[R] How do I provide path character string to extdata content?

[Ulrike Grömping]

Dear helpeRs,

I have some png files in the inst/extdata directory of a package (e.g.,
man.png), and I want to provide character strings containing the paths to
these files; of course, these path strings have to depend on the individual
installation. So far, I have written a function that - if called - writes
the correct strings to the global environment, but that is not CRAN
compatible.

Ideally, I want the package namespace to export these text strings. I have
played with .onLoad without luck. I do not have a good understanding of
which hook is for which purpose. How can I go about this?

Best, Ulrike