ref: 7e6d7d36f83f05f372cfbce43534a2747bfc39c3 dir: /test/t.array1/
{for(i=1; i<=NF; i++) { if (x[$i] == "") y[++n] = $i x[$i]++ } } END { for (i=0; i<n; i++) print (y[i], x[y[i]]) }