# test.R
# Parse and use command line arguments
# Invoke % R --slave --args 100 < test.R 

Args <- commandArgs();      # retrieve args
x <- c(1:as.real(Args[4])); # get the 4th argument
y <- c(x^2);                # work out square
png(filename="image.png");  # create image file
plot(x,y);                  # plot image

##</code><code>##

[1] "/usr/lib/R/bin/exec/R" 
[2] "--slave" 
[3] "--args"               
[4] "100"