$ perl -pe " s{\\u(....)}{\\x{$1}}g " [\u0009-\u000D\u0020\u0085\u00A0\u1680\u180E\u2000-\u200A\u2028-\u2029\u202F\u205F\u3000] [\x{0009}-\x{000D}\x{0020}\x{0085}\x{00A0}\x{1680}\x{180E}\x{2000}-\x{200A}\x{2028}-\x{2029}\x{202F}\x{205F}\x{3000}]