r - Provides hash-bang (#!) capability for R (www.r-project.org)

       Jeffrey Horner <jeff.horner@vanderbilt.edu>.  Dirk Eddelbuettel <edd@debian.org>.

r                                                September 2006                                             R(1)

       Launches  GNU  R to execute the specified file containing R commands, or takes commands from stdin if '-'
       is used to denote stdin, using the specified options. This makes it suitable to create R scripts via  the
       so-called shebang '#!/' line. The optional Rarguments are stored in the R vector argv.

       Piping R commands:

        echo 'cat(pi^2,"\n")' | r

       Equivalently, R commands can be given on the command-line:

        r -e 'cat(pi^2, "\n")'

       Alternatively, commands can be stored in a file, which in turn might use R command 'readLines' to process
       stdin input:

        $ cat examples/fsizes.r
        fsizes <- as.integer(readLines())
        print(summary(fsizes))
        stem(fsizes)

       which can be evaluated by r with the following command:

        ls -l /boot | awk '!/^total/ {print $5}' | r examples/fsizes.r

       The script file may contain a "shebang" line:

        $ cat examples/install.r
        #!/usr/bin/env r
        # a simple example to install one or more packages
        if (is.null(argv) | length(argv)<1) {
          cat("Usage: installr.r pkg1 [pkg2 pkg3 ...]0)
          q()
        }
        repos <- "http://cran.us.r-project.org"
        lib.loc <- "/usr/local/lib/R/site-library"
        install.packages(argv, lib.loc, repos, dependencies=TRUE)

       and if it is executable, it can be called as:

        examples/install.r "TeachingDemos"

       See the examples directory in the sources for more.

       r - Provides hash-bang (#!) capability for R (www.r-project.org)

       The  executable  program  is called r, but the project is called littler to avoid confusion with the real
       GNUR.

-h, --help
              Display a short help list.

       --usage
              Give a short usage message.

       -V, --version
              Show the version number.

       -v, --vanilla
              Pass the '--vanilla' option to R.

       -t, --rtemp
              Use a per-session temporary directory as R does.

       -i, --interactive
              Force 'interactive()' to evaluate to TRUE, whereas the default is FALSE.

       -q, --quick
              Skip autoload (i.e. delayed assign) of default libraries.

       -p, --verbose
              Print the value of expressions to the console.

       -l, --packages list
              Load the R packages from the comma-separated 'list'.

       -d, --datastdin
              Evaluates 'X <- read.csv(file="stdin", stringsAsFactors=FALSE)' to read a data set from stdin.

       -L, --libpath dir
              Add directory to library path via '.libPaths(dir)'.

       -e, --evalexpr
              Evaluate 'expr' in R.

       The GNUR language is documented extensively at the R website (http://www.r-project.org) and  in  several
       manuals available in html, info and pdf.

r [options] [-|file] [Rarguments]

r can be used in command-line 'pipes' as well as in 'shebang'-style scripts.