Is there a package to process command line options in R?

Question

Is there a package to process command-line options in R?

I know commandArgs, but it\'s too basic. Its result is basically the equivalent to argc<

Answer 1

How about commandArgs with eval for a built in solution?

test.R

## 'trailingOnly=TRUE' means only parse args after '--args'
args=(commandArgs(trailingOnly=TRUE))

## Supply default arguments
if(length(args)==0){
    print("No arguments supplied.")
    ##supply default values
    a = 1
    b = c(1,1,1)
}else{
    for(i in 1:length(args)){
         eval(parse(text=args[[i]]))
    }
}
print(a*2)
print(b*3)

and to invoke it

R CMD BATCH --no-save --no-restore '--args a=1 b=c(2,5,6)' test.R test.out

The usual caveats w.r.t using eval apply of course.

Shamelessly stolen from this blog post.

Answer 2

getopt for R