sed 's/\b1\b/one/g;s/\b2\b/two/g;s/\b3\b/three/g;s/\b4\b/four/g;s/\b5\b/five/g;s/\b6\b/six/g;s/\b7\b/seven/g;s/\b8\b/eight/g;s/\b9\b/nine/g;s/\b0\b/zero/g' test