1#!/bin/awk -f 2# reverse whilelist domains 3function rev(s, i, n, ndom, dom) { 4 n = split(s, dom, ".") 5 ndom = dom[n] 6 for (i = n-1; i >= 1; i--) 7 ndom = ndom "." dom[i] 8 return ndom 9} 10NF == 1 { print } 11NF == 2 { printf "%s %s\n", $1, rev($2) } 12