if [[ -v DYLD_LIBRARY_PATH ]]; then
  DYLD_LIBRARY_PATH+=":$HOME/lib"
else
  DYLD_LIBRARY_PATH=$HOME/lib
fi

if [[ -v LIBRARY_PATH ]]; then
  LIBRARY_PATH+=":$HOME/lib"
else
  LIBRARY_PATH=$HOME/lib
fi

export {DYLD_,}LIBRARY_PATH
mkdir -p ~/lib