WISH: R -f and Rscript supporting URLs

[HenrikBengtsson]

(Adopted from Wiki entry)

Background

Executables Rscript and R -f takes R script files as input and source():s them, e.g.

$ echo "cat('Hello\n')" > hello.R
$ R --quiet -f hello.R
> "cat('Hello\n')"
[1] "cat('Hello\n')"
>

$ Rscript hello.R
[1] "cat('Hello\n')"

This only works with local files. If we try with an online file, we get an error;

$ Rscript https://example.org/hello.R
Fatal error: cannot open file 'https://example.org/hello.R': Invalid argument

A possible, but tedious, workaround is to use:

$ Rscript -e "source('https://example.org/hello.R')"
Hello

Wish

Add support for Rscript and R -f to recognize URLs and then try to source them as URLs and not local files, e.g.

$ R --quiet -f https://example.org/hello.R
> "cat('Hello\n')"
[1] "cat('Hello\n')"
>

$ Rscript -f https://example.org/hello.R
Hello

UPDATE: Fixed Rscript <url> example. /HB 2016-05-29