Update symlinks for GHC

update.sh

#!/bin/bash
EXECUTABLES="ghc ghc-pkg ghci haddock runghc"
VERSION=$1

if [ -z "$1" ]; then
  echo "ERROR: GHC version number needs to be specified. Exiting." 1>&2                                     
  exit 1
fi

pushd /opt/ghc/bin > /dev/null

for exe in ${EXECUTABLES}; do
  ls -l ${exe} | grep ${VERSION} >/dev/null
  [[ $? -eq 0 ]] && exit 0
  if [ ! -x ${exe}-${VERSION} -a ! -x "haddock-ghc-${VERSION}" ]; then                                      
    echo "ERROR: ${exe}-${VERSION} doesn't exist. Skipping." 1>&2                                           
    continue
  fi
  echo -n "Updating ${exe}..."
  sudo rm ${exe}
  if [ ${exe} = "haddock" ]; then
    sudo ln -s "haddock-ghc-${VERSION}" ${exe}
  else
    sudo ln -s ${exe}-${VERSION} ${exe}
  fi
  echo " done"
done

popd > /dev/null