On Mon, 26 Sep 2005, Marc Schwartz (via MN) wrote: > On Fri, 2005-09-23 at 15:37 -0500, Marc Schwartz (via MN) wrote: > > Hi all, > > > > I am setting up some R program files for use by our DB programmers to > > enable them to utilize some R functions which will be called from within > > TCL code. R has been installed on an RHEL server and R will process the > > results of SQL queries against an Oracle database. > > > > In some cases, they will generate a data file to be read in and > > processed by R, in others they will simply make the tabulated results > > available. > > > > I know that I could do the SQL queries from within R, however, this is > > the approach that has been defined for now for various reasons. > > > > I wanted to provide some flexibility for them, by passing some of the > > tabulated results via command line arguments to R functions, rather than > > via environment variables, which is easier for them to do in TCL it > > would seem. They would create these values at run time, based upon specs > > that I give them. > > > > Using the following as an example: > > > > $ R --slave --vanilla --args "c(5,5)" "c(.5,.5)" < RScript.R > > > > I can then process "c(5,5)" and "c(.5,.5)" as two arguments, via: > > > > Args <- commandArgs() > > > > where the two arguments are Args[5] and Args[6], respectively. I can > > then of course pass these as "eval(parse(text = Args[5]))" to other R > > functions. > > > > > > However, if there is any whitespace in the two arguments, such as: > > > > R --slave --vanilla --args "c(5, 5)" "c(.5, .5)" < RScript.R > > > > even though surrounded by double quotes (or single quotes or > > backquotes), the two arguments are parsed as four. > > > > Is this behavior expected? I was under the impression, from other C > > based programs and bash shell scripts for example, that the use of the > > double quotes would wrap such text and thus be parsed as a single > > argument.
Sort of. Unfortunately both the R front-end script and the R executable get to play here, so once the front-end has parsed the args the quoting gets lost. You might hope that double quoting would help, but it does not. > > > > This is using: > > > > Version 2.1.1 Patched (2005-09-22) on FC4. > > > Apologies for replying to my own post here, but I wanted to follow up > with a solution provided by Robert McGehee, which works here. > > The solution is as follows: > > echo "a <- c(5, 5); b <- c(0.5, 0.5)" | cat - RScript.R | R --slave \ > --vanilla > > > This uses echo and cat to pre-pend the 'a' and 'b' vector assignments to > the R program file, before passing the whole thing to R. > > This then allows for arguments with embedded whitespace to be passed as > required at run time. > > Thanks Robert! > > Marc > > ______________________________________________ > R-devel@r-project.org mailing list > https://stat.ethz.ch/mailman/listinfo/r-devel > > -- Brian D. Ripley, [EMAIL PROTECTED] Professor of Applied Statistics, http://www.stats.ox.ac.uk/~ripley/ University of Oxford, Tel: +44 1865 272861 (self) 1 South Parks Road, +44 1865 272866 (PA) Oxford OX1 3TG, UK Fax: +44 1865 272595 ______________________________________________ R-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-devel
