[Rd] URL for a vignette on CRAN?

[Spencer Graves]

Thanks to both Paul Grosu and Dirk Eddelbuettel for informative and 
useful replies.  Spencer


On 1/23/2016 8:58 PM, Dirk Eddelbuettel wrote:
> Spencer,
>
> On 23 January 2016 at 20:27, Spencer Graves wrote:
> |        How can I get a full URL for anything on CRAN?
> |
> |        Using Safari, Google Chrome, and Firefox under OS X 10.11.2, I
> | select a CRAN mirror from "www.r-project.org" and get a URL like
> | "https://cran.rstudio.com/".  Then I select "packages" and get a
> | different web page, but the URL displayed doesn't change.  I'd like to
> | access the full URL of a vignette in a package, but modern web browsers
> | hide that detail.
>
> 1)  All CRAN mirrors use the same layout.
>
> 2)  Using a CDN such as cran.rstudio.com, or now the equivalent
>      cloud.r-project.org is 'A Good Thing (TM)' because the resulting location
>      will almost always be close to any reader -- as it adapts based on the
>      reader location. See Wikipedia on 'Content Deliver Networks' for more details.
>
> 3)  http://cloud.r-project.org/package=sos is preferred for any pkg, here
>      your sos package
>
> 4)  It flattens to https://cloud.r-project.org/web/packages/sos/index.html
>
> 5)  You can derive the vignette from that page or just construct it:
>          https://cloud.r-project.org/web/packages/sos/vignettes/sos.pdf
>      This is of the form ${SERVER}/web/packages/${PACKAGE}/${VIGNETTE}
>
> I have been using url such as the one in 5) for a long while. Works like a charm.
>
> Now, from your vague text above, maybe you prefer NOT to use a CDN. In that
> case, insert an _explicit_ server, say Berkeley's mirror and you get
>         https://cran.cnr.berkeley.edu/web/packages/sos/vignettes/sos.pdf
> but that is _still_ of the form ${SERVER}/web/packages/${PACKAGE}/${VIGNETTE}
> yet simple uses a different value for ${SERVER}.
>
> Makes sense?
>
> Dirk
>