[R] Capturing output of a C executable

[Dennis Fisher]

R 3.0.1
OS X

Colleagues,

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:
	dyn.load(“FILE.so”)
(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:
	[[1]]
	[1] "../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?

Dennis

Dennis Fisher MD
P < (The "P Less Than" Company)
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