ghc-pkg-clean and ghc-pkg-reset compatible with both zsh and bash

ghcPkgUtils.sh

# unregister broken GHC packages. Run this a few times to resolve dependency rot in installed packages.
# ghc-pkg-clean -f cabal/dev/packages*.conf also works.
function ghc-pkg-clean() {
  for p in `ghc-pkg check $* 2>&1  | grep problems | awk '{print $6}' | sed -e 's/:$//'`
  do
    echo unregistering $p; ghc-pkg $* unregister $p
  done
}

# remove all installed GHC/cabal packages, leaving ~/.cabal binaries and docs in place.
# When all else fails, use this to get out of dependency hell and start over.
function ghc-pkg-reset() {
  if [[ $(readlink -f /proc/$$/exe) =~ zsh ]]; then
    read 'ans?Erasing all your user ghc and cabal packages - are you sure (y/N)? '
  else # assume bash/bash compatible otherwise
    read -p 'Erasing all your user ghc and cabal packages - are you sure (y/N)? ' ans
  fi

  [[ x$ans =~ "xy" ]] && ( \
    echo 'erasing directories under ~/.ghc'; command rm -rf `find ~/.ghc/* -maxdepth 1 -type d`; \
    echo 'erasing ~/.cabal/lib'; command rm -rf ~/.cabal/lib; \
  )
}

alias cabalupgrades="cabal list --installed  | egrep -iv '(synopsis|homepage|license)'"

I'm getting the following error:

❯ ghc-pkg-reset
readlink: illegal option -- f
usage: readlink [-n] [file ...]
ghc-pkg-reset:read:4: -p: no coprocess

@kevinSuttle, I got the same issue on FreeBSD. See my comment here
Or try this version of ghc-pkg-reset https://gist.github.com/p-alik/4f8cc64ace8a20a8bebcb8e8e1cba2a4