[R] Capturing output of a C executable
dwinsemius at comcast.net
Mon Feb 3 19:27:34 CET 2014
On Feb 2, 2014, at 5:09 PM, Dennis Fisher wrote:
> R 3.0.1
> OS X
> I am experimenting with incorporating C code into R. After compiling the C code with:
> R CMD SHLIB -o FILE.so FILE.c
> and executing:
> (without any errors), I execute the following R functions in a terminal window:
> READSAS <- function(sourcefile) .C("readsas", sourcefile)
> OUTPUT <- READSAS("../SASFILES/sdrug.sas7bdat")
> R / C then reads a sas7bdat file and sends the contents to the terminal window.
> I expected OUTPUT to contain the text that appear in the terminal window (i.e., the contents of the file). But, that is not the case; OUTPUT contains:
>  "../SASFILES/sdrug.sas7bdat"
> It is not clear to my how to capture that appears in the terminal window.
> Ultimately, I may need to modify the C code so that the output goes to a file, which I then read into R. However, it would be better if I did not need to modify the C code.
> Does anyone have any ideas of how I can capture this output within R?
I wonder if this is a follow-up to the suggestion to look at ReadStat?: https://github.com/WizardMac/ReadStat
I could imagine calling it from R but then directing results to a comma separated file along the lines of the second example. If my guess is correct, you might assist the R community and get valuable advice by posting your source and Makefile on R-devel.
> Dennis Fisher MD
> P < (The "P Less Than" Company)
> Phone: 1-866-PLessThan (1-866-753-7784)
> Fax: 1-866-PLessThan (1-866-753-7784)
Alameda, CA, USA
More information about the R-help