Fall back on shasum if sha256sum is unavailable

basename="ruby-${version}.tar.gz"

major_minor_version=$(echo ${version} | cut -d '.' -f 1,2)

url="https://cache.ruby-lang.org/pub/ruby/${major_minor_version}/${basename}"

if command -v sha256sum >/dev/null; then

  sha256=$(sha256sum "$release_directory/$basename" | cut -d ' ' -f 1)

elif command -v shasum >/dev/null; then

  sha256=$(shasum -a 256 "$release_directory/$basename" | cut -d ' ' -f 1)

else

  echo "$0 requires sha256sum or shasum to be installed on the system."

  exit 1

fi

cat > "$file" <<EOS

!TODO! copy openssl line from other release with the same major.minor version