[Rd] Rscript on Windows

[Gabor Grothendieck]

On UNIX one can use #! notation.  It would be nice to be able to do something
similar on Windows.

This could be done by giving Rscript the capability of skipping over
the first few
lines.  For example, there might be a --skip=n argument or perhaps Rscript would
skip over any consecutive leading lines that begin with @ in the R
file since that
cannot be syntactically correct R but does  have meaning to Windows batch,
namely, it means do not display the line beginning with @ (but still run it).
For example, if we implement the @ idea then a sample 3 line file
called grep.bat might look like this:

  @Rscript grep.bat %1
   for(L in grep(commandArgs(TRUE), readLines(file("stdin")), value = TRUE))
      cat(L, "\n", sep = "")

and then we would run it as a Windows batch file like this from the
Windows console to find all lines with the word target:

   grep target < myfile.txt

or if we implemented --skip it might look like this:

  @Rscript --skip=1 grep.bat %1
   for(L in grep(commandArgs(TRUE), readLines(file("stdin")), value = TRUE))
      cat(L, "\n", sep = "")