[gentoo-dev] Re: [PATCH] linux-mod.eclass: IUSE default support for MODULES_OPTIONAL_USE

[Martin Vaeth]

Robin H. Johnson <robbat2@g.o> wrote:
> That is counter-intuitive for somebody that puts
> MODULES_OPTIONAL_USE_IUSE_DEFAULT=0
> Or tries to otherwise have it unset.

What I usually do is:

case ${MODULES_OPTIONAL_USE_IUSE_DEFAULT:-n} in
  [nNfF]*|[oO][fF]*|0|-)  # false case
    ;;
  *) # true case
esac

This covers most of the "intuitive" attempts (0 - Off FALSE no ...)
to switch it off, and everything else (nonempty) means "on".