validatecompressors() {
# Validate package extension set in bldpkg.conf
  SM_VALIDPKGEXTENSIONS=( "tgz" "tbz" "tlz" "txz" )
  if ! inarray "${PKGEXT}" "${SM_VALIDPKGEXTENSIONS[@]}" ; then
    echo "[ERROR] $PKGEXT is not a valid package extension for an SMLinux"
    echo "[ERROR] installer file! Aborting!"
    exit 1
  fi

  # Figure out the compression tool to be used based on the $PKGEXT variable set in bldpkg.conf. At the same time,
  # export the compressor options set for makepkg to import from the build environment.
  case "$PKGEXT" in 
    tgz) COMPRESSOR=gzip 
         COMPRESSOPTS="$SM_GZIPOPTS"
         export COMPRESSOPTS ;;
    tbz) COMPRESSOR=bzip2 
         COMPRESSOPTS="$SM_BZIPOPTS"
         export COMPRESSOPTS ;;
    tlz) COMPRESSOR=lzip 
         COMPRESSOPTS="$SM_LZIPOPTS"
         export COMPRESSOPTS ;;
    txz) COMPRESSOR=xz 
         COMPRESSOPTS="$SM_XZOPTS"
         export COMPRESSOPTS ;;
  esac
  
  echo -n "Validating $COMPRESSOR...."
  # Borrowed from slackware's installpkg utility
  if ! $COMPRESSOR --help 1> /dev/null 2> /dev/null ; then
    echo "[FAILED]"
    exit 1
  else
    echo "[OK]"
  fi
}
