Evaluating content of command line arguments

Hello everyone,

I am writing an R script which will be provided with command line arguments
by a shell script. I read them with commandArgs() but I have an issue to
make that fool proof.

For example, with test.R containing:

? ? ? ?args=commandArgs(trailingOnly=TRUE)
? ? ? ?args

I get:

? ? ? ?$ Rscript test_commandLineArgs.R 3 4 5
? ? ? ?[1] "3" "4" "5"

Now, to make the input more flexible and robust, I want to pass *named*
arguments, so that the R script does not depend on the order of arguments
passed and can check which are present/absent etc. I.e.

? ? ? ?$ Rscript test_commandLineArgs.R foo=3 bar=4 5
? ? ? ?[1] "foo=3" "bar=4"

But I am stuck on how to actually execute the code within those strings so
as to get two variables foo and bar equal to 3 and 4 respectively. I looked
at eval, deparse, substitute and all that but did not find anything. Is that
possible?

Otherwise I will resort to parsing the arguments with strsplit but I would
much prefer and more elegant solution.

Thank you very much in advance. Sincerely,

JiHO
---
http://jo.irisson.free.fr/