/usr/bin/R
> cat("Hello world.\n")
>
> This of course doesn't work, because /usr/bin/R is a shell script.
>
> I have been able to create a binary wrapper that calls R with the
> correct arguments, which is documented here:
>
> http://kavaro.fi/mediawiki/index.php/Using_R_from_the_shell
>
> This still lacks eg. standard input (but I have no idea how I can
> implement it in R) and full command line argument passing (can be
> done), but am I on the right track, or is there already something that
> does what I need?
If you search the mailing list archives:
http://tolstoy.newcastle.edu.au/R/
you can find entries like the following (searching on "bang"):
http://tolstoy.newcastle.edu.au/R/devel/05/01/1910.html
which implements similar functionality. But I thought this would be a
fun little (distracting) project, so I created an R wiki page:
http://wiki.r-project.org/rwiki/doku.php?id=developers:rinterp
with source code describing how to solve this problem by embedding R
within your C program. Here's the main function:
/* rinterp: shebang support for R
*
* Usage:
*
* From the command line:
* $ rinterp filename
*
* In a file:
* --------------------
* #!/path/to/rinterp
* cat("hello world\n");
* --------------------
*/
int main(int argc, char **argv){
/* R embedded arguments */
char *R_argv[] = {"RINTERP", "--gui=none", "--slave", "--silent",
"--vanilla","--no-readline"};
int R_argc = sizeof(R_argv)/sizeof(R_argv[0]);
struct stat sbuf;
/* Setenv R_HOME: insert or replace into environment.
* The RHOME macro is defined during configure
*/
if (setenv("R_HOME",RHOME,1) != 0){
perror("ERROR: couldn't set/replace R_HOME");
exit(1);
}
/* Assume last argument is the file we want to source.
* Ignore other args for now.
*/
if (argc > 1) {/* don't try and source rinterp binary */
if (stat(argv[argc-1],&sbuf) != 0){
perror(argv[argc-1]);
exit(1);
}
} else {
fprintf(stderr,"Usage: rinterp filename\n");
exit(1);
}
/* Initialize R interpreter */
Rf_initEmbeddedR(R_argc, R_argv);
/* Now call R function source(filename) */
call_fun1str("source",argv[argc-1]);
exit(0);
}
Feel free to logon to the R wiki and contribute to the page. I think it
would be interesting to solve this once and for all.
Cheers!
--
Jeffrey Horner Computer Systems Analyst School of Medicine
615-322-8606 Department of Biostatistics Vanderbilt University
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