good documentation on use of Rscript. where to find?

What is the correct format for the shebang line and what options are
allowed or necessary along with this?

I find plenty of blogs and opinions, but few authoritative answers.

I want an R script to run and update packages periodically, with a
cron job that launches it. What is necessary to put in
line one of the R program. Aside from the basic part

#!/usr/bin/Rscript

what else can there be, or should there be?

Various people suggest adding things like "--vanilla" but those seem
not to be accepted, at least on RedHat EL 6 with R-2.15.1.  I'd like
to run this with a command line like:

$ R-labSelectInstall-02.R > /tmp/Rupdate.txt 2>&1

so that all the standard output and err goes to a text file, but I've
not found a way to make it work comparably to the R command line
option --vanilla or such.

# ./R-labSelectInstall-02.R --vanilla
'ARNING: unknown option '--vanilla

See what I mean?

Paul E. Johnson
Professor, Political Science      Assoc. Director
1541 Lilac Lane, Room 504      Center for Research Methods
University of Kansas                 University of Kansas
http://pj.freefaculty.org               http://quant.ku.edu