A character vector containing the name of the executable and the
  user-supplied command line arguments.  The first element is the name
  of the executable by which R was invoked.  The exact form of this
  element is platform dependent: it may be the fully qualified name, or
  simply the last component (or basename) of the application, or for an
  embedded R it can be anything the programmer supplied.
If trailingOnly = TRUE, a character vector of those arguments
  (if any) supplied after --args.