This will get the current option in getOption('repos'), and if that is not set to a url, then it will prompt the user to select a mirror, unless ind is set, in which case, it will use that mirror (in chooseCRANmirror())

getCRANrepos(repos = NULL, ind)

## Arguments

repos

A CRAN-like repository

ind

an integer of which mirror to use in chooseCRANmirror()